In a new study, published in Circulation, scientists assessed the impact of daily nut consumption on the risk of heart and vascular disease in older people.
Frequently eating nuts is an important part of various plant-based diets. It is known that their regular use is associated with a 15% reduction in the risk of developing cardiovascular diseases and a 23% reduction in mortality from them. This is due to the fact that they are a good source of omega-3 acids (alpha-linolenic). Previously, small studies have shown that nuts have the ability to lower blood cholesterol levels. However, many aspects of this effect are still unknown.
“Previous research has shown that nuts – and walnuts in particular – are associated with a reduction in heart disease and stroke. One reason is that they may lower low-density lipoprotein (LDL, “bad” cholesterol – ed.) levels. Now we know more no reason: they change the quality of the LDL particles,” said Emilio Ros, director of the Lipid Clinic of the Endocrinology and Nutrition Service of the Barcelona Hospital Hospital.
Ros said that LDL particles can be of different sizes. It was previously known that smaller, denser LDL particles were more likely to be associated with the development of atherosclerosis. In a new study, scientists went further — they assessed the effect of eating walnuts on changes in the level of all blood lipoproteins
Scientists analyzed the data that were obtained in a study of the effect of walnuts on healthy aging. It followed 708 people aged 63-79 for two years. Participants in one group had to add half a cup of walnuts (30-60 grams) to their daily diet, the other did not.
The authors of the study tested cholesterol levels and particle sizes of lipoprotoeins, which carry it in the blood, in all participants.
In people who ate more walnuts over a two-year period, total cholesterol and low-density lipoprotein levels dropped significantly (by 4.3 and 8.5 mg/dL, respectively). Nut consumption was associated with a decrease in total LDL particles, especially small particles.
Walnuts have also been associated with a decrease in medium-density lipoprotein. Recently, they are considered an important marker of the risk of cardiovascular disease.
The effect of nuts on men was more pronounced: their LDL levels in the blood decreased by almost 9%, in women — by 2.6%.
Scientists noted that for some, this reduction in cholesterol levels may seem insignificant. However, half of the participants in the study took medication to normalize it (statins). That is, in this case, the level of «bad» cholesterol in people without nuts was normal or close to it.
“Eating a handful of nuts a day is an easy way to maintain cardiovascular health. Many people worry about possible weight gain due to the presence of nuts in the diet. Our study found that healthy fats do not contribute to the appearance of excess body weight,” Ros said.