Chromium is an essential trace mineral for the human body. It’s important in processing carbohydrates and fats, and it helps cells respond properly to insulin.
The best food sources of chromium are meats and whole-grain products, while fruits, vegetables and milk have very low quantities of this substance. Although many studies have been performed in order to explain the way Chromium acts in the body, or whether it can be an aid to lose fat since its function are in some way related to metabolism, this subject is still unclear.
A reliable scientific study has been performed in School of Public Health, Harbin Medical University in China. The objective was to study the effects of chromium on the level of leptin and insulin in obese rats.
Binding of leptin to Ventral Medial nucleus of the hypothalamus signals to the brain that the body has had enough to eat – a sensation of satiety. Taking into a count this correlation of leptin concentrations with percentage of body fat, the hoped result should be an increase of this substance after the intake of Chromium (Some suggest Chromium Picolinate, others chromium polynicotinate, or also known as chromium nicotinate). However, in general, obese people have an unusually high circulating concentration of leptin, which leads to the theory that they are resistant to the effects of leptin, in much the same way that people with type 2 diabetes are resistant to the effects of insulin. Aparently, the high sustained concentrations of leptin from the enlarged fat stores result in the cells that respond to leptin becoming desensitised.
As the experiment was performed over 32 obese model rats, the positive result was an increase in their leptin levels. So the rats were divided randomly into four groups, from which we will just compare the one who was given chromium (3 mg/kg bw), with the high fat diet one.
After six weeks, fats around kidney and spermary were weighted and blood samples were collected to determine the level leptin and insulin. According to the results, the level of leptin and insulin in experimental group were lower than those in high fat diet group, as well as the ratios of fats around kidney and/or around spermary to body weight.
Regarding chromium picolinate – combination of chromium with picolinic, which aids in its absorption – its action over humans, results of a double-blind, placebo controlled clinical study published some years ago on the Current Therapeutic Research show that chromium aids in the loss of body fat, improving body composition, determined by the ratio of fat-free mass versus the amount of fatty tissue in the body. However, the dosage given to all patients were of 400 micrograms per day, which exceeds the “safe and adequate intake”, according to the United States Recommended Daily Allowances (USRDA) committee.
Although its ingestion in supplement form does not seem to imply major problems in the short term, the effects of its long-term use are a concern for some experts. According to a study published in the Federation of American Societies for Experimental Biology, daily ingestions of chromium supplements of 600 micrograms for five years may lead to an accumulation of this substance in tissues, which is apparently related to chromosome damage. However, it is worth to make clear that once again, this has been not proved over humans, since the study was performed over hamster ovary cells.
Regarding chromium in its natural form, a diet rich in whole-grain breads – the less processed grain, the more chromium levels – and cereals should provide enough amounts. However, if a supplement is chosen, the usual advisable maximum per day is 50-200 micrograms, while the FDA to recommend a daily intake of approximately 130 mcg, as infinitesimal amounts of chromium are needed to aid the transport of blood glucose across cell membranes.
At the moment, the use of chromium supplements is related to some controversy, since some sources claim it is a reliable aid to fat loss while some others claim just the opposite. It seems like all kinds of trials have been performed in order to support one theory or the other, though the most reliable ones are those performed on rats, since they come from a well-recognized source. Although this study may give a good perspective about chromium actions in humans, it is obvious that there is still some more serious research to do.