Elderly people with low levels of the mineral selenium may have poor muscle strength. People commonly lose muscle mass and strength as they age, which contributes to falls, injuries and illness in elderly adults. And low selenium levels may be one of the reasons for age-related muscle weakness. Selenium is a mineral that people require in only small amounts. Food sources of selenium include grains, certain nuts, like Brazil nuts, and some meats and seafood, such as beef and tuna. The body incorporates selenium into proteins called selenoproteins, which act as antioxidant enzymes; antioxidants, in turn, help protect body cells from damage. Older adults with low selenium may have "sub-optimal" selenoprotein activity in their muscles, contributing to deteriorations in strength. Researchers from the Tuscany Regional Agency in Florence, Italy measured plasma selenium and hip, grip, and knee strength in a cross-sectional study of 891 men and women aged 65 years and above. They were made to give blood samples and go through a series of muscle-strength tests. In general, one-quarter of the people with the lowest selenium levels were twice as likely to have poor muscle strength as the quarter of adults with the highest selenium levels. Thus, the findings indicate that selenium level is one of the factors, with other factors like chronic disease, overall calorie intake and weight, which must also be taken into account. However, it is still unclear whether a higher dietary intake of selenium will improve or maintain muscle strength in older community-dwelling adults with low plasma selenium concentrations, and more research is required in this regard.
American Journal of Clinical Nutrition,
August 2007