When you walk through the grocery store and see an organic product, you’ll notice two things: The manufacturer seems super proud of its organic status, and they’re eager to make consumers cough up some extra money for the privilege. Organic foods are often marketed as being “cleaner,” more natural, and ultimately healthier than conventional, non-organic foods. As a consumer, this begs the question: In terms of health, is forking over some extra money for organic products actually worth it?
What does “organic” mean?
Weighing the costs and benefits of organic food products requires a basic knowledge of what distinguishes organic foods from conventional foods. Organic food production practices are primarily intended to promote sustainability, soil fertility, biological diversity, and minimization of the use of synthetic materials. For instance, fields in which organic crops are grown must be free from synthetic chemical treatments for at least three years, and such crops can not be genetically modified or grown with the use of synthetic pesticides, fertilizers, or ionizing radiation. Organic livestock must be fed organic food, must be free from antibiotic and hormone treatments, and must be raised in conditions that accommodate their natural behaviors (like grazing). This does not mean that all organic crops are raised in the absence of fertilizers or pesticides; it simply means that the fertilizers and/or pesticides used do not contain synthetic chemicals.
Before moving forward, I’d like to nip something in the bud here. You might feel an urge to go ahead and make a conclusion already– organic is natural, conventional may not be, natural stuff is good, so what’s there to argue? This logic may feel correct at a very basic level, but it is a prime example of a logical fallacy referred to as “appeal to nature.” The reality of the matter is that nature is riddled with potent toxins, and there are countless safe (and in many cases, health-promoting) synthetic materials. When it comes to non-organic agricultural practices, each process or material should be considered on an individual basis with regard to its potential for health-related effects, along with its likelihood to actually induce these effects under normal circumstances.
Nutrient composition and pesticide exposure
Several studies have been conducted to determine if the nutrient content of organic food is different from that of conventional food. Largely, the answer appears to be no. In one systematic review, authors concluded that conventional foods tended to be higher in nitrogen, whereas organic foods tended to be higher in phosphorus [1]. For all other nutrients evaluated, differences were not statistically significant. A separate study concluded that organic produce may contain slightly more vitamin C than conventional produce, in addition to lower protein content but higher protein quality [2]. Nonetheless, the authors concluded that there is insufficient evidence to suggest differences with regard to other nutrients, and the small differences observed between organic and conventional foods were not large enough to make a meaningful impact on health. Unfortunately, the literature on this topic is highly inconsistent, but for justifiable reasons. The nutrient content of produce depends on several factors, including fertilizer use, pesticide use, growing conditions, season, ripeness, storage conditions, and many more. As such, there is a great deal of variation in the nutrient content of a given crop, even when comparing the same exact conventional food grown on two different farms or at two different times throughout the year. In general, any differences in nutrient content between organic and conventional crops are too inconsistent to rely on, and too small to impact health in a meaningful way. The same can be said for meat from organic livestock; while differences in fatty acid composition have been noted [3], the differences are wildly inconsistent between studies, influenced by many extraneous factors, and unlikely to meaningfully influence health outcomes.
When it comes to pesticide residues, organic foods (unsurprisingly) expose you to lower levels than conventional produce [4][5]. In addition, the presence of antibiotic-resistant bacteria is significantly higher in conventional chicken and pork in comparison to organic varieties [5]. The case for choosing organic foods is starting to look pretty strong, but there are a few important considerations to keep in mind. First, there are many contaminants that can affect food outside of pesticide residues and antibiotic-resistant bacteria, and both conventional and organic foods are equally susceptible to general environmental contaminants [4]. Second, the presence of a difference does not necessarily mean that a meaningful or important difference is present. Although there may be differences in the absolute amount of certain contaminants in conventional foods, experts suggest that the risk of actually exceeding allowable limits and suffering health symptoms in response to exposure is quite low [5].
Does it ever make sense to eat organic?
In nutrition, few things are truly “black and white.” There are some instances in which the tendency to choose organic options might be more justifiable than others. For instance, foods can vary widely with regard to their risk of exposing you to pesticide residues. The Environmental Working Group (www.ewg.org) has a list of foods with particularly high levels of such residues, which they call the “dirty dozen.” If you habitually consume large quantities of the dirty dozen, which includes strawberries, spinach, and potatoes, the preference for organic options would not be totally unwarranted. On the other hand, the Environmental Working Group also maintains a list of produce with particularly low levels of pesticide residues, which they call the “clean fifteen.” For these products, which include asparagus, corn, and cauliflower, paying extra for organic sources seems less justifiable in comparison. I should note that these lists are not peer-reviewed or published in academic outlets, and the EWG tends to have a generally pro-organic stance. As such, these lists should be viewed as guidelines rather than rigorous scientific evidence.
For another scenario, consider the underdeveloped filtration and detoxification systems of embryos and fetuses. The term “teratogen” refers to any substance that causes harm to a developing embryo. For an adult woman, a single exposure to a moderate dose of alcohol or a normal treatment dose of certain prescription medications would be reasonably harmless; for an embryo that she may be carrying, it could be devastating. This is because embryos and fetuses haven’t yet fully developed the systems required to successfully eliminate teratogens from the body without harm, so even small levels of exposure can be problematic. If an expecting or breastfeeding mother were to decide that she was not thoroughly convinced that residues associated with conventional produce lacked teratogenic effects, and she chose to err on the side of caution as a result, I could see a justifiable tradeoff between the extra cost of organic produce and the peace of mind it might bring with it. Having said that, the current scientific evidence does not indicate that such a strategy would effectively influence the child’s health or development, and the recommendation for pregnant or breastfeeding women to exclusively consume organic foods is not supported by scientific evidence. So, I’m not ready to claim that pregnant and breastfeeding women should eat organic, or that conventional food products will cause harm to their developing child, but I understand the extra layer of caution. There are also some instances in which individuals suspect that they may have an allergic reaction to particular food dyes, additives, or residues. In such cases, it might not be a terrible idea to select organic options as a means to temporarily remove these substances from the diet, which would allow for objective observations about potential changes in symptoms. Again, there is a lack of evidence to actually support this suspicion, but lack of research in an area cannot be used to refute the possibility of a relationship.
Aside from health-related reasons, there is evidence to suggest that organic food production is more environmentally-friendly. Research has shown that organic farming practices are generally more favorable with regard to soil fertility, biodiversity, and the protection of natural resources [6]. However, this comes at a cost, as the crop yield from organic farming tends to be 20-25% lower than conventional methods [6]. Finally, I’d be remiss to neglect the fact that there’s no reason to believe there is any detriment to organic food consumption. So, aside from an inflated grocery bill, you can’t say that a strictly organic diet is doing any harm. As a result, some people eat organic foods for the same reason that others try a new supplement with minimal evidence supporting its efficacy: it could help, and definiteley won’t hurt. For some people, that justification is good enough to roll with.
Conclusion
The “appeal to nature” fallacy is certainly a tempting one. On the surface, it makes sense that natural stuff is good, and synthetic stuff is bad. But when it comes to choosing between organic and conventional foods, it’s a bit more complicated than that. From a nutrient perspective, the two can be viewed as equivalent. When it comes to overall exposure to environmental contaminants, they are approximately equal as well. Conventional produce probably does contain higher levels of pesticide residues, but the difference doesn’t appear to have a meaningful impact on health outcomes. While there may be some specific scenarios in which organic food options are more justifiable than others, there is currently no evidence to suggest that eating organic foods leads to better health outcomes than eating conventional foods. So, purely from a health perspective, it’s hard to say that the extra cost of organic food is worth the potential benefits in otherwise healthy individuals.
References
- Dangour AD, Dodhia SK, Hayter A et al.: Nutritional quality of organic foods: a systematic review. Am J Clin Nutr. 2009;90(3):680-5.
- Magkos F, Arvaniti F, Zampelas A: Organic food: nutritious food or food for thought? A review of the evidence. Int J Food Sci Nutr. 2003;54(5):357-71.
- Srednicka-Tober D, Baranski M, Seal C et al.: Composition differences between organic and conventional meat: a systematic literature review and meta-analysis. Br J Nutr. 2016;115(6):994-1011.
- Magkos F, Arvaniti F, Zampelas A: Putting the safety of organic food into perspective. Nutr Res Rev. 2003;16(2):211-22.
- Smith-Spangler C, Brandeau ML, Hunter GE et al.: Are organic foods safer or healthier than conventional alternatives?: a systematic review. Ann Intern Med. 2012;157(5):348-66.
- Niggli U: Sustainability of organic food production: challenges and innovations. Proc Nutr Soc. 2015;74(1):83-8.
