Americans may not be consuming enough of the mineral chromium, an essential mineral thought to enhance insulin sensitivity, according to research presented yesterday.
The study, carried out by chromium supplement maker Nutrition 21, analyzed consumption of chromium food sources using data from the Continuing Survey of Food Intakes by Individuals (CSFII) for 1994-1996.
"Overall the study suggests that American diets are inadequate in the essential mineral chromium," said Dr Vijaya Juturu, lead investigator of the study and nutritional scientist at Nutrition 21. "Chromium is found in very small quantities in foods and it is difficult to estimate how much chromium we normally consume," he added.
The Nutrition 21 researchers suggest that low intake of chromium may be linked to insulin resistance, a condition affecting one in three Americans and associated with obesity, type 2 diabetes and cardiovascular disease.
Intakes of chromium from select food sources known to be high in chromium, such as wheat, cooked peas, American cheese, liver, egg and margarine were calculated using CSFII96.
More Caucasians (27.54 per cent) reported consumption of selected food sources of chromium than did other groups, according to the results. Margarine, cheese and beverages were found to be the largest sources of dietary chromium.
However the team added that the current database is not adequate to determine dietary chromium intake because the contentof chromium in foods is variable among different foods lots and may be influenced by processing and cooking at high temperatures.
The Institute of Medicine (IOM) recently published an Adequate Intake (AI) for chromium of 25-35mcg per day, which was determined by estimating the average amount of chromium a healthy American obtains from the diet. The AI for chromium is substantially lower than the Reference Daily Intake (RDI) of 120mcg.
Nutrition 21 argues that dietary chromium alone may not be enough to meet the needs of this important mineral and advises chromium supplements to ensure healthy insulin function.
The company cites findings that daily supplementation with 200-1,000 mcg per day of chromium, as chromium picolinate, increases insulin function and promotes blood sugar metabolism in both obese people and people with type 2 diabetes.
A recent study however found that chromium picolinate, often taken to speed up weight loss, caused severe DNA damage in fruitflies. Published in the Proceedings of the National Academy of Sciences, researchers reported that the compound led to lethal genetic mutations and sterility in fruit flies. Industry has however declared this insufficent evidence to question the supplement's safety in humans.
Results of the new study were presented yesterday at the Experimental Biology 2003 meeting in San Diego, California.