The importance of dietary antioxidants on plasma antioxidant capacity and lipid peroxidation in vivo in middle-aged men

Abstract

Background: Sustainable nutritional strategies to reduce risk factors of cardiovascular diseases are highly needed. Inclusion of meal replacements may increase adherence to plant-based diets (PBDs). Objective: The aim of this study was to test the effects of a transition from a western-type diet to a new nutritional paradigm with a PBD from predominately unrefined whole food sources, eaten ad libitum and including nutrient-enriched plant-based meal replacements twice daily. Design: This was a single-arm, prospective interventional trial for 10 weeks in 36 participants with extension to 36 weeks in 18 participants. The main endpoint was serum low-density lipoprotein (LDL)-cholesterol measured at baseline, after 10 weeks (phase 1), and after 36 weeks (phase 2). Secondary endpoints included total, non-high-density lipoprotein (HDL) and HDL-cholesterol, fasting glucose, uric acid, and insulin-like growth factor-1 (IGF-1). Results: The mean reduction in LDL-cholesterol was 0.6 (95% confidence interval [CI], 0.3–0.8) mmol/L (−15%, P < 0.001) at the end of phase 1, with no further change by the end of phase 2. Similar reductions were noted for non-HDL-cholesterol and total cholesterol. HDL-cholesterol was reduced by 0.16 mmol/L (95% CI, 0.1–0.2). There was a borderline reduction in fasting glucose (5.2 to 5 mmol/L in phase 1, P = 0.08) and a small significant rise in serum uric acid levels of 15 (95% CI, 1–28) μmol/L, P < 0.05. Median baseline value for IGF-1 concentration was 156 μg/L. Participants with baseline IGF-1 below median had a significant increase in IGF-1 value from baseline 110 ± 31 to 132 ± 39 at the end of phase 1 (mean change of +22 μg/L, 95% CI, 11–33, P = 0.001). Participants with baseline IGF-1 above median had no significant change in IGF-1. Significant reductions in body weight, body fat, and visceral fat were observed. Conclusions: Supplemented, unrefined PBD eaten ad libitum was effective in improving total and LDL-cholesterol, non-HDL-cholesterol, and IGF-1 in low baseline IGF-1 subgroup. This trial is registered as NCT02905448 at https://clinicaltrials.gov, registered 19.9.2016, https://clinicaltrials. gov/ct2/show/NCT02905448.