People who tend to eat mostly plants may be less likely to develop type 2 diabetes, a research review suggests. Researchers examined data from nine previously published studies with a total of 307,099 participants, including 23,544 people who developed type 2 diabetes. The length of the studies ranged from 2 to 28 years. All of the studies used food frequency questionnaires to assess participants' diets.

Overall, people who most closely adhered to a vegan, vegetarian or other type of plant-based diet were 23 percent less likely to develop type 2 diabetes than people who consumed the least amount of plant-based meals, researchers report in JAMA Internal Medicine.

"Plant-based diets can promote metabolic health and reduce diabetes risk through many pathways, including preventing excess weight gain, improving insulin sensitivity, reducing inflammation, and other mechanisms," said Dr. Qi Sun, senior author of the study and a researcher at the Harvard T.H. Chan School of Public Health and Brigham and Women's Hospital in Boston.

People who eat a healthy variety of plant-based meals can lower their diabetes risk even when they're not strict vegetarians — avoiding meat, poultry and fish or vegans also avoiding animal products like milk and eggs.

But they may not benefit as much if their plant-based diet is full of foods like French fries, white bread, and white rice, Sun said by email.

"It does matter what veggies people eat and how the veggies are processed," Sun said. "Therefore, consuming healthy plant foods that are not or minimally processed, such as fresh fruits and vegetables, legumes, nuts, and whole grains, should be emphasized." People in the study who followed this advice

with the healthiest mix of fruits, vegetables and whole grains in their plant-based diets, were 30 percent less likely to develop type 2 diabetes than participants who tended to ignore this idea.

Type 2 diabetes, the most common form, is linked to obesity and aging and happens when the body can't properly use or make enough of the hormone insulin to convert blood sugar into energy. Left unchecked, diabetes can lead to serious complications like nerve damage, blindness, amputations, kidney damage and heart problems.