Insulin is a hormone synthesized in the beta cells of the pancreas. It acts primarily as a storage hormone for both carbohydrates and fat. In fact, it’s a primary promoter of fat synthesis, stimulating fat-cell enzymes that produce fat. Insulin also helps the body convert carbohydrates into glycogen, the storage form of carbs in liver and muscle. As an anabolic hormone, insulin promotes amino acid entry into muscle and may be anticatabolic in that it may help prevent excess muscle breakdown.
Since insulin is involved in the synthesis of bodyfat, the reasoning is that chromium supplements would help insulin work better, decreasing insulin output and thereby promoting fat loss. For that reason chromium is an ingredient in many fat-loss food supplements.
A new study did a meta-analysis of 10 randomized, double-blind controlled studies regarding chromium’s effect on weight loss.1 Careful analysis of those studies showed that chromium picolinate supplements did produce a modest increase in weight loss. The effect was so modest, however, that the authors think that it’s of “dubious clinical relevance.” In simple English they’re saying that the results are too ambiguous to make any definite conclusions about the effectiveness of chromium for weight-loss purposes.
Chromium supplements are available in various forms, primarily as chromium picolinate and chromium polynicotinate, each of which has vociferous proponents. Proponents of the polynicotinate form point to research showing possible toxicity problems related to the picolinate form. On the other hand, polynicotinate advocates claim that their form of chromium is more natural and less likely to promote toxicity.
A recently published case history suggests that one woman who used the polynicotinate form of chromium developed toxic hepatitis, a liver inflammation usually caused by ingesting a substance toxic to the liver.2 Oral anabolic steroids can cause that type of hepatitis, as can many other drugs. The 33-year-old woman discussed in the case study showed such symptoms as nausea, fatigue, itchy skin, dark urine and jaundice, which she had for a week before showing up at a clinic.
For five months the woman had followed a weight-loss regimen that included chromium polynicotinate and various herbal extracts. The herbal extracts were ruled out as a possible cause of her liver problem, but a biopsy of her liver showed chromium levels 10 times higher than normal, pointing to her chromium intake as the primary cause.
What’s curious about the case is that the dose of chromium she took for five months was only 200 micrograms. The suggested dietary range is 50 to 200 micrograms daily, so she was well within the safety margin for chromium. In addition, the body only absorbs 1 to 25 percent of any form of chromium taken by mouth, so it’s hard to understand how so much of the mineral could build up in her liver.
Further obfuscating the issue is the fact that countless other people take the same amount of chromium each day for longer than five months yet show no signs of hepatitis. This woman likely had what physicians call an idiosyncratic, or rare, reaction. The case does not in any way implicate chromium in liver problems—or any other problems, for that matter.
The authors of this toxicity case study apparently were not aware of animal studies showing that at least one of the herbs this woman took in conjunction with the chromium does, in fact, have the potential to cause toxic effects in the liver. As for the buildup of chromium in her liver, that was also predictable. Studies done with animals show that liver stores of the mineral increase to levels 10 times above normal after six weeks of continuous supplementation. A study of humans taking chromium supplements likewise showed that after three months’ supplementation chromium stores increased considerably in the liver but caused no apparent problems.
One way to assess any effect of chromium on the liver is to see if the liver stores of chromium drop rapidly following the discontinuation of chromium supplements, but that wasn’t reported in the toxicity study. What it all adds up to is the likelihood that chromium was unjustly blamed as the cause of the subject’s liver problems.
References
2 Lanca, S., et al. (2002). Chromium-induced toxic hepatitis. Eur J Internal Med. 13:518-520.
©,2013 Jerry Brainum. Any reprinting in any type of media, including electronic and foreign is expressly prohibited.
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