Two Studies Bust Common Myths about Potatoes

You might have heard misconceptions that eating starchy foods like potatoes can increase the risk of type 2 diabetes (T2D) and cause challenges in managing blood sugar. However, two new studies from Harvard and the University of Toronto may help clear the air on the potential impact of potatoes on T2D, blood sugar, and satiety.

Study 1: Potato Consumption and Risk of Type 2 Diabetes¹

This study assessed the relationship between potato consumption and T2D risk. The sample included 105,531 generally healthy adults aged 25-72, with 65% identifying as female. A subset of participants had a history of cardiovascular disease.

Key findings:

• Total potato consumption—whether baked, boiled, fried, or mashed—showed no association with increased T2D risk regardless of consumption level.
• Baked, boiled, and mashed potatoes as a combined category were also not associated with T2D risk, regardless of weekly intake.
• Only fried potatoes were linked to a slight increase in T2D risk (12% increase with more than one serving per week). However, serving sizes varied widely, ranging from 2.5 to 6 ounces in different studies.

Study 2: Comparing Potatoes and Rice for Glycemic Impact and Satiety²

This study compared how potatoes and rice influence calorie intake, blood sugar and satiety when paired with either animal or plant protein. The sample included 26 healthy, normal weight adults (13 males/13 females) aged 18-45 years.

Key findings:

• Participants consumed 23-25% fewer calories in meals containing white potatoes compared to those with rice, regardless of protein type.
• Daily calorie intake was reduced by 13% when either baked fries or instant mashed potatoes were paired with animal protein versus rice.
• Daily calorie intake was reduced by 14-19% with instant mashed potatoes and fries, respectively, paired with plant protein versus rice.
• Blood sugar responses varied by meal timing:
• Baked fries resulted in a slightly higher blood sugar peak after the first meal but had the lowest blood sugar rise after the second meal.
• Instant mashed potatoes led to blood sugar responses comparable to rice after the first meal and lower changes than rice after the second meal.

Both studies received funding from the Alliance for Potato Research and Education (APRE). For more details, please visit APRE.org.

[1] Djousse L, Zhou X, Lim J, Kim E, Sesso HD, Lee IM, Buring JE, McClelland RL, Gaziano JM, Steffen LM, Manson JE. Potato Consumption and Risk of Type 2 Diabetes Mellitus: A Harmonized Analysis of 7 Prospective Cohorts. J Nutr. 2024 Aug 16:S0022-3166(24)00401-2. doi: 10.1016/j.tjnut.2024.07.020.

[2] Amr AM, Anderson GH, Vien S, Fabek H. Potatoes Compared with Rice in Meals with either Animal or Plant Protein Reduce Postprandial Glycemia and Increase Satiety in Healthy Adults: A Randomized Crossover Study. The Journal of Nutrition. 2024 Aug 23:S0022-3166(24)00468-1. doi: 10.1016/j.tjnut.2024.08.017. Epub ahead of print.