A Plant-Based Diet Is Linked to a 23 Percent Reduced Risk for Type 2 Diabetes
Updated: Aug 11, 2020
Eating fewer animal products, including eggs, dairy, and meat, and more plants, such as fruits and veggies, may help keep diabetes at bay, a study suggests.Opting for plant-based protein such as chickpeas is a boon to your health.
Smart diet and lifestyle choices are critical for maintaining health, especially when you’re looking to prevent type 2 diabetes. For the more than 1 in 3 Americans with prediabetes, losing weight and increasing physical activity can mean avoiding a type 2 diabetes diagnosis and potentially having a longer life, according to the Centers for Disease Control and Prevention (CDC).
Building healthy eating patterns can be challenging, but a new analysis suggests a good starting point. The review, published in July 2019 in JAMA Internal Medicine, found that following a plant-based diet, even if you don’t lose weight, may lower your risk for type 2 diabetes.
“We found that individuals who ate largely plant-based diets, including vegan or vegetarian diets and other diets with an emphasis of plant foods, had a lower risk of developing type 2 diabetes,” says the senior study author, Qi Sun, MD, an associate professor in the department of nutrition at Harvard T.H. Chan School of Public Health in Boston.
This study has two simple yet critical takeaways, says Mladen Golubic, MD, PhD, the medical director for the Center for Lifestyle Medicine at Cleveland Clinic in Lyndhurst, Ohio, who was not involved in the research. “Eat more plants and make sure those plant foods are unrefined and unprocessed,” says Golubic.
To uncover the impact a plant-based diet could have on type 2 diabetes risk, researchers used data from nine previously published prospective studies that involved 307,099 participants. Subjects were followed anywhere from 2 to 28 years.
The average age of subjects ranged from 36 to about 65 years old, and their mean body mass index (BMI) was 23 to 26.7, meaning some of the participants were of normal weight and some were overweight, per the CDC.
The authors defined a plant-based diet as any eating pattern where a person consumed more plant-based foods, and limited or eliminated animal-based foods like meat, dairy, eggs, and fish. The studies were similar in their attempts to quantify the benefits of a plant-based diet, but they had different designs and endpoints. Participants in all the studies used the Food Frequency Questionnaire to report their food intake.
During the follow-up, participants reported or researchers evaluated whether they developed type 2 diabetes, answering questions on diagnosis, symptoms, and medications to confirm their condition.
A total of 23,544 participants (7.7 percent) developed type 2 diabetes during the trial periods. By comparing the diets and the diagnosis of diabetes in each study, researchers calculated that following a more plant-based diet was associated with a 23 percent risk reduction for developing diabetes.
In five of these studies researchers were actually able to measure the dose response, noted Dr. Golubic. “The people who ate healthier plant-based foods and limited processed foods had a greater risk reduction for developing diabetes,” says Golubic.
What Happens in Your Body When You Eat More Fruits, Vegetables, and Whole Grains?
Previous summary studies of observational studies and randomized controlled trials have shown that substituting plant-sources of protein or fat for those from animal-sources is associated with improved heart and metabolic health, among other benefits, says Frank Qian, MPH, a current medical student at the University of Chicago and a coauthor of the study. A presentation at the 2019 American Heart Association meeting found that adding high-quality plant-based foods to your diet decreases your risk of premature death from heart disease and other causes. Those foods include fruits, vegetables, whole grains, and legumes.
When you eat a plant-based diet, you take in hundreds of beneficial compounds that interact through countless pathways to influence the body's weight homeostasis, glucose-insulin response, inflammation and oxidative stress (which are linked to various health conditions, past research notes), and gut microbiome composition and function, says Qian. “These pathways all likely contribute to the beneficial association we observed,” he adds.
Some of the risk reduction could be due to the effects of plant-based diets on weight control, says Dr. Sun. “Most of the foods that comprise a plant-based diet have been shown in prior observational and interventional studies to mediate weight loss or prevent long-term weight gain,” says Qian.
Because researchers wanted to measure benefits of the plant-based diet and not the benefits of weight loss, they controlled for BMI in the statistical analyses. “We essentially removed the benefits through weight control from the estimated reduction of diabetes risk for eating plant-based diets,” says Sun. Because of that, the 23 percent reduction may be an underestimate; the risk reduction may be higher if a person also loses weight, he adds.
“It’s important to note that a person can eat a fully plant-based diet that is full of sugar and refined grains like bread and pastas, and that clearly is not helpful,” says Golubic. Eating foods like that actually increases the risk for diabetes and other diseases, he says.