Effect of Supplementation With High-Selenium Yeast on Plasma Lipids

Randomized, placebo-controlled trial in older adults in the United Kingdom with relatively low selenium status. Volunteers aged 60 to 74 years were recruited from general practices and assigned to one of three active selenium arms or placebo.

Participants received high-selenium yeast (SelenoPrecise, Pharma Nord) or placebo yeast once daily for 6 months. Active selenium doses were 100, 200, or 300 mcg/day; route was not stated.

Selenium supplementation produced modest, dose-specific improvements in plasma lipids, but the pattern was not uniform and the clinical significance is uncertain. In the 100 mcg/day arm, total cholesterol fell more than placebo by -0.22 mmol/L (95% CI -0.42 to -0.03; P=0.02) and non-HDL cholesterol by -0.20 mmol/L (95% CI -0.37 to -0.04; P=0.02). In the 200 mcg/day arm, total cholesterol decreased by -0.25 mmol/L (95% CI -0.44 to -0.07; P=0.008), non-HDL cholesterol by -0.27 mmol/L (95% CI -0.43 to -0.10; P=0.001), and the total-HDL cholesterol ratio by -0.15 (95% CI -0.26 to -0.03; P=0.02). In the 300 mcg/day arm, HDL cholesterol increased by 0.06 mmol/L (95% CI -0.00 to 0.11; P=0.045) and the total-HDL ratio decreased by -0.18 (95% CI -0.30 to -0.05; P=0.005). No serious adverse events occurred, and 12 reported adverse events were mainly stomach or abdominal discomfort and were not dose-dependent.

Effects were modest, dose-specific, and not consistent across all lipid outcomes or selenium doses. The trial was only 6 months long, involved older UK adults with relatively low selenium status, and used nonfasting plasma lipids, which limits generalizability and makes the clinical importance uncertain. The authors also noted that selenium should not be advocated as dyslipidemia treatment on this basis alone.