Effects of Monounsaturated Fatty Acids on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis

Abstract

The appropriate pattern of macronutrient distribution for dietary protocols aimed at treating or preventing obesity and its associated cardiovascular diseases is still a controversial topic of discussion. Recommendations considering a specific percentage or range for monounsaturated fatty acids (MUFA) are rare. It was the aim of this study to analyze long-term, randomized, controlled dietary intervention trials and to investigate the effects of MUFA on the biomarkers of obesity and cardiovascular risk factors. Dietary regimens with a high amount of MUFA (>12%) were compared to those with ≤12%. The biomarkers taken into account were weight, waist circumference, fat mass, total cholesterol, LDL cholesterol, HDL cholesterol, triacylglycerols, systolic and diastolic blood pressure, as well as C-reactive protein. A total of 12 studies met the inclusion criteria. Data analysis was performed using the Review Manager 5.0.25 software. Significant differences between high- and low-MUFA protocols could be observed with respect to fat mass [–1.94 kg (confidence interval –3.72, –0.17), p = 0.03], systolic blood pressure [–2.26 mm Hg (confidence interval –4.28, –0.25), p = 0.03] and diastolic blood pressure [–1.15 mm Hg (confidence interval –1.96, –0.34), p = 0.005] favoring the dietary protocols with >12% MUFA. Therefore, MUFA might represent a useful tool in the design of dietary regimens for obesity and cardiovascular disease.

Olive oil has a beneficial effect on impaired glucose regulation and other cardiometabolic risk factors. Di@bet.es study

“…High-MUFA regimes seem to have a significantly more pronounced impact on fat mass than on total weight. 11 The results of this national, crosssectional study show that obese persons and persons with a carbohydrate metabolism disorder generally consumed less olive oil and that persons who consumed olive oil tended to have a lower prevalence of obesity and type 2 diabetes mellitus, supporting the hypothesis of a lower risk for obesity and type 2 diabetes mellitus in persons who consume olive oil, as found in several prospective studies 32,33 and in a recent clinical trial in persons at high risk for cardiovascular disease. 34 Of particular note was the association found between olive oil consumption and the population pattern of insulin resistance.…”

“…22 The relations between the type of dietary fat, plasma lipid levels and cardiovascular risk have repeatedly been confirmed in experimental as well as clinical and epidemiological studies. 11 Low-fat diets usually reduce both LDL cholesterol and HDL cholesterol. [23][24][25] The replacement of carbohydrates by dietary fats reduces triglyceride levels and increases HDL cholesterol, [26][27][28] whereas the substitution of saturated fats by monounsaturated fats decreases levels of LDL cholesterol 27 or at least does not change them 28,3 but increases levels of HDL cholesterol 26,28 In our study, persons who consumed olive oil had lower values of triglycerides and slightly higher (but nonsignificant) levels of LDL cholesterol, and both men and women had higher levels of HDL cholesterol, with a significantly lower probability of having low HDL cholesterol levels.…”

“…7 Most studies have examined the role of the saturated fatty acids and the n-6 and n-3 fatty acids, [8][9][10] with less being known about the role played in body weight by the monounsaturated fatty acids (MUFA). 11 Although the biological effect of a MUFA-rich diet on plasma lipids has been known since the middle of the last century, it was not until more recently that different studies determined the effect of dietary MUFA on the risk for obesity, type 2 diabetes mellitus, the various plasma lipid patterns and numerous other clinical and biological variables. [11][12][13] Despite the highly significant increase in cardiovascular risk factors in recent years in Spain, 14 the prevalence and incidence of cardiovascular diseases have not risen at the expected rate; 15 this situation has become known as the 'Spanish paradox'.…”

“…11 Although the biological effect of a MUFA-rich diet on plasma lipids has been known since the middle of the last century, it was not until more recently that different studies determined the effect of dietary MUFA on the risk for obesity, type 2 diabetes mellitus, the various plasma lipid patterns and numerous other clinical and biological variables. [11][12][13] Despite the highly significant increase in cardiovascular risk factors in recent years in Spain, 14 the prevalence and incidence of cardiovascular diseases have not risen at the expected rate; 15 this situation has become known as the 'Spanish paradox'. 16 The aim of this study was to examine the association between consumption of olive oil and the presence or absence of various cardiometabolic risk factors in the context of a large study representative of the whole Spanish population.…”

Dietary Fatty Acids and Cardiovascular Disease: A review

“…Two additional meta-analyses of randomized clinical trials and cohort studies also reported the beneficial effects of MUFA-rich diets on the reduction of CVD, although these findings were not conclusive 37,38 .…”