The research, published in the Archives of Internal Medicine, examined data from 25 different studies that looked at nut consumption of 583 people and its relationship to cholesterol levels. It found that eating an average of 2.4 ounces (67g) of nuts a day reduced total cholesterol by an average of 5 percent, LDL (low-density lipoprotein, or ‘bad’) cholesterol by 7 percent, and improved the ratio of LDL and HDL (high-density lipoprotein, or ‘good’) cholesterol.
Co-author of the report and chair of Linda Loma University’s nutrition department at the university Dr. Joan Sabaté said the review provided "the best evidence yet that eating nuts reduces LDL cholesterol and improves the blood lipids profile”.
The authors wrote that their most significant finding of the study was that heart health benefits from eating nuts seemed to be dose-related and have the strongest effect on thinner people and those with higher baseline LDL cholesterol.
However, they added that more research was needed to find out why nuts are less effective in lowering the blood cholesterol of obese subjects.
Sabaté said that the type of nuts eaten did not seem to make a difference to the overall effect on health.
“Nuts are a matrix of healthy nutrients, and the most obvious reason for the cholesterol-lowering effect is their unsaturated fat content," he said. "Nuts also contain fiber, vegetable protein, phytoesterols and other antioxidants."
The authors recommended a maximum consumption of three ounces of nuts a day due to their being high in calories.
“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 CHD risk,” they concluded.
The research was partly funded by the International Tree Nut Council Nutrition Research and Education Foundation, but it did not play any role in the study.
Source: Archives of Internal Medicine
Vol. 10 (No. 9), 2010, pp. 821-827
“Nut Consumption and Blood Lipid Levels: A Pooled Analysis of 25 Intervention Trials”
Authors: Joan Sabaté, Keiji Oda, Emilio Ros