Organic tomatoes really are better for you, and they taste better to boot, according to the findings of a recent study conducted by researchers from the Federal University of Ceara, Brazil and published in the journal PLOS ONE.Although most consumers assume that organic fruits and vegetables have lower levels of toxic chemical residue, the new study found that they actually have higher nutritional content. The researchers believe that this is because when plants experience the normal stresses of growing outdoors, and are not buffered by synthetic pesticides and fertilizers, they load up on defensive antioxidants that make them healthier to eat.
The researchers compared the weights and biochemical makeup of tomatoes harvested from 30 separate plants at two farms in Brazil that were only 1.5 kilometers (about a mile) apart, and therefore represented very similar natural environments. The only difference was that one farm used organic agriculture techniques while the other used more "conventional" techniques. On the organic farm, no synthetic pesticides were used and only animal manure and vegetable compost were used as fertilizer. On the other farm, the tomatoes were treated with synthetic fertilizers and the pesticide FASTAC 100.
The researchers found that while the organically grown tomatoes weighed about 40 percent less than the conventional ones, they were dramatically higher in a number of powerful antioxidants. They were also higher in natural sugars, corresponding with a better flavor.
Specifically, the organic tomatoes were 57 percent higher in vitamin C and approximately 100 percent higher in the antioxidant compounds known as phenols. These phenols included lycopene, which has been shown to slow tumor growth and reduce the risk of prostate cancer. The researchers also found that the enzyme phenylalanine ammonia lyase (PAL) was 100 percent more active in organic tomatoes than in conventionally grown ones.
Protecting plants and people
All these compounds help fight oxidative stress in the body, and therefore can help reduce the risk of chronic diseases such as cancer, heart disease and dementia. Antioxidants are also believed to slow the effects of aging.
It appears that tomato plants also contain these same stress-fighting effects. The researchers suspect that when growing plants are experienced to stressors such as insect attacks, mild nutrient shortages and inclement weather, they boost their production of antioxidants such as phenols and vitamin C in order to protect themselves. When humans later eat the fruits, they gain the same health benefits.
This suggests that farmers are making a mistake when they try to eliminate all stressors from their growing environments, the researchers said. Instead, a better strategy for producing healthier food would be to find a balance between the stress needed to increase the nutrient content of foods without having too large a detriment to yield size.
Of course, higher nutrient content is not the only reason that many consumers prefer organic fruits and vegetables. Other reasons include lower pesticide residues, a smaller overall environmental impact, and safer conditions for farm workers and residents of rural areas.
