March 11 (HealthDay News) -- Increased consumption of magnesium-rich foods such as whole grains may reduce male smokers' risk of cerebral infarction, which occurs when blood flow to the brain is blocked, a new Swedish study suggests.

Researchers at the Karolinska Institute in Stockholm analyzed the diets and other health/lifestyle habits and characteristics of 26,556 Finnish men, aged 50 to 69, who smoked but had never had a stroke. During an average of 13.6 years of follow-up, 2,702 of the men had cerebral infarctions, 383 had intracerebral hemorrhages (bleeding into the brain tissue), 196 had subarachnoid hemorrhages (bleeding between the brain and the tissues that cover it), and 84 had unspecified types of strokes.

After they adjusted for age and cardiovascular risk factors (such as diabetes and cholesterol levels), the researchers concluded that men who consumed the most magnesium (an average of 589 milligrams per day) had a 15 percent lower risk for cerebral infarction than those who consumed the least amount of magnesium (an average of 373 milligrams per day). The association was stronger in men younger than 60.

There was no association between magnesium consumption and risk for intracerebral or subarachnoid hemorrhage, said the researchers, who added that calcium, potassium and sodium intake weren't associated with risk for any type of stroke.

The findings were published in the March 10 issue of the Archives of Internal Medicine.

"An inverse association between magnesium intake and cerebral infarction is biologically plausible," the study authors wrote. Magnesium lowers blood pressure and may also affect cholesterol concentrations and the body's use of insulin to turn glucose into energy, both of which would affect the risk for cerebral infarction, but not hemorrhage.

"Whether magnesium supplementation lowers the risk of cerebral infarction needs to be assessed in large, long-term randomized trials," the study authors added.

Recent studies have suggested that changes in diet may help reduce stroke risk, according to background information in the study. High blood pressure is a risk factor for stroke, which means that dietary changes that lower blood pressure may reduce stroke risk.

SOURCE: JAMA/Archives journals, news release, March 10, 2008