People whose blood contains high levels of selenium levels may be at lower risk for cancer, a new study shows.

Selenium is a nutritional trace element found in many foods, including fish, shellfish, meat, milk and eggs and certain South American nuts, such as Brazil nuts.

As a nutritional trace element, selenium forms an essential part of our diet, and now a team of European researchers have demonstrated that high blood selenium levels are associated with a decreased risk of developing liver cancer.

In addition to other risk factors, the study also examines in how far selenium levels may influence the development of other types of cancer.

In this case-control study, the team of European researchers investigated a cohort of 477,000 participants, and selected individuals who had developed hepatocellular carcinoma during a 10-year follow up. Blood samples were also chosen from healthy participants and subsequently analyzed to determine their selenium status.

They found the third of the subjects with lowest selenium status had a five-to-ten-fold increased risk of developing s liver cancer. Previous studies have also suggested a similar relationship between a person's selenium status and their risk of developing colon cancer, as well as their risk of developing autoimmune thyroid disease.

While the research not show that selenium supplementation directly protects against liver cancer, it does confirm the importance of a balanced diet, of which selenium forms an integral part," they added, referring to the study, which appears in the American Journal of Clinical Nutrition.