MedicalResearch.com Interview with:
Liana Del Gobbo PhD
Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA; and
Life Sciences Research Organization, Bethesda, MD
Medical Research: What is the background for this study? What are the main findings?
Dr. Del Gobbo: Accumulating evidence suggests that nut intake lowers risk of cardiovascular disease. But the specific mechanisms by which nuts may exert beneficial effects (eg. through lowering blood cholesterol, blood pressure, inflammation, etc.) were not clear. Two prior reviews on this topic only evaluated one type of nuts, and only a few cardiovascular risk factors.
To address these knowledge gaps, we performed a systematic review and meta-analysis of controlled trials to examine the effects of eating tree nuts (walnuts, pistachios, macadamia nuts, pecans, cashews, almonds, hazelnuts, Brazil nuts) on major cardiovascular risk factors including blood lipids (total cholesterol, LDL, HDL, triglycerides [TG]), lipoproteins (ApoA1, ApoB, ApoB100), blood pressure (systolic, SBP; diastolic, DBP), and inflammation (C-reactive protein, CRP) in adults 18 years or older without cardiovascular disease.
A daily serving of nuts (1oz serving, or 28g per day) significantly lowered total cholesterol, LDL, ApoB, and triglycerides, with no significant effects on other risk factors, such as HDL cholesterol, blood pressure or inflammation. To give you an idea of a 1oz serving size of nuts, it is about 23 almonds, 18 cashews, 21 hazelnuts, 6 Brazil nuts, 12 macadamia nuts, 14 walnut halves, 20 pecan halves, 49 pistachios.
We did not see any differences in cholesterol-lowering effects by nut type.
Medical Research: What should clinicians and patients take away from your report?
Dr. Del Gobbo: Enjoy a serving of nuts per day to lower your cholesterol.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Del Gobbo: Our findings highlight the need for investigation potential stronger effects at lowering LDL cholesterol at high nut intakes, and among diabetic populations.
Liana C Del Gobbo, Michael C Falk, Robin Feldman, Kara Lewis and Dariush Mozaffarian
Effects of tree nuts on blood lipids, apolipoproteins, and blood pressure: systematic review, meta-analysis, and dose-response of 61 controlled intervention trials
Am J Clin Nutr ajcn110965; First published http://ajcn.nutrition.org/citmgr%3Fgca=ajcn%3Bajcn.115.110965v1online November 11, 2015.doi:10.3945/ajcn.115.110965
Liana Del Gobbo PhD (2015). One Serving of Tree Nuts Daily Linked To Lower Lipid Profile