French fries are often called an unhealthy food. New research says they may be riskier than other ways of cooking potatoes.
A big study published in The BMJ looked at more than 205,000 U.S. health professionals over almost 40 years. People who ate three servings of French fries each week had a 20% higher chance of getting type 2 diabetes.
Eating the same amount of boiled, baked, or mashed potatoes did not show a clear rise in risk.
What Happens When You Swap Foods?
Replacing three weekly servings of potatoes with whole‑grain foods cut diabetes risk by about 8%. If the potatoes were French fries, the risk dropped almost 19%.
Changing potatoes to white rice did the opposite – it raised the risk.
Why Potatoes Matter
Potatoes give fiber, vitamin C, and magnesium, but they also contain a lot of starch and have a high glycemic index, which can spike blood sugar quickly.
The study showed that the way potatoes are cooked matters a lot for health.
Details From the Study
At the start, none of the participants had diabetes, heart disease, or cancer. Every four years they filled out detailed food questionnaires.
During the follow‑up, 22,299 people developed type 2 diabetes. After adjusting for lifestyle and other foods, every three weekly servings of all potatoes raised diabetes risk by 5%, while French fries alone added a 20% increase.
Things to Keep in Mind
This was an observational study, so it cannot prove that fries cause diabetes. Other unmeasured factors could be involved.
The participants were mainly health‑care professionals of European descent, so the results may not apply to every group.
Takeaway
Potatoes are not a single food in terms of health effects. How they are prepared and what they replace in the diet both influence diabetes risk.
More research with diverse populations is needed to confirm these findings.