Statement on diets devoid of animal source foods

Lindsay H. Allen

I wish to clarify a recent statement that I made about vegan diets that has been widely reported in the press, mostly in the UK, Australia and New Zealand. The situation arose in a meeting of the American Association for the Advancement for Science, where I was speaking in a symposium on "Better Nutrition for a Better World", addressing food-based approaches to alleviating micronutrient malnutrition in developing countries.

First, the context of my research and in which the press statements were made. I have spent the past 25 years working with populations where micronutrient deficiencies are widespread because there are insufficient animal source foods in the diet, and mothers, and particularly young children, suffer major problems as a result. Few people working in international nutrition would disagree with this fact. The main global nutrition problem is vitamin and mineral deficiencies due to a poor quality diet, rather than protein or energy deficiency. For example, an advisory group to the World Health Organization stated that for adequate complementary feeding of young children in developing countries "meat, poultry, fish or eggs should be eaten daily, or as often as possible. Vegetarian diets cannot meet nutrient needs unless nutrient supplements or fortified products are used". (Milk was not mentioned because of the reasonable fear that it would displace breast feeding).

At the AAAS conference I was asked to review the data on "Animal Source Foods to Improve Micronutrient Malnutrition in Developing Countries". (Other scientists presented on research to improve micronutrient status through plant breeding and the importance of high quality foods for young children). As part of my talk I presented the results of a study conducted by UCLA and the University of Nairobi, in which I played the relatively minor role of analyzing the micronutrient status of the children. The study compared the impact of supplementing rural Kenya children with maize and bean snacks, daily in school over two years, on their growth, nutrition and development. Having additional meat or milk in the snacks improved muscle deposition, cognition and school test performance, and activity levels in play compared to a control and a non-intervention group. It also eliminated the very high prevalence of severe vitamin B-12 depletion. The results were published in a supplement to The Journal of Nutrition in 2003, so they have been widely-circulated for some time.

To put this study in perspective, the purpose of doing it was to find local, food-based solutions to the very widespread, chronic problem of micronutrient deficiencies in developing countries, and their adverse effects on human function. The past 20 years has been a time in which governments and agencies worldwide have recognized the problem and tried to deal with it by providing supplements (usually only iron for pregnant women, or vitamin A for children under age 5 years). Micronutrient fortification of staple foods by governments is also gaining popularity but does little to help people like these Kenyan children, who eat locally produced foods. We were pleased to be able to show that including even small amounts of local animal source foods could improve the lives of these children who have few other alternatives.

The press was interested in how this research related to people who choose to avoid animal source foods in industrialized countries. In my comments to the press conference held two days after my talk, I repeated that the work done by myself and others shows that a lack of animal source foods can cause micronutrient deficiencies. It is important that women and young infants who consume low intakes of animal source foods find a way to replace those micronutrients in their diets. For example, there is no vitamin B-12, preformed vitamin A, or vitamin D in natural plant foods and iron and zinc absorbability is much lower. Studies done 15-20 years ago on macrobiotic women and children in Boston, and children fed macrobiotic diets in The Netherlands show how these diets adversely affected child development at that time.

Are things different today? Absolutely yes. There is much more awareness about the need for people who avoid animal source foods to consume fortified foods and supplements, and alternative fortified foods are much more available. In spite of fears in the UK about potential adverse effects of soy formula on infant development, there insufficient evidence that these effects are well-founded and the American Pediatric Association concluded that parents seeking a vegetarian-based diet for a term infant can be advised to use isolated soy protein-based formula. At least one newspaper article in the UK correctly repeated my statement that vegan diets are safe for adults if fortified foods and supplements are used - they unfortunately reported that I thought this was too difficult for infants when what I said (or meant) is that it is more difficult for infants. Moreover I agree that a well-planned vegan diet that includes fortified foods and/or vitamin-mineral supplements may be healthier for many adults than an omnivorous diet that does not meet the Dietary Guidelines.

So why was there so much hype over my interview? The confusion resulted from the press being most interested in the potential publicity that they could create from my talk. While I was only interested in talking about developing countries, they asked us to extrapolate our results from the Kenyan study to industrialized countries. I agreed with their statement that some nutrients were only found in meat (although I added, milk as well), said that including these in the diet would benefit pregnant women and children, and repeated the fact that other studies had shown the adverse effects of excluding animal source foods for these groups. I stated clearly that if animal source foods could not be consumed, fortified foods and supplements were the next best strategies for assuring adequate micronutrient status.

In the press briefing before my radio interview I made the statement that I believed it was unethical for pregnant and lactating women, and their young infants, to consume "macrobiotic" diets due to risk of nutrient deficiencies - unless they were careful to find additional sources of those nutrients through fortified foods or supplements. I did not make this statement in my radio interview - until prompted to do so by the reporter who stopped recording and asked me to "say again what you said in the press briefing about macrobiotic diets being unethical". Although surprised, as this was a live recording (by the BBC!) I did not stop to think and unwisely repeated what the reporter told me to say. The prompting that I received from the reporter was not recorded. I most certainly clarified my views and modified my use of the word "unethical" when the BBC and other papers called me back to check on the story, but again this did not appear in any reports. Nevertheless, I fully admit that I should not have fallen for the reporter's trap, or used the word "unethical" at all, realizing now how this word is what attracted the reporter's interest in the first place. Moreover, vegans often avoid animal source foods for ethical reasons, and are highly motivated to consume a well-balanced diet.

In summary, the press was anxious to turn a story that should be used to improve nutrition of the developing world into one that would excite the public in industrialized countries. My research and my concern is for the poor in developing countries, However I take full responsibility for using the word "unethical" which was unwise, and hope that those who were offended by its use will understand that my only intention was to emphasize the responsibility that parents have to understand how to safely eliminate animal source foods from their diets and those of their young children, and to obtain the missing nutrients critical for their development. I have no doubt that this is possible, and good nutrition advice is available about how to use supplements and fortified alternative foods. Some of the available advice is poor, however, and I remain concerned about the misinformation concerning the nutritional value of some plant source foods that the public has relayed to me during my interactions with them as a result of this experience. I hope that more studies on how vegan parents feed their infants will be initiated as a result of these discussions, with the aim of providing them with consistently sound information.

Because of my dedication to improving the nutritional status of the world's women and children, who do not have access to the kinds of foods and supplements that are readily available in industrialized countries and wealthier segments of the population, I intend to continue my research on food based approaches to improve micronutrient status, evaluating animal source foods, fortified foods, and improved plant based diets in addition to dietary supplements. As noted by the BBC reporter, my primary interest is in the causes and consequences of vitamin B-12 deficiency which we are just realizing is very common in the developing world - for example over 40% of adult women and young children in the Mexico National Nutrition Survey have low plasma levels of the vitamin. We are working in Guatemala City where about two thirds of breastfed infants at 7 months of age have deficient or low plasma vitamin B-12 levels. Our goal is to learn if this deficiency is adversely affecting child development and if it is, to find solutions for its prevention. It is much easier to become vitamin B-12 deficient than is usually assumed, and it is very important to follow the usual recommendation that people who avoid animal source foods should take B-12 supplements or fortified foods.

I wish to address suspicions about possible financial explanations for my comments. I was not a Principal Investigator of the Kenya study. My lab did the biochemical analyses of samples from the children and the only funding we received was part-time support for students who did laboratory work and statistical analyses. The financial support that we received came entirely from the US Agency for International Development, and not from the beef or dairy industry who were minor sponsors of the overall project and sponsors of a Supplement to The Journal of Nutrition where the results of all the investigators in Kenya were published. The research was completed several years ago while I was a Professor in the Department of Nutrition at the University of California Davis. I take complete responsibility for my presentation and comments and do not speak for the University of California, the funders of the research, the USDA, or even the Principal Investigators of the Kenya project.