Improvements in blood cholesterol levels are linked with eating nuts, according to this week’s Archives of Internal Medicine.
Authors writing in the journal say that dietary interventions to lower blood cholesterol concentrations and to modify blood lipoprotein levels are the cornerstone of prevention and treatment plans for coronary heart disease.
Nuts are rich in plant proteins, fats (especially unsaturated fatty acids), dietary fiber, minerals, vitamins and other compounds, such as antioxidants and phytoesterols. The contents of nuts are a focus because of the potential to reduce coronary heart disease risk and to lower blood lipid – fat and cholesterol – levels.
Emory University’s Cheryl Williams, RD, LD, clinical nutritionist, Emory Heart & Vascular Center, Emory HeartWise Cardiac Risk Reduction Program, says nuts are among the heart healthiest whole foods as they provide a variety of health promoting compounds such as dietary fiber, vitamins (vitamin E), minerals (selenium), antioxidants and phytoesterols.
While most of the calories provided from nuts come from fat, notes Williams, it is mostly unsaturated fats (mono and polyunsaturated), which have been shown to help lower elevated serum cholesterol, and to some extent triglyceride levels (via omega 3 fatty acids provided from walnuts).
The results of the study, says researcher and study author Joan Sabaté, MD, of Loma Linda University, support the inclusion of nuts in therapeutic dietary interventions for improving blood cholesterol levels. The study findings increasing the consumption of nuts as part of an otherwise prudent diet can be expected to favorably affect blood lipid levels (at least in the short term) and have the potential to lower coronary heart disease risk, notes Sabaté.
Researchers looked at 25 nut consumption clinical trials conducted in seven countries and involving 583 women and men with high cholesterol or normal cholesterol levels. All the studies compared a control group to a group assigned to consume nuts. Participants were not taking lipid-lowering medications.
The authors write that different types of nuts had similar effects on blood lipid levels and how many nuts a person consumed was important.
Nuts are an integral part of a heart healthy diet, says Williams. However, controlled portions are key – as with all heart healthy fats – since they are high in calories. For example, patients in the clinical trials reviewed consumed an average of 2.4 ounces of nuts per day, which is equal to about 400 calories (as much as a main meal).
Thus, says Williams, to reap the benefits of nuts and avoid an expanding waistline, especially since studies showed improvement in lipid levels in subjects with lower BMI -higher LDL cholesterol, stick to 1 ounce portions (about 1/4 cup). Additionally, cut out empty calories (cookies, sweetened beverages, etc.) to make room for nuts, which are both nutrient and calorie dense.