Tree Nuts May Lower Cardiovascular Health Risk, Especially In Diabetic Populations

Photo © iStockphoto.com/ GeoffBlack

A new systematic review and meta-analysis published in the American Journal of Clinical Nutrition suggests that consuming tree nuts may lower cardiovascular health risk. Researchers found that people who consumed approximately 2 ounces of tree nuts per day had lower total cholesterol, triglycerides, LDL cholesterol and apolipoportein B (ApoB), especially in populations with type-2 diabetes.

The study included 61 crossover and parallel trials that examined the effects of a variety of tree nuts on blood lipids, lipoproteins, blood pressure, and inflammation in adults aged 18 and older without prevalent cardiovascular disease (CVD). Nuts used in the studies included almonds, Brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pine nuts, pistachios, and walnuts. A total of 2,582 individuals were included in the study.

Compared to the control groups, consumption of tree nuts was found to significantly lower total cholesterol by 4.7 mg/dL, LDL cholesterol by 4.8 mg/dL, ApoB by 3.7 mg/dL, and triglycerides by 2.2 mg/dL, with no statistically significant effects found on other outcomes. The amount of nuts provided in the trials varied from 5 to 100 grams per day, with the meta-analysis finding stronger effects observed at more than 60 grams of nuts per day.

“Accumulating evidence suggests that nut intake lowers the risk of cardiovascular disease,” says Lina Del Gobbo, PhD, lead author of the study and researcher of cardiovascular medicine at Stanford University (Stanford, CA). “Our findings, showing that nut intake lowers LDL cholesterol, ApoB, and triglycerides in clinical trials, provide mechanistic evidence to support this relationship.”

Stronger Effect on Type-2 Diabetes

The meta-analysis also found that the effects of nut consumption on ApoB were especially pronounced in populations with type-2 diabetes. Compared to reducing ApoB by an average of 2.5 mg/dL in health populations, consuming tree nuts appeared to reduced ApoB by 11.5 mg/dL in populations with type-2 diabetes, reported researchers.

“ApoB can provide even better information about risk of heart disease than LDL concentrations,” explained Dariush Mozaffarian, MD, DrPH, senior author of the study and dean, Friedman School of Nutrition Science and Policy, Tufts University (Medford, MA). “Our new findings suggest that eating nuts may be especially important for lowering cardiovascular risk in the setting of diabetes or insulin resistance.”

Additionally, researchers found that nut dose appeared to be a more significant determinant of lowering cholesterol than nut type.

“This new analysis provides further support that nuts can and should be part of a heart-healthy diet,” says Maureen Ternus, MS, RD, executive director, International Tree Nut Council Nutrition Research & Education Foundation (Davis, CA). “Just 1.5 ounces of nuts per day (about 1/3 cup) can provide many of the important vitamins, minerals, and energy we need throughout the day.”

Read more:

Tree Nuts and Type 2 Diabetes: Is the Science Conclusive?

Eating Nuts in Pregnancy May Lower Risk of Common Food Allergy

A Nutty Way to Prevent Cancer?

Michael Crane
Associate Editor
Nutritional Outlook Magazine
michael.crane@ubm.com

Disclosures:

Del Gobbo LC et al., “Effects of tree nuts on blood lipids, apolipoproteins, and blood pressure: systematic review, meta-analysis, and dose-response of 61 controlled intervention trials,” American Journal of Clinical Nutrition,” vol. 102, no. 6 (December 2015): 1347-56