The study was carried out in an area of China where the population tends to have low selenium intake. The 120 participants had an average daily intake of 10 micrograms - significantly lower than the recommended daily amount is 55 micrograms.
The researchers found that less than half the amount of selenomethionine was needed to boost selenium to optimal levels, compared to selenium. What's more selenomethionine, an organic compound and the form of selenium that most often occurs naturally in food products, is twice as bioavailable as selenium. The study has been accepted for publication in the American Journal of Clinical Nutrition.
Selenium, a trace mineral found in soil, is understood to boost the body's antioxidant immune system detoxifier and may deliver health benefits including reduced risk of some types of cancer and cardiovascular disease and promotion of normal liver function.
The selenomethionine compound used in the Vanderbilt University study was Selenium SeLECT supplied by Sabinsa Corporation. The same product is also being used by the National Cancer Institute in two studies into the effects of selenium and vitamin E - one, a 12-year study, investigates its potential to reduce the risk of prostate cancer and the other to prevent the onset of memory damage, including Alzheimer's, with age.
Dr Vladimir Badmaev, Sabinsa's VP of scientific and medical affairs, said that three more studies using the company's product are due to commence soon.
In 2003 the FDA issued a qualified health claim on selenium: "Selenium may reduce the risk of certain cancers. Some scientific evidence suggests that consumption of selenium may reduce the risk of certain forms of cancer. However, FDA has determined that this evidence is limited and not conclusive."