Vitamins are organic substances (made by plants or animals), minerals are inorganic elements that come from the soil and water and are absorbed by plants or eaten by animals. Your body needs larger amounts of some minerals, such as calcium, to grow and stay healthy. Other minerals like chromium, copper, iodine, iron, selenium, and zinc are called trace minerals because you only need very small amounts of them each day.
As many as 90% of American diets are low in chromium, but few people are deficient in this important mineral. The elderly, people who indulge in strenuous exercise, those who consume excessive amounts of sugary foods, and pregnant women are most likely to be deficient in chromium. Low chromium levels can increase blood sugar, triglycerides (a type of fat) and cholesterol levels and increase the risk for a number of conditions, including diabetes and heart disease.However,the benefit of chromium supplements for diabetes has been studied and debated for a number of years.
Chromium, one of the most common elements in the earth’s crust and seawater, exists in our environment in several oxidation states, principally as metallic (Cr0), trivalent (+3), and hexavalent (+6) chromium. The latter is largely synthesized by the oxidation of the more common and naturally occurring trivalent chromium and is highly toxic. Trivalent chromium, found in most foods and nutrient supplements, is an essential nutrient with very low toxicity.
Chromium is an essential mineral found in very low concentrations in the human body.researchers discovered that a compound extracted from pork kidney called "glucose tolerance factor (GTF)" helped diabetic rats use insulin more efficiently.It was believed that chromium helps insulin bring glucose from the blood into the cells for energy.
Chromium picolinate is very common nutritional supplement often marketed to individuals with diabetes. Research into supplementation with chromium picolinate has shown variable success in improving diabetic control. The dietary reference intake for chromium is 25 mcg/day. The average US diet contains 15 mcg /1000 Kcal. Chromium picolinate at doses in excess of 1000 mcg daily may positively influence diabetic control. Larger randomized trials are currently in process. However, relatively little data are available regarding side effects or long term toxicity of chromium. The hexavalent form is a known carcinogen although this effect has not been noted for chromium picolinate the trivalent form of chromium, further studies regarding safety are warranted.
Many foods which are rich in Non-starch polysaccharides [NSP] (especially soluble forms), such as pulses, have a low glycaemic index. Other carbohydrate-containing foods (e.g. certain types of pasta), which are not especially high in NSP, also have a low glycaemic index. Low glycaemic index foods, regardless of their NSP content, are not only associated with a reduced glycaemic response after ingestion when compared with foods of higher glycaemic index, but are also associated with an overall improvement in glycaemic control (as measured by haemoglobin A1c) in people with diabetes .
A low glycaemic index does not, however, per se, confer overall health benefits, since a high fat or fructose content of a food may also result in a reduced glycaemic index and such foods may also be energy-dense. Thus while this property of carbohydrate-containing foods may well influence the risk of developing type 2 diabetes, the evidence is accorded a lower level of strength than the evidence relating to the NSP content. Similarly, the level of evidence for the protective effect of n-3 fatty acids is regarded as “possible” because the results of epidemiological studies are inconsistent and the experimental data inconclusive. There is insufficient evidence to confirm or refute the suggestions that chromium, magnesium, vitamin E and moderate intakes of alcohol might protect against the development of type 2 diabetes.
Lack of chromium may lead to nerve problems and may decrease the body's ability to use sugar properly.The body needs chromium for normal growth and health. For patients who are unable to get enough chromium in their regular diet or who have a need for more chromium, chromium supplements may be necessary.There is not enough evidence to show that taking chromium supplements improves the way your body uses sugar (glucose tolerance).
Recently study suggested that chromium has also been demonstrated to inhibit phosphotyrosine phosphatase, the enzyme that cleaves phosphate from the insulin receptor, leading to decreases in insulin sensitivity. Activation of insulin receptor kinase and inhibition of insulin receptor phosphatase would lead to increased phosphorylation of the insulin receptor and increased insulin sensitivity . The balance between kinase and phosphatase activity may facilitate the role of insulin in rapidly moving glucose into cells. In addition, it has been suggested that chromium enhances insulin binding, insulin receptor number, insulin internalization, and ß-cell sensitivity.
Some commercial organizations promote chromium picolinate as an aid to body development for athletes and as a means of losing weight. But a number of studies have failed to demonstrate an effect of chromium picolinate on either muscle growth or fat loss.
The controversy surrounding chromium supplementation is due in part to substantial variability in the results of studies that have evaluated the effects of chromium in patients with or without diabetes. Results from some trials have indicated that chromium supplementation increases muscle gain and fat loss associated with exercise and improves glucose metabolism and the serum lipid profile in patients with or without diabetes. In contrast, those from other studies have indicated little or no benefit of chromium on any of these variables.
People with type 2 diabetes often take chromium supplements to help keep their blood sugar levels under control, but new findings from a Dutch study raise doubts about the value of this approach.
"In non-Western diabetic populations, there is some evidence that chromium might be beneficial," Dr. Nanno Kleefstra, told Reuters Health. "In Western populations ... it does not seem to help in the dosages used."
Kleefstra, from Isala Clinics in Zwolle, and colleagues investigated the effects of chromium in people with type 2 diabetes residing in a northern region of the Netherlands. Fifty-seven patients were randomly assigned to take 400 micrograms of chromium per day or a placebo.
After 3 and 6 months of treatment, there were no differences between the chromium group and the placebo group for fasting blood glucose levels, long-term control of glucose levels as measured by A1c, blood pressure, body fat percentage, weight, lipid profile, and how well they responded to the insulin their bodies produced, the investigators report in the medical journal Diabetes Care.
"Especially in Western patients, chromium is not beneficial for improving glycemic control," Kleefstra concluded, probably because most people already get sufficient amounts of chromium.
"It would be interesting to study a deficient population," Kleefstra added. To do so, "I think it is essential to get a tool with which we can detect whether patients are chromium-deficient or not."
Another data shawn that chromium may improve insulin sensitivity, which can modify the risk of diabetes and cardiovascular disease (CVD). Therefore, we evaluated the association between toenail chromium and CVD in diabetic men.
Despite widespread use by patients with diabetes and anecdotal reports in the past regarding its efficacy, until recently, data in humans concerning chromium’s effects on insulin action in vivo or on cellular aspects of insulin action were scarce. Consequently, significant controversy still exists regarding the effect of chromium supplementation on parameters assessing human health.
Furthermore, elucidating the cellular and molecular mechanisms by which chromium supplements affect carbohydrate metabolism in vivo is necessary before specific recommendations can be made regarding its routine use in the management of diabetes. This review focuses on providing current information about this trace mineral’s specific mechanisms of action and clinical trials in patients with diabetes.
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