Watch glass holds two grams of pure chromium (III) picolinate powder manufactured by NUTRITION 21 as "Chromax II." It is a reddish crystalline powder, 12.5% Cr(III) by weight, very sparingly soluble in water.
Chromium(III) picolinate is a chemical compound sold as a nutritional supplement to prevent or treat chromium deficiency. Another is chromium polynicotinate, and six forms of Chromium are sold for this purpose. This bright-red coordination compound 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. Chromium(III) picolinate has been described as a "poor choice as a nutritional supplement".
Health claims and debates
A pilot trial of 15 patients suggested that chromium picolinate might have antidepressant effects in atypical depression. 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. 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.
In 2004, 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 failure 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.
- ^ Preuss, H. G.; Echard, B.; Perricone, N. V.; Bagchi, D.; Yasmin, T.; Stohs, S. J. (2008). "Comparing metabolic effects of six different commercial trivalent chromium compounds". Journal of Inorganic Biochemistry 102 (11): 1986–1990. doi:10.1016/j.jinorgbio.2008.07.012. PMID 18774175.
- ^ Review of Chromium Expert Group on Vitamins and Minerals Review of Chromium, 12 August 2002
- ^ Stearns DM (2000). "Is chromium a trace essential metal?". Biofactors 11 (3): 149–62. doi:10.1002/biof.5520110301. PMID 10875302.
- ^ John B. Vincent "Chromium: celebrating 50 years as an essential element?" Dalton Transactions, 2010, pp. 3787-3794. doi:10.1039/B920480F
- ^ Davidson JR, Abraham K, Connor KM, McLeod MN (2003). "Effectiveness of chromium in atypical depression: a placebo-controlled trial". Biological Psychiatry 53 (3): 261–264. doi:10.1016/S0006-3223(02)01500-7. PMID 12559660.
- ^ Docherty JP, Sack DA, Roffman M, Finch M, Komorowski JR (September 2005). "A double-blind, placebo-controlled, exploratory trial of chromium picolinate in atypical depression: effect on carbohydrate craving". J Psychiatr Pract 11 (5): 302–14. doi:10.1097/00131746-200509000-00004. PMID 16184071.
- ^ Anton SD, Morrison CD, Cefalu WT et al. (October 2008). "Effects of Chromium Picolinate on Food Intake and Satiety". Diabetes Technol. Ther. 10 (5): 405–12. doi:10.1089/dia.2007.0292. PMC 2753428. PMID 18715218. //www.ncbi.nlm.nih.gov/pmc/articles/PMC2753428/.
- ^ Vincent J.B.; Sack, DA; Roffman, M; Finch, M; Komorowski, JR (2003). "The potential value and toxicity of chromium picolinate as a nutritional supplement, weight loss agent and muscle development agent". Sports Medicine 33 (3): 213–230. doi:10.2165/00007256-200333030-00004. PMID 12656641.
- ^ Althuis MD, Jordan NE, Ludington EA, Wittes JT (1 July 2002). "Glucose and insulin responses to dietary chromium supplements: a meta-analysis". American Journal of Clinical Nutrition 76 (1): 148–155. PMID 12081828. http://www.ajcn.org/cgi/content/full/76/1/148.
- ^ Kalman DS (1 July 2003). "Chromium picolinate and type 2 diabetes". American Journal of Clinical Nutrition 78 (1): 192; author reply 192–3. PMID 12816793. http://www.ajcn.org/cgi/content/full/78/1/192.
- ^ Gunton JE, Cheung NW, Hitchman R et al. (2005). "Chromium supplementation does not improve glucose tolerance, insulin sensitivity, or lipid profile: a randomized, placebo-controlled, double-blind trial of supplementation in subjects with impaired glucose tolerance". Diabetes Care 28 (3): 712–3. doi:10.2337/diacare.28.3.712. PMID 15735214. http://care.diabetesjournals.org/cgi/pmidlookup?view=long&pmid=15735214.
- ^ Singer GM, Geohas J (2006). "The effect of chromium picolinate and biotin supplementation on glycemic control in poorly controlled patients with type 2 diabetes mellitus: a placebo-controlled, double-blinded, randomized trial". Diabetes Technol. Ther. 8 (6): 636–43. doi:10.1089/dia.2006.8.636. PMID 17109595.
- ^ Iqbal N, Cardillo S, Volger S et al. (January 2009). "Chromium Picolinate Does Not Improve Key Features of Metabolic Syndrome in Obese Nondiabetic Adults". Metab Syndr Relat Disord 7 (2): 143–50. doi:10.1089/met.2008.0048. PMC 3135886. PMID 19196082. //www.ncbi.nlm.nih.gov/pmc/articles/PMC3135886/.
- ^ Balk EM, Tatsioni A, Lichtenstein AH, Lau J, Pittas AG (2007). "Effect of chromium supplementation on glucose metabolism and lipids: a systematic review of randomized controlled trials". Diabetes Care 30 (8): 2154–63. doi:10.2337/dc06-0996. PMID 17519436. http://care.diabetesjournals.org/cgi/pmidlookup?view=long&pmid=17519436.
- ^ Broadhurst CL, Domenico P (December 2006). "Clinical studies on chromium picolinate supplementation in diabetes mellitus--a review". Diabetes Technol. Ther. 8 (6): 677–87. doi:10.1089/dia.2006.8.677. PMID 17109600.
- ^ Trumbo PR, Ellwood KC (August 2006). "Chromium picolinate intake and risk of type 2 diabetes: an evidence-based review by the United States Food and Drug Administration". Nutr. Rev. 64 (8): 357–63. doi:10.1111/j.1753-4887.2006.tb00220.x. PMID 16958312.
- ^ Chaudhary S, Pinkston J, Rabile MM, Van Horn JD (2005). "Unusual reactivity in a commercial chromium supplement compared to baseline DNA cleavage with synthetic chromium complexes". Journal of Inorganic Biochemistry 99 (3): 787–794. doi:10.1016/j.jinorgbio.2004.12.009. PMID 15708800.
- ^ Hininger I, Benaraba R, Osman M, Faure H, Marie Roussel A, Anderson RA (2007). "Safety of trivalent chromium complexes: no evidence for DNA damage in human HaCaT keratinocytes". Free Radic. Biol. Med. 42 (12): 1759–65. doi:10.1016/j.freeradbiomed.2007.02.034. PMID 17512455.
- ^ Stallings DM, Hepburn DD, Hannah M, Vincent JB, O'Donnell J (2006). "Nutritional supplement chromium picolinate generates chromosomal aberrations and impedes progeny development in Drosophila melanogaster". Mutat. Res. 610 (1–2): 101–13. doi:10.1016/j.mrgentox.2006.06.019. PMID 16887379.
- ^ Hepburn DD, Xiao J, Bindom S, Vincent JB, O'Donnell J (2003). "Nutritional supplement chromium picolinate causes sterility and lethal mutations in Drosophila melanogaster". Proc. Natl. Acad. Sci. U.S.A. 100 (7): 3766–71. doi:10.1073/pnas.0636646100. PMC 152996. PMID 12649323. //www.ncbi.nlm.nih.gov/pmc/articles/PMC152996/.
- ^ Anderson R, Cheng N, Bryden N et al. (1997). "Elevated intakes of supplemental chromium improve glucose and insulin variables in individuals with type 2 diabetes". Diabetes 46 (11): 1786–1791. doi:10.2337/diabetes.46.11.1786. PMID 9356027.
- ^ "Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc (2001)". http://www.nap.edu/openbook.php?record_id=10026&page=197.
- ^ Bailey MM, Boohaker JG, Sawyer RD et al. (2006). "Exposure of pregnant mice to chromium picolinate results in skeletal defects in their offspring". Birth Defects Res. B Dev. Reprod. Toxicol. 77 (3): 244–9. doi:10.1002/bdrb.20081. PMID 16767758.
- ^ Stout MD, Nyska A, Collins BJ et al. (April 2009). "Chronic Toxicity and Carcinogenicity Studies of Chromium Picolinate Monohydrate Administered in Feed to F344/N Rats and B6C3F1 Mice for 2 Years". Food Chem. Toxicol. 47 (4): 729–33. doi:10.1016/j.fct.2009.01.006. PMC 2718538. PMID 19166900. //www.ncbi.nlm.nih.gov/pmc/articles/PMC2718538/.
- ^ Safe Upper Levels for Vitamins and Minerals Food Standards Agency - May 2003
- ^ Risk assessment: Chromium Expert Group on Vitamins and Minerals, 2003
- ^ STATEMENT ON THE MUTAGENICITY OF TRIVALENT CHROMIUM AND CHROMIUM PICOLINATE COM/04/S3 - December 2004
- ^ Agency revises chromium picolinate advice Food Standards Agency - 13 December 2004