Consuming more nuts is the key to a heart-healthy diet, according to a new study published in the Archives of Internal Medicine. The study combined the results of 25 nut-feeding studies and evaluated their effect on risk of heart disease. All studies included an experimental group that added nuts to the diet (average of 2.4 oz/day) and a control group that ate meals similar in saturated fat but with no added nuts.
The experimental groups had an average drop in total cholesterol of 11 mg/dL (5.1 percent) and a drop in LDL cholesterol of 10 mg/dL (7.4 percent). HDL levels actually rose slightly (0.2 percent), but the change was not significant. The ratio of LDL cholesterol to HDL cholesterol dropped 8.3 percent. The reduction in LDL cholesterol was greatest in those with the highest LDL cholesterol to start with which is good news to those with high cholesterol levels.
Researchers also found that eating nuts reduced blood triglyceride levels by 21 mg/dL (10.2 percent) in those who had elevated triglycerides. All of these changes reduce the risk of a heart problem. They found that different nuts used in the feeding trials (almonds, walnuts, peanuts, pistachios, pecans, and macadamias) all had beneficial benefits.
Nut consumption improved blood lipid levels in a dose-response manner – the more nuts the study participants ate the greater the reduction in cholesterol levels and coronary risk. The researchers pointed out that the benefits of eating nuts exceeds the reduction in blood cholesterol levels which is modest (about a 7.4 percent reduction in LDL cholesterol levels), especially when compared to taking statin drugs. Statins drop cholesterol levels a lot, but only have a modest drop in coronary risk (about 30-35 percent). Nuts only lower LDL cholesterol a little, but the actual reduction in coronary risk from eating nuts is quite high, indicating that nuts have other benefits to heart health besides lowering cholesterol. When combining the results of 4 large epidemiologic studies, eating nuts 4 times per week reduced the risk of heart disease by 37 percent or 8.3 percent for each serving of nuts eaten per week.
Nuts provide a good nutritional addition to the diet. They are a nutrient dense food:
Rich in plant proteins (10-25 percent)
Rich in unsaturated, healthy fats (50-75 percent)
Rich in dietary fiber
High in minerals that are good for the heart (copper, magnesium, and potassium)
High in vitamins that are good for the heart (folic acid, niacin, vitamin E, and vitamin B6)
Full of antioxidants (phenolic antioxidants and phytosterols)
Added heart-health benefits of eating nuts include:
Improving endothelial function (the lining of the arteries which help control blood flow and clotting)
Lowering oxidative stress (helping prevent oxidation of cholesterol, etc.)
Reducing lipoprotein(a) levels (elevated levels are linked to higher coronary risk)
Lowering the risk of developing type 2 diabetes
And research shows that frequent nut eating does not lead to weight gain.
In conclusion, the researchers state, "Our findings confirm the results of epidemiological studies showing that nut consumption lowers coronary heart disease risk and supports including nuts in a therapeutic diet for improving blood lipid levels."
Reference:
Sabate J, et al. Nut consumption and blood lipid levels. Archives of Internal Medicine. 2010;170(9):821-827.
