- After a 2-year study, participants who consumed about half a cup of nuts each day had low-density lipoprotein (LDL) cholesterol levels lower than their levels at the start of the study.
- These people also experienced a reduction in total cholesterol.
- The research was funded by a grant from the California Walnut Commission.
A growing body of scientific research suggests that nuts, which are high in omega-3 fatty acids, may protect against heart disease.
Over the years, a number of studies have investigated whether eating nuts can reduce cardiovascular risk factors.
For example, a
New study, which appears as a research letter in the journal of the American Heart Association Circulation, studies whether adding nuts to the daily diet for 2 years specifically influences cholesterol levels. In addition, this study focuses on the elderly.
The authors found that including nuts in the diet lowered total cholesterol and slightly lowered LDL cholesterol levels, which people often refer to as “bad” cholesterol.
Additionally, the scientists measured the participants’ LDL cholesterol subclasses. One of these subclasses, small, dense particles of LDL, is more often associated with atherosclerosis, which occurs when fatty deposits build up in the arteries.
In their study, they found that daily consumption of nuts reduced both the number of total LDL particles and small LDL particles.
Dr Emilio Ros, principal author of the present study and director of the Lipid Clinic of the Endocrinology and Nutrition Department of the Hospital Clínic de Barcelona in Spain, spoke with Medical News Today. He explained how he and his colleagues have studied the health benefits of nuts for many years.
Dr. Ros does not hesitate to sing the praises of nuts, which he includes in his diet. “Nuts have an optimal composition of nutrients and bioactives, including significant amounts of alpha-linolenic acid, vegetable omega-3 fatty acid, the highest polyphenol content of all nuts and phytomelatonin,” he explained.
In this study, research indicates, according to Dr. Ros, that “eating nuts regularly will lower your LDL cholesterol and improve the quality of LDL particles, making them less atherogenic (less likely to enter the arterial wall and develop atherosclerosis. , the basis of cardiovascular disease), and it will occur without unwanted weight gain despite the high fat (healthy vegetable fats, however) content of nuts.
Dr Ros said MNT he chose to conduct this study because no other research had examined the composition of lipoproteins, which, he said, “may provide additional information about the anti-atherogenic potential of nuts.”
A total of 636 participants aged 63 to 79 completed the study. They all resided in Barcelona, Spain, or Loma Linda, California.
Of the participants, 67% were women. The participants were cognitively healthy and had no significant health problems.
About half of the participants were taking medication for high blood pressure or high cholesterol, which Dr. Ros says is typical of this elderly population. Of the participants, 32% were taking statins.
The researchers asked a group of participants not to eat nuts. The other group incorporated half a cup of raw nuts into their daily meals. Health care practitioners monitored the participants, looking for how well they were following their diet and any changes in their weight, every two months.
The researchers tested the participants’ cholesterol levels and analyzed the concentration and size of lipoproteins by nuclear magnetic resonance spectroscopy.
During the study, participants who consumed nuts reduced their LDL cholesterol levels by an average of 4.3 milligrams per deciliter (mg / dl) and their total cholesterol levels by an average of 8.5 mg / dl. . Participants in the nut group reduced their total LDL particle count by 4.3% and small LDL particle counts by 6.1%.
Among participants who consumed nuts, changes in LDL cholesterol differed by gender. In men, LDL cholesterol was reduced by 7.9%. Among women, it fell 2.6%.
Dr Sanjiv Patel, interventional cardiologist at MemorialCare Heart & Vascular Institute at Orange Coast Medical Center in Fountain Valley, Calif., said MNT Let the study not be a game-changer when it comes to adding to what scientists already know about diet and the heart.
“We already knew that nuts are good for your health,” he said.
He appreciated that the researchers followed the participants over a period of 2 years. “It was not some kind of study of a few weeks,” he said.
Dr. Patel pointed out that the study participants experienced only a modest drop in LDL cholesterol. “There is a reduction in their [cholesterol] profile but not at the level of what you get from taking statins, ”said Dr Patel. “So people who are at high risk for heart disease or who already have heart disease shouldn’t substitute nuts for statins. They can additionally take the nuts to add to the benefit but not replace it.
Indeed, Dr Ros said MNT that in the future, he would like to conduct a study on the impact of adding nuts to the diet of people at risk of cardiovascular disease.
Dr Patel also cautioned that people reading this study shouldn’t think it’s okay to pour bag after bag of nuts. He advises sticking to no more than a handful per day.
Dr Ros also pointed out some limitations of the study when he spoke with MNT. For example, he explained that the study was not “blind”. In other words, the participants knew they were part of the drown group.
He also explained that “the study was not conducted in a controlled feeding setting, but in individuals living in the wild, who could choose their daily foods, so it was not an isoenergetic intervention, and it there was an increase in energy and fat intake in the nut group, which may have influenced the results.
Importantly, Dr. Patel also noted that the research was funded by a grant from the California Walnut Commission, which was established to represent California walnut growers and operators. “Obviously that kind of tainted the data a bit,” he said.