Years of research have yielded conflicting results on whether chromium supplements can reduce blood glucose levels. Now, a new meta-analysis (analysis of data from several clinical trials) from the University of Miami indicates that supplementation of the nutrient is not effective at lowering fasting blood glucose levels in people with or without diabetes.
Chromium is a trace mineral needed by the body to help process carbohydrate, protein, and fat and to enhance the action of insulin. It is found in foods such as red meat, chicken, eggs, liver, whole grains, brewer’s yeast, and some fruits and vegetables. According to the Institute of Medicine, adequate daily intakes of chromium for men and women range from 24–35 micrograms (mcg) per day, with men requiring more than women. Deficiencies of the nutrient are thought to be rare in the United States.
Previous meta-analyses and systemic reviews have indicated that chromium supplementation significantly lowers fasting blood glucose levels in people with diabetes, but not in people without diabetes. According to the new research, however, the methods of statistical analysis used in these studies had limitations that could have affected the results.
To address these limitations, the current study used improved methods of analysis to interpret the data from 16 studies published from 1985 to 2012. A total of 809 participants, ranging from 36 to 67 years old, were included, taking doses of chromium chloride, chromium picolinate, chromium nicotinate, chromium dinicocysteinate, or chromium yeast ranging from 200 mcg to 1,000 mcg per day.
The analysis showed that there was not a significant effect of chromium supplementation on fasting blood glucose levels in either people with diabetes or those without diabetes, indicating that supplementation with the nutrient is unlikely to provide blood glucose benefits in populations where chromium deficiency is unlikely.
“Some previous research reported that chromium supplements lower the levels of fasting glucose. However, the effect may have been exaggerated or mistaken for the effects of other concurrent treatments, such as exercise training,” noted study author Christopher H. Bailey, a PhD candidate in the Department of Kinesiology and Sport Sciences at the University of Miami’s School of Education and Human Development.
Bailey notes, however, that chromium may still have health benefits. “Although chromium supplementation doesn’t lower fasting blood sugar, there may be other beneficial effects on the body that require more research. Fasting blood sugar is only one aspect of human health.”
For more information, read the article “Are chromium supplements helpful in lowering blood sugar levels?” or see the study’s abstract in the journal Biological Trace Element Research. And to learn more about chromium, see this piece by certified diabetes educator and registered dietitian Amy Campbell.