Nuts May Help Lower Cholesterol Levels

May 11, 2010— -- Eating nuts improves cholesterol and other blood lipid levels, which may help stave off heart disease, researchers found.

In a pooled analysis of 25 intervention trials, eating an average of 67 grams of nuts a day (2.4 ounces) reduced total cholesterol by 5.9 percent and LDL, or bad, cholesterol by 7.4 percent, according to Dr. Joan Sabaté of Loma Linda University in California and colleagues.

The ratios of total to HDL (good) cholesterol and of LDL to HDL cholesterol also were reduced, they reported in the May 10 Archives of Internal Medicine.

Epidemiological studies have linked nut consumption with a reduced risk of coronary heart disease, and many dietary intervention trials have studied the effects of nut consumption on blood lipid levels.

"This study gives evidence that the cholesterol-lowering mechanism is one of the driving forces in the previously discovered relationship that nuts prevents heart attack," Sabaté said in an interview

In 2003, the U.S. Food and Drug Administration okayed a qualified health claim that evidence suggests -- but does not prove -- that eating 1.5 ounces (43 grams) of nuts per day as part of a diet low in saturated fat and cholesterol reduces coronary heart disease risk.

The government allows the claim on dietary labeling for specific nuts, including almonds, hazelnuts, pecans, pistachios, walnuts, peanuts, and some pine nuts.

Although the decrease in LDL cholesterol in the current analysis is modest compared with that seen with statins, "the value of regular nut consumption for coronary heart disease prevention is unlikely due to the blood cholesterol-lowering effect alone," Sabaté and his colleagues wrote.

Indeed, they wrote, "nut consumption exerts beneficial effects by improving endothelial function, lowering oxidative stress, and reducing lipoprotein(a) level."

To assess the effects of nut consumption, the researchers performed a pooled analysis of raw data from 25 intervention trials conducted in seven countries that included 583 men and women with various blood lipid problems. None of the participants was taking lipid-lowering medications. Sample size ranged from 10 to 49.