WALNUTS could be nature’s secret weapon against prostate cancer.
Scientists have evidence that eating modest quantities of the nuts on a regular basis can hold back tumours.
Prostate cancer growth was reduced by 30% in mice fed the human equivalent of two handfuls of walnuts every day for two months. Tumours in mice given the nut diet were half as big as those of animals not fed on walnuts.
The US researchers believe the findings are directly relevant to humans.
Study leader Paul Davis, from the University of California at Davis, said: “Walnuts should be part of a prostate-healthy diet.
“They should be part of a balanced diet that includes lots of fruit and vegetables.”
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.
Scientists recently showed walnuts can help combat heart disease by reducing levels of endothelin, a chemical that increases inflammation in blood vessels. Walnuts also reduced levels of “bad” cholesterol or low-density lipoprotein in the blood.
Helen Rippon, of the Prostate Cancer Charity, said: “Nuts are a rich source of nutrients and should be enjoyed as part of a balanced diet. However, over-consumption is not to be recommended because of their high content of saturated fat, which could cause other problems like obesity.”
Another team of US scientists have concluded that infertile men have an increased risk of developing high-grade, aggressive prostate cancer that grows and spreads quickly.
Scientists believe there may be as-yet unknown common biological pathways underlying both conditions.
Researchers looked at more than 22,000 men assessed for infertility at 15 Californian clinics.
Their incidence of prostate cancer was compared with that of a sample of men of similar age from the general population.
Men confirmed as infertile were 2.6 times more likely to be diagnosed with high-grade prostate cancer than men not found to be infertile, said the researchers.