Organic food better for health
Organic fruit and vegetables may be better for you than conventionally grown crops, US research suggests.
A ten-year study comparing organic tomatoes with standard produce found almost double the level of flavonoids - a type of antioxidant.
Flavonoids have been shown to reduce high blood pressure, lowering the risk of heart disease and stroke.
Writing in the Journal of Agricultural and Food Chemistry, the team said nitrogen in the soil may be the key.
Dr Alyson Mitchell, a food chemist at the University of California, and colleagues measured the amount of two flavonoids - quercetin and kaempferol - in dried tomato samples that had been collected as part of a long-term study on agricultural methods.
These findings also confirm recent European research, which showed that organic tomatoes, peaches and processed apples all have higher nutritional quality than non-organic
They found that on average they were 79% and 97% higher respectively in the organic tomatoes than in the conventionally grown fruit.
New Scientist magazine reported that the different levels of flavonoids in tomatoes are probably due to the absence of fertilizers in organic farming.
Flavonoids are produced as a defense mechanism that can be triggered by nutrient deficiency, such as a lack of nitrogen in the soil.
The inorganic nitrogen in conventional fertilizer is easily available to plants and so, the researchers suggests, the lower levels of flavonoids are probably caused by over-fertilization. Source: BBC
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