Where as, eating the same quantity of boiled, baked, or mashed potatoes was associated with only 5% increase in risk.
Eating three servings of French fries a week could significantly raise your risk of developing type 2 diabetes, a new US study published in the British Medical Journal has found.
Researchers from Harvard and Cambridge universities analysed dietary data from more than 200,000 adults who were free of diabetes, heart disease, or cancer at the start of the study. Over a follow-up period of 40 years, about 22,300 participants developed diabetes.
Not All Potatoes Are Equal
The study revealed that consuming three servings of French fries a week was linked to a 20% higher risk of type 2 diabetes. In contrast, eating the same quantity of boiled, baked, or mashed potatoes was associated with only a modest 5% increase in risk, which researchers did not find statistically significant.
Importantly, the impact of potatoes on diabetes risk appeared to depend on what foods they replaced. Substituting three weekly servings of potatoes with whole grains reduced diabetes risk by 8%, while replacing French fries with whole grains lowered it by 19%. Conversely, replacing potatoes with white rice was linked to a higher risk.
Preparation Methods and Dietary Context Matter
Potatoes are rich in fibre, vitamin C, and magnesium, but they are also high in starch and have a high glycaemic index, meaning they cause rapid spikes in blood sugar. The findings highlight that preparation methods and dietary context matter greatly when assessing potatoes’ health effects.
While potatoes themselves are not inherently harmful, consuming them as French fries carries a significantly greater diabetes risk compared to healthier alternatives such as whole grains.
