Nutritionists have known for some time that walnuts and other tree nuts such as almonds and pecans are good for you -they’re high in dietary fibre, chock full of vitamins and they contain unsaturated fats which are known to lower cholesterol. But a new study shows that particularly for older adults, eating walnuts can improve blood cholesterol levels without resulting in weight gain.
“The preliminary results of the study demonstrate that daily consumption of walnuts for one year by a sizable cohort of aging free-living persons has no adverse effects on body weight,” says Dr. Emilio Ros, director of the Lipid Clinic, Endocrinology & Nutrition Service at the Hospital Clinic of Barcelona.
The study followed 707 older adults who added a daily dose of walnuts to their diet (approximately 15 per cent of daily caloric intake) without any further advice or instruction on diet or behaviour. After one year, in comparison with a control group, the walnut-munchers were found to have significant LDL cholesterol reductions without noticeable weight gain.
“Acquiring the good fats and other nutrients from walnuts while keeping adiposity at bay and reducing blood cholesterol levels are important to overall nutritional well-being of aging adults. It’s encouraging to see that eating walnuts may benefit this particular population,” says Dr. Ros.
Cholesterol comes in two forms -HDL cholesterol, the good kind, helps to lower the amount of plaque build-up within the bloodstream, while LDL cholesterol, the bad kind, effectively increases plaque build-up, which can increase the risk for heart disease. Many foods are known to help with increasing HDL cholesterol and decreasing LDL cholesterol. Fibre-rich foods like beans, oats, fruits and nuts all help to decrease LDL’s while foods like avocados, tree nuts and olive oil are all rich in monounsaturated fatty acids, also helpful in lowering LDL cholesterol.
Trans fats and saturated fats are known to raise LDL cholesterol levels. The walnut study was presented as an abstract at the Experimental Biology 2016 conference in San Diego and therefore its results are still considered preliminary. The study was supported in part by the California Walnut Commission, established in 1987, whose mission is to encourage export market development.
Meanwhile, a study presented at this year’s American College of Cardiology showed that an experimental drug aimed at lowering bad cholesterol levels actually does the job of lowering HDL levels but does not have a net positive impact on health. The study involved over 12,000 people at high risk for heart disease who took either the drug evacetrapib or a placebo for a period of 1.5 years. Researchers found that evacetrapib lowered LDL cholesterol levels by 37 per cent but had no significant impact on heart health, prompting researchers to end the trial.
“It really does matter how you lower LDL,” says Dr. Steven Nissen, chair of cardiovascular medicine at the Cleveland Clinic and chair of the steering committee for the study. “This drug did all the right things to lipids but didn’t do anything to morbidity and mortality from heart disease.”
The study was funded by the drug company Eli Lilly, makers of evacetrapib.