Plasma Selenium Levels and the Risk of a First Stroke

A Chinese study has shown that there is a significant negative association between plasma selenium concentrations and the risk of a first stroke in males but not in females. This is not the first time that sex differences have been reported relative to selenium metabolism. More on that later.

Picture of the brain
Typically, there were many more cases of first ischemic stroke, usually caused by a blood clot, than there are cases of first hemorrhagic stroke, usually caused when a blood vessel leaks or breaks open). Adequate selenium supply to the brain may protect against the risk of stroke.

Plasma Selenium Levels and the Risk of a First Stroke

The Chinese researchers analyzed the results from a nested case-control study with 1255 first stroke cases and 1255 matched controls [Hu 2021].

N.B. In this study,  there were many more cases of first ischemic stroke (n=1079) than there are cases of first hemorrhagic stroke (n=171). Five cases were of uncertain origin.

Evidence from Other Studies of Selenium Level and Stroke Risk

The results from studies of selenium level and stroke risk have been somewhat confusing to date: read more

Selenium and Antioxidants to Prevent Heart Disease

Heart trouble
Selenium deficiency (< 70 mcg/L) and low selenium status (70 – 100 mcg/L) are associated with reduced exercise capacity and higher risk of death in heart failure patients [Bomer 2019].
Canadian researchers have concluded that the addition of selenium should be considered for antioxidant supplements if the antioxidant mixtures are to be associated with reductions in the risk of heart disease and all-cause mortality [Jenkins 2020].

How did they arrive at this conclusion? First, they did a preliminary analysis of the available research literature and found that antioxidant supplements seemed to reduce incidence of all-cause death when the supplements included selenium [Jenkins 2020].

Systematic Review of Supplements With and Without Selenium

Next, they did a systematic review and meta-analysis of randomized controlled trials to evaluate the effect of selenium supplementation alone and the effect of antioxidant mixtures with or without selenium on the risk of heart disease and all-cause mortality [Jenkins 2020]. read more