Higher selenium levels linked to lower diabetes risk: Harvard study

Increased levels of selenium in the body may be associated with a 25% reduction in the risk of type-2 diabetes, says a new study from Korea and Harvard.

Data from 3,630 women and 3,535 men indicated that increasing levels of selenium in toenails were associated with lower risks of diabetes, with the relationship appearing to be linear, according to findings published in Diabetes Care.

“Further research is required to determine whether varying results in this study versus prior trials relate to differences in dose, source, statistical power, residual confounding factors, or underlying population risk,” said the researchers.

Selenium facts

Selenium is an essential micronutrient, and is considered to be an antioxidant. High levels of selenium have been inversely associated with risk of developing several cancers, including bladder, prostate and thryroid.

The mineral is included in between 50 and 100 different proteins in the body, with multifarious roles including building heart muscles and healthy sperm. However, cancer prevention remains one of the major benefits of selenium, and it is the only mineral that qualifies for a Food and Drug Administration (FDA)-approved qualified health claim for general cancer reduction incidence.

A recent review paper by Joyce McCann and Bruce Ames from the Nutrition and Metabolism Center at Children’s Hospital Oakland Research Institute in Oakland (CHORI) indicated that moderate deficiency in selenium may have long-term detrimental effects (FASEB Journal, 2011, Vol. 25, pp. 1793-1814).

Study details

Scientists from Yeungnam University in Korea and Harvard analyzed data from two separate US cohorts. None of the participants were diabetic at the start of the study.

Over the course of the study the researchers documented 780 new cases of type-2 diabetes. The highest average levels of selenium in toenails was associated with a 24% reduction in the risk of the disease.

“At dietary levels of intake, individuals with higher toenail Se levels are at lower risk for [type-2 diabetes],” they concluded.

Source: Diabetes Care

Volume 35, Issue 7, Pages 1544-51

“Toenail selenium and incidence of type 2 diabetes in U.S. Men and women”

Authors: K. Park, E.B. Rimm, D.S. Siscovick, D. Spiegelman, J.E. Manson, J.S. Morris, F.B. Hu, D. Mozaffarian