EXPERT WITNESS REPORT
I am engaged by McDonald's in the UK to provide independent advice on food policy issues and on how the company should respond to them. I have been working with McDonald's since February 1991.
If we are dealing with a poison such as cyanide or a pathogenic organism which causes a fatal disease such as typhoid, then it is clear that these should not be present in food. However, the relationship between the agent and its manifestation is quite simple in the sense that there is only one factor involved and the time scale between cause and effect is very short.
However, when we have to consider diet-related diseases, there are major complications. While it is now generally accepted that diet does play an important role in the development of the socalled degenerative diseases, which include coronary heart disease (CHD) and some cancers, the precise role of the different components in the diet are very difficult to elucidate. In contrast to a poison, the time scales can be very long. The deterioration of the arteries which ultimately contributes to a heart attack is a process which may continue throughout life. Post-mortems on teenagers, killed in accidents, show that there can be extensive arterial damage in relatively young people. Furthermore, these diseases tend to be multi-factorial - lack of exercise, smoking, stress and genetic factors can all interact with diet to produce the conditions which result in the disease.
While there is agreement that diet does play a critical role in the development of certain diseases, it is extremely difficult for scientists to conduct investigations which will provide an understanding of how the individual dietary constituents function 24
in the body. It is necessary to use a variety of different disciplines and strategies in order to gain some insight into what is actually happening. These include :
the study of disease patterns in different locations
studying the chemical reactions in the body
animal experimentation -
studying animals in the hope and belief that this will provide clues into what happens in humans
It is important to appreciate that all of the individual approaches have their own strengths and limitations. It is an essential part of the conventional scientific approach that there is continuous debate and discussion between scientists and even within one discipline the arguments can be very vigorous. Not surprisingly, when an issue stimulates research in many different disciplines, then the difficulties of reaching agreement are accentuated. Very often, the research debate is ill-informed because specialists from different backgrounds simply do not understand the culture of disciplines outside their own expertise. While this obviously creates problems for the scientists themselves, it can be extremely confusing and disconcerting for any non-scientists who get involved.
In this section of the report, I will describe some of the difficulties which are encountered in research which is designed to understand the relationship between diet and disease. Then I will explain the procedures that are used to evaluate the current state of the art. Lastly, I will explain the dietary recommendations, their implications for the general public and the McDonald's perspective.
Various approaches are adopted. Descriptive studies describe the patterns of disease occurrence in one or more populations, in components of the same populations, or in a single population over time. These patterns may then be related to data on diet in order to suggest possible relationships. There have been numerous studies in which national food consumption statistics are related to patterns of disease incidence or mortality. While these are useful in generating hypotheses, care must be taken in drawing conclusions from them. The approach does have limitations. The data on the incidence of the disease do not necessarily cover the whole country so that the data on food consumption does not correspond to the information disease patterns. Food intake data is normally based only on food sold in the shops and takes no account of food grown at home and does not allow for wastage or possibly food given to pets. The picture obtained from this is extremely general and it is impossible to allow for variations between individuals.
In an attempt to overcome some of these difficulties, case control studies are done in which investigators collect data for individuals rather than for groups. Individuals suffering from the disease are matched with corresponding controls which are healthy. However, there are major difficulties here as well. Loss of appetite is a common feature of serious illness and, in any case, it must be recognised that the diet consumed many years previously may be a contributory cause of the disease. This means that the people involved have to be asked for information on what they used to eat many years before. This type of method is extremely unreliable and little credence can be given to data obtained in this way.
The ideal type of epidemiological study is the prospective study. With this approach, the current diet is determined in a group of normally healthy individuals and the cohort is then followed for many years. This means that a dietary history is being established which can ultimately be related to those who contract a specific type of disease. However, an enormous effort is needed, because the study must continue for many years and a very large number of people have to be included. One study of this type was started in the United States in 1980 involving 89,538 registered nurses. In this investigation, the participants fill in a dietary questionnaire at regular intervals. Although this may seem impressive, many workers are critical of the way in which the dietary information is obtained. The period for which the food information is collected may not be typical of the regular diet of the individual. It is relatively easy for people to forget items that are eaten, especially away from home. It is difficult to deal with the wastage aspects. Ideally, the food actually consumed should be weighed. Finally, there can be marked variation in the composition of individual foods. For example, lean beef may contain only 2-3% fat, whereas other cuts may have up to 30% as fat. The only way to cope with this is for the foods to be analysed. For a large prospective study, the costs of weighing and analysing the food consumed by everyone taking part would be prohibitive.
To obtain conclusive evidence, it would be necessary to take a large number of people and divide them into different groups, each of which would be subjected to a specific dietary treatment. This would have to be maintained for many years if it was to produce results that would be valid. Obviously, this approach is quite unrealistic for logistical and ethical reasons. Hence other approaches have to be used in spite of their limitations. The use of laboratory investigations with experimental animals is, therefore, favoured by some scientists because they have much greater control over the conditions used. Nevertheless, there are still limitations because the response in the laboratory animals may not necessarily reflect what would happen in humans. Further details on the methodological problems encountered are given in Appendix I.1
EVALUATING THE EVIDENCE
It has to be recognised that the research effort designed to find out the relationship between diet and disease is very large. It is very common for conflicting messages to be given to the public by individual scientists who participate in radio and television programmes or write articles for magazines and newspapers. In order to overcome this, it is quite common for governments to set up a committee of reputable scientists which is given the brief to evaluate the current scientific state of knowledge and prepare a report which can be accepted as credible and authoritative. Sometimes individual scientists review the field and publish the results in a reputable scientific Journal. Usually national committees are also asked to prepare recommendations which can be used as a basis for giving advice to the general public.
Such exercises can be very valuable because they have to decide on the merit of individual studies. It must be emphasised that because of the difficulties explained above, many studies reported in the scientific literature do have serious weaknesses and so cannot be regarded as significant. Furthermore, even in studies which are considered to be reliable, there can often be conclusions from different investigations which are apparently in conflict with each other. So for individuals who wish to have advice on how to adjust their diet to keep the risks of various diseases to a minimum should on no account rely on isolated scientific papers or even on the views of an individual specialist researcher. This perspective will only give them a very restricted picture of what is happening, which may be completely different from that of another researcher. It is imperative that they use sources which, at least, attempt to take all of the available information into consideration. The guidelines apply to professional bodies or to government agencies which normally would wish to present a balanced view.
In June 1980, the National Cancer Institute commissioned the National Research Council (NRC) to conduct a comprehensive study of the scientific information pertaining to the relationships of diet and nutrition to cancer. The brief included the following requests to the study group ;
(1) to review the state of knowledge and information pertinent to diet/nutrition and the incidence of cancer
(2) to develop a series of recommendations related to dietary components and nutritional factors which can be communicated to the public
As a result of the work done, a report entitled 'Diet, Nutrition and Cancer was published in 1982. With regard to dietary fat, the group concluded that epidemiological studies have repeatedly shown an association between dietary fat and the occurrence of cancer at several sites, especially the breast, prostate, and large bowel. It was observed that in various populations, both the high incidence of and mortality from breast cancer have been shown to correlate strongly with higher per capita fat consumption; the few case-control studies conducted have also shown this association with dietary fat. Like breast cancer, increased risk of large bowel cancer has been associated with higher fat intake in both correlation and case-control studies. The Committee concluded that of all the dietary components it studied, the combined epidemiological and experimental evidence is most suggestive for a causal relationship between the fat intake and the occurrence of cancer.
It is important to recognise that the Committee here is being somewhat tentative. It has, of course, recognised the limitations inherent in the various strategies. Furthermore, there is also considerable difficulty in distinguishing between the effect of fat per se and the effect of a high calorie intake. Diets which are high in calories are usually high in fat content. This is because fat is a very concentrated source of calories - a unit of fat would have over twice as many calories as a unit of sugar or of protein. Furthermore, the Committee made very little effort to consider the role of the different types of fat which may be present in food. (I will refer to this again when I consider the role of fat in relation to coronary heart disease). It must also be recognised that it can be rather dubious to consider the role of fat on its own because its effect may be influenced by other constituents in a person's diet.
In March 1989, Professor Walter Willett, who is in the Harvard School of Public Health and also in charge of the nurses' study mentioned earlier, published a review in the journal "'Nature" entitled .t The search for the causes of breast and colon cancer". He commented as follows :
"The occurrence of both breast and colon cancer is strongly associated with modern affluence, suggesting that they may share important aetiological factors. Indirect evidence, largely based on differences in cancer rates between countries and changes in rates among migrants, has implicated diet as potentially important, but specific aspects of diet have not yet been definitively identified from epidemiological investigations. Much of the available information is derived from case-control studies in which reports from cancer patients about their past dietary practices are compared with those of persons without cancer. The possibility of biased reporting of former diets in these studies is difficult to eliminate .... The existing limited data suggest that, despite gross similarities in the epidemiology of breast and colon cancer, incidence of the colon cancer is likely to be more responsive to dietary change and thus be easier to prevent."
He considers there is strong evidence for a substantial genetic contribution to the risk of breast and colon cancers. However, because there are wide variations in the incidence of these two cancers, he believes that breast and colon cancer almost certainly involve a strong interaction of genetics and the environment.
It has been estimated that 90% of colon and 80% of breast cancers in the USA may be attributed to non-genetic factors. The big challenge is to identify the specific environmental factors. Although there have been numerous proposals, well established risk factors are few and do not account for the major international differences or lead directly to practical preventive measures. Before commenting on the dietary factors, it is worth mentioning some of the other factors associated with breast cancer. These include : 1. Age at which a woman gives birth to her first child -the earlier the better
2. Age at monarch - the later the better
3. Possible role of sex hormones in the development of breast cancer has raised concerned that oral contraceptives and post-menopausal replacement hormones might increase the incidence but little evidence to suggest there is any relationship between oral contraceptive use or hormone replacement therapy and breast cancer incidence
For colon cancer, few specific factors have been established. Below are extracts from Willett's paper on his view of the role of dietary fat in breast cancer and in colon cancer :
"For the last decade, the dominant aetiological hypothesis for breast cancer has been that high fat intake, and animal fat in particular, is the primary cause of the large differences in rates between countries. This notion is based largely on two lines of evidence: striking international correlations (approximately 0.80) between per capital consumption of fat and breast cancer rates; and animal experiments in which diets high in fat increase the occurrence of mammary tumours. Subsequent evidence has not, overall, supported this hypothesis.
It is tempting to draw causal inferences from the international correlations, but these studies provide only weak evidence because the actual causes might involve many other factors related to economic development. Factors such as physical activity, reproductive variables, body composition at different times in life and energy balance are particularly difficult to measure and control in correlational analyses. A recent survey of cancer rates in 65 rural counties in China with similar low levels of economic development strongly suggests that the international comparisons are seriously confounded by factors related to industrialisation: fat intake ranged from 5-47% of energy but breast cancer rates did not vary with fat intake and were at most about one-tenth of those in the United States .... For breast cancer, no material association with fat intake has been found in case-control studies from New York, Hawaii, Australia, Greece and Japan. Although a study from Canada was originally reported as showing a positive association, it was not statistically significant and examination of the date indicates that the average fat intake reported by cases was virtually identical to that reported by controls. In other case-control studies, only a limited list of foods was included; some have construed sporadic associations with foods containing fat as evidence that fat causes breast cancer. These data are difficult to interpret because of the tendency to focus on foods within a study for which associations are seen and because other aspects of the diet, including total energy intake, cannot be controlled for.
The potential for distortion of associations because-of differential recall of past diet is inherent in case-control studies but is eliminated in prospective investigations. Only two prospective studies with a comprehensive assessment of diet have been published. In the larger, based on a dietary questionnaire completed by 89,538 registered nurses in the United States in 1980, weak inverse associations with incidence of breast cancer were seen for total saturated, and polyunsaturated fat. In the other, there was a statistically significant protective effect of total dietary fat but this inverse relationship was weaker and no longer significant after controlling for total energy intake. In prospective studies with limited dietary data, a positive association was seen with meat intake in Japan but not among Seventh-Day Adventists in California. In the latter, breast cancer rates tended to increase, rather than decrease, the longer a Seventh-Day Adventist vegetarian diet, which contains substantially less animal fat than the general diet of North Americans, was consumed.
Findings from case-control and prospective cohort studies, which generally fail to support the dietary fat hypothesis, have been criticised on the basis that diets in the populations studies are not sufficiently heterogeneous and the methods for measuring diet are not accurate enough to detect potential associations. But even when the degree of measurement error associated with the dietary questionnaire used in the larger of the two prospective studies is accounted for, the data are compatible with only a very weak positive association with fat intake .... The published case-control and cohort studies cannot exclude the possibilities that reducing fat intake to well below 30% of total energy intake, the level now frequently recommended, or at an earlier period in life, might influence breastcancer rates. No appreciable reductions in breast-cancer risk among vegetarian nuns and Seventh-Day Adventists have, however, been observed, which argues against an important influence of animal fat over several decades.
The relationship between fat intake and the occurrence of mammary tumours in animals remains controversial. Restricting energy intake dramatically lowers the incidence of mammary tumours. As fat is uniquely dense in energy, a low-fat diet also tends to be low in energy unless the available energy intake is carefully controlled. Thus, rats on a low-fat ad libitum diet have lower tumour incidence than those on a high-fat ad libitum diet; in one typical study, a reduction of 40% was seen. In the same study, however, when the high-fat diet was restricted to provide 20% less total energy intake, tumour incidence decreased by 90% Albanes has performed a meta-analysis of the experiments on diet and mammary cancer in mice over the past 50 years, in which he finds an extremely strong overall positive association for total energy intake.
The plausibility of the fat- and breast-cancer hypothesis would be greatly enhanced if it could be shown that fat influences a biochemical mediator of breast cancer, but unfortunately no such mediator has been well established. Blood or urinary oestrogen levels are the most promising candidates, but the relationships between diet and hormone levels are unclear at present.
Comment : This extract demonstrates very effectively the complexities faced by scientists who are trying to understand how the diet can play a role in the development of breast cancer. For example, if animal fat is the culprit, why is it that there is no appreciable reduction in breast cancer amongst vegetarian nuns? Again, this paper emphasises how difficult it is to distinguish between the effects of fat and of energy. It will also be evident from this, that there are major problems in devising experiments that will actually provide valuable information. It is perfectly understandable that scientists and those who read their publications, sometimes over-play the significance of their results and under-play the deficiencies!
"In contrast to breast cancer, epidemiological studies provide some, but not conclusive, evidence that animal fat or meat intake is associated with risk of colon cancer. In comparisons between countries, rates of colon cancer are strongly associated with intake of animal fat and meat. High total fat intake has been associated with increased risk of colon or rectal cancer in case-control studies from Canada, Australia, Utah, England, New York State and eastern Australia, although the last study is suspect as data from controls were not collected concurrently. In similar studies from southern France, Paris and Belgium, however, no association was found. In the French and Belgium studies, intake of vegetable fats were inversely related to risk of colon cancer. The numbers of colon cancers in prospective studies have been relatively small. Among Japanese-Hawaiian men, those with the highest fat intake had a reduced risk of colon cancer and among Chicago men no association was found between fat intake and colon cancer. In preliminary reports, animal fat intake was positively associated with risk of colon or large bowel cancer among the 89,538 women in the Nurses' Health Study and among 35,000 Seventh-Day Adventists.
In case-control studies of diet and colon cancer, there is a notably consistent positive association with total energy intake. This is particularly puzzling because higher energy expenditure seems to reduce risk of colon cancer and obesity is unrelated, or at most weekly associated, with this disease. The positive association with total energy intake has important implications for interpreting data on specific nutrients, because all tend to be correlated with total energy intake. It is important to adjust statistically for total energy intake in the analysis of these studies to distinguish between the effect of overall food intake and that of dietary composition, especially for nutrients such as dietary fat that are highly correlated with energy intake. Individuals must alter their intake of specific nutrients primarily by manipulating the composition rather than the total amount of food eaten, unless they are to alter substantially their physical activity or weight. Thus, the intake of nutrients adjusted for total energy intake is most informative for making decisions about changes in diet. The association of dietary saturated fat with colon cancer was independent of total energy intake in one study but not in another; most other case-control studies have not evaluated whether the observed association with overall fat intake in independent of energy intake.
Comment : With colon cancer, there is some suggestion that animal fat or meat intake is associated with the risk of colon cancer. Nevertheless, a number of studies do not fit in with this conclusion. Once again, the problem of distinguishing between total energy intake and fat intake is apparent.
I have also examined the papers cited by the defendants in support of their position. My comments are given in Appendix I.2.
Conclusion : Given the current state of knowledge, it is quite unjustified to condemn any individual food on the grounds that because it is high in fat (or in animal fat) it will cause cancer.
As a result of numerous exercises to evaluate the scientific literature, various recommendations on diet have evolved, which are promoted by governments and health professionals. In the UK, there is general agreement that there is a need to alter the average national diet by 1) Reducing total fat 2) Reducing saturated fat 3) Reducing sugar 4) Reducing salt 5) Increasing dietary fibre
It must be emphasised that these recommendations apply to diets not foods. There is no question that all foods should comply with the recommendations. Many foods such as potatoes, lettuce, tomatoes, beans, skim milk, low fat yoghurt, lean meat and sugar contain little or no fat. Other foods such an meat pies, convenience meals, butter, cooking oil, avocados can have very high fat contents. What is absolutely crucial is the composition of the total spectrum of foods eaten by an individual. So there is absolutely no reason why McDonald's should be condemned for selling products which have a content of fat higher than that recommended for the whole diet by a UK Government body (in this case the Committee on Medical Aspects of Food Policy). What is important is that individual consumers should be aware of the dietary guidelines and of how they should construct a diet which is in line with the recommendations. The booklet, McDonald's Food : The Facts, provides advice on how to make up a diet which had variety and balance. The dietary recommendations are spelled out and information is provided on the nutrition composition of McDonald's products.
In my opinion, it is quite unreasonable to expect McDonald's or any other company for that matter to limit their products to those which comply with the dietary recommendations. This was never intended by those formulating the recommendations.
APPENDIX I.1 METHODOLOGICAL PROBLEMS AND LIMITATIONS
Based on the major report "
Diet and Health : Implications for Reducing Chronic Disease Risk"
Prepared by the Committee on Diet and Health, Food and Nutrition Board Commission on Life Sciences, National Research Council, National Academy of Sciences, USA
This Committee was set up to undertake a comprehensive analysis of the scientific literature on diet and the spectrum of major chronic diseases and to evaluate the criteria used to assess the strength of evidence on associations of diet with health. The report is widely recognised as one of the most thorough evaluations conducted in the field of diet and health in recent years. ERRORS THAT MAY OCCUR IN ASSESSING FOOD INTAKE
1) Sampling errors - because of variations in diet between individuals, small samples may provide estimates of food intakes by populations which are highly unrepresentative even when individual data items are accurate.
2) Non response bias. Randomly selected samples are designed to represent an entire population. Therefore, a high refusal rate may introduce a serious bias if those who refuse to participate differ significantly from those who do respond.
3) Reporting errors. In recall methods, subjects may fail to remember accurately all food eaten. This can apply especially to old people and to young children. Subjects may report intakes of foods and amounts they believe the investigator approves instead of their actual intake. They may also be reluctant to admit to binge eating or high alcohol consumption. If respondents are required to weigh or measure their foods, they may alter their usual dietary habits to make recording easier or to provide answers they thing will please the investigator.
4) Errors Relative to Day-to-Day Dietary Variability. Because individuals vary widely from day to day in their food consumption, even an accurate 24-hour recall may not include the most common foods eaten if they were not consumed on the day of recall.
5) Interviewer bias. Poorly trained interviewers may introduce errors by suggesting answers or by leading respondents.
6) Errors due to use of food consumption tables. Any food item can vary widely in composition because it can be influenced by conditions of growing, storage, processing or preparation. Hence the single values given in tables may be quite different from the actual value applicable to a specific food.
ASSESSMENT OF DISEASE INCIDENCE AND PREVALENCE
The criteria for diagnosing a disease may vary among regions, and there may be local biases in diagnosing certain diseases. Thus, there are many opportunities for errors and differences in disease measurement and classification that could bias the results and the conclusions drawn from them. Intensive studies of death certificate data have shown that the accuracy of disease rates based on conventional death certificates varies greatly among cities, countries and cause of death.
1) Misclassification. If these are systematic and vary from group to group, they may bias the means in different ways and thus bias the comparisons of interest. For example, if certain diseases are under-reported in countries with both poor medical services and low intake of a specific nutrient, 8 spurious correlation of the disease with high nutrient intake may be introduced or a correlation in the other direction observed.
2) Temporal relationships. Dietary intake after 8 disease is established may not be an index of the relevant exposure since the disease may have affected the diet rather than vice versa. Misclassification of this type is especially serious in studies of chronic diseases, most of which develop over long periods during which they do not produce readily detectable signs or symptoms.
3) Confounding. This refers to association" that are real but do not indicate a causal link. For example, absence of teeth may be associated with the consumption of large quantities of milk but milk is definitely not the cause of the condition. This aspect can be critical in attempts to relate nutrition to chronic diseases, because most of these have multiple causes and because nutrition is also greatly affected by social, cultural, economic and geographical factors.
4) Case-control. Potentially, severe limitations when used to examine dietary causes of chronic diseases. The major problem is relating time of exposure to time of disease origin. Furthermore, choice of control subjects can influence study findings especially when dealing with a chronic disease where the incidence is high.
APPENDIX I.2 CONSENTS ON VARIOUS SCIENTIFIC PAPERS
A. THE CAUSES OF CANCER Richard Doll and Richard Peto
"Diet is a chronic source of both frustration and excitement to epidemiologists. For many years there has been strong but indirect evidence that most of the cancers that are currently common could be made less so by suitable modification of national dietary practices. This is even more plausible now than it was 10 years ago, but there is still no precise and reliable evidence as to exactly what dietary changes would be of major importance" (emphasis added)
... Colorectal and breast cancer are generally associated with a high standard of living in adult life and have been suspected of being due to a high proportion of fat or possible (in the case of colorectal cancer) of meat. Correlations between the national consumption of fat and meat per head of population and the incidence of these types of cancer are strong - nearly as strong as the correlation between the consumption of fat and the incidence of endometrial cancer. However, the cancers are not uniformly uncommon in vegetarians, and the low incidence in Seventh-Day Adventists (who are largely vegetarian) is matched by a similarly low incidence in Mormons (who are not vegetarians) and who do not avoid fat in their diet. Gaskill et al have pointed out that the mortality from breast cancer within different national and racial groups correlates with the proportion of the population that continues in adult life to secrete substantial amounts of lactose (an enzyme produced to aid the digestion of milk), They find that within the United States, breast cancer mortality correlated more strongly with the consumption of milk fat than other types of fat.
Comment : This shows that while the national data may indicate that there is an association between a diet which is high in fat (or meat) and a high incidence of cancer of the breast or cancer of the colon, this does not prove a definite link between cause and effect. We still need to know much more about the role of the different types of fat and the effect of other constituent in the diet.
Doll and Peto have pointed out that in diet, protective agents may be of more practical importance than causative agents. Before we can make strong recommendations to the public, it is essential to understand the relative importance of causative and protective agents. B. "SUGAR, FAT AND THE RISK OF COLORECTAL CANCER" B Bristol, PM Emmett, KW Heaton and Ron Williamson British Medical Journal (1985) 291 ppl467-1470
This is a case control study in which 28 men and 22 women with cancer of the large bowel were compared with controls, who were matched in terms of age, sex, marital status and social class. The habitual diet of each group was determined and it was found that on average
* Total fat intake was 14% higher among patients with large bowel cancer than in the controls
However, it was also observed that in the patients
* Total daily energy intake was 16% higher than in the controls
* Sugar consumption was 41% higher than the controls
* It was particularly noticeable that fat consumed in combinations with sugars - eg, as in cakes and biscuits, was 36% higher than in the controls.
There was no difference between the groups in consumption of fibre. Comment : On the basis of this study, it would not be justified to conclude that there is a definite link between high fat consumption and a high incidence of bowel cancer. In fact, there are other factors which might be important. In particular, the authors themselves show that the high fat intake is due at least in part to the consumption of combinations of fat and sugar (as found in cakes, biscuits and confectionery).
It is possible that if diet is a contributory factor, then the higher energy in the cancer cases could be responsible rather than the fat per se.
C. "ENVIRONMENTAL FACTORS AND CANCER OF THE COLON AND BREAST"
c) BE Drasar and Doreen Irving British Journal of Cancer (1973) 27, 167
This study compares the incidence of various cancers for 37 different countries with data on fat, protein and fibre consumption taken from estimates by the Food and Agriculture Organisation. Comparisons were also made with other factors such as the number of motor vehicles, which are used as an index of standard of living. The authors concluded that cancer of the colon and cancer of the breast were highly correlated with indicators of affluence such as a high fat diet rich in animal protein and the availability of motor vehicles. The correlation with fat and animal protein was higher than for other factors.
No correlation was found with fibre, which might have been expected to be protective.
Comment : This paper can be criticised on many of the grounds discussed earlier. The data are somewhat dubious - certainly the information on diet for many of the countries included in the study cannot be regarded as reliable.
Even if the association has been established, this does not demonstrate cause and effect. There could be another factor which varies in the same way as dietary fat.
The study is on dietary fat and no attempt is made to elucidate the role of the different types of fat that are present in the diets. D. Paper by TG Hislop, AJ Coldman, JM Elwood, G Brauer and L Ran
"Cancer Detection and Prevention" (1986) 9, 47-58
This is a case-control study in which 846 women with breast cancer were matched with 862 controls in British Columbia between 1980 and 1982. All cases and controls were asked to complete a mailed self-administered questionnaire which asked about family history, reproductive and medical history, oestrogen usage and supplementary vitamin usage. They were asked to provide dietary information for 4 different age periods, childhood (up to age 13), teens (13-19 years), young adulthood (20-40 years) and older adulthood. Frequency of consumption was requested for 31 specific items.
Comment : This study suffers from the fact that data collected in this way is extremely unreliable. It is quite unrealistic to expect individuals to remember accurately what the habitual food consumption patterns were in the past. Furthermore, the variation in the composition of different foods would mean that the data would be of little value. Hence the conclusions cannot be taken seriously. INTRODUCTION
Food additive usage is subject to detailed legislative control. This means that for all practical purposes, the risks to public health are arguably as low as can be expected given the nature of the contemporary food supply. In this section, initially I will consider the critical role of food additives in facilitating a very wide range of food products that are safe, nutritious and attractive to eat. Then I will describe the principles and systems of regulation with particular reference to safety and need. I will present a summary of the recent evaluations on the safety of the additives listed by the defendants. Finally, I will explain the McDonald's approach to food additives.
There are widespread misconceptions about food additives among the general public. For example, a recent survey conducted by Gillian Wright and Nick Howcroft in the University of Bradford found that out of 920 respondents
89% AGREED with the statement "There are too many additives in food's
87% AGREED with the statement Additives in food can be dangerous
WHAT ARE FOOD ADDITIVES ?
According to the Codex Alimentarius :
'Food additive' means:
"Any substance not normally consumed as a food by itself and not normally used as a typical ingredient of food, whether or not it has nutritive value, the intentional addition of which to food for a technological (including organoleptic) purpose in the manufacture, processing, preparation, treatment, packing, packaging, transport or holding of such food results in, or may be reasonably expected to result, (directly or indirectly) in it or its by-products becoming a component of or otherwise affecting the characteristics of such. The term does not include "contaminants or substances added to food for maintaining or improving nutritional qualities"
There are many different categories of food additives. Here is a resume:
Preservatives. In the absence of any special treatment many food crops begin to deteriorate immediately after harvest. Micro-organisms cause spoilage and may also be a health hazard. Preservatives act chemically to kill or retard the growth of the micro-organisms in prepared foods after processing. There are also physical methods of preservation such as heat treatments, pasteurisation, sterilisation) and cold storage (eg, chilling, freezing) each of which reduces the need for preservatives by chemical means. Similarly, developments in packaging (eg, retort packing, controlled atmosphere, vacuum packing, all have a role to play in preventing deterioration. One advantage of irradiation is that it reduces the need for preservatives. Sugar and salt have been used to preserve food since earliest times. More recently, for example, chemicals such as propionic acid have been introduced to extend the shelf life of bread and cakes.
Anti-oxidants. These inhibit the deterioration of many naturally occurring constituents in foods, especially the polyunsaturated fatty acids and the fat-soluble vitamins. Two of the most widely used are butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) prevent rancidity in such foods as baked goods, cereals and snack-foods.
Emulsifiers and stabilisers. An emulsifier helps to form an emulsion of two substances which would not usually mix, such as oil and water. A stabiliser helps to maintain the emulsion once it has been formed. Lecithin is one example of a stabiliser which is used in margarine.
Colours. These are used to enhance the attractiveness of products. In some cases they may be used to replace colours which have been lost during processing. Examples are: p-carotene, a constituent of carrots, chlorophyll and quinoline yellow.
Flavours/flavour enhancers. Used to make manufactured food attractive to consumers and to increase the variety in processed foodstuffs. They are sometimes used to replace flavours lost during processing or storage. The best known flavour enhancer is monosodium glutamate (MSG), widely used in Chinese restaurants and prepared foods. It is present naturally in seaweed but more usually prepared from sugar beet or wheat.
Seguestrants. Used to enhance the action of anti-oxidants by inactivating certain metals which could otherwise promote oxidation reactions in foods. They are also used without antioxidants to inhibit oxidation which is facilitated by metals.
Anti-caking agents. Used to prevent particles aggregating so that products such as dry mixes can flow freely.
Acids. buffers and bases. Used to control the pH (acidity or alkalinity) during processing and in the final product.
Humectants. Absorb water from the atmosphere which compensates for natural drying out and so extends the shelflife (eg, cakes). Glycerol is often used in confectionery.
Firming and crisping agents. Used in prepared or processed vegetables such as lettuce to prevent water loss, thereby maintaining the texture. They are also used in prepared fruits.
Sweeteners. Includes ingredients added to provide sweetness. Sugar is also regarded as a nutrient because it contributed to the energy content of a food.
Enzymes. Biological catalysts which facilitate chemical reactions. The enzyme rennin obtained from the stomach of calves is used to coagulate milk in the initial stages of cheese manufacture. However, innovations in technology have led to the development of alternative methods for cheese production.
Bleaching agents are used to whiten flour and hence white bread.
Flour improvers such as sulphur dioxide aid the development of doughin bread-making.
In addition, many other types of additives are used to facilitate processing and, perhaps more importantly, affect the presentation of food to the consumer. These include raising agents, thickeners, bulking agents, chelating agents, diluents, glazing agents, mineral hydrocarbons, gases used in packaging, release agents, solvents and polyphosphates.
There is general agreement that a system of regulatory control is essential. Governments accept that they have a responsibility to evaluate the evidence on the safety of individual food ingredients and use this as a basis for formulating regulations/ directives. This means that manufacturers, retailers and consumers all know where they stand and what they have to do vis-a-vis food additives in order to comply with the legislation. If this was not done, then it would be left to individual companies to do their own evaluation. The resources required for this would be prohibitive. Furthermore, it would be almost impossible for individual companies to convince the public at large that they were capable of conducting assessments that are authoritative and objective. In fact, the reality in that certain companies would use safety of additives to gain a marketing advantage. To some extent, this has happened already with some companies making claims such as "NO ARTIFICIAL ADDITIVES", "NO PRESERVATIVES, etc. I am convinced that the removal of some additives for marketing reasons has tended to exaggerate public fears about food additives. It has undoubtedly reinforced the views of those consumers who believe that the use of additives is not essential. It raises the question:
"If companies are now taking them out, why were they put there in the first place?"
The regulatory system of control for food additives has become extremely detailed in the last 40 years. Until the 1920s, apart from the general provision of the Sale of Food and Drugs Act (1875) which was in force at the time, there were no specific controls on the use of food additives. The first significant step was the prohibition of a few colours which were obviously dangerous. However, by the 1950s, because of :
* Advances in toxicology which indicated that the regular ingestion of a small amount of material over a long time could be hazardous
* Improvements in analytical techniques which enables very small amounts of constituents in food to be detected and measured
* Growth in the degree and sophistication of food processing with the result that there has been a tendency for the use of additives to increase
the concept of the permitted list was introduced. This means that only those additives which are specifically approved can actually be used. This principle now applies to virtually all categories of additives. In order to formulate regulations, the UK now has a system whereby the Food Advisory Committee (FdAC) considers applications for new additives and advises the Government whether they should be approved. The FdAC takes advice from the Committee on Toxicity of Chemicals in Food Consumer Products and the Environment (COT). This Committee consists of independent experts with a background in academia, medicine or research. It is their function to review all the evidence on safety which is included in the application as well as any other relevant information. Nowadays, there are relatively few applications for new additives to be approved and most of the regulatory effort is devoted to the conduct of reviews on those already in use in the light of any new information that becomes available.
The EC has a system which is essentially quite similar. The key body involved here is the Scientific Committee for Food (SCF).
The regulatory bodies have 2 key questions to answer :
1. Are Food Additives Necessary?
2. Are Food Additives Safe? Necessity
The considerations here vary from one category of additives to another. The case for preservatives is self-evident - obviously it is beneficial to inhibit the growth of micro-organisms which reduce keeping quality or, more importantly, can be iifethreatening. At the other end of the spectrum, the view is regularly expressed that colours are not needed. According to the FACC (1979 report) the principal reasons for which colours are used may be summarised as follows :
(a) to reinforce colours introduced into foods by their ingredients but where, without added colouring matter, the colour imparted to the final food by those ingredients would be weaker than the colour the consumer would associate with a food of that type or flavour (eg, soft drinks, fruit yoghurts, pickles and sauces);
(b) to ensure uniformity of colour from batch to batch, where ingredients of varying colour intensity have to be used (eg, jams in transparent containers where the customer can compare like with like in the shop);
(c) to restore something of the food's original appearance in those cases where the natural colours have been destroyed by heat processing and subsequent storage (eg, canned peas, beans, strawberries and raspberries); or bleached out by the use of preservatives (eg, fruit preserved with sulphur dioxide for jam making out of season); or are not light stable during prolonged storage (eg, soft drinks)
(d) to give colour to foods which otherwise would be virtually colourless (eg, boiled sweets, instant desserts, ice follies) n The FdAC concluded that if consumers are to continue to have an adequate and varied diet, attractively presented, the responsible use of colouring matter, the safety-in-use of which has been fully evaluated, still has a valid part to play in the food industry. The FdAC recommended that the use of colouring matter in food should continue to be permitted.
The EC position on need has been expressed as follows :
The use of food additives is justified only where they serve one or more purpose set out from (a) to (d) and only where these purposes cannot be achieved by other means which are economically and technologically practicable and do not present a hazard to the health of the consumer
a) to preserve the nutritional quality of the food; an intentional reduction in the nutritional quality of a food would only be justified where the food does not constitute a significant item in a normal diet, or where the additive is necessary for the production of foods for groups of consumers having special dietary needs; b) to provide necessary ingredients or constituents for foods manufactured for groups of consumers having special dietary needs;
c) to enhance the keeping quality or stability of a food or to improve its organoleptic properties provided that this does not so change the nature, substance or quality of the food as to deceive the consumer;
d) to provide aids in manufacture, processing, treatment, packing, transport or storage of food; provided that the additive is not used to disguise the effects of the use of faulty materials or of undesirable (including unhygienic) practices or techniques during the course of any of these activities"
Additives are essentially a diverse group of technological aids which are available to the food industry. For any given purpose, there may be a range of options, from which to choose. For example, the shelf life can be extended by a variety of heat treatments and cold storage as well as by using chemical preservatives. Within recent years, there have been very significant advances in these technologies. Some of these such as ultra-high-temperature (UHT) and cold-chain have advantages in terms of improved flavour and texture when compared with traditional methods of preservation. However, the risks of food poisoning may be increased, because it is more difficult to maintain the conditions required to prevent proliferation of pathogenic bacteria. The regulatory control by means of permitted lists simply lays down a framework for the industry. However, it is important to recognise that market forces provide an additional form of control. If there is a demand for foods which are free of additives or certain categories of additives then these can be made available. Certainly, this is happening today - the supermarkets are detecting consumer concerns and responding to them.
On the other hand, it would be quite unreasonable for such demands to be reflected in the permitted lists. There are still a very large number of consumers who are not worried about additives and may even prefer them. What is much more important is that they should have access to the necessary information which will enable them to make a sound judgement on which foods to choose.
Consumer attitudes and perceptions can change rapidly, are not necessarily logical (not is there any reason why they should be) and the industry can respond quickly. By contrast, the system of legislative control is by its very nature fairly slow to respond and as far as possible should be based on a sound logical foundation.
This is determined in the UK by the COT. Over the years, a system of classification has evolved and when the evidence on safety has been evaluated, each additive is placed in one of the following categories :
Group A: substances that the available evidence suggest. are acceptable for use in food
Group B: substances that on the available evidence may be regarded meanwhile as provisionally acceptable for use in food, but about which further information must be made available within a specified time for review
Group C: substances for which the available evidence suggests possible toxicity and which ought not be permitted for use in food, until adequate evidence of safety has been provided to establish their acceptability
Group D: substances for which the available information indicates definite or possible toxicity and which ought not to be permitted for use in food
Group E: substances for which inadequate or no toxicological data are available and on which it is not possible to express an opinion as to their acceptability for use in food
As a general rule, only those which fall into the Groups A and B would be recommended for inclusion in the permitted lists, some times with restriction in the amounts that are allowed.
SAFETY OF FOOD ADDITIVES WITHIN THE CONTEXT OF THE WHOLE DIET
There is a distinct danger that too much emphasis is being placed on controlling food additives. It is important to understand that the regulatory controls have become progressively more stringent over the past 40 years. We have probably now reached the point where very little further improvement can be achieved. There is no doubt that additives are needed if we are to continue to have the range of foods currently available. There is actually a danger that if we continue to reduce the number of additives that this will actually increase the usage of those which are still permitted. Should any of these subsequently be found to be hazardous, then the high level of consumption might cause some adverse effect to health.
Nevertheless, it must be emphasised that the risk associated with additives are very small indeed, at least as far as we can determine at present. It is, therefore, necessary to relate any hazards linked to additives to others that may arise from the total diet.
In the US, Howard Roberts of the Food and Drugs Administration has assessed food safety hazards in terms of the following criteria :
* Severity - the type of effect - ranging from death and disability
* Incidence - the number of cases or rate of occurrence of the effect
* Onset - whether the effect occurs from acute to long term .
Applying these criteria, Roberts obtained the following ranking :
1. Food-borne hazards of microbial origin
3. Environmental contaminants
4. Mycotoxins and natural toxicants
5. Food additives
An earlier attempt by V O Wodicka, Director of the Bureau of Foods, Food & Drug Administration (FDA) gave a rather similar ranking :
3. Environmental contaminants (pollutants)
4. Natural toxicants
5. Pesticide residues
6. Food additives
Explaining why he put food additives at the bottom of the list,
Dr Wodicka said : "In spite of the fact that there is considerable public concern and suspicion of the minor constituents used in formulated foods, there is no credible evidence that the permitted ones are, in fact, harmful. This is one of the reasons why I put this class of hazards last on the priority list, and the other reason is that these materials have been under close regulation by FDA or the Department of Agriculture. At some point in time the regulatory agencies had to be convinced that the substance WAS harmless under the conditions of use or it would not be permitted in the food supply".
As shown above, the major hazards are microbiological and nutritional. In the OR, The officially recorded cases of food poisoning have been increased steadily for years. At the end of 1988, the famous statement by Mrs Currie, at the time a Junior Minister of Health, triggered off a series of scares about salmonella and listeria. One of the prime concerns was the fact that salmonella incidence had been increasing. Despite all the measures introduced, the position continues to deteriorate, so clearly there is considerable scope for improvement here.
THE REGULATORY BODIES
From the perspective of the UK and the EC, the key Committees involves in evaluating the evidence and providing advice on regulatory control are
1. The FdAC , which has the following terms of reference :
To assess the risk to humans of chemicals which are used or occur in or on food and to advise Ministers on the exercise of powers in the Food Safety Act 1990 relating to the labelling, composition and chemical safety of food. In exercising its functions, the Food Advisory Committee will take advice and work of the Committee in Toxicity and other relevant advisory Committees into account"
The FdAC was formed on 1 November 1983 by merging the Food Standards Committee and the Food Additives and Contaminants Committee. These two Committees used to share the responsibilities now undertaken by the Food Advisory Committee. The members include distinguished academics and researchers as well as senior people from the food industry who are appointed for their expertise not to represent the interests of the industry. Members are also appointed from consumer bodies. The current chairman is Dr Ewan Page, Vice-Chancellor of Reading University.
2. The Scientific Committee for Food (SCF) has an EC role, which parallels that of the Food Advisory Committee in the UK
3. Joint Expert Committee on Food Additives, which is organised by the World Health Organisation (WHO) and the Food and Agriculture Organisation (FAO). At regular intervals, experts meet for up to 14 days in order to evaluate recent evidence on the safety of food additives. Over the years, there has been strong representation from the UK at these meetings. The results of the deliberations are published and are therefore available to governments as an input when deciding on their own national regulations.
It is crucial to emphasise that the available evidence on the safety of additives is being regularly reviewed. When doubt arises, then steps will be taken to remove the additives from the approved list or to restrict their use so that any possible hazards are kept to an absolute minimum. Many different approaches are used to determine the safety. Some of these consist of feeding much larger amounts than would ever be used in practice to a variety of different animal species. Others involve detailed biochemistry in order to find out what happens to the additive after it has been ingested.
All the additives mentioned in the statements have been evaluated in recent years. Here is a summary :
This was considered by the FdAC a few years ago (Final Report on the Review of the Colouring Matter in Food Regulations - FdAC/REP/4 HMSO 1987).
When the Food Additives and Contaminants Committee (FACC) reviewed Amaranth in 1979, they considered some evidence which cast doubts on the status of this colour. As a consequence, the FACC requested further studies which were made available for the subsequent review. These new investigations showed that there is little Amaranth absorbed from the gut of several different animal species so that the colour and its break-down products are rapidly excreted in faeces and urine, the former containing substantial amounts of unchanged colour. There was no evidence of specific tissue accumulation following a single oral dose. The fact that there was little build up of the additive or its break-down products is clearly very positive from the perspective of safety. Further studies failed to demonstrate any carcinogenic effects. In the light of this information, the FdAC recommended that the use of Amaranth in food is acceptable and classified it as Group A - substances that the available evidence suggests are acceptable for use in food.
According to the current Proposal for an EC Council Directive on colours for use in foodstuffs, Amaranth is listed in Annex I -list of permitted food colours. Amaranth has been given an Acceptable Daily Intake (ADI) of O - 0.8 mg/kg body weight by the SCF.
This colour was also considered by the FdAC at (see FdAC/REP/4 HMSO 1987). This one had been classified as Group A in the 1979 report. The results of the studies which had become available after the 1979 report was released were subjected to detailed evaluation. As a consequence, the Committee was satisfied on the safety aspects and recommended that Sunset Yellow should continue to be classified in Group A. Sunset Yellow is also included in Annex I of the Proposal for an EC Council Directive on colours for use in foodstuffs. The SCF has established an ADI of O - 2.5 mg/kg body weight. BHT (E321)
The SCF reviewed all the available studies on BHT and published its opinion in Reports of the SCF (Twenty-second series - EUR 12535 EN, 1989)
Although tumours were observed in studies with rats, the Committee concluded that there we. a threshold for carcinogenesis which was consistent with a variety of other evidence. This consisted of metabolic data from a variety of species, including man, mutagenicity studies and special studies on the thyroid, blood and post-natal development and behaviour.
Taking all this evidence into account, the Committee considered that the no-effect level (NEL) for BHT is approximately 100 ppm in the diet, equivalent to an intake of about 5 mg/kg body weight/day. In view of the nature of the effects, a safety margin of 100-fold is appropriate to establish an ADI of O - 0.5 mg/kg body weight. BEB (E320)
The SCF has considered the evidence on BHA in 1978, 1983 and again in 1987. The latest opinion is published in Reports of the SCF (Twenty-second series - EUR 12535 EN, 1989)
In the 1983 evaluation, the SCF considered results from a Japanese study in which BHA had produced forestomach tumours in rats. In 1987, when the results of further studies had become available, the SCF concluded that the action of BHA in producing forestomach hyperplasia and tumours in rodents may not be relevant for man. This view was reinforced by other studies which showed that mutagenicity data were negative and that no genotoxic effects could be demonstrated. Negative results were also obtained for a teratogenicity. In the light of this information, the SCF agreed that it was acceptable to get a temporary ADI for BHA. It was agreed that this should be 0 - 0.5 mg/kg body weight.
The Committee noted that the actual (estimated) daily intake of BHA is far less than allowed by the temporary ADI.
(Recently considered by the SCF - Reports of the SCF - Twenty sixth series 1992 - EUR 13913 EN)
Nitrate can be converted to nitrite during processing or during digestion. Nitrite is the active form. Vegetables, in general, contribute more than 75% of the total dietary intake of nitrate. In the recently published US Food Surveillance Paper N° 32 entitled "Nitrate, Nitrite and N-Nitroso Compounds in Food : Second Report" it was found that the estimated dietary intake of nitrates was 54 mg/person/day in 1985 and 61 mg/person/day in 1979. By contrast, a study in 1987/88 found that vegans consumed 185 mg/person/day and lacto-ovo-vegetarians consumed 194 mg/person/day. This is because the major sources of nitrate in the British diet are vegetables. Hence those who include meat in their diet have a very much lower intake of nitrate than those who do not. For nitrite, the average consumption is 4.2 mg/person/day of which 0.24 mg originates from meat products.
Mean nitrate intakes from all sources in many Western countries have been estimated to be well within the previously established acceptable daily intake (ADI) of 5 mg/kg body weight (as sodium nitrate) although individual consumers may exceed this level. Nitrite controls several undesirable micro-organisms -particularly Clostridium botulinum as well as improving shelf life.
Minimum effective concentration of nitrite with respect to Clostridium botulinum depends on several factors, including hygiene status, pH, water activity, concentration of other salts. SCF considers 50 - 100 mg added nitrite (as sodium nitrite per kg meat products) may be enough for many purposes but some products may require up to 150 mg/kg. This would normally result in residue levels of less than 50 mg/kg because some of the-nitrite would decompose during processing and storage. The concern about the safety of nitrites arises from the fact that nitrosamines, which are carcinogenic, can be formed from it.
The SCF concluded that
(a) the use of nitrate as a food additive makes a relative small contribution to the total intake, most of which originates in vegetables and drinking water
(b) intakes of nitrate and nitrite from food are generally well within the ADIs, except in areas where levels of nitrate in vegetables are high and levels in drinking water exceed Community standards
(c) no direct toxic effects are, therefore, expected from food additive uses of nitrates and nitrites when used according to the SCF guidelines
The SCF is understandably cautious and recommended that exposure to preformed nitrosamines in food should be minimised by appropriate technological practices such as lowering levels of nitrite and nitrate added to foods to the minimum required to achieve the necessary preservative effect and to ensure microbiological safety. The SCF emphasised the importance of only using nitrite mixed with salt in meat production and this would automatically limit the amount of nitrite which can be added and prevent accidental poisoning through the addition of excessive quantities to food.
With these additives, it is important to understand the need to balance the control of micro-organisms such as Clostridium botulinum, which is extremely virulent against the risk of adverse effects due to the additives themselves. There in widespread agreement amongst scientists who have addressed this issue that it is preferable by far to ensure that the Clostridium botulinum is kept at bay.
The FdAC classified Carrageenan as Group A when it conducted a review, published in 1970. Group A is defined as substances that the available evidence suggests are acceptable for use in food. However, as a result of further information becoming available, the most recent review (1992) has recommended that this substance be reclassified as Group B.
Group B is defined as substances that on the available evidence may be regarded meanwhile as provisionally acceptable for use in food, but about which further information must be made available within a specified time for review.
Monosodium glutamate (MSG)
This consists of two parts - glutamate, which is derived from glutamic acid and sodium, which is present in common salt. The amount of sodium that could be derived from this source is very small compared with the intake in the form of salt. Therefore, investigations on safety focus on the role of the glutamate. Glutamate is actually a normal constituent of the body. For example, human milk contains 1.2% protein, of which 20% is bound glutamate, equivalent to 3 g/litre calculated as MSG. The daily intake of free glutamic acid by the breast-fed infant is about 36 mg/kg bodyweight (equivalent to 46 mg/kg bodyweight as MSG).
Glutamate is present in virtually all organs of the human body. Muscle contains about 6 gas and brain just over 2 gas.
Glutamate is present as a natural constitutent of many common foods. For example, in Western Europe, it has been estimated that 8 million tonnes of tomatoes contain about 14,000 tonnes of MSG.
Various experts have given their views on the safety of MSG.
"Based on the information that we have heard, I personally have no reservations about the general use of glutamate as a food additive. I cannot conceive of any situation in which people could possibly consume glutamate in sufficient concentrations to produce brain damage (RJ Wurtman*)
* In "Glutamic Acid : Advances in Biochemistry and Physiology" edited by W Filer, Jr. et al. Raven Press : New York 1979
"It is now possible to say with confidence that (with) concentration of MSG of the order of O.75%, it is extremely unlikely that any of the symptoms will be experienced by even a demonstrably sensitive individual. Furthermore, at a level of 1.5%, only a few individuals will be affected.' (RA Kenny**)
** In Glutamic Acid : Advanced in Biochemistry and Physiology" edited by LJ Filer, Jr. et al. Raven Press : New York 1979
Data on the safety of MSG has been evaluated by the Joint FAD/WHO Expert Committee on Food Additives (World Health Organisation, Technical Report Series 759, WHO, Geneva 1987). This Committee commented on the alleged link between MSG and Chinese restaurant syndrome" as follows :
"Following early anecdotal reports of subjective symptoms after ingestion of Chinese meals and experiments involving the administration of MSG, MSG was implicated as the causative agent of "'Chinese restaurant syndrome". Extensive studies in human volunteers have been carried out subsequently and have been reviewed recently. These studies have failed to demonstrate that MSG is the causal agent in provoking the full range of symptoms of Chinese restaurant syndrome. Properly-conducted double-blind studies among individuals who claimed to suffer from the syndrome did not confirm MSG as the causal agent. Food symptom surveys have been considered technically flawed because of the questionnaire design.
Twenty-four subjects, including 18 who had a history of subjective flushing symptoms after eating Chinese restaurant food, were challenged with 3- 18.5 gm MSG. No-one reported flushing sensations. Six subjects, 3 with a history of flushing, were challenged with 35-285 mg MSG/kg bodyweight or 7.1-7.4 mg pyroglutamate/kg bodyweight. None reported flushing sensations and significant changes in facial cutaneous blood flow were not recorded".
The Committee concluded that the ADI should be "not specified".
Substances given an ADI "not specified'' are of low toxicity. On the basis of the available data (chemical, biochemical, toxicological and other) the total dietary intake of glutamates arising from their use at the levels necessary to achieve the desired technological effect and from their acceptable background in food do not, in the opinion of the Committee, represent a hazard to health. For that reason, the establishment of an acceptable daily intake is not deemed necessary.
Potassium bromate was one of a number of flour improvers permitted in the UK by the Miscellaneous Additives in Food Regulations 1980 to improve the baking properties of dough. It acts slowly and continuously throughout the dough fermentation. It is used for two functions. First, for doughs which have a relatively low protein content, such as those found with wheat grown in Europe, it produced loaves of a volume normally only associated with strong wheat from North America. Second, it can help to produce a fine vesiculated crumb structure. The amount required varies between 15 and 45 mg/kg. There were specific limits imposed for use in bread by the Bread and Flour Regulations 1984 to ensure that no detectable residues occur in bread when it is eaten. If it is not used, there is a marked reduction in loaf volume and the crumb structure is relatively coarse. In 1988, the Committee on Toxicity (COT) conducted a review of potassium bromate because of concerns about its possible carcinogenicity in rodents. In the light of new evidence which had emerged, the Committee requested further information provided by the Committee on Mutagenicity the COT advised the FdAC that
(1) bromate-treated flour should no longer be available on retail sale to consumers since they could be directly exposed to bromate in the raw, uncooked flour and there could be no assurance that under variable baking conditions in the home, the bread would be free of bromate residues
(2) bromate-treated flour should no longer be used in the dusting of commercial products after baking since this could expose consumers directly to bromate; and
(3) the acceptability of the continued use of bromatetreated flour in commercial bakeries has been dependent upon previous findings which had indicated that residues of bromate were absent in the bread itself. The new analytical data which have been provided by MAFF's Food Science Division Laboratories do indicate that residues of bromate are commonly present in commercially baked bread and, therefore, the COT concluded at its meeting on 26 September 1989 that this use of bromate should no longer be approved
These views were considered by the FdAC together with information from the baking industry on the economic implications. In the light of this, the FdAC concluded that the use of bromate as a flour improver should be prohibited and recommended the necessary amendments to the Regulations.
The report of the FAC was released on 8 November 1989. On the same day, the Food Minister, David Maclean, stated in the House of Commons that he had accepted the advice of the FAC and had initiated the necessary procedures for amending the Regulations. He also noted that flour millers and bakers were already making changes to their production.
On 9 March 1990, David Maclean announced that new regulations to remove potassium bromate from the list of permitted flour improvers would come into force on 1 April 1990. THE MCDONALD'S APPROACH
Quite simply, the McDonald's approach is to keep additive usage to a minimum. Additives are only used when absolutely essential to manufacture a particular product. Furthermore, all additive usage is strictly within the law. Suppliers are given firm instructions to this effect. When changes are introduced, the company responds as soon as possible, which may be somewhat in advance of the regulatory requirements.
1. On colours, McDonald's fully recognises the concerns and wherever possible they are not used. However, in some cases, colours do play an important role in the appeal to the consumer and so they are retained. McDonald's is in full support of the position taken by the FdAC in 1987, which was expressed as follows:
In our society food is not generally eaten just to provide nutrition, important though that function is. Eating should be an enjoyable experience and the taste, aroma, texture and appearance of food are important to the consumer. It is inevitable that, as a result of their manufacturing process or the ingredients used, some foods will lack colour or their colour will vary from batch to batch. Such foods, even though they may be nutritious, may not be usually appealing."
The FdAC endorsed the principle that the responsible use of colour will continue to have a role in providing consumers with a choice of attractively presented foods. 2. Nitrates/Nitrite. This is only used in the bacon - a constituent Of the "Bacon & Egg McMuffin. McDonald's is in total agreement with the view that the risks of botulism far outweigh those which arise because of the possibility of cancer from nitrosamines.
McDonald's suppliers add 200 mg of sodium nitrate to bacon. Nitrate per se has a very low toxicity and any adverse effects are the results of the conversion of sodium nitrate either before ingestion or in viva. It has been established that the 200 mg sodium nitrate is converted to 150 mg sodium nitrite during processing. This is in line with the recommendations of the SCF.
3. Antioxidants. BHA used to be included in the chocolate topping of the chocolate flavoured donut at a level of much less than 1 mg/kg. The level recommended in the proposed EC directive is 200 mg/kg, so it was extremely small. In any case, this has not been used since 1988. The only other use is in the frying oil for trench fries and hash browns to prevent the deterioration of oil. In the absence of an antioxidant, the oil could become rancid very quickly. This would clearly have an adverse effect on the eating quality of the products. It would also mean that the oil would have to be changed more frequently, thereby increasing the cost of production that would inevitably result in a higher cost to the customers. 4. Carrageenan. This is used in the birthday cakes and in all milk shakes. It is a natural gum that is prepared by extraction from red seaweeds. It is used in food as a gelling agent and stabiliser, particularly in milk products because it can react very well with milk protein to produce a high-strength gel without the use of heat.
5. Monosodium Glutamate. This is only used in sausage patties. As I have explained earlier, the glutamate is a normal constituent of the body and it has been given unqualified approval by regulatory bodies. 6. Potassium Bromate. The role of this additive has been explained earlier. It is important to note that McDonald's and their supplier reacted immediately the Food Minister, David Maclean, announced that new regulations would be introduced withdrawing approval as recommended by the FdAC. This was on 8 November. Within days, McDonald's supplier ceased using this additive although the actual regulation did not come into force until 1 April 1990.
Clearly, this is an issue that generates considerable alarm and concern, especially amongst parents of young children. Nevertheless, it is vital to recognise that the proportion of individuals that have a genuine reaction to food additives is extremely small. Furthermore, it must also be recognised that people are also allergic to many common foods such as milk, eggs, oranges, strawberries, peanuts. It has been estimated that of all food-related allergies, only about 20% can be linked to food additives, while the rest are related to foods.
The FdAC in its 1987 report, considered the question of intolerance or hypersensitivity to Tartrazine because of the widespread views that this colour often provokes intolerance reactions. The Committee recognised that Tartrazine is capable of provoking such reactions but that similar evidence of intolerance might well be obtained for a variety of natural food ingredients. In the light of this, the FdAC did not consider there was sufficient evidence that Tartrazine poses more problems than any other colours or food ingredients and so it recommended that Tartrazine should be classified in Group A. It is also worth noting that the EC agrees with this decision and Tartrazine is included in Annex I in the draft Directive.
There is an important issue at stake here. If any food or food ingredient is deemed to be unacceptable and therefore banned on the grounds that a small number of people have an adverse reaction to it, then very very few foods indeed would be left in the market. There has to be a balanced view taken, otherwise the obsession with safety would result in starvation!
McDonald's endorse the position taken by these official bodies but in order to assist those who need to avoid specific additives or other food ingredients, all the relevant information is available for customers.
June 8, 1993|
Appeared in court|
exhibit: For Professor Verner Wheelock
transcripts of court appearances: