A plant-based diet (eating lots of plant foods - fruits, vegetables, whole grains, legumes, seeds and nuts) once again shows health benefits in a new study - here a lower incidence of type 2 diabetes. But what kind of plant-based foods one eats is important: consumption of a plant-based diet that emphasized healthy plant foods was associated with a larger decrease (34%) in diabetes risk, while consumption of a plant-based diet high in less healthy plant foods (soda, fruit juices, sweets/desserts, refined grains) was associated with a 16% increased diabetes risk. From Medical Xpress:
Consuming a plant-based diet—especially one rich in high-quality plant foods such as whole grains, fruits, vegetables, nuts, and legumes—is linked with substantially lower risk of developing type 2 diabetes, according to a new study from Harvard T.H. Chan School of Public Health.
While previous studies have found links between vegetarian diets and improved health outcomes, including reduced risk of type 2 diabetes, this new study is the first to make distinctions between healthy plant-based diets and less healthy ones that include things like sweetened foods and beverages, which may be detrimental for health. The study also considered the effect of including some animal foods in the diet.
The researchers followed more than 200,000 male and female health professionals across the U.S. for more than 20 years who had regularly filled out questionnaires on their diet, lifestyle, medical history, and new disease diagnoses as part of three large long-term studies. The researchers evaluated participants' diets using a plant-based diet index in which they assigned plant-derived foods higher scores and animal-derived foods lower scores.
The study found that high adherence to a plant-based diet that was low in animal foods was associated with a 20% reduced risk of type 2 diabetes compared with low adherence to such a diet. Eating a healthy version of a plant-based diet was linked with a 34% lower diabetes risk, while a less healthy version—including foods such as refined grains, potatoes, and sugar-sweetened beverages—was linked with a 16% increased risk. Even modestly lowering animal food consumption—for example, from 5-6 servings per day to about 4 servings per day—was linked with lower diabetes incidence, the study found.
The researchers suggested that healthful plant-based diets could be lowering type 2 diabetes risk because such diets are high in fiber, antioxidants, unsaturated fatty acids, and micronutrients such as magnesium, and are low in saturated fat. Healthy plant foods may also be contributing to a healthy gut microbiome, the authors said.