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For humans, however, the evidence was not as clear until quite recently. In October, 1996 a study published in a peer-reviewed medical journal looked at 154 slightly overweight individuals split into three groups who were supplemented with either 200 mcg of chromium as the picolinate compound, 400 mcg of Chromium as the picolinate compound or a placebo.
Previously, some human studies had shown either no effect, an effect similar to that seen in animals (that is, reduction in fat and increase in muscle) or an effect in women but not in men. The main problem with these older studies was that they had looked at very few individuals sometimes as few as 12; so, while it appeared that chromium was having an effect on body composition, since there were so few persons involved in the studies we could not be absolutely certain.
Further, some of the prior studies looked at young athletes (such as college football players) who, because of their high degree of fitness upon entering the study would not, in all likelihood, make the best subjects in which to observe these changes.
This latest study examined average Americans in Texas who were given no special instructions in diet or exercise just the chromium at either dosage level or the placebo. The study was double-blind and randomized. What these researchers found after the 72 days of the study was a statistically significant difference in the chromium groups vs. the placebo group in change of body composition index (BCI, a sum of the loss in body fat plus the gain in muscle mass) loss of body fat and total weight loss.
The authors conclude:
These data suggest that supplementation with chromium picolinate can lead to significant improvements in body composition when a BCI [body composition index] is used as the outcome criterion that represents a sum of the net gains in nonfat mass added to the sum of the net losses of body fat.While the mechanism of action whereby Chromium has this apparent effect is not known, it is interesting to note that therapies for diabetes that increase insulin levels in the blood are associated with weight gain (insulin injections and sulfonylureas such as Diabinese and Micronase) while therapies that decrease insulin levels (such as Glucophage and the not-yet-released oral agent troglitazone) are associated with no weight gain or even weight loss. Since chromium supplementation has been associated with decreased insulin levels, it is tempting to speculate that it is through this effect (that is, decreasing insulin resistance with the attendant drop in circulating insulin) that chromium works in altering body composition.
Kaats GR, Blum K, Fisher JA and Adelman JA. Effects of chromium picolinate supplementation on body composition: A randomized, double-masked, placebo-controlled study. Current Therapeutic Research, 57(10):747-765, Oct. 1996
"In the majority of all chromium supplementation studies in the United States, at least half the subjects with impaired glucose tolerance improved upon chromium supplementation, suggesting that the lower ranges of chromium intake from typical U.S. diet are not optimal with regard to chromium nutriture."Few foods are rich sources of chromium in the Western diet, the best being organ meats, mushrooms, wheat germ, broccoli and processed meats. It is theorized that Stone Age people ingested more chromium than modern people because they regularly ate organ meats from the animals they hunted (which contained higher levels chromium as well as other trace elements).
RDA 10th Edition 1989
Not only did these early people likely have a higher chromium intake than modern ones, but perhaps more important than their higher intakes, it is most likely that they lost less chromium in their urine than we do. This is because Stone Agers did not ingest nearly as much simple sugars as modern people and simple sugar intake causes chromium to be lost in the urine. These ingested sugars (such as table sugar and products made with it) bring insulin and chromium into the blood and cause chromium to be excreted in the urine after it's through working with the insulin on the increase in blood sugar.
We Americans consume an average of 120 pounds of sugar per year from all sources. Thus, we can conclude that for hundreds of thousands of years of human evolution, our ancestors most likely took in more and lost less of this essential trace element than modern Americans.
Another interesting fact demonstrated in large numbers of people both in the U.S. and the U.K.--is that Chromium tissue levels in humans decrease over our lifetimes. In fact, the highest tissue levels of chromium are found in newborns: they get chromium in the womb across the placenta from their mothers. There is also evidence that pregnancy depletes a woman's chromium stores, which may be one reason that as a total population our bodies show loss of chromium as we age. Contact I-Supplements for Additional Information on this Article.
From this evidence inadequate chromium intake, increased chromium losses, decreasing chromium tissue levels as we age, improvement in blood sugar in significant numbers of diabetics and pre-diabetics with modest chromium supplementation and widespread insulin resistance (25% of Americans have some degree of insulin resistance, though only a portion of this insulin malfunction appears to be due to chromium deficiency) experts in chromium nutrition urge supplementation with small amounts of this trace element on a daily basis.
These experts feel that chromium supplementation for diabetics should take its place alongside the two other proven ways of decreasing insulin resistance: low-fat, high complex-carbohydrate diets for weight loss/weight maintenance and regular exercise.
On March 14, 1996, a safety study conducted by the U. S. Department of Agriculture was presented at the Society of Toxicology's annual meeting. This study looked at various supplemental doses (including none) of chromium chloride and chromium picolinate fed to rats for 6 months, The highest doses were equal to a human consuming 5,000 tablets of 200 micrograms chromium picolinate. At regular intervals during the study the rats were weighed and blood was taken for laboratory tests.
At the end of the study the livers and kidneys (organs that would have the highest tissue levels of chromium) were examined under the microscope. There were no differences in any of the measurements or examinations between the various groups. The investigators were unaware ("blinded") as to which group the animals were in when the measurements and evaluations were performed. powerhouse-supplements.com
The safety issue had been raised by a study published in December, 1995 which attempted to link chromosomal damage in the test tube to oral supplementation of chromium picolinate. These researchers used cultured Chinese hamster ovarian cancer cells to which they directly added unnaturally high amounts of chromium compounds, including chromium picolinate. Some of these cells showed chromosomal damage (clastogenic effects).
This was not particularly surprising, since this concentration directly applied to these cells in a test tube was 3,000 times the blood level of people who are ingesting chromium picolinate as supplements!
Very few essential minerals tested in this way would be found to be without toxicity; for example, merely doubling the blood concentration of the mineral calcium is fatal to humans. When tested by the Ames test (a specific test for mutagenicity) for cancer-causing potential, chromium picolinate was proven negative.
Again, the standard medical reference on nutrition:
"Trivalent chromium has such a low order of toxicity that deleterious effects from excessive intake of this form of Chromium do not occur readily. Trivalent chromium becomes toxic only at extremely high amounts.- chromium then acts as a gastric irritant rather than as a toxic element interfering with essential metabolism or biochemistry."
Modern Nutrition In Health and Disease, Eighth Ed., 1994. Shils, Olson and Shike, eds.
Although some of the above is speculative, it would seem prudent for Americans to supplement their diets with small amounts of trivalent chromium (for example, 200 mcg of chromium picolinate) since the benefits of supplementation may be significant for certain individuals and the safety of this regimen is well-supported by a large amount of data.
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