In a study that tracked the diets of more than 205,000 adults over decades, French fries were associated with an increased risk of developing type 2 diabetes (T2D). According to findings of the study published in the ‘BMJ’, other forms of potatoes—including baked, boiled, and mashed—did not increase risk of developing T2D.

The study, led by Harvard T.H. Chan School of Public Health also found that swapping any form of potato for whole grains may lower the risk of T2D. “Our study offers deeper, more comprehensive insights by looking at different types of potatoes, tracking diet over decades, and exploring the effects of swapping potatoes for other foods,” said lead author Seyed Mohammad Mousavi, postdoctoral research fellow in the Department of Nutrition.

“We’re shifting the conversation from, ‘Are potatoes good or bad?’ to a more nuanced—and useful—question: How are they prepared, and what might we eat instead?” The researchers examined the diets and diabetes outcomes of 205,107 men and women enrolled in the Nurses’ Health Study, Nurses’ Health Study II, and Health Professionals Follow-up Study.