Most of us think of chromium as the shiny metal in the bumpers of cars. Chrome bumpers are long gone, but the metal plays a crucial role in human health, reports Harvard Men's Health Watch.

* Chromium and cholesterol. In rats, chromium deficiency leads to high cholesterol levels. In humans, the results have been contradictory. With such scattered scientific information, it's too early to recommend chromium supplements for cholesterol. But there may be an exception to that rule when it comes to low HDL (good) cholesterol. The best ways to boost HDL levels are lifestyle changes such as exercise and diet. But if those don't help, chromium may be worth a try. Some clinical trials have reported a benefit.

* Chromium and heart disease. A new study reports a link between chromium levels and heart attack risk: the lower the levels, the higher the risk. The association of low chromium and heart attacks was unrelated to diabetes or diet.

* Chromium and diabetes. Since chromium influences insulin action and glucose metabolism, diabetes is a logical candidate for chromium replacement therapy. However, studies have yielded conflicting results. The American Diabetes Association states that "at present, benefit from chromium supplements has not been conclusively demonstrated." It's an invitation for more scientific study.

* Chromium and weight loss. Despite the popularity of chromium picolinate as a diet aid, scientists agree that chromium supplements are not effective in producing sustained weight loss. Most of us think of chromium as the shiny metal in the bumpers of cars. Chrome bumpers are long gone, but the metal plays a crucial role in human health, reports Harvard Men's Health Watch.

* Chromium and cholesterol. In rats, chromium deficiency leads to high cholesterol levels. In humans, the results have been contradictory. With such scattered scientific information, it's too early to recommend chromium supplements for cholesterol. But there may be an exception to that rule when it comes to low HDL (good) cholesterol. The best ways to boost HDL levels are lifestyle changes such as exercise and diet. But if those don't help, chromium may be worth a try. Some clinical trials have reported a benefit.

* Chromium and heart disease. A new study reports a link between chromium levels and heart attack risk: the lower the levels, the higher the risk. The association of low chromium and heart attacks was unrelated to diabetes or diet.

* Chromium and diabetes. Since chromium influences insulin action and glucose metabolism, diabetes is a logical candidate for chromium replacement therapy. However, studies have yielded conflicting results. The American Diabetes Association states that "at present, benefit from chromium supplements has not been conclusively demonstrated." It's an invitation for more scientific study.

* Chromium and weight loss. Despite the popularity of chromium picolinate as a diet aid, scientists agree that chromium supplements are not effective in producing sustained weight loss.

Is chromium right for you? When it comes to dietary chromium, the answer is yes; whole grains, nuts, broccoli, and green beans, which contain the mineral, are all healthful foods. But before you opt for supplements, talk with your doctor.