Is organic food more nutritious than conventional?

Recent research flies in the face of studies that found no nutritional differences between conventional and organic foods. [1]

Organic dairy appears to be more nutritious

A study published in the British Journal of Nutrition in 2016 found that organic milk contains significantly higher levels of polyunsaturated fatty acids, omega-3 fatty acids, alpha-tocopherol, and iron than conventional milk. [2] The differences in feeding regimens explained the observed difference. Cows raised organically eat higher levels of fresh forage (e.g. grass), which increases concentrations of fatty acids, antioxidants, and vitamins.

However, not all vitamins were higher in organic milk. Organic milk contained slightly lower levels of iodine and selenium compared to conventional milk. [3] This difference is likely due to the vitamin and mineral supplementation utilized by conventional farmers. Although organic dairy farmers are allowed to use nutritional supplementation, the majority of the cow’s nutrition comes from grazing. Soil levels of iodine and selenium have degraded over the years. Consequently, the food (in this case cow’s milk) will only be as nutritious as the soil that grew the cow’s food.

Organic produce

Another meta-analysis published in the British Journal of Nutrition in 2014 found meaningful differences between organic and conventional crops. [4] Polyphenols were significantly higher in organic foods. Polyphenols play important roles in plant ecology, such as releasing and suppressing growth hormone, UV protection, deterrence of herbivores, prevention of infections, signaling growth processes, and preservation against rot.

Health protective plant chemicals were substantially higher in organic produce than conventional produce:

• Phenolic acids were 19% higher

  • Phenolic acids are absorbed through the intestinal walls, and function as antioxidants that prevent cellular damage and inflammation. [5]

• Flavanones were 69% higher

  • Flavanones are a subgroup of flavonoids found in citrus fruits that function as antioxidants that prevent free radical damage, cancer, and diabetes; boost blood and vessel health; and protect the liver. [6]

• Stilbenes were 28% higher

  • Stilbenes are another type of antioxidant and anti-inflammatory polyphenol, such as resveratrol (everyone’s favorite excuse to drink red wine). [7]

• Flavones were 26% higher

  • Flavones inhibit aromatase activity and decrease estrogen to protect against breast and prostate cancers. [8]

• Flavonols were 50% higher

  • Flavonols are also members of the flavonoid family associated with reduced risk of cardiovascular disease, mortality, stroke, and hypertension; reduced inflammation; and increased physical endurance. [9]

• Anthocyanins were 51% higher

  • Anthocyanins are antioxidants that have been shown to boost cognitive function, protect liver and eye health, prevent cancer (e.g. breast, prostate, colon, oral, and tumor metastasis), reduce high cholesterol and risk of heart disease, and assist with healthy weight. [10]

Additionally, pesticide residues were four times higher in conventional produce than in organic produce. Conventional produce also had significantly higher concentrations of toxic metal cadmium. According to Occupational Safety and Health Administration (OSHA), cadmium exposure has been shown to be highly toxic, cause cancer, and target multiple body systems (e.g. cardiovascular, renal, gastrointestinal, neurological, reproductive, and respiratory). [11]

Higher concentrations of health-promoting antioxidants and lower concentrations of toxic heavy metals were attributed to adherence to organic farming practices that do not involve synthetic fertilizers. [12] As a result, organic crops grow more slowly. They have more time to produce secondary plant metabolites and uptake nutrients from the soil. [13] Organic farmers tend to take good care of their soil with crop rotation and compost application.

Organic plants have to fight stress just like we do

The same compounds that help the plant survive their stress help us deal with the stress of our environment.

Unlike conventionally raised crops, organic plants are not sprayed with tons of synthetic insecticides, herbicides, fungicides, and other agrochemicals. They must naturally build up defenses—via polyphenols and other compounds—to ward off insects, pests, and predators. They must compete with other plants (e.g. weeds) for the resources to grow, and be resilient in the face of unfavorable growing conditions.

In light of more recent data, organic food appears to be more nutritious. What do you think? Are you skeptical? Does it even matter to you? Leave your thoughts in the comments below.

References:

[1] http://annals.org/aim/article/1355685/organic-foods-safer-healthier-than-conventional-alternatives-systematic-review
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4838834/
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4838834/
[4] https://www.ncbi.nlm.nih.gov/pubmed/24968103
[5] https://www.verywell.com/what-is-phenolic-acid-2507071
[6] http://freefitnesstips.co.uk/5-flavanone-health-benefits/
[7] https://www.verywell.com/stilbenes-plant-antioxidants-2507072
[8] http://www.zhion.com/phytonutrients/Flavonols.html
[9] http://easacademy.org/trainer-resources/article/the-effect-of-flavonols-on-health-and-exercise-eas-academy
[10] http://www.naturallivingideas.com/7-reasons-to-eat-more-anthocyanins-and-top-foods/
[11] https://www.osha.gov/SLTC/cadmium/
[12] https://www.ncbi.nlm.nih.gov/pubmed/24968103
[13] http://www.npr.org/sections/thesalt/2016/02/18/467136329/is-organic-more-nutritious-new-study-adds-to-the-evidence

Disclaimer: These statements have not been evaluated by the FDA. These products are not intended to diagnose, treat, cure, or prevent any disease.