Chromium
When talking about chromium we’re not talking about that stuff that gets applied to metals to make them shiny.
For more than 20 years I’ve been interested and intrigued by its role in metabolism. This month’s issue of Harvard Men’s Health Watch highlights some of the research indicating possible links between chromium deficiency and diabetes, high cholesterol, heart disease and weight management.
The journal is only available for subscribers, but let me summarize some of the data for you.
Chromium exists in many forms and not all are either absorbed or biologically active. Antacids, phytates found in grains and tannins found in tea may all lower the absorption of chromium.
A point that always comes up when we discuss supplements is that some people will feel that recommended daily allowances are too low and that using larger – sometimes vast – amounts will achieve additional biological effects. There is some evidence that very large amounts of chromium may damage cells in tissue culture but very little evidence for chromium toxicity in humans. People probably vary greatly in their tolerance to chromium.
- Diabetes: Chromium has attracted most interest because of its action on the binding of insulin to at least one of the insulin receptors. Insulin is more effective if chromium is present. Chromium also has a positive influence on one of the glucose transporters in cultured fat cells. The effects of chromium on glucose and insulin seems to vary in different species. So it is difficult to extrapolate from an animal study to humans. In people with both the major types of diabetes, the consensus seems to be that chromium supplements containing 200-1,000 mcg chromium as chromium picolinate a day have been found to improve blood glucose control. Chromium picolinate is the most efficacious form of chromium supplementation. There is a small pilot study that found that in women with polycystic ovarian syndrome, a low dosage of chromium picolinate improved glucose tolerance, but did not help with the hormonal or ovulatory disturbances. This has just been confirmed in a study using a higher dosage (1,000 mcg/day). Based on a detailed review of the literature, the United States Food and Drug Administration (FDA) has determined that chromium – at least chromium picolinate – does not reduce the risk that you might develop insulin resistance or diabetes and the American Diabetes Association agrees that the benefit of chromium supplements has not been conclusively demonstrated.
- Cholesterol: Chromium deficient rats develop high cholesterol levels. But the evidence that chromium supplementation helps cholesterol levels in humans is thin. Chromium may also help people with diabetes to lower their cholesterol levels. The published evidence indicates that any beneficial effects of chromium on cholesterol is much smaller than the effects of diet and exercise.
- Coronary artery disease: There is a study suggesting a correlation between chromium levels and the risk of having a heart attack, with lower levels being associated with higher heart attack risk. That does not, of course, necessarily mean that taking chromium supplements will reduce the risk of a heart attack.
- Weight management: Despite all the advertisements, chromium supplements have not been shown to be effective in producing sustained weight loss.
There remains a possibility that some other form of chromium may be more effective on some of these parameters. There has recently been some interest in a product called Diachrome, that contains chromium and biotin. There have been several very interesting presentations about it at international meetings, but we need to see if the results pass peer review and replication.
A diet containing plenty of whole grains, nuts, broccoli, and green beans, should provide you with enough chromium. Chances are that taking a supplement will not cause harm and may perhaps help if you are at high risk of diabetes. But the evidence is still controversial.
I know of several other studies that are underway, and I shall report them to you as they appear.
But for now, when it comes to buying supplements, this is another one of those times that I say, “Caveat emptor!“
Dr. Richard G. Petty, MD is a world-renowned authority on the brain, and his revolutionary work on human energy systems has been acclaimed around the globe.
He is also an accredited specialist in internal and metabolic medicine, endocrinology, psychiatry, acupuncture and homeopathy. He has been an innovator and leader of the human potential movement for over thirty years and is also an active researcher, teacher, writer, professional speaker and broadcaster. He is the author of five books, including the groundbreaking and best selling CD series Healing, Meaning and Purpose. He has taught in over 45 countries and 48 states in the last ten years, but spends as much time as possible on his horse farm in Georgia.
