Play it safe with chromium
While chromium supplements have gained fame lately, food remains the best and safest source of the trace element found in brewer's yeast, mushrooms, prunes and nuts
By Susan Biali
The first time I heard of chromium as a treatment for diabetes was years ago, at a health fair here in Vancouver. As they were using the "c-word"—cure—in association with their claims, I pretty much ignored the whole thing. Still, it stuck in my head, and over the years I've seen more and more press about chromium's benefits from more reputable sources. I decided to do further research on it after a diabetic patient told me she'd do anything to get Health Canada to allow chromium picolinate back onto health food store shelves, as her blood sugar readings had been "fantastic" when she was taking it as a daily supplement.
Chromium is a trace element, long known for its ability to potentiate insulin action. Chromium III, the trivalent form, is the most stable state and is the form found in food. It's distributed widely across our food supply, though most foods provide less than 2 mcg. Brewer's yeast is the most concentrated source; mushrooms, prunes, nuts, asparagus, wine and beer also contain significant amounts.
The 2002 American Dietary Reference Intakes recommend 35 mcg per day for adult men, and 25 mcg per day for women. Other sources recommend from 50 mcg to 200 mcg per day, and those who recommend supplementation may go as high as 1,000 mcg. The average North American diet provides 15 mcg per 1,000 calories. Diets high in sugar and refined flour increase chromium excretion, and some medications such as antacids can limit its absorption.
Some researchers and promoters of supplementation have postulated there is a high prevalence of chromium deficiency in North Americans, which may account for the high prevalence of diabetes and the beneficial effects of chromium supplementation on blood sugar. Unfortunately this has never been proven, as body chromium levels are difficult to determine, and the majority of studies have not even attempted to quantify this in their subjects.
Most of the research to date has been done using chromium picolinate, the form which is the most easily absorbed. You can't buy it here in Canada, though it's still available in the U.S. (and presumably carted by some patients across the border). Other forms include polynicotinate and chloride. The hazards of supplemental chromium seem to be limited to the picolinate form: There have been two case reports of chronic interstitial nephritis in those taking supplements, and a 1996 study from Dartmouth College showed chromium picolinate damaged the DNA of hamster cells, raising concerns about possible carcinogenic effects.
Dr. John Vincent (PhD), a chemistry professor at the University of Alabama, reported that chromium picolinate enters cells and reacts with antioxidants to produce a reduced form that can cause DNA mutations. According to the University of California at Berkeley's Wellness Letter, England's Food Standards Agency warned consumers last May not to take chromium picolinate as it could potentially cause cancer.
So why do many people still want to take it? All kinds of claims abound, promising weight loss, fat-burning, increased lean muscle mass, decreased cholesterol and glycemic control. I couldn't find any proof for the first three, and effects on cholesterol are iffy but possible, requiring further research.
The evidence for chromium's effects on blood sugar is pretty strong. A study published in the November 1997 issue of Diabetes showed subjects with type II diabetes had significant improvement in Hemoglobin A1c after two months of 1,000 mcg of chromium picolinate per day, with an associated decrease in total plasma cholesterol as well.
A 1995 study in Diabetes Research and Clinical Practice looked at the effect of supplementation in healthy young adults; those with initially elevated fasting insulin levels had significant decreases in insulin after daily supplementation with 220 mcg of chromium nicotinate. Chromium might even help with reactive (a.k.a. functional) hypoglycemia: Joseph Pizzorno's Textbook of Natural Medicine refers to a study that claimed eight women given 200 mcg of chromium a day for three months reported "alleviation" of their symptoms.
As for the evidence on lipids, a study in the 1990 Western Journal of Medicine reported 200 mcg per day of chromium picolinate increased cholesterol by 7% and low-density lipoprotein by 11%, while increasing high-density lipoprotein by 5.7%. A randomized controlled trial in the 1991 Annals of Internal Medicine demonstrated 600 mcg per day for eight weeks increased HDL by 16%. Niacin and chromium reportedly act synergistically to lower blood glucose. But before you go trying this one as a catch-all treatment for diabetic patients with increased lipids, remember niacin can also act to increase insulin resistance. Sigh.
So what's the bottom line? Thanks to the other "c-word"—carcinogen—I think I and my patients should stay away from chromium picolinate, at least until we know more. And unfortunately, we don't really know much about the other less studied, but locally available, forms. I'd love to be able to recommend them some day, once it's established they are safe and have the same benefits as picolinate. But for now I'm going to stick with the Berkeley Wellness Letter's conclusion: "The best and safest form of chromium is food."
Source:
http://www.medicalpost.com/mpcontent...23_142536_4632
Article: Play It Safe With Chromium 
