French fries, a popular comfort food worldwide, might be more than just a guilty pleasure. According to a recent study published in The British Medical Journal, consuming fried potatoes significantly raises the risk of developing type 2 diabetes, while other forms of potatoes like boiled, baked, or mashed do not share this risk.
How Much Is Too Much?
The study found that eating three servings of fried potatoes per week can increase the risk of type 2 diabetes by 20%. In contrast, consuming the same amount of potatoes prepared by boiling, baking, or mashing showed no significant link to diabetes risk. This highlights the impact cooking methods can have on health outcomes.
The Science Behind the Findings
Potatoes are not nutritionally empty—they provide fiber, vitamin C, and magnesium. However, they also contain high levels of starch, which results in a high glycemic index. Foods with a high glycemic index can lead to blood sugar spikes, contributing to diabetes risk.
Previous research had not clearly differentiated between potato cooking methods and their effects on diabetes. This new investigation, conducted by researchers at Harvard’s School of Public Health, examined dietary data from over 205,000 health professionals across three large U.S. studies between 1984 and 2021. None of the participants had diabetes, heart disease, or cancer at the start. Their diets were tracked every four years.
The Role of Fried Potatoes
Over roughly 40 years of follow-up, 22,299 participants were diagnosed with type 2 diabetes. When adjusting for lifestyle and dietary factors, the consumption of three weekly servings of any potato increased diabetes risk by 5%. However, fried potatoes alone were associated with a 20% increased risk.
Healthier Alternatives: Whole Grains Over White Rice
The study also explored the effects of substituting potatoes with other carbohydrates. Replacing potatoes—regardless of cooking method—with whole grains reduced diabetes risk by 8%. Notably, swapping fried potatoes for whole grains decreased the risk by 19%. Conversely, replacing potatoes with white rice was linked to an increased diabetes risk.
What This Means for Your Diet
Although this observational study cannot prove causation, it supports existing dietary guidelines that recommend prioritizing whole grains as part of a healthy diet to prevent type 2 diabetes. Boiled, baked, or mashed potatoes can fit into a balanced diet, but fried potatoes should be consumed with caution.
Dining and Cooking