Effects of high-quality protein supplementation on cardiovascular risk factors in individuals with metabolic diseases: A systematic review and meta-analysis of randomized controlled trials.

Uncertainties still existed about the effect of high-quality protein supplementation on cardiovascular disease (CVD) risk factors, although high-quality proteins such as soy and milk proteins have proposed to be beneficial for cardiometabolic health. A systematic search in PubMed, Web of Science, Cochrane Library, Scopus, and Embase was conducted to quantify the impact of high-quality protein on CVD risk factors. 63 RCTs on 4 types of high-quality protein including soy protein, milk protein, whey, and casein were evaluated. Soy protein supplementation decreased systolic blood pressure (SBP, −1.42 [-2.68, −0.17] mmHg), total cholesterol (TC, −0.18 [-0.30, −0.07] mmol/L), and low-density lipoprotein cholesterol (LDL-C, −0.16 [-0.27, −0.05] mmol/L). Milk protein supplementation decreased SBP (−2.30 [-3.45, −1.15] mmHg) and total cholesterol (−0.27 [-0.51, −0.03] mmol/L). Whey supplementation decreased SBP (−2.20 [-3.89, −0.51] mmHg), diastolic blood pressure (DBP, −1.07 [-1.98, −0.16] mmHg), triglycerides (−0.10 [-0.17, −0.03] mmol/L), TC (−0.18 [-0.35, −0.01] mmol/L), LDL-C (−0.09 [-0.16, −0.01] mmol/L) and fasting blood insulin (FBI, −2.02 [-3.75, −0.29] pmol/L). Casein supplementation decreased SBP (−4.10 [-8.05, −0.14] mmHg). In the pooled analysis of four high-quality proteins, differential effects were seen in individuals with different health status. In hypertensive individuals, high-quality proteins decreased both SBP (−2.69 [-3.50, −1.87] mmHg) and DBP (−1.34 [-2.09, −0.60] mmHg). In overweight/obese individuals, high-quality proteins improved SBP (−1.40 [-2.22, −0.59] mmHg), DBP (−2.59 [-3.20, −1.98] mmHg), triglycerides (−0.09 [-0.15, −0.02] mmol/L), TC (−0.14 [-0.22, −0.05] mmol/L), LDL-C (−0.12 [-0.16, −0.07] mmol/L), and HDL-C levels (0.02 [0.01, 0.04] mmol/L). According to the benefits on CVD risks factors, whey ranked top for improving cardiometabolic health in hypertensive or overweight/obese individuals. Our study supports a beneficial role of high-quality protein supplementation to reduce CVD risk factors. Further studies are still warranted to investigate the effects of different high-quality proteins on CVD risks in individuals with cardiometabolic disorders. [ABSTRACT FROM AUTHOR]