Not all potatoes are the same, and recent research sheds light on their connection to type 2 diabetes (T2D). A study conducted by Harvard’s School of Public Health discovered that consuming three servings of fries weekly may increase the risk of developing T2D by 20%. In contrast, baked, boiled, or mashed potatoes showed no such link.
Seid Mohammad Musabi, a postdoctoral researcher and one of the leading authors of the study, suggested that it’s worth considering not just whether potatoes are good or bad, but how they’re prepared and what they replace in our diets.
The research, published in the British Medical Journal, monitored more than 200,000 Americans over a span exceeding three decades, examining dietary habits and health outcomes. From the participants, 22,299 were diagnosed with type 2 diabetes. To support these conclusions, the study also referenced a meta-analysis involving over 587,000 individuals across four continents.
As the third most consumed food crop in the U.S., the discourse surrounding potatoes and their relation to T2D is becoming increasingly relevant. While potatoes offer nutrients like fiber, vitamin C, and potassium, their high glycemic index can lead to significant blood sugar spikes. This concern is further compounded by the fact that different cooking methods can negatively impact health.
The study highlights that the consumption of fried potatoes—particularly French fries—largely drives the noted increase in T2D risk. When potatoes are fried in hot oil, not only are key nutrients stripped away, but this process also generates harmful byproducts through the Maillard reaction.
The good news? By making simple dietary swaps three times each week, individuals can notably lower their risk of diabetes. Replacing fries with whole grains can reduce that risk by 19%, while opting for healthier potato varieties over fries can decrease it by 8%.
Water Willett, a professor of epidemiology and nutrition and one of the study’s authors, emphasized the straightforward yet powerful public health message: small dietary adjustments can greatly affect T2D risk.
According to the CDC, diabetes affects over 38 million Americans—roughly 10% of the population—with most cases being type 2 diabetes. This number has been steadily rising over the past two decades.
Willett also noted the importance for policymakers to focus on food preparation methods and the overall diet context when developing effective guidelines. He added that not all carbohydrates are created equal, nor are potatoes, which underscores the need for nuanced dietary advice.
The research team is keen on further exploring how cooking methods, such as using butter or different frying oils, might impact health outcomes, as well as comparing these with sweet potatoes that have distinct nutritional qualities.
However, Potato USA, representing U.S. potato growers, remarked that the average American consumes about half the quantity used in this study, arguing the findings may not reflect real-world eating habits. They mentioned that, with moderation, even fries can fit into a healthy diet.
They further suggested that since many Americans struggle to meet vegetable intake recommendations, incorporating fries with other vegetables may encourage higher overall vegetable consumption.
