Chromium(III) picolinate
Encyclopedia
Chromium picolinate is the chemical compound
that is sold as a nutritional supplement to prevent or treat chromium deficiency
. This bright-red coordination complex is derived from chromium
(III) and picolinic acid
. Small quantities of chromium are needed for glucose
utilization by insulin
in normal health, but deficiency is extremely rare and has only been observed in hospital patients on long-term defined diets. No biochemical basis for the human body's need for chromium has been identified.
. A larger follow-up trial failed to reproduce this effect, but indicated that the use of chromium picolinate could help to reduce carbohydrate cravings and regulate appetite in these patients. A post-hoc analysis
of a subpopulation of patients in this study that experienced high carbohydrate cravings suggested that patients treated with chromium picolinate experienced significant improvements in their depression (as measured by the 29-item Hamilton Depression Rating Scale
) compared to those treated with a placebo
. A more recent study focused on the effects of chromium picolinate supplementation on food intake and satiety. It indicated that chromium supplementation led to reduced cravings for fat, not carbohydrates.
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.
There are claims that the picolinate form of chromium supplementation aids in reducing insulin resistance
, particularly in diabetics, but a meta-analysis
of chromium supplementation studies showed no association between chromium and glucose or insulin concentrations for non-diabetics, and inconclusive results for diabetics. This study has been challenged on the grounds that it excluded significant results. Subsequent trials gave mixed results, with one finding no effect in people with impaired glucose tolerance, but another seeing a small improvement in glucose resistance. A further study on obese adults with metabolic syndrome
, was published in 2009, this found no significant effect on insulin sensitivity, but increased short-term levels of insulin. The study also observed no effect on weight or serum lipids.
In a review of these trials it was again concluded that chromium supplements had no effect on healthy people, but that there might be an improvement in glucose metabolism in diabetics, although the authors stated that the evidence for this effect remains weak. However, opinions differ on this conclusion, a review published in 2006 argued that these data instead supported the clinical efficacy of chromium picolinate for the treatment of diabetes. In 2006, the U.S. Food and Drug Administration stated that the "relationship between chromium picolinate intake and insulin resistance is highly uncertain".
Initial concerns were raised that chromium picolinate is more likely to cause DNA damage and mutation
than other forms of trivalent
chromium, but these results are also debated. These concerns were based, in part, on studies in fruit flies, where chromium(III) picolinate supplementation generates chromosomal aberrations, impedes progeny development, and causes sterility and lethal mutations. However, other studies indicate that chromium picolinate is safe even at very high doses. [This statement is not supported by its reference] In mice, one study observed that chromium(III) picolinate supplementation caused skeletal defects in their offspring. However, a two-year study of the long-term effects of this supplement in rats and mice found no effects on overall survival, or on the animal's body weight and food consumption, the authors of this review also found no toxicity beyond an increase in preputial gland adenoma which was tentatively considered equivocal.
that might have been caused by this supplement and called for further research into its safety. In December 2004, the Committee on Mutagenicity published its findings, which concluded that "overall it can be concluded that the balance of the data suggest that chromium picolinate should be regarded as not being mutagenic in vitro" and that "the available in-vivo tests in mammals with chromium picolinate are negative.". Following these findings, the UK Food Standards Agency withdrew its advice to avoid chromium picolinate, though it plans to keep its advice about chromium supplements under review.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
that is sold as a nutritional supplement to prevent or treat chromium deficiency
Chromium deficiency
Chromium deficiency is a disorder that results from an insufficient dietary intake of chromium. Whether or not such a deficiency ever occurs in people eating a normal diet is debated, and clear cases of deficiency have only been observed in hospital patients who were fed defined liquid diets...
. This bright-red coordination complex is derived from chromium
Chromium
Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...
(III) and picolinic acid
Picolinic acid
Picolinic acid is a pyridine compound with a carboxyl side chain at the 2-position. It is an isomer of nicotinic acid, which has the carboxyl side chain at the 3-position. It is a catabolite of the amino acid tryptophan.- Chelating properties :...
. Small quantities of chromium are needed for glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
utilization by insulin
Insulin
Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
in normal health, but deficiency is extremely rare and has only been observed in hospital patients on long-term defined diets. No biochemical basis for the human body's need for chromium has been identified.
Health claims and debates
A pilot trial of 15 patients suggested that chromium picolinate might have antidepressant effects in atypical depressionAtypical depression
Atypical depression is a subtype of dysthymia and major depression, sharing many of the symptoms of both, but also being characterized by mood reactivity—being able to experience improved mood in response to positive events. In contrast, sufferers of "melancholic" depression generally cannot...
. A larger follow-up trial failed to reproduce this effect, but indicated that the use of chromium picolinate could help to reduce carbohydrate cravings and regulate appetite in these patients. A post-hoc analysis
Post-hoc analysis
Post-hoc analysis , in the context of design and analysis of experiments, refers to looking at the data—after the experiment has concluded—for patterns that were not specified a priori. It is sometimes called by critics data dredging to evoke the sense that the more one looks the more likely...
of a subpopulation of patients in this study that experienced high carbohydrate cravings suggested that patients treated with chromium picolinate experienced significant improvements in their depression (as measured by the 29-item Hamilton Depression Rating Scale
Hamilton Depression Rating Scale
The Hamilton Rating Scale for Depression , also known as the Hamilton Depression Rating Scale or abbreviated to HAM-D, is a multiple choice questionnaire that clinicians may use to rate the severity of a patient's major depression. Max Hamilton originally published the scale in 1960 and reviewed...
) compared to those treated with a placebo
Placebo
A placebo is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient...
. A more recent study focused on the effects of chromium picolinate supplementation on food intake and satiety. It indicated that chromium supplementation led to reduced cravings for fat, not carbohydrates.
Some commercial organizations promote chromium picolinate as an aid to body development for athletes and as a means of losing weight
Weight loss
Weight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...
. But a number of studies have failed to demonstrate an effect of chromium picolinate on either muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
growth or fat
Adipose tissue
In histology, adipose tissue or body fat or fat depot or just fat is loose connective tissue composed of adipocytes. It is technically composed of roughly only 80% fat; fat in its solitary state exists in the liver and muscles. Adipose tissue is derived from lipoblasts...
loss.
There are claims that the picolinate form of chromium supplementation aids in reducing insulin resistance
Insulin resistance
Insulin resistance is a physiological condition where the natural hormone insulin becomes less effective at lowering blood sugars. The resulting increase in blood glucose may raise levels outside the normal range and cause adverse health effects, depending on dietary conditions. Certain cell types...
, particularly in diabetics, but a meta-analysis
Meta-analysis
In statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses. In its simplest form, this is normally by identification of a common measure of effect size, for which a weighted average might be the output of a meta-analyses. Here the...
of chromium supplementation studies showed no association between chromium and glucose or insulin concentrations for non-diabetics, and inconclusive results for diabetics. This study has been challenged on the grounds that it excluded significant results. Subsequent trials gave mixed results, with one finding no effect in people with impaired glucose tolerance, but another seeing a small improvement in glucose resistance. A further study on obese adults with metabolic syndrome
Metabolic syndrome
Metabolic syndrome is a combination of medical disorders that, when occurring together, increase the risk of developing cardiovascular disease and diabetes. It affects one in five people in the United States and prevalence increases with age...
, was published in 2009, this found no significant effect on insulin sensitivity, but increased short-term levels of insulin. The study also observed no effect on weight or serum lipids.
In a review of these trials it was again concluded that chromium supplements had no effect on healthy people, but that there might be an improvement in glucose metabolism in diabetics, although the authors stated that the evidence for this effect remains weak. However, opinions differ on this conclusion, a review published in 2006 argued that these data instead supported the clinical efficacy of chromium picolinate for the treatment of diabetes. In 2006, the U.S. Food and Drug Administration stated that the "relationship between chromium picolinate intake and insulin resistance is highly uncertain".
Initial concerns were raised that chromium picolinate is more likely to cause DNA damage and mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...
than other forms of trivalent
Valence (chemistry)
In chemistry, valence, also known as valency or valence number, is a measure of the number of bonds formed by an atom of a given element. "Valence" can be defined as the number of valence bonds...
chromium, but these results are also debated. These concerns were based, in part, on studies in fruit flies, where chromium(III) picolinate supplementation generates chromosomal aberrations, impedes progeny development, and causes sterility and lethal mutations. However, other studies indicate that chromium picolinate is safe even at very high doses. [This statement is not supported by its reference] In mice, one study observed that chromium(III) picolinate supplementation caused skeletal defects in their offspring. However, a two-year study of the long-term effects of this supplement in rats and mice found no effects on overall survival, or on the animal's body weight and food consumption, the authors of this review also found no toxicity beyond an increase in preputial gland adenoma which was tentatively considered equivocal.
Regulation
In 2003, the UK Food Standards Agency advised consumers to use other forms of trivalent chromium in preference to chromium picolinate until specialist advice was received from the Committee on Mutagenicity. This was due to concerns about if chromium picolinate might cause cancer (its genotoxicity) raised by the Expert Group on Vitamins and Minerals: the committee also noted two case reports of renal failureRenal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...
that might have been caused by this supplement and called for further research into its safety. In December 2004, the Committee on Mutagenicity published its findings, which concluded that "overall it can be concluded that the balance of the data suggest that chromium picolinate should be regarded as not being mutagenic in vitro" and that "the available in-vivo tests in mammals with chromium picolinate are negative.". Following these findings, the UK Food Standards Agency withdrew its advice to avoid chromium picolinate, though it plans to keep its advice about chromium supplements under review.