by Thomas Incledon, PhD(c), RD, LD/LN, RPT, NSCA-CPT, CSCS
The wonder supplement of the nineties, touted to increase muscle and decrease fat, now has warnings of being damaging to DNA, our very own life imprint. Why has Chromium Picolinate (CrP) gone from the media darling to the doghouse? Let’s get picky with CrP and unearth all there is to know about this interesting supplement. We will focus on the research performed on healthy people, not diabetics. The use of supplements for diabetics will be addressed in a future article. Of course, this article is not intended to replace the advice of your medical professional.
Chromium (Cr) works in the body by increasing the ability of insulin to bind to cells. Cr can be incorporated into a protein called glucose tolerance factor (GTF). GTF attaches to the insulin receptor (IR) on the surface of cells and helps insulin bind to the IR. Once insulin binds to a cell, it opens a “doorway” for glucose, amino acids, and fatty acids to enter the cell. With low levels of insulin, most of these nutrients go to muscle cells. With high levels of insulin, these nutrients can enter fat cells, as well. Chromium allows insulin to do a more efficient job of getting nutrients into muscle cells, so less insulin is needed. Since fat cells are not fed nutrients, they shrink. Most people have enough Cr, so giving them more serves no purpose. The idea behind CrP is to give more Cr to people who have low Cr stores in an attempt to manage insulin and reduce body fat.
While people are concerned with CrP’s ability to favorably change body composition, most don’t know that it can decrease the risk of cardiovascular disease. 200 micrograms (mcg) of CrP was given to 28 volunteer subjects for 42 days. After 42 days of CrP, low-density lipoprotein cholesterol (LDL-C) and apolipoprotein B (apo-B) levels decreased, while apolipoprotein A-I (apo-A1) levels increased. LDL-C and apo-B are the “bad guys,” and apo-A1 is one of the “good guys,” in terms of risks for cardiovascular disease. The fact that CrP decreased the negative risk factors and improved the positive risk factor is a very important point. If you try CrP to see if it lowers your blood lipids, get your blood work before you take it, and stay on it for at least 30 days before getting blood work done again. That way you’ll know if it works for you.
Effects on Lean Body Mass
Chromium ads still bombard local newspapers with promises of more muscle and less fat. Are these claims supported by research or are they just more supplement hype? In one study using 59 students divided into four groups (males placebo and females placebo, males CrP and females CrP). The treatment groups took 200 mcg of CrP each day (200 mcg/d) for 12 weeks. The CrP increased body weight (BW) significantly for the women, but not the men. This BW increase was fat, however, and not muscle. Another study gave 200 mcg/d for 9 weeks to college football players. CrP supplementation had no effects on body composition or strength. A third study examined the effects of CrP on 36 men lifting weights. After 8 weeks, no effects of CrP were found on body composition or strength. More recently, another study on women also found that CrP increased BW in the form of body fat, while another form of chromium, chromium nicotinate, reduced BW in women. Based on the research it appears that for healthy, active people, CrP does not increase lean body mass or decrease body fat. In addition, studies have shown that women taking CrP actually gained weight in the form of fat, not muscle. This is definitely the opposite of what people want and advertisements claim.
Effects on Weight Loss
So far CrP hasn’t held up its end of the bargain with building muscle. Its other claim that it helps get rid of body fat is slowly getting chiseled down, too. None of the studies above showed decreased body fat from CrP use. A study done on Navy personnel examined the effects of 400 mcg/d of CrP on 79 men and 16 women for 16 weeks. The researchers concluded that CrP was ineffective in enhancing body fat reduction. Another study done for 16 months, compared 50 g of carbohydrates (CHO) with 200 mcg CrP, 100 mg caffeine, and 20 g fiber versus 50 g CHO and a placebo for female subjects on very low calories diets. The CrP, fiber, and caffeine group did not lose more weight than the control group, so even after all those supplements, no significant changes in body composition occurred. There is one German study where 200 mcg/d CrP was found to increase lean body mass and reduce fat after 26 weeks. Overall, though, CrP’s claim of decreasing body fat is weak.
Side Effects
While CRP is sold over the counter and you don’t need a prescription, that doesn’t mean it can’t be misused or abused. Based on evidence from animal and cell studies, chromium can accumulate in your body and increase tissue concentrations high enough to damage DNA. Long-term use of CrP concerns nutrition professionals because there is still much to be learned about CrP. In a review of the scientific literature, we came across several case studies that discuss side effects of CrP supplementation. In one case, a 49 year-old female nurse developed renal failure after taking 600 mcg of CrP/d for 6 weeks. A renal biopsy led to a diagnosis of chromium-induced nephrotoxicity, although nonspecific, consistent with chronic interstitial nephritis from heavy-metal exposure. In another case, a 33 year old woman ingested 1200-2400 mcg CrP/d for 4-5 months to lose weight. She developed renal and liver problems. She had a blood transfusion and underwent dialysis to get rid of the Cr in her blood. After 6 days her liver function returned to normal and after 12 days her kidneys were back to normal. Another report involved a 24 year-old bodybuilder taking 1200 mcg/d of CrP over 48 hours and developing rhabdomyolysis. Rhabdomyolysis is severe damage to skeletal muscle, resulting in the release of the muscle cell contents into plasma. These case studies were not presented to scare or intimidate you. Rather they serve as guideline for the safe use of CrP.
Getting Picky
Some people may have low levels of chromium due to a poor diet or an excessive loss of chromium from exercise. But chromium is easily replenished by eating foods such as mushrooms, nuts, meats, liver, asparagus, wine, beer, whole grains, cheese, and prunes. There may be some support for CrP supplementation for people with low levels of chromium and/or impaired GTF proteins. However, you won’t know if this applies to you unless you have your Cr levels checked. .However, if you are eating the foods mentioned above, your Cr levels should be adequate. While the current evidence for healthy and mildly obese people does not support CrP use, many will still want to try it out. If that is your decision, use caution and do not exceed dosages greater than 400-600 mcg/d in order to minimize potential side effects.
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