People with Type 2 diabetes are advised to avoid potatoes and other high glycemic index (GI) foods – due to the persistent perception that these foods can elevate blood glucose levels. Diabetics are generally asked to avoid or limit starchy vegetables like potatoes, especially during the night when blood glucose tends to spike. That’s because starchy vegetables are rich in carbohydrates, which may raise a person’s blood glucose levels. However, for the first time, a rigorously controlled clinical study challenged this general perception and suggested that individuals with type 2 diabetes needn’t avoid eating potatoes based on GI.
Diabetics can eat potatoes
According to the study published within the journal Clinical Nutrition, diabetics can better maintain overnight glycemic control after they eat high GI like potatoes in a night meal versus low GI carbohydrate food – basmati rice. The researchers found that participants had better blood sugar control once they ate a mixed meal with skinless white potatoes compared to a meal that included an occasional GI basmati rice.
“These findings are contrary to it of traditional dietary guidance that has led some to believe potatoes don’t seem to be an appropriate food choice for people with type-2 diabetes,” said corresponding author of the study Brooke Devlin from Australian Catholic University in Melbourne.
“Our study shows high GI foods, like potatoes, may be consumed as a part of a healthy evening meal without negatively affecting Glycemic response, and while delivering key nutrients in relatively few calories, which is important for people with type-2 diabetes.”
The study involved 24 adults with type-2 diabetes, who got the identical breakfast and lunch. However, the participants were randomly assigned to 1 of 4 dinners, each including either skinless white potatoes (test meal) prepared in three other ways (boiled, roasted, boiled then cooled then reheated) or basmati rice (control meal).
Participants repeated the experiment. Blood samples of the participants were collected regularly (both immediately after the meal and again every half-hour, for 2 hours). They also wore a continual glucose monitor overnight to track changes in glucose levels while sleeping.
The findings showed there have been no differences between meals in glucose response following the dinner that contained any of the potato dishes or basmati rice. In fact, participants’ overnight glycemic response was more favorable after eating the evening meal that included any of the potato side dishes compared to low basmati rice, said the study.
Despite many limitations, the researchers concluded that “potatoes are a vegetable that’s sustainable, affordable and nutrient-dense, and thus, they will play a vital role in modern diets no matter metabolic health status.”
However, the researchers cautioned that individuals with diabetes should still follow the diet suggested by their dietitian.
Devlin BL, Parr EB, Radford BE, Hawley JA. Lower nocturnal blood glucose response to a potato-based mixed evening meal compared to rice in individuals with type 2 diabetes. Clin Nutr. Published online October 8, 2020.