Walnuts could prevent prostate cancer, research finds
Experiments showed that eating a diet rich in walnuts reduced the size and growth rate of prostate cancer in mice.
Scientists believe that the secret lies in walnuts’ ability to reduce levels of endothelin, a substance that increases inflammation of blood vessels.
Researchers from the University of California Davis decided to test the benefits of eating walnuts because people who suffer prostate cancer are known to have higher levels of endothelin.
They found that mice which were fed on walnuts developed prostate cancers around 50 per cent smaller than a control group which were given soya bean oil instead.
Dr Paul Davis, who headed the study, said: “Walnuts should be part of a prostate-healthy diet.
“They should be part of a balanced diet that includes lots of fruits and vegetables.”
The researchers deliberately chose to feed the animals the equivalent of about a handful of actual nuts each day rather than a supplement-like extract.
"We decided to use whole walnuts in the diet because when a single component of a food linked to cancer prevention has been tested as a supplement, that food's cancer-preventive effects disappear in most cases," said Dr Davis.
Although susceptibility may be partly inherited, experts believe the disease is strongly linked to environmental factors such as diet.
Walnuts are packed with health-giving substances including omega-3 fatty acids, an inflammation-fighting form of vitamin E, polyphenol plant compounds and antioxidants.
The new findings were presented to the 239th National Meeting of the American Chemical Society in San Francisco.
Helen Rippon, head of research management at The Prostate Cancer Charity, said: "This new research, which is yet to be fully peer-reviewed, does provide new clues about the development of prostate cancer and how a man's diet might help prevent the disease by regulating their hormone levels and the way that genes work.”