This December I presented on my research at the American Anthropological Association in D.C. (woohoo!) What a blast! The conference was bursting with anthropologists all over the globe; the 5-day event was so packed with presentations that the program which included just names of talks & authors ran about 500 pages.
Anyway, one of the interesting moments from the trip was a scholar (I believe she did some work in Latin America but I don’t know what kind of anthropologist she was), who was seemingly bothered by our session on food and nutrition. Our talks focused on “healthy eating” as a social construct [phenomenon or idea
The question this lady asked was why we spoke of healthy eating as something created and perceived by humans as if there is no objective healthy diet supported by science.
It’s a bit funny to hear someone being surprised that concepts are discussed as a social creation vs. an objective reality at an anthropology meeting.. but that shows how food and healthy eating can be quite emotional when one is health conscious! I would bet this scholar was someone who personally cares about eating well for her own health. Understandable. Food is a very emotional topic- it is not only good/bad for health and looks, it also represents our identity, our culture, our experiences, etc.
Part of my answer to her was that science might not be able to give her what she is looking for- the objective healthy diet. Not because science sucks, but because nutrition studies are lengthy, complicated, and costly (see my post on why nutrition science doesn’t suck HERE). My favorite example of why nutrition science is hard to rely on is SUGAR. Look at this World Health Organization 2003 report (see full report).
The common sense might tell you that added sugar can’t be good- it adds calories, maybe it makes you hungrier or disrupts bodily processes, maybe it’s just unnatural. People I interview often mention that sugar is one of the main causes of weight gain. Common sense, right? Well, look at the WHO report and check out Free Sugars (= all monosaccharides and disaccharides added to foods by the manufacturer, cook or consumer, plus sugars naturally present in honey, syrups and fruit juices). The only convincing evidence from scientific studies is that free sugars increase the risk of dental caries. Not weight gain, not diabetes, not heart disease. Does this mean sugar is only bad for teeth? No, it means there isn’t evidence that it causes other disease with the studies that we have. So if you want to state with complete confidence that added sugars lead to chronic disease and obesity, you might have a hard time backing it up.
Thinking that there is no such thing as a healthy diet is unsettling. We want clarity. :S Saying that “healthy eating” is an idea constructed socially, however, doesn’t mean that there is no such thing as healthy eating. It does mean that there are multiple ways one can eat well to avoid disease- it can be vegetarian, vegan, paleo, regular calorie restricted diet, Mediterranean diet, etc. etc. etc.
Historical perspective on what good/healthy eating is.
The official stance on a healthy diet is not purely unbiased either- the political and historical context shapes what is officially recognized. I heard a very interesting talk on the differences in nutrition perceptions between Denmark and Germany during 1940-1945 by Dr. Jensen (University of Copenhagen). She talked how in the early 20th century macronutrients, salts, water and ash were believed to be the sole constituents of food. Then vitamins were discovered resulting in growing scientific interest in identifying new “micronutrients”, a development that altered (diminished) the perceived importance of the macronutrients (protein, fat, carbs). So as in Denmark micronutrients became the focus, good nutrition became about vegetables- the source of many micronutrients. In Germany, however, a country experiencing hunger during WWII, macronutrients remained as most important considerations in nutrition textbooks (with protein considered the primary element of food- for the satiety and strength it provides, especially for a country at war!). The point is- the scientific (and thus public) perceptions of what good eating means is shaped by societal circumstances.
It all just depends…
Back to whether an objective healthy diet exists or not. If we ignore for a second that people disagree on the details of what one should eat to stay healthy (is carb or fat evil? is animal protein toxic? should you go vegan? avoid gluten like the plague?), most folks at the minimum agree that eating “real” or whole foods is important (or in other words- avoiding or limiting modern processed foods and focusing on the less modified foods). I suppose we could say that this definition of a healthy diet is generally accepted. If we move on from processed vs. whole, though, here are a couple of examples of when something generally healthy might not be good for you or vice versa:
– Cabbage! A wonderful plant full of micronutrients (vitamin K! Vitamin C!) that protect one from various diseases; the plant is often stated to have anti-inflammatory and anti-cancerous properties. Awesome. Unless you have hypothyroidism since cabbage is one of the foods that interfere with the thyroid function.
– Dairy! Gets a lot of bad rep from the paleo community and others. While recently thought as very important for bone health and what not, there is a lot of talk that we have not evolved to tolerate it quite well and it is thus an unhealthy substance to consume. Our genes are still adapted to the pre-agricultural diet (before ~10,000 yrs ago), as many paleo proponents will argue. Yet there is evidence to challenge the assumption that humans are essentially unchanged since the Paleolithic era. E.g. “recent” evolution of lactase persistence and variation in the number of genes that code for amylase production tied to starch consumption. In other words, mutations have occured that allow many folks to digest and thrive on dairy and grains just fine.
– Phytates. Plants have a lot of great ingredients that generally affect us positively (e.g. vitamins protecting from disease), but it depends.. For example, phytates in grains and nuts are usually viewed as bad for us because they can bind to certain dietary minerals leading to deficiencies (iron, zinc, etc.).. In West Africa, many Hausa plants contain substantial amounts of these phytates (especially in cereals and legumes) but these botanical chelators have a potential malaria-suppressive effect (awesome!!). However, this anti-malarial effect may be antagonized by antioxidants in other foods (e.g. such free radical traps as Vitamins C, E, beta carotene, selenium). Antioxidants is something many of us try to increase in the diet..yet if you are living in malaria-prone regions of the African continent, you might want to concentrate on the opposite dietary strategy- phytate-rich and antioxidant-poor foods.
So is there an objectively healthy diet? Generally- all eating is healthy since it is required for survival.. undereating and overeating is not good.. lacking a variety nutrients is not good.. and that’s mostly it. Of course, different things work for people- someone might not tolerate dairy, others might feel miserable on a vegan diet; some thrive on salads others can’t digest raw plants well. If only we could all grasp the wonderful concept of moderation and apply it in our lives without struggle. In fact, it is because self-control is so hard to maintain that we want simplified solutions- a diet plan, a list of “bad” foods to simply avoid, etc.
Happy Holidays– don’t overeat on most days, yet don’t let yourself stress so much about what you’re eating that you are unable to enjoy life! 😉 *grabs a big fat piece of dark chocolate and kicks back*.