Chromium is an essential trace mineral that occurs naturally in small amounts in some foods, including brewer's yeast, lean meat, cheese, pork kidney and whole grain bread and cereals. It is poorly absorbed by the human body but is known to play an important role in the metabolism of carbohydrate, fat and protein.
Several reports have indicated that chromium picolinate is better absorbed by humans than other forms of the mineral.
The review, co-authored by Philip Domenico from Nutrition 21 who produce chromium picolinate supplements, is a timely summary of the state-of-play for the mineral that could offer significant benefits to the growing number of diabetics.
An estimated 39m people are affected by diabetes in the US and EU 25. The total costs in the US alone are thought to be as much as $132bn, with $92bn being direct costs from medication, according to 2002 American Diabetes Association figures.
C. Leigh Broadhurst and Domenico reviewed data from fifteen studies (14 focused in type-2 diabetes) with a total of 1,690 subjects, including 1,505 receiving chromium picolinate. Doses ranged from 200-1000 micrograms of chromium per day and supplementation periods ranged from one week to nine months.
"The data indicate that chromium picolinate supplementation represents a uniquely efficacious modality for glycaemic control in subjects with diabetes," wrote reviewers C. Leigh Broadhurst and Philip Domenico.
"Indeed, 13 of 15 clinical studies reported significant improvement in at least one outcome of glycaemic control."
Broadhurst and Domenico report that six out of ten studies measuring fasting glucose levels showed a significant improvement of 15.3 per cent, and postprandial glucose levels of 18.9 per cent. Fasting insulin levels, measured in four studies, improved by 29.8 per cent, while postprandial insulin improved by 15 per cent from baseline as a result of chromium picolinate supplementation.
The authors note that a recent meta-analysis of chromium supplementation with respect to diabetes did not report significant benefits, but this may due to the form of the mineral and that people with type-2 diabetes may need higher doses than normal people for a benefit to be observed.
"The main messages are that all forms of chromium are not equivalent, and that higher doses of chromium picolinate are required for people with type 2 diabetes," said Broadhurst in a statement. "Previous chromium reviews examined all types of chromium at widely varying doses. But separating out chromium picolinate, which yields highly consistent results in research studies, compared to other chromium supplements shows that at doses between 200--1000 mcg it is a superior nutritional adjunct to diabetes treatments."
The supplement has a "compelling safety profile", said the researchers, and is an inexpensive and efficacious way of improving diabetes control and could be used in combination with existing medications, as well as reducing the requirement of these expensive medications.
"Though the data supporting the benefits of supplemental chromium picolinate for subjects with diabetes are strong, future studies may require a more careful selection of subjects to pinpoint its usefulness," they concluded.
Source: Diabetes Technology and Therapeutics Volume 8, Number 6, Pages 677-687 "Clinical Studies on Chromium Picolinate Supplementation in Diabetes Mellitus - A Review" Authors: C.L. Broadhurst, P. Domenico