Nut a day keep doctor away

Two Brazil nuts a day keep low selenium at bay - and may stave off cancer and heart disease, say Otago University scientists.

Professor Christine Thomson, who has led a world-first study into how much of the essential micronutrient people can obtain from Brazil nuts, health club said New Zealanders generally had "marginal" selenium levels because the soil was deficient in selenium.

"There is mounting evidence that a marginal selenium status can lead to an increased risk for a range of conditions, including cancer and cardiovascular disease."

Selenium is a trace mineral essential for producing antioxidant enzymes and other proteins, which protect cells from damage.

The Otago study, which has just been published in the American Clinical Journal of Nutrition, involved 60 volunteers who were divided into three groups: one ate two Brazil nuts a day, one received a 100 microgram selenium supplement and one was given a placebo.

Professor Thomson and her colleagues from the Department of Human Nutrition found that after 12 weeks health club, the blood selenium concentrations of the Brazil nut group had increased by 64.2 per cent, compared with 61 per cent in the selenium supplement group.

When they measured the activity levels of a key antioxidant, the Brazil nut eaters' levels went up by 13.2 per cent, versus 5.3 per cent in the supplement group.

Research is under way to investigate the association between low selenium levels and higher rates of cancer and heart disease health club.

Wellington Nut Store co-owner David Upchurch said: "Kiwi farmers have been feeding selenium supplements to their cattle for years ... but it's only in the past few years that people have cottoned on to the fact it might be good for them too health club."