Examining the Selenium, Cancer, Heart Disease and Longevity Link
To sort this out, researchers conducted a study of almost 14,000 adults. The study examined them selenium levels over 12 years and attempted to link those levels to the overall risk of death, death by cancer and death by heart disease. One of the things the study was trying to determine was if high levels of selenium lead to an increased risk of death.
Too Much of a Good Thing
Researchers found that higher (but not too high) levels of selenium were associated with a decrease in overall death rate and the death rate from cancer. They did not find a link between selenium level and heart disease. Researchers also found that individuals with selenium levels in the blood over 130 ng/ml were more likely to die of cancer. They conclude that moderate increases in selenium level can be linked to increased longevity through a decrease in the risk of cancer and overall death. However, extremely high levels of selenium are no longer helpful and may actually decrease longevity.
Selenium is found in seafood, grains, nuts and other dietary sources. Learn more about selenium as a supplement, its risks and side effects.
Source:
Joachim Bleys, MD, MPH; Ana Navas-Acien, MD, PhD; Eliseo Guallar, MD, DrPH. Serum Selenium Levels and All-Cause, Cancer, and Cardiovascular Mortality Among US Adults. Arch Intern Med. 2008;168(4):404-410.

