Oil Consumption and Cardiovascular Disease: An Umbrella Review of Systematic Reviews and Meta-Analyses

Abstract

Objectives Cooking oils are composed of various fatty acids (FA) with different proportions which could influence on cardiovascular disease (CVD) differently. The effect of tropical oil consumption and the negative health impact of saturated fats consumption on CVD are controversial. Methods We performed an umbrella review of the systematic reviews and meta-analyses that investigated the effect of edible oils by isocaloric substitution for other oils consumed for at least 2 weeks on lipid profiles and CVD. Electronic databases including Medline, Scopus, Embase and Cochrane were searched until December 2018 by 2 independent reviewers without restriction of language and year of publication. Results The umbrella review identified 9 meta-analyses and 2 systematic reviews investigated the effect of oils on lipid levels and CVD, respectively. Corrected covered area was 7.4% illustrating the moderate overlap of primary trials. Our study demonstrated that replacement of polyunsaturated FA-rich oils (PUFAs) and monounsaturated FA-rich oils (MUFAs) by palm oil consumption significantly increased LDL-cholesterol by 4.75 mg/dL (95%CI: 0.45, 9.06) and 9.26 mg/dL(95% CI: 3.01, 15.51), respectively and HDL-cholesterol by 1.89 mg/dL (95%CI: 1.23, 2.55) and 0.53 mg/dL (95%CI: −1.71, 2.77), respectively. However, replacement of PUFAs or other saturated fats by coconut oil significantly increased HDL-c by 2.27 mg/dL (95%CI: 0.93, 3.6) and 1.48 mg/dL (95%CI: 0.20, 2.76), respectively but not LDL-c. The substitution of lard for MUFAs and PUFAs showed the increasing of LDL-c by 8.39 mg/dL (95%CI: 2.83, 13.95) and 9.85 mg/dL (95%CI: 6.06, 13.65), respectively but there was no significant effect on HDL-c. Soybean oil substituted for other PUFAs had no different effect on lipid levels while rice bran oil substitution decreased LDL-c. The association of edible oil consumption and the cardiovascular event and mortality could not be revealed due to small number of the studies. Conclusions Our study confirmed the deleterious effect of saturated fats on lipid profiles and showed the different effect of saturated fats from animal and plant. We demonstrated only the modest benefit of coconut oil on HDL-c but could not reveal the benefit on cardiovascular outcomes. Thus, dietary saturated fats should be replaced with either PUFAs or MUFAs. Funding Sources Thai Health Promotion Foundation.

Raw and Cooked Vegetable Consumption and Risk of Cardiovascular Disease: A Study of 400,000 Adults in UK Biobank

“…For example, Lee et al found that vitamin C retention after cooking ranged from 0 to 91% for various combinations of cooking methods and vegetable, with higher retention after microwaving and lower retention after boiling ( 22 ). Third, the seasoning and oils used in cooking vegetables often increase intake of sodium and fat, which are known risk factors for CVD incidence and mortality ( 23 , 24 ).…”

“…For example, Lee et al found that vitamin C retention after cooking ranged from 0 to 91% for various combinations of cooking methods and vegetable, with higher retention after microwaving and lower retention after boiling (22). Third, the seasoning and oils used in cooking vegetables often increase intake of sodium and fat, which are known risk factors for CVD incidence and mortality (23,24). Despite these proposed mechanisms, this study indicates that observed associations of vegetable intakes with CVD risk and all-cause mortality are likely to be mostly accounted for by residual confounding.…”