A new analysis of published studies regarding nut consumption and blood fats reveals eating plenty of nuts leads to healthier cholesterol levels, however, thin people, those whose diets are less healthy, including those with high levels of bad LDL cholesterol and triglycerides, seem to benefit the most from doing so.
Dr. Joan Sabate of Loma Linda University in California talking to Reuters Health said studies on participants from different countries have shown nuts lower cholesterol by preventing its absorption, making the results pretty much universal.
Nuts are known to contain a number of healthy substances, such as, good fats, fibre and antioxidants. In 2003, the US Food and Drug Administration (FDA) recommended eating 1.5 ounces of certain nuts a day, in order to reduce the risk of heart disease.
Sabate and colleagues pooling data from 25 studies from seven countries, with 583 participants, some with high and some with normal cholesterol, examined the cholesterol-lowering effects of nuts to find out whether a person’s overall diet, body size or other factors, strengthened or weakened their beneficial effect on cholesterol.
According to them, eating an average of 67 grams (about 2.4 ounces) of nuts daily lowered total cholesterol levels by 11 points (a 5% reduction); harmful LDL cholesterol levels by 10 points (a 7% drop); including shifting the ratio of total cholesterol or LDL cholesterol to good HDL cholesterol in a favourable direction. The benefits were visible in people with both normal and high cholesterol levels.
However, the nuts seemed to reduce triglyceride levels by 21 points in those with high triglycerides levels i. e. 150 milligrams per decilitre or higher, they had no effect on those with normal triglycerides levels.
As well, researchers found the more nuts people ate, the greater the changes in their cholesterol levels, including the fact that eating different types of nuts had similarly healthy effects on blood fats.
The findings apply to tree nuts like walnuts, almonds, pistachios, macadamias, hazelnuts and peanuts.
Although peanuts actually belong to the legume family, they are considered to have many of the same nutritional components as walnuts, almonds and other tree nuts.
Researchers found the biggest effect of eating nuts was on people starting out with LDL cholesterol levels above 160 milligrams per decilitre, those with a low body weight, and those who ate more of a Western diet i. e. more saturated fats and refined carbohydrates.
This explains why people already eating a more Mediterranean diet rich in olive oil, fish, whole grains and other healthy foods do not show much benefit from adding nuts to their diet.
But, people can improve their lipid profile by eating one to two servings of nuts a day, though consuming two handfuls of nuts a day appears to work better than one, as well as, drastically decreasing their risk of heart attack. One serving of almonds is about eight nuts; a serving of smaller nuts like peanuts is about 15 to 20 nuts.
The study was funded by several different trade groups for nut producers, including the International Tree Nut Council Nutrition Research and Education Foundation.
The results have been published in the Archives of Internal Medicine.