Vegan and Vegetarian Diets' Impact on Blood Lipids: A Comprehensive Meta-Analysis

A research article reviewed past studies on vegan diets to see how they impact heart disease risk factors like cholesterol. The researchers found strong evidence that vegan diets lower bad cholesterol and may reduce the chance of heart attacks and strokes.

What the Study Found

The study combined and analyzed data from 11 previous experiments comparing vegan/vegetarian diets to non-vegetarian ones. In total, over 800 adults participated across diverse countries. On average, switching to a vegan diet:

Lowered total cholesterol by about 14 mg/dL

Lowered “bad” LDL cholesterol by about 13 mg/dL

Lowered “non-HDL cholesterol” by 12 mg/dL

Lowered “good” HDL cholesterol by 4 mg/dL

So vegan diets improved 3 out of 4 heart disease risk factors. The authors estimate eating vegan could cut someone's heart disease risk by 9-11%.

Why Vegan Diets Are Heart-Healthy

Vegan diets are free of cholesterol and saturated fats found in meat and dairy. They also have lots of fiber, vitamins, antioxidants from plants that prevent “bad” cholesterol from clogging arteries.

For example, nutrients called phytosterols stop cholesterol absorption. Other plant compounds improve cholesterol levels via different methods.

Together, these factors give vegans better overall cholesterol levels compared to meat-eaters. As a result, switching to vegan drops heart attack/stroke risk.

Caveats of the Study

A few limitations existed. Participants weren’t blinded - they knew which diet they were on. Also, vegans lost 2-3x more weight which could partially explain cholesterol improvements. Lastly, HDL (“good”) cholesterol unfortunately decreased too.

Still, the total evidence showed clear heart health benefits from plant-based diets. No study perfectly proves anything, but this adds to extensive research about vegan diet perks.

The Bottom Line

This thorough study analysis provides strong evidence that switching to a vegan diet substantially lowers cholesterol and likely reduces long-term heart disease risk. So for better heart health, consider ditching meat and dairy for more fruits, vegetables, beans, lentils, nuts and whole grains!

Wang F, Zheng J, Yang B, Jiang J, Fu Y, Li D. Effects of Vegetarian Diets on Blood Lipids: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Am Heart Assoc. 2015 Oct 27;4(10):e002408. doi: 10.1161/JAHA.115.002408. PMID: 26508743; PMCID: PMC4845138.