Note: this article has been updated and re-published. Please view and comment there.
Organic foods have been increasingly popular these days moving from local co-ops and farmer’s markets to large retail chains that specialize in organic foods (such as Whole Foods) to general large retail chains who dedicate portions of their produce sections to organic produce. Even dairy and meat sections of most supermarket chains have sections that contain organic products.
So what are organic foods? They are usually crops, meat or other animal products (milk, cheese, honey) which have been produced without the use of synthetic pesticides and fertilizers, as well as genetic modification and certain preservation techniques such as food irradiation. Also the meats and animal products are produced without the use of antibiotics and growth hormones. Organic farming was pioneered in the early part of the 20th century based on the unproven idea that chemical pesticides and fertilizers supposedly had a negative effect on flavors and nutritional values of foods. Over the years, organic farming has grown into a huge business based on the supposed health and flavor benefits, but also on the the potential benefits that organic agriculture may have on the environmental impact of agricultural chemicals. In addition, there is a lot of concern about the persistence of pesticides on our food sources.
Governments usually set standards for foods to be legally sold as organic. In some countries, the regulatory role is taken on by non-governmental agencies. The Soil Association performs such a function in the UK, while the European Union sets its own rules for organic certification. In the United States, the USDA does have a certification program (which still allows pesticides), but so long as the food does not use the USDA Certified Organic logo, it can be sold as “organic” without any regulation. For many people who purchase organic foods, the USDA’s idea of organic is probably not organic. Therefore, some people rely upon individual organizations or states to set standards. California’s Certified Organic Farmers sets its own rules for organic certification, which appear to be quite complex and rigorous, but if you were seeking out an organic tomato in your local grocery store, would you know if it met one standard or another? This is a major problem with organic foods. Who knows if they’re really organic.
Organic foods have become a cultural icon in the developed world. About 58% of Americans prefer organic food to regular food, according to a 2011 Thomson Reuters-NPR Health Poll (pdf), and about 34% are concerned about “toxins” in non-organic foods. A minority also believe they taste better and are better for the environment, there are broad reasons for preferring organic foods. Another poll in 2003 found that 68.9% of Vermonters believed that organic food was “healthier.”
But, are those organic really better for you? Well, according to Are Organic Foods Safer or Healthier Than Conventional Alternatives?: A Systematic Review published last week in the Annals of Internal Medicine, which concludes, in terms that you don’t find too often in scientific literature, that “the published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods.” And a review of 50 years of research comparing the nutritional advantages between organic and non-organic foods, Nutrition-related health effects of organic foods: a systematic review, in Clinical Nutrition, found that “evidence is lacking for nutrition-related health effects that result from the consumption of organically produced foodstuffs.” Finally, another article, Nutritional quality of organic foods: a systematic review, came to nearly the same conclusion that “there is no evidence of a difference in nutrient quality between organically and conventionally produced foodstuffs.”
Of course, nutritional quality isn’t the only reason to buy organic foods. The first review mentioned above in the Annals of Internal Medicine stated that “consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.” Not exactly a ringing endorsement, and the evidence overall was all over the place with regards to the supposed benefits to food safety:
- Two studies included in the review reported significantly lower urinary pesticide levels among children consuming organic versus conventional diets. However, the studies made no indication whether there was any clinical significance to this result.
- The risk for contamination with detectable pesticide residues was lower among organic than conventional produce, but differences in risk for exceeding maximum allowed limits were small. Again, clinical significance was lacking.
- On the other hand, studies of biomarker and nutrient levels in serum, urine, breast milk, and semen in adults did not identify clinically meaningful differences. Yes, I said that!
- Estimates of differences in contaminant levels in foods were highly variable except for the estimate for phosphorus, which were significantly higher than in conventional produce, although not clinically so.
- Escherichia coli contamination risk did not differ between organic and conventional produce.
- Bacterial contamination of retail chicken and pork was common but didn’t differ between organic or non-organic farming methods. However, the risk of finding bacteria resistant to 3 or more antibiotics was higher in non-organic than in organic chicken and pork. This difference might be important if that bacterial contamination spreads to family members.
- Only 3 of the human studies examined clinical outcomes, finding no significant differences between groups that consumed either organic or conventional foods for allergic outcomes (eczema, wheeze, atopic sensitization) or symptomatic Campylobacter infection.
In other words, there is some very slight evidence that the foods are safer. But mostly, the evidence was equivocal or nonexistent. Given the higher cost of organic foods, it’s hard to come up with a cost:benefit equation that is convincing, especially if you can’t develop a realistic clinical risk from small pesticide contamination, although some may argue no pesticides is the best level.
But what if simply washing the fruits and vegetables removes most of the pesticides and other chemical contaminants? That reduces any risk that might be of concern with conventional produce. And since we are supposed to thoroughly cook poultry and pork, don’t we reduce the risk of bacterial contamination? If we can reduce the the minor risks of chemical and bacterial contaminations from organic agricultural produce and we derive no known nutritional benefits from them, then why are we paying so much more for it?
There are a few reasons, which are really dependent upon person feelings.
- Taste. OK, this is totally subjective. Some produce comes from heirloom plants, which are cultivars that were commonly grown during earlier periods in human history, but which is not used in modern large-scale agriculture. Many heirloom fruits and vegetables have kept their traits through, such as potato open pollination, while fruit varieties such as apples (red and green apples instead of black) have been propagated over the centuries through grafts and cuttings. They do have different flavors and textures that can be interesting and quite tasty. But they are expensive, and can only be found at local markets, some specialized supermarkets, and rarely off-season.
- Green. An argument can be made that organic farming is better for the environment, and better for global warming.
- Support small farmers. Sure. Again, the cost is going to be higher, and this does limit these foods to a certain upper class of people who can afford the food. Remember, large agribusiness does drive costs of food down, so that larger numbers of people can afford food, which is a separate discussion. It is sad that the perceived quality of food goes down as prices go down.
- Evidence be damned, no chemicals are going into my kids. Don’t breathe then. What am I going to say to that? Some people want to reduce risk to near 0%. I guess in that case organic produce might do that. But how do you know that your produce is actually organic? Or that the fertilizer wasn’t contaminated with some type of manure that was infected with some obscure bacteria? Reducing risk to zero is impossible.
As Steven Novella says at Science-Based Medicine,
The recent review of organic vs conventional produce agrees with previous systematic reviews that there is insufficient evidence to conclude that organic produce is healthier or more nutritious that conventional produce. Despite the scientific evidence, the alleged health benefits of organic produce is the number one reason given by consumers for buying organic. This likely represents the triumph of marketing over scientific reality.
Hey, let’s connect the dots. Big marketing programs triumph over science. And a big chunk of organic foods are sold by Big Agriculture. Oh wait, I get to make one of those strawman arguments like the vaccine denialists make! This was fun.
But seriously, if you’ve got the money, go ahead buy some organic produce. It’s just not going to do much for you.