- A new study suggests that baked and roasted potatoes can help people with type 2 diabetes maintain healthy blood sugar levels and reduce their waistlines.
- The study compared baked potatoes with another carbohydrate — an equivalent portion of white rice.
- Potatoes in any form that have been fried are not beneficial to one’s health, so their method of preparation is key, experts warn.
There are more than 4,000 types of potatoes worldwide packed with nutrients. A new study finds that these compact vegetables when cooked properly, can help people with diabetes lose weight and maintain healthier blood sugar levels.
Compared to a control group consuming an equivalent amount of white rice, people eating baked potatoes experienced a modest decrease in fasting blood glucose levels, waist circumference, resting heart rate, and improvements in body composition.
The principal investigator of the study was Neda Akhavan, PhD, RD, assistant professor in the Kinesiology and Nutrition Sciences Department of the University of Nevada.
Each of the 24 participants had type 2 diabetes.
Half of the individuals were given a 100 mg baked potato containing 20 grams of carbohydrates. They were expected to eat them along with the potato skin as a snack or side dish with their meals daily for 12 weeks. They were asked not to fry their baked potatoes.
The remaining participants were given an equivalent amount of white rice, with the same number of carbohydrates and calories.
Participants were allowed to adorn their snacks/sides with up to half a tablespoon of butter and add herbs or spices to taste.
It is important to note that the results of this study have not yet been published in a peer-reviewed journal. The Alliance for Potato Research and Education was also a collaborator.
Potatoes are often considered an unhealthy food choice, and this may often be true, depending on the means by which they are cooked.
French fries and potato chips are all fried, for example. Michelle Routhenstein, MS, RD, CDCES, preventive cardiology dietitian at EntirelyNourished.com explained how the frying process turns a healthy potato into a nutritional problem.
“Frying potatoes introduces unhealthy trans fats and adds extra calories, worsening overall health and heart health. [This]makes them unhealthy because it creates Advanced Glycation End-products (AGEs), which can cause inflammation and oxidative stress, raising the risk of chronic diseases,” she explained.
According to Akhavan, the healthiest ways to prepare potatoes are by baking or roasting them.
Routhenstein agreed, saying, “Baked potatoes are rich in nutrients such as potassium, vitamin B6, folate, and dietary fiber, which help to support heart health, digestive function, and can assist in weight management.”
Routhenstein suggested various toppings that can enhance the flavor of a baked potato and that are healthy for people with diabetes.
These include plain Greek yogurt for protein, non-starchy vegetables for fiber, lean proteins such as grilled chicken or tofu, fresh herbs for flavor, and avocado for healthy fats.
“These additions help keep blood sugar levels stable,” she said.
A little extra virgin olive oil and a pinch of rosemary are also delicious additions to roasted potatoes.
Although boiling potatoes is better than frying them, this preparation method is not as healthy as baking or roasting.
“Boiling potatoes can reduce their nutritive value by causing the loss of minerals, including potassium, in which potatoes are rich, [causing them to] leach into the cooking water,” Akhavan noted.
“Additionally, boiling potatoes can also decrease their fiber content when compared to baking potatoes, due to the way the cooking process affects the potato’s structure. When potatoes are boiled, their cell walls break down more extensively, and some of the soluble fiber can also leach into the cooking water.”
— Neda Akhavan, PhD, RD
The study compared potatoes to white rice, which is similar to refined pasta in that it is “processed in a way that reduces its fiber content. This can increase its glycemic index, causing faster spikes in blood sugar, which is not ideal for diabetics especially,” said Akhavan.
“Brown rice typically offers better health benefits than white rice due to its higher fiber content and retained nutrients such as B vitamins and magnesium. This can lead to more stable blood sugar levels and improved digestive health,” she said.
Whole grain pasta, therefore, “has more fiber and other nutrients, similar to brown rice, which helps with better blood sugar control and even satiety,” she added.
In any event, portion control remains important for potatoes and rice or pasta, as does the method of preparation and other foods consumed throughout the day.
Potato skins provide a significant amount of a potato’s nutritional value in any event.
“If the skins are removed before boiling a potato, a significant portion of its fiber can be lost since most of the fiber is concentrated in, or just below, the skin,” warned Akhavan.
The potato skin contains “‘resistance starch,’” which Akhavan explains, is a “type of starch that escapes digestion in the small intestine and reaches the large intestine, where it functions similarly to dietary fiber (which is also a non-digestible carbohydrate).”
Further, “Studies have shown the health benefits of resistant starch for improving blood sugar levels and lipid profiles, in addition to supporting gut health by promoting the growth of beneficial bacteria,” she added.
Some people resist eating potato skins on baked or roasted potatoes.
“In order to maximize the benefits from consuming potatoes, you always want to eat the skin, which can be seasoned and has a great savory and nutty flavor (especially when baked). Don’t knock it ‘til you try it, you may really like it!” she said.
