*I’d like to preface this post by stating that I am certainly not in expert in the field of organic food (farming or the study of its effects on human health). As always, if you have any sound, scientific data (not just conjecture) that refutes what I’m saying, please send it my way. The More You Know…
August has been my month of (attempted) sustainable eating. When I was trying to put my ideas of sustainability into words, I first googled “sustainability,” to gain inspiration… and maybe cheat a little. Indeed, the first hit (high five, Wikipedia) defined it as “the capacity to endure,” which I think fits perfectly with my philosophy of sustainability- both from production and human health standpoints.
I defined sustainable eating as organic, GMO-free, and local. Organic food is considered sustainable because the methods for producing the food are much more environmentally friendly than those used for conventionally grown foods. As far as GMO’s are concerned, there is the belief that by tinkering with the genes in plants, we are eliminating the plant’s need and ability to respond to environmental pressures. In doing so, the plant species can’t evolve, which can have some very bad long term effects on the food supply as well as the environment. And lastly, eating local is a more sustainable food practice because a) it reduces the carbon footprint of food production since the food itself isn’t traveling nearly as far to get from the farm to your plate, and b) it’s sustainable from an economic perspective, as your money remains in your local economy. Love thy neighbor.
Like most topics in nutrition, GMO-free and organic foods are topics that I try to avoid in conversation. This originated from my strong mental “allergic” reaction to pretentiousness and dispositions towards food based on an inflammatory media that is not at all grounded in truth or data. Many people claim to go organic/GMO-free because it’s better for human health, and that we have proof that the chemicals used in food production and genetic modifications of food are killing us. Someone please show me that “proof.”
If you haven’t figured it out by now (have you even been paying attention?), I’m a stickler for the evidence. We lack definitive proof that any of these things are adversely affecting human health. What we have are a lot of theories that have yet to pan out. One such theory is that organic farming yields foods with higher nutrient (vitamins, minerals, phytochemicals) content than conventionally grown foods. The reason for this is that foods grown without pesticides have to make their own defenses against the natural world, and they do so by increasing their nutrient content. This is theorized to benefit the consumer because we will then ingest more of those nutrients. It’s a nice theory, and I wish it were/hope it will one day prove to be true. Studies that have researched this phenomenon do in fact show that nutrient content is slightly higher in organically grown foods. Unfortunately, this doesn’t seem to translate to human health. This is probably because we don’t absorb all of the nutrients we ingest, and when you look at the scale of the human body and all the tissues to which nutrients get distributed, that small amount of increased nutrient content in an organically grown food is unlikely to have impact on overall human health.
That’s one example of the organic food debate, and there are many other claims that have yet to be proven. Another issue that many people take with conventionally grown foods is pesticide content, of which organically grown foods have proven to have significantly lower levels than conventionally grown foods. Now, conventionally grown foods do pass the US government’s standards for the max amount of pesticides considered safe for human consumption. Granted, there are some issues with this, as I don’t know how that level was determined. But what I’m interested in has to do with the mechanisms by which these pesticides could impact human health. Some websites state that pesticides are “toxic” and slowly killing you. How, though? How much does it take? Anyone know? Please share if you do.
Despite how it sounds, I’m actually not really a naysayer of the organic foods for human health movement. I just want more information. One of the reasons that we may not be showing an effect of organic food on health is because of the limitations of the tools we use to measure these effects. The media, every blog, every tumblr/instagram/pinterest account will have you believe that we know everything there is to know about foods and human health (Cinnamon for blood sugar! Grapefruit for weight loss! Cherries for rheumatoid arthritis! It’s all hogwash.) The fact of the matter is that nutrition science is subjected to a slew of inaccuracies from which we try to draw conclusions.
So let me give you a run down of the issues with studying nutrition. Let’s say that we want to do an observational study in which we ask the question: Does eating organic foods decrease the risk of developing X (where X is a disease…let’s say cancer)? Here are some things that we have to take into consideration:
1) To what are we comparing organic food intake? If you were simply to ask people if they eat organic foods, those who reply yes are different than those who reply no in a variety of ways. People who eat organic foods are likely to be fairly health conscious individuals, so in order to avoid contamination from any other factor, we need to compare them to people who are extremely similar, but don’t eat organic foods. To give an idea of what that would look like, we would want to compare people who have the same average age, BMI, smoking status, overall diet (fruits and vegetables, fat, saturated fat, carb, protein, etc. intake), physical activity levels, etc. As you can imagine, finding a difference between people who are similar in every other way other than organic food intake is going to be hard to do because you’re unlikely to have enough people (sample size) that you can appropriately test.
2) Measuring dietary intake: This is the real zinger. Despite all of the advances in technology, biotechnology, screening, and so on, our methods for measuring dietary intake yield an extremely rough estimate, at best. If you want to look at a large population (which is what you would need to answer this particular question), you’re going to be asking people to report on their diet. This in and of itself is flawed because people are flawed. They lie (perhaps inadvertently), they forget what they ate, and they don’t know how to determine serving sizes. That on top of the fact that diet databases are limited by the number of items in them. Most of these databases are great for quantifying diets heavy in processed foods, but they can’t stand up to foods made from scratch and ethnic foods. On top of that, they provide a rough average of nutrient content of foods. As an example, the nutrient content of a vegetable can vary widely based on the time of year it was grown, soil conditions, how it was stored after harvesting, how it was prepared, etc. Take all of these seemingly small factors together, and you can see how widely varied our estimates of nutrient intake can be. I’d say, on average, these estimates are accurate ±10%. And then you want to compare people whose only difference in food intake and lifestyle practices are whether or not they eat organic? Good luck.
3) Exposure. This is another important issue that could potentially explain why we have yet to show an effect of organic eating practices on human health. On top of deciding what qualifies as eating organic vs not (<50% vs ≥50% of intake? I don’t know), what time frame is sufficient to see an effect? It’s likely that if there is a beneficial effect of eating organic on human health, it will take years to decades to determine. And I don’t think that organic foods have been widely available for long enough to see that effect.
That’s me up on my scientific soapbox about why we probably don’t know much about the impact of organic food intake on human health.
However, there are a few things that we have some evidence to support:
- Organic food intake may actually be beneficial in infancy and into the toddler years in terms of allergic manifestations. One study showed a nonsignificant reduction in eczema in toddlers fed a strictly organic diet (1).
- Organic animal products probably give you the most bang for your buck: In that same study, when the researchers looked strictly at organic dairy intake, that reduction in eczema became significant (1).
- Organic farming practices are better for the environment. Screw human health–this is my reason for why people should go organic. We’re talking about the health of our planet here, and that’s something with which I can get on board. If I weren’t a nutritionist/physiologist, I would be an ecologist.
So, as usual, my issue with organic food isn’t with the food at all, it’s with the consumers of the food. I think it’s great that people are taking a deeper look at where their food comes from and that there is this vast movement towards responsible consumer practices. However, it’s equally important to not be so anti “the man,” that you lose sight of reason and the value of evidence. For some additional reading, I recommend this article entitled A Hippie’s Defense of GMO’s. She makes a great point about food issues that are probably a lot more important than keeping GMO’s out of the kitchen. Definitely worth the read.
I’ll post my final stats and my take on sustainable eating in a few days (hopefully). Spoiler: it’s expensive.
1. Kummeling I, Thijs C, Huber M, et al. Consumption of organic foods and risk of atopic disease during the first 2 years of life in the Netherlands. Br J Nutr 2008; 99:598-605.