Chromium intake has been shown to increase insulin sensitivity, glucose tolerance, and the ratio of high density lipoprotein cholesterol to low density lipoprotein cholesterol, all factors that benefit the health of the heart.
However, the epidemiologic evidence on the association between chromium and cardiovascular disease is very limited, according to the study authors from Johns Hopkins University.
They measured the chromium in toenail samples from 684 men who had previously had a myocardial infarction recruited from hospitals in eight different European countries and Israel. Toenail clippings give indication of chromium levels over the long-term.
Compared with a control group of men that had never had a heart attack, the study group had lower levels of chromium : 1.10 mug/g on average, versus 1.30 mug/g in controls, or 15 per cent lower.
"Toenail chromium concentration was inversely associated with the risk of a first myocardial infarction in men," write the researchers in the 15 July issue of the American Journal of Epidemiology (vol 162, issue 2, pp157-64).
Men with the highest levels of chromium were 35 per cent less likely to have a heart attack than those with the lowest levels, the found.
"These results add to an increasing body of evidence that points to the importance of chromium for cardiovascular health," they conclude.
Cardiovascular disease causes nearly half of all deaths in Europe - more than 4.35 million each year.
The researchers noted that some evidence shows that the chromium intake of many Americans may be well below those considered adequate, yet 'considerably more evidence' is needed to substantiate claims that chromium supplements will improve blood sugar control and weight loss.
Nutrition 21, the manufacturer of one form of the mineral called chromium picolinate, claims however that it has more than 50 scientific studies to support a health claim that the supplement can help reduce risk of insulin resistance, type 2 diabetes and related disease.
It is currently awaiting approval from the US Food and Drug Administration for this claim.
The report also said that more evidence is needed on the long-term safety of chromium supplementation in humans. The UK's Food Standards Agency has however found chromium picolinate to be safe for use in supplement form.