Effects of a Vegetarian Diet on Cardiometabolic Risk Factors, Gut Microbiota, and Plasma Metabolome in Subjects With Ischemic Heart Disease: A Randomized, Crossover Study

Abstract

Background A vegetarian diet (VD) may reduce future cardiovascular risk in patients with ischemic heart disease. Methods and Results A randomized crossover study was conducted in subjects with ischemic heart disease, assigned to 4‐week intervention periods of isocaloric VD and meat diet (MD) with individually designed diet plans, separated by a 4‐week washout period. The primary outcome was difference in oxidized low‐density lipoprotein cholesterol (LDL‐C) between diets. Secondary outcomes were differences in cardiometabolic risk factors, quality of life, gut microbiota, fecal short‐chain and branched‐chain fatty acids, and plasma metabolome. Of 150 eligible patients, 31 (21%) agreed to participate, and 27 (87%) participants completed the study. Mean oxidized LDL‐C (−2.73 U/L), total cholesterol (−5.03 mg/dL), LDL‐C (−3.87 mg/dL), and body weight (−0.67 kg) were significantly lower with the VD than with the MD. Differences between VD and MD were observed in the relative abundance of several microbe genera within the families Ruminococcaceae, Lachnospiraceae, and Akkermansiaceae. Plasma metabolites, including l ‐carnitine, acylcarnitine metabolites, and phospholipids, differed in subjects consuming VD and MD. The effect on oxidized LDL‐C in response to the VD was associated with a baseline gut microbiota composition dominated by several genera of Ruminococcaceae. Conclusions The VD in conjunction with optimal medical therapy reduced levels of oxidized LDL‐C, improved cardiometabolic risk factors, and altered the relative abundance of gut microbes and plasma metabolites in patients with ischemic heart disease. Our results suggest that composition of the gut microbiota at baseline may be related to the reduction of oxidized LDL‐C observed with the VD. Registration URL: https://www.clini​caltr​ials.gov ; Unique identifier: NCT02942628.

Effects of a Lacto-Ovo-Vegetarian Diet on the Plasma Lipidome and Its Association with Atherosclerotic Burden in Patients with Coronary Artery Disease—A Randomized, Open-Label, Cross-over Study

“…All participants provided oral and written informed consent. The primary outcome of this trial was to investigate difference in change in plasma oxidized LDL-C between diets, which has been published elsewhere [ 14 ]. The sample-size calculation was based on previous studies in which a VD or food supplements (nuts, soy-based cereal, cranberry juice) were shown to reduce oxidized LDL-C by 10% compared to no intervention and was based on an estimated 10% dropout rate.…”

“…The sample-size calculation was based on previous studies in which a VD or food supplements (nuts, soy-based cereal, cranberry juice) were shown to reduce oxidized LDL-C by 10% compared to no intervention and was based on an estimated 10% dropout rate. A total of 31 subjects were enrolled [ 14 ].…”

“…The flowchart of the study is presented in Figure 1 . The study design has been described previously [ 14 ]. In brief, the vegetarian diet in patients with ischemic heart disease (VERDI) trial was a prospective, randomized, open-labelled, cross-over study.…”

“…Detailed information of diets has been described previously [ 14 ]. Subjects were provided with ready-made frozen lunches and dinners based on traditional Swedish recipes, produced and supplied by Dafgård, Källby, Sweden.…”

“…In a recent randomized open-labelled cross-over study, we reported that a 4-week VD improved levels of oxidized low-density lipoprotein cholesterol and cardiometabolic risk factors including body mass index (BMI), body weight, total cholesterol, and low-density lipoprotein cholesterol, compared with an isocaloric meat-containing diet (MD) [ 14 ]. The goal of the current exploratory study was to determine the effects of a VD on the plasma lipidome and to investigate associations between plasma lipids and CAD burden, assessed by coronary angiogram from a recent percutaneous coronary intervention (PCI).…”