What is the Effect of Tree Nuts on Cholesterol, Triglycerides?
Title: Effects of tree nuts on blood lipids, apolipoproteins, and blood pressure: systematic review, meta-analysis, and dose-response of 61 controlled intervention trials
Authors: Del Gobbo et al
Journal: American Journal of Clinical Nutrition
Objective: To examine the effects of tree nuts (walnuts, pistachios, macadamia nuts, pecans, cashews, almonds, hazelnuts, and Brazil nuts) on blood lipids [total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein, and triglycerides], lipoproteins [apolipoprotein A1, apolipoprotein B (ApoB), and apolipoprotein B100], blood pressure, and inflammation (C-reactive protein) in adults aged older than 18 y without prevalent CVD.
There is a growing body of evidence regarding the health benefits of nuts. Previously, I have made a video regarding the health benefits of nuts. I would encourage you to check that out but the highlight reel includes the following:
- Heart disease
- Cardiovascular disease
- Cancer mortality
- Respiratory disease mortality
- Improved blood sugar control
- bad cholesterol (LDL)
- blood clots (thromboembolic disease)
- clogged arteries (atherosclerosis)
- Weight loss and healthy weight maintenance
- Improved cognition, reduction in risk and progression of alzheimer’s disease
The authors of this article sought to do a systematic review to look at the effects of tree nuts on blood lipids, apolipoproteins and blood pressure.
The authors conducted a systematic review and meta-analysis. For those that do not know, a systematic review and meta-analysis is the gold standard for combining multiple studies into one publication to try to answer a question or series of questions.
Of the 1301 potentially eligible studies, a total of 61 were included in the final analysis.
Of the sixty-one trials included, a total of 2582 individuals were included in analysis and the interventions ranged from 3 to 26 wks.
They standardized doses between the different studies and also controlled for age, sex, background diet, baseline risk factors, nut type, disease condition, and duration.
Nut intake (per serving/d) lowered
- total cholesterol (24.7 mg/dL; 95% CI: 25.3, 24.0 mg/dL),
- LDL cholesterol (24.8 mg/dL; 95% CI: 25.5, 24.2 mg/dL),
- Apolipoprotein B (23.7 mg/dL; 95% CI: 25.2, 22.3 mg/dL), and
- triglycerides (22.2 mg/dL; 95% CI: 23.8, 20.5 mg/dL)
The dose-response between nut intake and total cholesterol and LDL cholesterol was nonlinear (P-nonlinearity , 0.001 each); stronger effects were observed for more than 60 g nuts/d.
Significant heterogeneity was not observed by nut type or other factors. In other words, it did not appear that one nut was substantially better than any other.
For Apolipoprotein B, stronger effects were observed in populations with type 2 diabetes (211.5 mg/dL; 95% CI: 216.2, 26.8 mg/dL) than in healthy populations (22.5 mg/dL; 95% CI: 24.7, 20.3 mg/dL) (P-heterogeneity = 0.015).
Tree nut intake lowers total cholesterol, ldl cholesterol, apolipoprotein B and triglycerides.
This effect is true regardless of which nuts you eat.
The impact is also more profound with higher servings of nut intake.
This study highlights the importance of nut intake in your diet as a preventative or therapeutic treatment for high lipid values.
The significance specifically in type 2 diabetics requires more research.
Gobbo, L. C., Falk, M. C., & Feldman, R. (2015). 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, 102(6), 1347-1356. doi:10.3945/ajcn.115.110965