Effects of a Paleolithic Diet on Cardiovascular Disease Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Abstract

ABSTRACTThere is some evidence supporting the beneficial effects of a Paleolithic diet (PD) on cardiovascular disease (CVD) risk factors. This diet advises consuming lean meat, fish, vegetables, fruits, and nuts and avoiding intake of grains, dairy products, processed foods, and added sugar and salt. This study was performed to assess the effects of a PD on CVD risk factors including anthropometric indexes, lipid profile, blood pressure, and inflammatory markers using data from randomized controlled trials. A comprehensive search was performed in the PubMed, Scopus, ISI Web of Science, and Google Scholar databases up to August 2018. A meta-analysis was performed using a random-effects model to estimate the pooled effect size. Meta-analysis of 8 eligible studies revealed that a PD significantly reduced body weight [weighted mean difference (WMD) = −1.68 kg; 95% CI: −2.86, −0.49 kg], waist circumference (WMD = −2.72 cm; 95% CI: −4.04, −1.40 cm), BMI (in kg/m2) (WMD = −1.54; 95% CI: −2.22, −0.87), body fat percentage (WMD = −1.31%; 95% CI: −2.06%, −0.57%), systolic (WMD = −4.75 mm Hg; 95% CI: −7.54, −1.96 mm Hg) and diastolic (WMD = −3.23 mm Hg; 95% CI: −4.77, −1.69 mm Hg) blood pressure, and circulating concentrations of total cholesterol (WMD = −0.23 mmol/L; 95% CI: −0.42, −0.04 mmol/L), triglycerides (WMD = −0.30 mmol/L; 95% CI: −0.55, −0.06 mmol/L), LDL cholesterol (WMD = −0.13 mmol/L; 95% CI: −0.26, −0.01 mmol/L), and C-reactive protein (CRP) (WMD = −0.48 mg/L; 95% CI: −0.79, −0.16 mg/L) and also significantly increased HDL cholesterol (WMD = 0.06 mmol/L; 95% CI: 0.01, 0.11 mmol/L). However, sensitivity analysis revealed that the overall effects of a PD on lipid profile, systolic blood pressure, and circulating CRP concentrations were sensitive to removing some studies and to the correlation coefficients, hence the results must be interpreted with caution. Although the present meta-analysis revealed that a PD has favorable effects on CVD risk factors, the evidence is not conclusive and more well-designed trials are still needed.