Discover what clinical trials say about a plant-based diet.

This randomized controlled trial studied 48 patients with heart disease to see if intensive lifestyle changes could reverse artery blockages over one year. The low-fat plant-based diet, exercise, stress management, and quitting smoking group showed a decrease in artery narrowing (40.0% to 37.8% on average), while the usual-care group worsened (42.7% to 46.1%). Among those with more severe blockages, narrowing decreased further (61.1% to 55.8%), while it worsened in the control group (61.7% to 64.4%), with 82% of lifestyle-change patients improving, suggesting heart disease can be reversed without medication. PubMed

This randomized controlled trial followed 48 heart disease patients for five years to assess whether intensive lifestyle changes could sustain heart disease reversal without medication. The low-fat plant-based diet, exercise, stress management, and smoking cessation group saw artery narrowing improve by 1.75 percentage points after one year and 3.1 points after five years, while the control group worsened by 2.3 points at one year and 11.8 points at five years (P = .001 between groups). The lifestyle group also had half as many cardiac events (25 vs. 45), showing that long-term adherence can further reverse heart disease and reduce complications. PubMed

This randomized clinical trial compared two low-fat diets in 120 adults over four weeks to assess their effects on cholesterol levels. Both diets met previous American Heart Association guidelines, but one included more vegetables, legumes, and whole grains. The plant-rich diet led to greater reductions in total cholesterol (-17.6 mg/dL vs. -9.2 mg/dL, P = 0.01) and LDL cholesterol (-13.8 mg/dL vs. -7.0 mg/dL, P = 0.02), suggesting that nutrient-dense plant foods enhance cholesterol-lowering effects beyond just reducing fat intake. PubMed

In this randomized study, 99 individuals with type 2 diabetes followed either a low-fat vegan diet or the American Diabetes Association (ADA) guidelines for 22 weeks. The vegan group saw greater improvements, with an average HbA1c reduction of 1.23 percentage points (vs. 0.38 in the ADA group, P = 0.01) among those who didn’t change medications. They also lost more weight (6.5 kg vs. 3.1 kg, P < 0.001) and had a greater reduction in LDL cholesterol (21.2% vs. 10.7%, P = 0.02). Overall, the low-fat vegan diet led to more significant improvements in blood sugar control, weight, and cardiovascular risk factors.. PubMed

This randomized controlled trial examined the effects of the Lifestyle Heart Trial (including a low-fat, plant-based diet) on psychological well-being over five years in heart disease patients. The intervention group (n = 28) followed an intensive lifestyle program, while the control group (n = 20) received usual care. After one year, the intervention group had significantly lower psychological distress and hostility (p < .05), with hostility improvements maintained at five years. Notably, only those with high adherence maintained reduced psychological distress. Additionally, better diet and stress management were linked to reductions in coronary artery narrowing (p < .05).. PubMed

In this study evaluating the Multisite Cardiac Lifestyle Intervention Program (an ongoing health insurance-covered lifestyle intervention), 27 participants with coronary artery disease or risk factors followed an intensive lifestyle program that included a plant-based diet, exercise, and stress management for 12 weeks. Compared to a control group, the experimental group showed a significant improvement in blood vessel function (FMD) by about 10%, while the control group experienced a slight decline. Additionally, inflammation markers like C-reactive protein and interleukin-6 dropped significantly in the experimental group, indicating that lifestyle changes can improve heart health and reduce inflammation. These results support the effectiveness of intensive lifestyle changes in improving cardiovascular health.. PubMed

The Mount Abu Open Heart Trial tested the effectiveness of a unique healthy and happy lifestyle (HLS) program in patients with moderate to severe coronary artery disease. The program included a low-fat, high-fiber vegetarian diet, moderate exercise, and stress management through Rajyoga meditation. Among 123 participants, those who adhered most to the program showed an 18.23% reduction in coronary artery blockage and fewer cardiac events compared to those with low adherence (risk ratio: 4.32). PubMed

This randomized controlled trial tested an 18-week low-fat plant-based diet in employees with overweight or type 2 diabetes at 10 corporate sites. Compared to the control group, the plant-based diet led to greater weight loss (-6.4 lbs] vs. -0.1 lbs], P < 0.001), lower LDL cholesterol (-8.1 mg/dL vs. -0.9 mg/dL, P < 0.01), and improved blood sugar control (-0.6 vs. -0.08 percentage points in HbA1C, P < 0.01). The findings suggest that a low-fat plant-based diet can improve weight, cholesterol, and diabetes markers in a workplace setting. PubMed

This randomized controlled trial compared a plant-based, no-added-fat diet to the American Heart Association (AHA) diet in 30 children (ages 9-18) with obesity and high cholesterol over 4 weeks. The plant-based diet led to greater reductions in BMI z-score (-0.14), systolic blood pressure (-6.43 mm Hg), total cholesterol (-22.5 mg/dL), LDL cholesterol (-13.14 mg/dL), and inflammation markers (P < 0.05), while the AHA diet primarily improved waist circumference (-2.96 cm). Both diets improved cardiovascular risk factors, but food accessibility was a barrier to plant-based adherence. Larger, long-term studies are needed to confirm these findings. PubMed

This 6-month randomized controlled trial examined nutrient intake and Dietary Inflammatory Index (DII) scores among 63 overweight and obese adults (BMI 25.0-49.9 kg/m²) assigned to vegan (n = 12), vegetarian (n = 13), pescovegetarian (n = 13), semivegetarian (n = 13), or omnivorous (n = 12) diets. At 2 months, the vegan group showed greater reductions in fat, saturated fat, and cholesterol, and higher fiber intake compared to most other diets (P < 0.05). Vegan, vegetarian, and pescovegetarian groups had lower DII scores than semivegetarians at 2 months (P < 0.05), but differences were not sustained at 6 months. Strategies to support adherence to plant-based diets may enhance long-term benefits. PubMed

This 16-week randomized clinical trial tested the impact of a plant-based, high-carbohydrate, low-fat (vegan) diet on body weight, body composition, and insulin resistance in 75 participants. The vegan group experienced significant weight loss (−6.5 kg), reduced fat mass (−4.3 kg), and improved insulin sensitivity (reduction in HOMA-IR by −1.0). Increased carbohydrate and fiber intake were associated with reductions in BMI, fat mass, and visceral fat, as well as improved insulin resistance. PubMed

This 8-week randomized controlled trial with 100 participants with coronary artery disease, compared a vegan diet to the American Heart Association (AHA)-recommended diet. They found that the vegan diet led to a significant 32% reduction in high-sensitivity C-reactive protein (hsCRP), a marker of inflammation linked to heart disease risk (P=0.02). There were no significant differences in weight loss, waist circumference, or glycemic control between the two diet groups, and the vegan diet group had a 13% reduction in LDL cholesterol (P=0.01). These findings suggest a vegan diet may help reduce inflammation in people with coronary artery disease. PubMed

A 16-week randomized clinical trial in Washington, DC, tested the effects of a low-fat plant-based diet on weight loss, metabolism, and insulin sensitivity in 244 overweight adults. Participants in the diet group lost an average of 5.9 kg (13 lbs), had a 14.1% increase in post-meal metabolism, and showed significant improvements in insulin resistance. They also experienced a 34.4% reduction in liver fat and a 10.4% decrease in muscle fat, while the control group saw no significant changes. These findings suggest that a low-fat vegan diet can effectively promote weight loss, enhance metabolism, and improve insulin function.. PubMed

The 15-day Jumpstart program helped 389 participants adopt a low-fat whole-food, plant-based diet, leading to rapid health improvements. On average, participants lost 5.8 lbs, lowered systolic blood pressure by 6.8 points, and reduced cholesterol by 26 points (P < .001). Those with higher baseline risk saw even greater benefits, including a 16.8-point drop in systolic blood pressure (if >140) and a 44-point reduction in cholesterol (if >200). This structured, short-term intervention effectively improved key health markers through dietary changes, education, and social support.. PubMed

An eight-week randomized study from the CardioVeg study compared the nutrient profiles and health effects of a whole-food, plant-based diet (PBD) vs. an omnivorous diet in individuals with cardiovascular risk factors (PBD group: n = 36, control: n = 34). The PBD group had lower energy density, cholesterol, saturated fat, and salt intake, along with higher fiber consumption. While most vitamin and mineral needs were met, vitamin B12 was insufficient in the PBD group, and both groups had low vitamin D and iodine intake. Compared to the control group, the PBD group saw significant reductions in body weight, BMI, waist circumference, HbA1c, and fasting blood glucose, suggesting a more heart-healthy nutrient profile than an omnivorous diet. PubMed