White potatoes often get blamed for raising blood sugar, new research from Harvard suggests the real problem might be how they're prepared. In a large study of more than 200,000 people, eating three servings of French fries per week was linked to a 20% higher risk of type 2 diabetes. But baked, boiled, or mashed potatoes did not show the same risk.

Researchers believe frying is the main issue. It typically involves oils that trigger inflammation, damage blood vessels, and raise blood sugar. The study also found that replacing French fries with whole grains lowered diabetes risk by 19%, while switching to non-fried potatoes reduced risk by 4%.

Experts say you don’t need to give up potatoes entirely. Cutting back on fries and choosing home-baked or air-fried options made with healthier oils can make a real difference for long-term health.