My personal point of view about food and nutrition has been evolving over the three decades I have been teaching nutrition to undergraduate and graduate students who become Registered Dietitian Nutritionists as well as nutrition educators. The responsibility of educating future nutritionists and dietitians whose role it will be to give dietary advice to patients and clients is one that I take seriously. Thus the many publications and ideas that ignore scientific nutrition research and responsible nutrition advice and contradict much of my educational preparation makes my job quite challenging.
After reading Nutritionism by Gyorgy Scrinis, I decided that I needed a perspective on the concept of nutritionism from someone with a nutrition background. Dr. A.P. Boyar had reviewed In Defense of Processed Food and struck me as someone who could provide that viewpoint. Here is her view on the changing face of nutrition and how it is perceived by the general public.
The Advanced Nutrition course that I have taught since the late 1980s is organized around the principles of nutrients and phytochemicals in isolation: how they are identified biochemically, their physiological and biochemical roles in the body, food sources, consequences of deficiencies and excesses, interactions among nutrients and the effects of pharmaceutical agents. But can one learn to select the best way to eat based on recommendations for nutrient intakes?
With this nutrient approach, the course I teach has not been organized around the theme of specific foods and their health benefits or detriments, except to emphasize that certain foods tend to be rich sources of important nutrients and other constituents in foods may increase risk of disease through various mechanisms. For example, meat, fish, poultry and legumes are high in protein, iron, and vitamin B12. Whole grains, fruits and vegetables are high in carbohydrates and dietary fiber, while Brazil nuts are an extraordinarily rich source of the mineral selenium, and oysters are very high in zinc. Green leafy vegetables are high in folates, and magnesium. Partially hydrogenated vegetable oil is likely high in trans fats which appear to promote inflammatory processes. But in my rather long experience as a nutritionist and nutrition professor, foods were largely seen and studied as nutrient delivery systems or packages of nutrients. If one were to try to teach about foods rather than nutrients, how many total foods and ingredients, such as herbs and spices, and dietary supplements would need to be studied? In a one-semester course even only several hundred or so important foods and ingredients would be nearly impossible to examine for health-promoting vs health-depleting properties.
Certainly, I have discussed with my students the importance of certain types of dietary patterns: the Mediterranean diet, the Portfolio diet, the DASH diet, as ways of eating that tend to promote certain physiological outcomes and hopefully protect against disease. The Dietary Guidelines for Americans attempt to advise healthy eating based on nutrition research. However, Americans on the whole do not eat according to the recommendations of the Dietary Guidelines and instead for the most part eat according to convenience and taste.
So why rock the boat? This is how I was taught nutrition in the 1970’s and 80’s and this perspective was not called into question as a way of thinking about and teaching nutrition for me until about ten or so years ago with the publishing of Michael Pollan’s In Defense of Food in 2008 and Gyorgy Scrinis’ Nutritionism, published in 2013. These books raise questions about the best way to eat, with much emphasis on eating mostly plant foods in moderate amounts. More recent in the non-academic world of social media is the idea of “clean eating” which embraces those concepts as well as others, including sustainability in one’s food choices by eating seasonal and local organic whole foods, avoiding canned food or food served in plastic containers, avoiding sugar and other refined, highly processed foods (commercial pastries, fried foods, foods with preservatives, additives, etc), particularly those with hard-to-pronounce ingredients. Emphasized are non-GMO, pesticide and preservative-free fruits, vegetables and whole grains, and less meat and animal products particularly if not wild, free-range, or grass-fed.
In fact, unconventional diets are nothing new. For example detoxification diets have been talked about longer than a century ago. But the term clean eating is relatively new and is used both by non-credentialed nutritionists as well as those who are respected in the field. For example, Kathleen Zelman MPH, RD reports that the “clean-eating approach is your best bet to getting your body in tip-top shape” and that “the only type of detox diet that is worthwhile is one that limits processed, high-fat, and sugary foods, and replaces them with more whole foods like fruits and vegetables”. In summary, less emphasis on nutrients, and more emphasis on food, and how it got on your plate, how it is grown or raised, delivered, and packaged and even better if cooked from scratch.
Notably however, these concepts have been co-opted and have mutated into a hard to sustain lifestyle that criticizes frozen, dried and convenience foods and has morphed by some into gluten-free, grain/cereal-free, and dairy-free eating with the use of coconut oil. Coconut oil traditionally, and still supported by scientific research, is a highly saturated fat that does raise blood cholesterol levels. But social media again has driven the popularity of this food into the mainstream. Unsupported claims are made for the waist slimming effect of this oil. These restrictive eating patterns, including cutting out grains and cereals, both refined and whole, or eating raw vegan foods, goes against the eating patterns promoted by the Mediterranean diet, and by organizations that embrace evidence-based recommendations including the Academy of Nutrition and Dietetics, and the USDA.
How has nutrition science responded? A few critiques have been published by Registered Dietitians and food journalists here and here concerning the more extreme versions of the clean diet. Perhaps the conflicting information from nutrition scientists, credentialed practitioners, and food journalists, and others has contributed to the emergence of disordered eating or orthorexia nervosa, a clean eating obsession with strict rules restricting ones eating to foods thought to be “healthy” or “pure” and “natural.“
So how should we eat? How clean should our diet be? Should we concentrate on the latest list of superfoods that appear to boost the brain, and prevent premature physical impairment? Particularly if they taste good? Should we follow the entertaining yet evidence-based advice of Dr Michael Gregor, who tells us how not to die? Can healthy diets be individualized to take into account the more recent findings in the study of nutrigenomics, the intersection of nutrition and genetics? What promotes vitality, longevity, healthy aging, etc. beyond the recommended nutrient and food intakes as issued by the National Academy of Sciences and/or recommended by the Dietary Guidelines? According to Cornell professor Patsy Brannon in a recent conference on Nutrigenomics the best amount of nutritional intake for the individual is “impossible to know”.
With so much unknown and so much conflicting advice, how and what should we eat? What can I offer now? Foremost, keep thinking and questioning! The best advice, for me, and from me, is to eat good-tasting, wholesome, home-prepared (and home-grown if possible) mostly plant foods, in moderation, mostly organic or sustainably grown, enjoyably, with one’s family and friends!
Andrea P Boyar PhD, RDN, CDN
Andrea Boyar, Associate Professor of Dietetics, Foods, and Nutrition (DFN) in the Department of Health Sciences, and Director of the undergraduate Didactic Program in Dietetics, is a Registered Dietitian and Certified Dietitian/Nutritionist with the State of New York. She has worked previously on projects investigating the use of dietary changes to prevent recurrence of breast cancer. Her research interests include the use of dietary supplements for chronic disease prevention, and dietary modifications for health improvement. She was the Principal Investigator of a USDA grant designed to develop online instruction in the DFN programs at Lehman. She is an avid gardener, and loves to cook.
Next week: In defense of nutrients