Carb-rich plant-based diets improve type 1 diabetes, studies find

Plant-based diets rich in whole carbohydrates can improve insulin sensitivity and other health markers in individuals with type 1 diabetes, according to two case studies published by researchers from the Physicians Committee for Responsible Medicine.

Both case studies followed individuals with type 1 diabetes who adopted plant-based diets rich in whole carbohydrates – including fruits, vegetables, whole grains, and legumes. The patients’ health care teams tracked their blood sugar control, heart disease risk factors, and other health measurements before and after the diet change.

One case study followed a female patient who was diagnosed with type 1 diabetes in 2018. At the time, her A1c – a measure of blood sugar levels over a three-month period – was 8.7 percent. She initially adopted a low-carbohydrate (less than 30 grams of carbohydrate per day), high-fat diet that was high in meat and dairy. Her blood sugar stabilised, but she required more insulin per gram of carbohydrate consumed. Her total cholesterol also increased from 175 to 221 mg/dL. In January 2019, she switched to a plant-based diet, eliminating dairy products, eggs, and meat. The patient was able to decrease her insulin dosage, maintain her A1c level at 5.4 percent, and drop her cholesterol level to 158 mg/dL.

“This study challenges the misconception that carbs are the enemy when it comes to diabetes,” said study author Hana Kahleova, MD, PhD, director of clinical research at the Physicians Committee. “The patient in this case study experienced the opposite: Adding more healthful carbohydrates to her diet stabilised her glycemic control, reduced her insulin needs, and boosted her overall health.”

The other individual – a 42-year-old man who had been diagnosed with type 1 diabetes at age 25 – eliminated animal products from his diet and switched to a whole food, plant-based diet. He increased his consumption of carbohydrates from 150 grams to 400-450 grams per day. After adopting a carbohydrate-rich plant-based diet, he lost weight, required less insulin, and reduced his A1c from 6.2 percent to a range between 5.5-5.8 percent.

The authors noted that a previous small study supported the case studies’ results, finding that a high-carbohydrate, high-fibre diet improved glycemic control in 10 people with type 1 diabetes. As a next step, the authors suggested that randomised clinical trials are needed to verify the case studies’ findings, assess their generalisability, and quantify the effectiveness of plant-based diets in the management of type 1 diabetes.