Nutritionism reduces dietary advice to statements about a few nutrients, with sometimes unintended implications for science, industry, and the public. Although reductionist questions about nutrition are legitimate scientifically, a nutrient focus in the public arena forces the food industry to compete with the use of nutrient statements. Consumers must interpret information that may not be correct or relevant. The theory of food synergy, which postulates that the many constituents of individual foods and dietary patterns act together on health, leads to the idea that dietary policy would be clearer if it focused on foods. To illustrate this method, the food-based A Priori Diet Quality Score was described in the Iowa Women's Health Study; a substantial total mortality reduction for increasing quartiles of the score was found. The simple food-based rules implied in this a priori score support minimizing meat, salt, added sugar, and heavily processed foods while emphasizing phytochemical-rich foods. These principles could help improve nutrition policy, help industry to supply better food, and help to focus future scientific research. Although an understanding of what foods are best for health is a step forward in nutrition, other major challenges remain, including getting high-quality food to the masses and food sustainability.
Alex’s Notes: Brazil recently overhauled their dietary guidelines (published by the Brazilian Ministry of Health). Unlike the nutrient-based and outdated USDA guidelines here in the U.S., Brazil's focus more on sensible, mindful preparation and consumption of food. Although people eat food, not isolated nutrients, the practice talking about nutrition as a composite of nutrients and other biochemical rather than as food is widespread in the public. This thought process is called “nutritionism”, and it makes things more complicated than necessary.
Thinking of food in general, a lot is known about diet to prevent chronic diseases such as cardiovascular disease, diabetes, etc. With this knowledge, it ought to be easy to choose healthy foods, but the food industry advertises the use of nutrients to gain market edge. The consumer has to then decipher all this nutrient information – which ranges from ambiguous to just plain incorrect – and make decisions that will have a significant impact on their health. “Processed” is a useless term; some processing is good (such as cooking food) and other is highly questionable (such as adding preservatives and chemicals). Perhaps a better example regards dietary fat.
In the early 1980s, it was thought that a low-fat message would reduce “bad” fat intake. Aside from the fact that the low-fat message itself is misleading because not all fats are the same, industry reacted to the low-fat message by creating many new low-fat foods that were rich in sugars and chemicals. Thus, choosing low-fat food items didn’t lead to healthy food choices and more often than not, actually led to worse food choices. In the context of obesity, guidelines often continue to emphasize the central importance of calorie intake and highlight that fat is the most energy dense nutrient, which completely ignores the findings that people seem to compensate their eating habits by finding replacement foods.
Moreover, a focus on individual nutrients tends to suggest thinking of nutrition as similar to pharmacology, a comparison that may often be misleading. Nutrition, which is the fostering of health through diet, differs fundamentally from pharmacologic treatment of disease. There is nothing simple about basic nutrition, which keeps the multifaceted organism working well. Adding isolated substances to food helps only if the substance has a drug-like effect to begin with. Basically, the oversimplification of the nutrition message in terms of single nutrients in not a wise strategy.
To counter nutritionism, there exists the theory of food synergy, which proposes that food is composed of organisms which are nonrandom and complex mixtures of compounds, developed by evolutionary control. It recognizes that foods are complex compounds that exist in biologically dictated proportions that may be important to health. Unfortunately, for society to move beyond the limitations of nutritionism and nutrient-based guidelines, much more information about foods and health are needed, and this will require a different way of thinking as well as a change in funding priorities.
So how should we eat for longevity? “Eat foods, mostly plants, not too much, in colorful variety, maximizing nutrients per bits.” What this means is to avoid many forms of industrial processing that degrade access to nutrients and beneficial compounds, focusing on a variety of plant foods as dictated by their color, and not wasting your nutritional allotment on nutritionally-devoid foods.