A team at the University of Oveido report that in a group of elderly people, those with the highest selenium intake had a 63 per cent decreased risk of higher total homocysteine concentrations (more than 14 µmol/L).
Studies in rats have indicated that homocysteine levels in the blood may be increased with selenium supplementation although recent human studies have refuted this link.
The new research, published in this month's Journal of Nutrition (134:1736-1740), appears to suggest that the mineral could play a role in protecting against heart disease, the world's biggest killer.
Previous studies have indicated an association between raised levels of total homocysteine and stroke and heart disease. Folic acid, pyridoxine (vitamin B6), and cobalamin (vitamin B12) are known to reduce plasma homocysteine levels but lowering homocysteine has not yet been confirmed an effective strategy for reducing risk of stroke.
The new study also found an inverse association between protein intake and homocysteine levels in men, which could be mediated by addition of selenium, they say.
Low selenium levels in humans have also been associated with an impact on immune system. Recent UK research found that subjects lacking the nutrient had lower resistance to a polio virus.