By Kate Devlin, Medical Correspondent
May 27, 2008
Drinking organic milk has greater health benefits than drinking normal milk, according to a new study.
Scientists found higher levels of vitamins, antioxidants and "healthy" fat in milk from organically farmed animals.
The researchers believe that letting cows graze on fresh grass boosts the nutritional value of their milk. The benefits could include a lower risk of cancer and heart disease.
The study, which analysed produce from 25 farms, found that organic milk contained 67 per cent more antioxidants and vitamins than ordinary milk. Scientists at Newcastle University also found organic milk contained 60 per cent more of a healthy fatty acid called conjugated linoleic acid, or CLA9, which tests have shown can shrink tumours.
Similar levels of vaccenic acid, which has been linked to a reduced risk of heart disease, diabetes and obesity, were also found.
Organic milk contained 39 per cent more of the fatty acid Omega-3, which has been shown to cut the risk of heart disease, and 32 per cent the levels of the less healthy Omega-6.
Gillian Butler, the livestock project manager for the Nafferton Ecological Farming Group at Newcastle University, who led the study, said the research had potential health benefits even if consumers did not switch to organic milk.
"In an ideal world it would be better, but logistically I don't think there would be enough," she said.
"(Organic milk) is more expensive to produce as you get less milk per unit of land and it is more expensive to buy. But because it is higher in all these beneficial compounds you don't need to buy as much to get the health benefits.
"What I am trying to do is identify what it is about organic milk that makes it healthier then maybe we can use that to improve milk quality across the board."
The team found healthy fatty acids and antioxidants were most prevalent in organic milk during the summer, when cows ate fresh grass and clover.
Organically farmed cows get more than 80 per cent of their diet from grazing on grass. Conventional farms, which supply nine out of every 10 pints of milk in Britain, feed their cattle just 37 per cent of their diet from grazing.
Professor Carlo Leifert, who oversaw the study, said: "This paper is a major milestone in the project and clearly shows that if you manage livestock naturally then it's a win-win situation for both us and them."
However, the Food Standards Agency, the Government's food watchdog, said there was still little evidence to prove that organic food was more beneficial, although it would look at the Newcastle study.
Peter Melchett, from the Soil Association, which campaigns for more widespread use of organic farming methods, said: "This research confirms what organic farmers and consumers have long believed to be true.
"This latest research demonstrates that it is the cows' organic diet that makes their milk healthier."
The results were published online in the Journal of the Science of Food and Agriculture on Tuesday.