Organic food 'better' for heart
Tomatoes
Tomatoes contain compounds which are good for the heart
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
Peter Melchett, Soil Association
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 fertilisers in organic farming.
Flavonoids are produced as a defence mechanism that can be triggered by nutrient
deficiency, such as a lack of nitrogen in the soil.
The inorganic nitrogen in conventional fertiliser is easily available to plants
and so, the researchers suggests, the lower levels of flavonoids are probably
caused by over-fertilisation.
Conflicting evidence
Flavonoids have also been linked with reduced rates of some types of cancer and
dementia.
The Food Standards Agency says there is some evidence that flavonoids can help
to reduce the risk of cardiovascular disease and they are currently carrying out
a study to look at the health benefits in more detail.
However, a spokesperson said there was no evidence that organic food was
healthier.
"Our long-standing advice on organic food is there can be some nutrient
differences but it doesn't mean it's necessarily better for you."
For example, a recent study found that organic milk had higher levels of omega-3
fatty acids, but the FSA points out that these short-chain fatty acids do not
seem to have the health promoting benefits offered by long-chain omega-3 oils
found in oily fish.
Peter Melchett, Soil Association policy director said: "We welcome the now
rapidly growing body of evidence which shows significant differences between the
nutritional composition of organic and non-organic food.
"This is the second recent American study to find significant differences
between organic and non-organic fruit.
"These findings also confirm recent European research, which showed that organic
tomatoes, peaches and processed apples all have higher nutritional quality than
non-organic."
"As further scientific evidence emerges from new research looking at differences
between organic and non-organic food, the Soil Association will be asking the
FSA to keep their nutritional advice to consumers under review."
