It’s official! (Well, a study has found evidence of it.) Organic tomatoes contain higher levels of polyphenols than conventionally grown tomatoes.
Why is this important? Because the consumption of polyphenols – natural, plant-produced antioxidants – is associated with a reduced risk of cardiovascular disease, degenerative diseases and some cancers.
This is great news. The longer we live (and stay healthy), the more time we can spend gardening!
The researchers, from the University of Barcelona, said the use of fertilisers explained the difference between organic and conventional tomatoes.
“Organic farming doesn't use nitrogenous fertilisers; as a result, plants respond by activating their own defence mechanisms, increasing the levels of all antioxidants," says one of the study’s authors, Anna Vallverdú Queralt, in Science Daily.
Lead author Rosa M Lamulea adds: “The more stress plants suffer, the more polyphenols they produce.”
This ties in nicely with what Peter Cundall is always saying in Organic Gardener: give your tomatoes some stress and they will flower and fruit beautifully. Don’t mollycoddle them.
The new paper backs up previous studies. “A meta study done conjointly by the Washington State University and Dr Charles Benbrook of the Organic Center in the USA found that on average organic products have 30 per cent higher levels,” says the Organic Federation of Australia.
Increased levels of antioxidants explain why organic tomatoes taste so good too: many of the antioxidants are flavonoids, which are major components in the flavour of food.
The Barcelona team had recently shown higher antioxidant levels to exist in organic tomato juice and organic tomato sauce. Its new study can be found here.
Photo: Sean Watson