Effects of oils and solid fats on blood lipids: a systematic review and network meta-analysis

Lukas Schwingshackl,Berit Bogensberger,Aleksander Benčič,Sven Knüppel,Heiner Boeing,Georg Hoffmann

doi:10.1194/jlr.p085522

Lukas Schwingshackl, Berit Bogensberger + Show 4 more

Open Access

https://doi.org/10.1194/jlr.p085522

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Abstract

The aim of this network meta-analysis (NMA) is to compare the effects of different oils/solid fats on blood lipids. Literature searches were performed until March 2018. Inclusion criteria were as follows: i) randomized trial (≥3 weeks study length) comparing at least two of the following oils/solid fats: safflower, sunflower, rapeseed, hempseed, flaxseed, corn, olive, soybean, palm, and coconut oil, and lard, beef-fat, and butter; ii) outcomes LDL-cholesterol (LDL-C), total cholesterol (TC), HDL-cholesterol (HDL-C), and triacylglycerols (TGs). A random dose-response (per 10% isocaloric exchange) NMA was performed and surface under the cumulative ranking curve (SUCRA) was estimated. Fifty-four trials were included in the NMA. Safflower oil had the highest SUCRA value for LDL-C (82%) and TC (90%), followed by rapeseed oil (76% for LDL-C, 85% for TC); whereas, palm oil (74%) had the highest SUCRA value for TG, and coconut oil (88%) for HDL-C. Safflower, sunflower, rapeseed, flaxseed, corn, olive, soybean, palm, and coconut oil as well beef fat were more effective in reducing LDL-C (−0.42 to −0.23 mmol/l) as compared with butter. Despite limitations in these data, our NMA findings are in line with existing evidence on the metabolic effects of fat and support current recommendations to replace high saturated-fat food with unsaturated oils.

Highlights

The aim of this network meta-analysis (NMA) is to compare the effects of different oils/solid fats on blood lipids
The effects of oils on blood lipids can be predicted from their fatty acid composition [10], one question that still remains to be answered is: which type of oils/ solid fats offers the greatest improvements on blood lipids, combining direct and indirect evidence? To address this issue in the present systematic review, we used the methodology of network meta-analysis (NMA), which enables a simultaneous comparison of intervention trials [11]
Eligibility criteria Studies were included in the NMA if they met all of the following criteria: i) randomized study examining diets varying in composition of at least two of the following oils/solid fats: safflower, sunflower, rapeseed, hempseed, flaxseed, corn, olive, soybean, palm, and coconut oil, and lard, beef fat, and butter; ii) comparison of isocaloric exchange of the different oils/solid fats within a trial; iii) minimum intervention period of 3 weeks; iv) patients with a mean age 18 years; v) outcomes including: LDL-C and total cholesterol (TC), HDL-C, and TGs

Summary

Introduction

The aim of this network meta-analysis (NMA) is to compare the effects of different oils/solid fats on blood lipids. Sunflower, rapeseed, flaxseed, corn, olive, soybean, palm, and coconut oil as well beef fat were more effective in reducing LDL-C ( 0.42 to 0.23 mmol/l) as compared with butter. Despite limitations in these data, our NMA findings are in line with existing evidence on the metabolic effects of fat and support current recommendations to replace high saturated-fat food with unsaturated oils.—Schwingshackl, L., B.

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