Eating a plant-based diet can do wonders for your health. Studies have found limiting red meat and eating whole grains, legumes, and a variety of colorful fruits and veggies can lower cholesterol and the risk of cardiovascular disease, prevent type 2 diabetes and even prolong human life — not to mention the life of the planet.
When it comes to preventing diabetes, however, those benefits may only manifest if the plant-based diet is a healthy one that curtails foods that are highly processed or loaded with sugar, according to a new study that analyzed 206 different types of foods.
The 12-year analysis of dietary patterns of over 113,000 participants of the UK Biobank study, a longitudinal study of health among the country’s residents, placed people into four categories based on their intake of fresh fruit, vegetables and whole grains.
People in the top 25% mostly ate a plant-based diet low in sweets, desserts, refined grains and sugary drinks. People in the bottom 25% consumed many more of those unhealthy plant-based foods.
Compared with people in the lowest tier, those who ate the most whole grains, fresh fruits and vegetables and limited their intake of unhealthy options reduced their risk of diabetes by 24%, according to the study published Tuesday in the journal Diabetes & Metabolism.
People who ate the healthiest diet also had lower body mass index and waist circumference, as well as better blood sugar levels and lower inflammatory levels.
The benefit extended to people genetically predisposed to diabetes and those who had other risk factors for diabetes such as obesity, the study found.
“These data are really important, particularly for those thought to be at high risk of developing type two diabetes as it demonstrates they can greatly reduce their risk by following a healthy plant-based diet,” said first author Alysha Thompson, a doctoral student at Queen’s University Belfast in Northern Ireland, in a statement.
However, people eating the least healthy plant-based diet had a 37% higher risk of developing type 2 diabetes, along with a greater waist circumference and higher levels of triglycerides, a form of cholesterol, the study found.
In fact, obesity was a “key mediator underlying greater type two diabetes risk among individuals following unhealthful plant-based diets,” said coauthor Tilman Kühn, a lecturer from the Institute for Global Food Security at Queen’s University Belfast and chair in public health nutrition at the Medical University of Vienna, in a statement.
What’s the underlying mechanism?
How does a healthy plant-based diet help protect the body from type 2 diabetes? By impacting a range of antidiabetic mechanisms “including blood sugar and lipid levels and lower body fatness,” Kühn said.
Another finding was the important role played by the kidney and liver in reducing the risk of type 2 diabetes, said coauthor Aedín Cassidy, a professor at Queen University Belfast’s Institute for Global Food Security.
“For the first time we have shown that improvements in both metabolism and the function of the liver and the kidney as a result of a healthy plant-based diet, may explain how this diet can reduce the risk of type two diabetes,” Cassidy said in a statement.
Although the study only found an association, not a direct cause and effect, the findings were “interesting,” said Duane Mellor, a registered dietitian and senior teaching fellow at Aston Medical School in Birmingham, UK, in a statement to the Science Media Centre in London.
The analysis “looked at aspects of liver health and other measures of inflammation and explored how they might be linked to diet and risk of developing type 2 diabetes,” said Mellor, who was not involved in the study. “This suggests a number of possible designs for future research to actually assess if this type of plant-based diet can actually reduce risk of developing type 2 diabetes.”
