The belief that some foods are better than others indeed that some foods are inherently good while others are inherently bad has become a well-accepted underpinning of current nutrition lore. What does it mean to speak of a food as being good or bad? How can you tell if the food you are eating is good or bad? Is it helpful or even possible to think about foods as being good or bad?
The Good, the Bad, and the Confusing
The labeling of a food as good or bad is usually justified on the basis of the nutritional quality of that particular food and/or how the components of that food contribute to or detract from our health. While at first glance this may seem quite reasonable, upon closer inspection, there are important problems with this approach.
First of all, our scientific understanding of the health impact of any particular food is extremely limited. Most of the information we have collected to date on the relationship of individual foods to health comes from studies that look at the diets and the incidence of disease in large populations over extended periods of time. Extrapolating this information to the effect of individual foods on individual people is an extremely inexact science at best.1 When actual experimental data are available on specific foods, it is often from studies in which animals are fed these foods in quantities many times larger than what is ever normally consumed by humans. Once again, extrapolating results of such studies to humans is an extremely questionable undertaking.1
To make matters worse, our interpretation of what the research suggests to us about how foods, or specific components of food, relate to our health is constantly changing. Remember just a few years ago when all fats were considered to be bad? Then it was only saturated fats that were bad, then only some saturated fats. Most recently the villain du jour is trans fats. Carbohydrates, on the other hand what we were supposed to be eating instead of the bad fats were considered good. But now, only a few years later, they are bad. But not all carbohydrates are bad. Some carbohydrates are good and some are bad. Sugars are particularly bad. But some sugars are better than others; sucrose is not as bad as fructose, and so on and so on. Quite maddeningly, these confusing flip-flops have become a common occurrence with all different types of foods.
A recent cartoon captured the resulting mania nicely by showing a man listening to a radio announcement that proclaimed: "Today the FDA announced that everything that used to be bad for you is now good for you and visa versa."
But the issue is actually even more complex. Contrary to what often comes across in the media and even in the proclamations of some health experts, all foods have nutritional value. Even the much-maligned fats and sugars are essential elements in the diet. Fat provides energy, particularly in growing children, cushioning for our inner organs, material for the walls of our cells, and a means of absorbing the essential fat-soluble vitamins. Among other things, sugar provides critical energy, particularly for the brain and nervous system. Perhaps most importantly, both sugar and fat imbue our food with the flavor and taste that make eating so enjoyable.
It is not uncommon, however, to hear people say that sugar has no nutritional value. In fact, just a quick Internet search will turn up scores of articles supporting this belief, some written by health professionals. Unfortunately, this statement is clearly ludicrous. Sugar is a carbohydrate and a carbohydrate is a nutrient. If something is a nutrient, then by definition it must have nutritional value! In fact, sugar is the major source of fuel for vigorous physical activity. (When athletes need quick energy to bicycle or run a marathon for instance, they want sugar, and simple sugar at that; not broccoli, spinach, and whole wheat bread.)
Consider the Context
In reality, whether a food adds to or subtracts from a person's health is always relative; that is, the healthiness or unhealthiness of a specific food cannot be determined without considering the context within which that food is eaten.
For example, asked to pick which one of two foods is healthy and which one is not, most people would label broccoli as healthy and pizza as unhealthy. On a given day however, if an individual has eaten no protein but consumed plenty of fruits and vegetables, eating only broccoli might contribute less to health because the body in this context needs protein, not more fiber and antioxidants. If that same individual happened to be in prison for six months with the same two food choices, healthy broccoli or unhealthy pizza, which choice would best promote health? The answer is clearly the unhealthy pizza. In fact, choosing the healthy broccoli might just be fatal!
As another example, imagine your son having his eighth birthday celebration at your house and inviting ten of his closest friends. Everyone is wearing their party hats, running around and making lots of noise. As they pass around the plates of ice cream and cake, you respectfully decline the unhealthy offering in favor of a healthier plate of celery and carrots. In the larger context of family/social health, is this a healthier behavior?
Sex, Fries and Videotape
Not too many years ago, two women talking on Monday morning about how they had been bad over the weekend might have been referring to some sort of sexual escapade. Nowadays they would most likely be talking about going off their diet and eating something that wasn't on their good food list. Good eating has become almost a religion in this country, and it has become almost sinful to eat those foods on the latest bad food list. Indeed, foods are regularly talked about in moralistic terms, as when a weight loss company markets their low fat pizza as pizza without guilt or a fast food chain claims that their sandwiches are good, so you don't have to be.
So in addition to the confusion caused by the good food/bad food mania, we now have the added burden of moral anxiety to consider when making our food choices. Good foods will not only make us healthy but also righteous, and bad foods will kill us and also make us sinful. The end result is a population in a constant state of high alert for foods that will kill them or cure them, a population confused and anxious about everything they put in their mouths. This emotional turmoil is fueled by a never-ending flood of studies. As world-renowned nutritionist and feeding specialist Ellyn Satter remarks: "Almost every day some new bit of research scares us about what we eat or sends us off on another tangent in search of a magic potion to keep us healthy."2The Bottom Line
Overconsumption of any individual food is probably not healthy in the long run, but this certainly does not make any of these foods inherently bad. Almost anything taken to the extreme can be dangerous. While oxygen is absolutely essential for human survival, breathing air with too much oxygen in it can be very fatal. Similarly, while no one would argue about the benefits of eating fruits and vegetables, eating only fruits and vegetables would make for a boring and unhealthy diet. (Ironically, recent research indicates that people who follow vegetarian diets may actually have an increased risk of heart disease due to lowered vitamin B12 concentrations and elevated homocysteine levels.3)
Speaking of foods as good or bad is really not justified by our present level of scientific understanding and only contributes to an underlying lack of peace in people's relationships with eating. There are lots of different foods, with different textures, colors, smells, tastes, and nutritional composition. The bottom line is that there really are no bad foods with the possible exception of the green stuff we may find growing in the back of our refrigerators during the semi-annual cleaning. Yuck! Now that is bad food!
But then again isn't that the kind of stuff that penicillin is made from...?
1. Byers T. The role of epidemiology in developing nutritional recommendations: past, present, and future. American Journal of Clinical Nutrition 1999;69(suppl):1340S-8S.
2. Satter E. Secrets of Feeding a Healthy Family. Madison Wisconsin: Kelcy Press, 1999.
3. Herrmann W, Schorr H, Obeid R, Geisel J. Vitamin B-12 status, particularly holotranscobalamin II and methylmalonic acid concentrations and hyperhomocysteinemia in vegetarians. American Journal of Clinical Nutrition 2003;78(1):131-136.
Jonathan Robinson holds a doctorate in health education/exercise physiology and a master of science in human nutrition from Michigan State University where he is adjunct assistant professor. This article first appeared on TechCentralStation.com.