Chromium supplements are now being taken by millions based on claims that they improve insulin sensitivity and improve blood lipids and they help prevent or reverse type 2 diabetes mellitus (DM) and cardiovascular disease (CVD).
Back in the 1990s, Nutrition 21, a food supplement company in California, aggressively promoted chromium picolinate supplements as a weight loss aid. This company?s ads claimed chromium picolinate not only promoted fat loss, but also stimulated the growth of more lean tissues and increased strength.
Independent research done at the USDA Research Center in Beltsville, Md., found no difference in strength gains or body composition between a group of subjects taking the chromium supplements and ones without over a 12-week period with both groups weight training 3 times per week.1
Another study comparing 2 chromium supplements and a placebo in 3 groups of subjects that trained with weights for 8 weeks found no differences in either strength gains or body composition in the 3 groups.2
Based in large part on these two well-designed studies, the FTC ordered companies to stop making unsubstantiated weight loss and health claims for chromium picolinate.
Does Chromium Improve Insulin Sensitivity?
Many years ago it was shown that patients fed intravenously for a long time with a formula with virtually no chromium developed insulin resistance, type 2 DM and adverse changes in blood lipids. Adding chromium to the nutrition formula of these patients improved insulin sensitivity, cured their diabetes and corrected the lipid abnormalities.
Subsequent research established chromium as an essential trace mineral that is required in humans for proper function of insulin.3 However, while no one questions the important role chromium plays in human nutrition and insulin action, it has remained unclear whether people with impaired glucose tolerance (IGT) are deficient in chromium and so would benefit from taking chromium supplements.
A recent double-blind, controlled clinical trial in Australia examined the effect of chromium picolinate supplements on insulin sensitivity, blood lipids and body weight in 40 subjects with confirmed glucose intolerance. The researchers found no improvement in any of these parameters in subjects taking 800 mcg of chromium per day for three months compared with the placebo group. The authors conclude there was ?no beneficial effect of chromium supplementation in the treatment of people with IGT despite increases in serum chromium levels.?4
Other studies in people with type 2 DM have shown mixed results. Some have shown improvement in blood lipids such as higher HDL and lower triglycerides, and others have shown lower blood sugar levels and improved insulin sensitivity. Other studies have been unable to confirm these results. More research is needed to establish whether or not chromium supplements are safe and effective in people with type 2 DM.
The bulk of the scientific research to date proves beyond a reasonable doubt that chromium supplements are of no value for promoting weight loss, increasing muscle mass or strength or improving athletic ability. Most research suggests chromium supplements do little or nothing in people without type 2 DM including those with IGT or the Metabolic Syndrome. More research needs to be done before anyone should conclude chromium supplements benefit those with type 2 DM.
By James Kenney, PhD, RD, LD, FACN.
1 Med Sci Sports Exerc. 1996;28:139-44
2 Am J Clin Nutr. 1996;63:954-65
3 Fed Proc 1974;33:275-80
4. Diabetes Care. 2005;28:712-714
Judy’s passion for cooking began with helping her grandmother make raisin oatmeal for breakfast. From there she earned her first food service job at 15, was accepted to the world famous Culinary Institute of America at 18 (where she graduated second in her class), and went on to the Fachschule Richemont in Switzerland where she focused on pastry arts and baking. But after learning that the quality of a croissant directly varies with how much butter it has, Judy sought to challenge herself by coming up with recipes that were as healthy as they were tasty.
Judy received The Culinary Institute of America’s Pro Chef II certification, the American Culinary Federation Bronze Medal, Gold Medal, and ACF Chef of the Year. Her enthusiasm for eating nutritiously and deliciously leads her to constantly innovate and use the latest in nutritional science to guide her creativity, from putting new twists on fajitas to adapting Italian brownies to include ingredients like toasted nuts and cooked honey. Judy’s publishing company, Food and Health Communications, is dedicated to her vision that everyone can make food that tastes as good as it is for you.