“Organically grown produce is more nutritious than conventionally grown produce.”

Results show that in 191 (29.1%) comparisons, there were significant differences between organic and conventional foods. In a similar quantity of cases (190; 29.0%), there were divergences in the results since some studies reported significant differences while others did not. Finally, most of the comparative analyses (275; 41.9%) showed no significant difference between organic and conventional foods. Therefore, the results herein show no generalizable superiority of organic over conventional foods.

A meta-analysis published in the British Journal of Nutrition looked at 343 studies into compositional differences between organic and conventional crops, reporting differences including higher levels of certain anti-oxidants and lower levels of cadmium in organic crops. This study provides limited evidence that organically grown crops contain, on average, higher concentrations of some antioxidants, lower concentrations of cadmium, and are less likely to contain pesticide residues than conventionally grown crops.

A ground-breaking meta-analysis of 343 studies led by Newcastle University, U.K., has found that organic food delivers significantly more benefits compared to non-organic food. Among these are that organic food contains up to 69% more of key antioxidants and significantly lower concentrations of cadmium (50%), nitrates (30%), nitrites (87%) and pesticides.

Upon reviewing the existing literature regarding the nutritional value of organic foods, it was found that organic food contained higher levels of iron, magnesium and vitamin C.

The micronutrient analysis of grains revealed that conventionally produced chickpea grains had a lesser amount of Zn and Fe. This could be due to the higher copper concentration in the conventional chickpea grain, as it has been reported in previous studies that a high copper concentration can cause decreased absorption of other micronutrients from the soil.

Although there appears to be little variation between organic and conventional food products in terms of macro nutritional value (protein, fat, carbohydrate and dietary fibre), other compositional differences have been demonstrated. These include higher antioxidant concentrations (particularly polyphenols) in organic crops; increased levels of omega-3 fatty acids in organic dairy products; and improved fatty acid profiles in organic meat products. Organic foods have been shown to have lower levels of toxic metabolites, including heavy metals such as cadmium, and synthetic fertilizer and pesticide residues.

It isn't clear whether organic food has more nutrients, such as vitamins and minerals, than does conventionally grown food. The level of nutrients in food depends on a host of factors. Nutrients may be different between varieties of a plant. Levels also depend on the quality of the soil, harvest time, and the way products are stored and for how long.

The results indicate that organic crops and processed crop-based foods have a higher antioxidant activity and contain higher concentrations of a wide range of nutritionally desirable antioxidants/(poly)phenolics, and lower concentrations of the potentially harmful, toxic metal Cd. It also found a a four times higher frequency of occurrence of pesticide residues in conventional crops.

They did not find strong evidence that organic foods are more nutritious or carry fewer health risks than conventional alternatives.

They found that the published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods.

Regarding the comparison of the nutrient content of the analyzed products, the results obtained showed that in most cases the difference between production systems is non-existent, that is, no sufficiently robust results allowed the organic to be superior to conventional products in relation to nutritional content. Therefore, the choice for organic processed foods should not be made exclusively based on nutritional aspects, considering that the differences in nutrient contents in relation to those of conventional products are practically nonexistent.

A recent review published in the journal Nutrients shows that increased organic food consumption is associated with fewer incidences of infertility, birth defects, pre-eclampsia, allergies, middle ear infections in children, non-Hodgkin lymphoma, and metabolic syndrome, which increases a person's risk for heart disease and stroke.

A recent review of the scientific literature published in Nutrition Reviews examines the correlations between organic food intake and health. It highlights higher amounts of bioactive compounds and beneficial nutrients, more beneficial fatty acids in milk, higher concentrations of antioxidants in crops, and more 'good' fats in dairy products and meats.

Most independent studies indicate that there are no significant health or nutritional differences between food grown conventionally versus organically. Responding to widespread misconceptions, in April 2021, the United Nation's Food and Agricultural Organization, stated, “Organic food is often seen by consumers as healthy, tasty and environmentally friendly, but the organic food certification is not necessarily a synonym for safe food.”

Dr. Benbrook's research has established that organically grown vegetables and fruits contain higher levels of nutrients than their conventional counterparts. Organic foods were found to be clearly higher in antioxidants, vitamin C, nitrates and some polyphenols; and moderately higher in protein. Plant-based organic foods were consistently and clearly more nutrient dense, while animal-based organic foods were not consistently superior.

A 2012 systematic review published in the Annals of Internal Medicine analyzed 240 studies and concluded there is no strong evidence that organic foods are significantly more nutritious or safer than conventional foods in terms of vitamin, mineral, protein, or fat content.