A Vegetarian Diet May Help Improve Your Cholesterol, Blood Sugar Levels and Lead to Weight Loss

The American Heart Association’s recommendations for a healthy dietary pattern include a diet focused on minimally processed plant foods, fish, seafood, and low-fat dairy. The meta-analysis looked at 20 randomized controlled trials that show the role of a vegetarian diet in the prevention of cardiovascular diseases in the general population.

“This study aims to discuss the relationship between a plant-based diet and cardiometabolic risk factors, using randomized clinical trials,” said Jenna Litt, a registered dietitian at Northwell Lenox Hill Hospital, who was not involved in the study. “This study differs from previous studies, as it focuses on different types of vegetarian diets, like vegan versus lacto-ovo-vegetarian.”

Of all the studies that the researchers screened, they were able to find 20 articles to include with the average age of sample sizes ranging from 28 to 64 and the average study duration ranging from 2 to 24 months. Results of this study showed that vegetarian diets were associated with decreasing LDL-C or “bad” cholesterol within six months. Additionally, it led to better HbA1c (a measure for blood sugar) levels, and lower body weight. It showed a non-significant relationship between plant-based diets and systolic blood pressure.

This means that it may be beneficial for someone who is at high risk for cardiovascular disease to start incorporating vegetarian patterns into their diet.

“Based on this study, there is a clear relationship between a plant-based diet and reduction in cardiometabolic risk,” said Litt. “Thus, going forward, it may be beneficial for those who are at greater cardiometabolic risk to trial a modified plant-based diet.”

A modified plant-based diet means following plant-based one to two times a week to see if there is any improvement in weight, HbA1c, or LDL cholesterol levels.

Before anyone embarks on a vegetarian or plant-based diet, it’s important to understand what exactly that means.

“I’m frustrated with the term ‘vegetarian,’ because it doesn’t imply that people are choosing a healthy diet,” said Christopher D. Gardner, Ph.D., chair of the American Heart Association’s Lifestyle Nutrition Committee and the Rehnborg Farquhar Professor of Medicine at Stanford University in Stanford, California. “I much prefer a whole-food, plant-based diet as a term.”

Gardner conducted a study in 2005 that looked at two low-fat diets, both of which met the guidelines of the American Heart Association. One featured Snackwell cookies, chicken without the skin, and mashed potatoes with light margarine, while the other featured a spinach salad with an egg, whole grain bread with butter, and lentil soup with cheese. In that study, the convenience food low-fat diet lowered LDL by 5%. The second diet with whole foods lowered LDL by 10 percent.

“Our message to physicians was that they just can’t say ‘low fat’ when prescribing a diet. And it’s the same when using the word vegetarian,” he said.

The meta-analysis studies included patients with cardiovascular disease, diabetes, and those with at least two cardiovascular risk factors. The most commonly prescribed diets were vegan, lacto-ovo-vegetarian, and facto-vegetarian. Those who consumed a vegetarian diet for six months, versus comparison diets, had significantly greater decreases in LDL-C, A1c, and body weight, but the reduction in systolic blood pressure was not significantly greater.

“Given the lack of impact on blood pressure would lead me to look into the quality of the vegetarian diet. Was it possible that they were given convenience food vegetarian diets that had a lot of sodium, as a lot of packaged foods do? Maybe the foods were salted and that’s why the blood pressure didn’t drop,” Gardner said.

Litt added, “It is important to keep in mind that if you plan to start a plant-based diet, it may require increased research on the correct products to purchase, as there are many processed/packaged goods that brand themselves as plant-based, however, tend to be higher in sodium, sugar, or cholesterol.”

“The results [in the meta-analysis] are quite reasonable but fairly predictable,” Gardner noted. “If you have a vegetarian diet, it will have more fiber and less saturated fat so LDL cholesterol will go down. If you have less sodium, your blood pressure will go down. If you have less sugar and refined grains, your weight will go down. It’s nice that the studies were all pooled, but it’s repeating what we already knew.”

A meta-analysis finds that people on a vegetarian diet may see significant improvements in lowering LDL or “bad” cholesterol, help with blood sugar levels, and lower body weight.