Does Organic Food Increase Human Plasma Antioxidant Capacity Compared to Conventional Food

Background and methodology:

A growing percentage of consumers consider organic foods healthier than conventionally grown foods. However, so far, few nutritional intervention studies in humans are available that compare organic and conventional foods. This study compared the total antioxidant activity of organic versus conventional fruits (apples, pears, red oranges, lemons, strawberries and bananas), vegetables (lettuce, tomatoes, onions, garlic, carrots, beans, potatoes, celery, peas, courgettes and zucchini), red wine and milk. The oxygen radical absorbance capacity (ORAC) procedure was used to determine both the antioxidant activity of food from organic or conventional origin and the human plasma antioxidant capacity. Ten healthy Caucasian Italian men, ages 30 to 65 years, were recruited. Anthropometric parameters of all the participants were measured.


The ORAC values for most of the organic foods (fruits, vegetables as well as red wine and milk) were significantly higher than those of their conventional counterparts. Three organic foods – pears, lettuce and tomato salsas – had lower ORAC values than the conventional products. Researchers observed that the men exhibited a 21 percent increase in plasma levels and total antioxidant capacity after they consumed a 14-day Mediterranean diet of only organic food. This study also showed that organic food products have a higher total antioxidant activity and bioactivity than the conventional foods. The results could be used in public health campaign to increase the consumption of products able to provide significant health protection and prevent chronic diseases.


Di Renzo, L., Di Pierro, D., Bigioni, M., Sodi, V., Galvano, F., Cianci, R., La Fauci, L., & De Lorenzo, A. (2007). Is antioxidant plasma status in humans a consequence of the antioxidant food content influence? European Review for Medical and Pharmacological Sciences, 11(3), 185-92. Available on-line at: