Experts on healthy eating have found that daily consumption of walnuts reduces the level of bad cholesterol and the risk of developing cardiovascular diseases. The results of the study are published in the journal Circulation of the American Heart Association.
Walnuts are a rich source of alpha-linolenic acid, which belongs to the class of unsaturated omega-3 fatty acids. Previous studies have shown that people who regularly eat any nuts, particularly walnuts, are less likely to develop heart diseases and strokes.
Researchers from the United States and Spain, led by Emilio Ros, director of the Lipid Clinic of the Endocrinology and Nutrition Service of the Clinical Hospital of Barcelona, found out the reason – walnuts not only reduce the level of low-density lipoprotein cholesterol (LDL), known as bad cholesterol but also change the ratio of its particle sizes for the better.
“LDL particles come in different sizes. Small dense particles are more often associated with atherosclerosis, plaque or fat deposits that accumulate in the arteries,” Dr. Ros said in a press release from the American Heart Association.
The authors conducted a randomized study involving 708 people aged 63 to 79 years – healthy people living in Barcelona (Spain) and Loma Linda( California). The work was devoted to the study of whether walnuts contribute to healthy aging.
The participants were randomly divided into two groups: a working group and a control group. The former received half a cup of walnuts daily for two years. The participants of both groups were tested for cholesterol levels and the concentration and size of lipoprotein particles, the composition of which were analyzed by nuclear magnetic resonance spectroscopy. Such an extended test allowed scientists to more accurately determine the characteristics of lipoproteins, which are associated with an increased risk of developing cardiovascular diseases.
“Our study goes beyond controlling only the level of LDL cholesterol. We wanted to get a complete picture of all the lipoproteins and the impact of daily consumption of walnuts on reducing the risk of cardiovascular diseases,” Ros says.
After two years, the participants from the working group had a total cholesterol level decreased by an average of 8.5 percent, the LDL content — by an average of 4.3 percent, and the most harmful small LDL particles – by 6.1 percent. Intermediate-density lipoprotein cholesterol, which is a precursor to LDL, also decreased. At the same time, the researchers did not record a significant weight gain in the participants.
“Daily consumption of a handful of walnuts is an easy way to strengthen the health of the cardiovascular system. Many people worry about unwanted weight gain when they include nuts in their diet. Our study showed that the healthy fats in walnuts do not contribute to weight gain.” – the scientist notes.