NEW YORK A pooled analysis of 25 trials found that nut consumption may improve blood cholesterol levels.
The findings -- which were published in the May 10 issue of the Archives of Internal Medicine -- noted that nuts contain plant proteins, fats (especially unsaturated fatty acids), dietary fiber, minerals, vitamins and other such compounds as antioxidants and phytoesterols.
Joan Sabate, M.D., Dr.P.H., of Loma Linda University in California, and colleagues pooled primary data from 25 nut consumption trials conducted in seven countries and involving 583 women and men with high cholesterol or normal cholesterol levels. All the studies compared a control group with a group assigned to consume nuts; participants were not taking lipid-lowering medications.
Participants in the trials consumed an average of 67 grams (about 2.4 oz.) of nuts per day. This was associated with an average 5.1% reduction in total cholesterol concentration, a 7.4% reduction in low-density lipoprotein (LDL, or "bad" cholesterol) and an 8.3% change in ratio of LDL cholesterol to high-density lipoprotein (HDL, or "good" cholesterol). In addition, triglyceride levels declined by 10.2% among individuals with high triglyceride levels (at least 150 milligrams per deciliter), although not among those with lower levels.
"Nuts are a whole food that have been consumed by humans throughout history," the authors wrote. "Increasing the consumption of nuts as part of an otherwise prudent diet can be expected to favorably affect blood lipid levels (at least in the short term) and have the potential to lower coronary heart disease risk," noting that different types of nuts had similar effects on blood lipid levels.