Should You Eat Sweet Potatoes if You Have Diabetes? (2024)

Sweet potatoes can be good for people with diabetes. After all, these tubers are one of the most nutritious vegetables grown in the subtropical and tropical areas of the world. However, you still should eat them in moderation.

Although sweet potatoes may be high in carbohydrates, they may not cause blood sugar to skyrocket. Their glycemic index—how quickly they make blood sugar rise—can change depending on how you prepare them.

While people with diabetes don't need to steer clear of sweet potatoes altogether, it's important to keep in mind the amount, type, preparation, seasoning, and accompanying side dishes when eating sweet potatoes.

Types of Sweet Potatoes

Sweet potatoes grown in the United States come in five basic types, depending on color:

• Orange skin with orange flesh: Sweet potatoes with orange flesh are one of most popular varieties in the U.S. They're especially sweet and moist. Look for varieties like Jewell, Covington, Bellevue, and Beauregard.
• Red skin with orange flesh: These potatoes have a sweet flavor and are moist when cooked. Look for varieties like Garnet, Diane, Vermillion, and Burgundy.
• Yellow skin with white flesh: This type is less sweet, which makes it excellent for browning and crispness for sweet potato fries or hash. These qualities make these sweet potatoes great substitutes for regular potatoes. Look for varieties like Jersey, Bonita, O'Henry, DS White, and Hannah.
• Purple skin with white flesh: This type may also be known as Batata, Boniato, Japanese, Oriental, or Korean sweet potatoes. They're not too sweet and are somewhat more firm and dry. Try varieties like Murasaki and Kotobuki.
• Purple skin with purple flesh: This variety is loved for its bright purple interior and is an excellent source of nutrients. It is also known as the Okinawan sweet potato because came from Okinawa, Japan.
  

How Sweet Potatoes Affect Blood Sugar

Sweet potatoes do have a high level of carbohydrates, but they generally have a low glycemic index.

The glycemic index is a ranking system for how different carbohydrates affect blood sugar. Foods with a high glycemic index cause blood sugar to spike and then crash. Foods with a low glycemic index give you sustained energy because they are digested and absorbed slowly.

White-Flesh Sweet Potatoes

Sweet potatoes with white flesh can have complex carbohydrates and high amounts of dietary fiber. These two things can help slow the time it takes for your body to turn carbohydrates into glucose, which helps prevent spikes in blood sugar. They may create a better response to insulin in people with type 2 diabetes.

Purple-Flesh Sweet Potatoes

Purple sweet potatoes are known to have many health benefits. The color is due to the anthocyanins, a water-soluble element that is also known for pigmenting other fruits and vegetables that are purple, red, and blue. Anthocyanin is known for its antioxidant properties.

The purple varieties have more anthocyanins than orange sweet potatoes. Compared to orange and white sweet potatoes, they also have significantly higher concentrations of phenolic acids. Phenolic acids may have a positive effect on diabetes by helping with insulin sensitivity.

A 2020 study comparing purple potatoes to yellow potatoes found that the polyphenol-rich purple potatoes lowered glycemia, inflammation, and insulin. Purple sweet potato has a high glycemic index of 77.0.

Orange-Flesh Sweet Potatoes

Colloquially referred to as yams in the U.S., orange sweet potatoes are the most common sweet potato and are known for containing:

• Vitamin C
• Potassium
• Fiber
• Vitamin B6

They also have beta-carotene and a high glycemic index.

Other Benefits for Diabetes

Sweet potatoes contain many vitamins, antioxidants, and minerals that are helpful for your overall health. They are rich in the following vitamins and minerals:

• Vitamin Ain the form of beta-carotene
• Vitamin B6
• Vitamin C
• Potassium
• Fiber
• Zinc
• Magnesium

Vitamin A is an important vitamin for vision. It can help with eyesight, including in low light. It also produces pigments in the retina, part of the eye that sends the visual information to the brain.

Dietary fiber is good for you because it helps make you feel full. It also helps with digestion and can prevent constipation.

Also important to your health is Vitamin C. This powerful vitamin may be able to help reduce inflammation in people with obesity who have diabetes and/or hypertension (high blood pressure).

Although starch is sometimes considered bad, some starches are better than others. Some sweet potatoes, like the purple sweet variety, have resistant starch. Resistant starch is only partially broken down in the body and helps prevent spikes in glucose.

How to Prepare Sweet Potatoes

Sweet potatoes are known to be high in fiber and have a low glycemic index, which results in a less immediate impact on blood glucose levels. This can help people with diabetes keep their blood sugar levels in check.

Sweet potatoes can be:

• Baked or microwaved
• Steamed
• Boiled
• Sautéed
• Fried
• Grilled
• Enjoyed raw
• Added to soup
• Blended in a smoothie

One study on purple potatoes found how the potatoes were prepared affected the glycemic index. The lowest glycemic index was found in noodles made from sweet potatoes. Boiled purple sweet potatoes came in with a high glycemic index of 83.75. Look for sweet potato pasta at the grocery store.

As with any food, it's important to be mindful of serving size and cooking methods. Eating boiled or steamed sweet potatoes in moderation is your safest bet. Baking, roasting, or frying sweet potatoes increases their glycemic index, which can create havoc on your blood sugar levels.

Summary

People with diabetes may find some benefit in adding sweet potatoes to a meal or snack—in moderation. The powerful nutrients contained in these colorful tubers may be able to prevent blood sugar from spiking after eating.

It is important to speak with your healthcare provider to understand the proper way to consume sweet potatoes when you have diabetes. The way you prepare them can also affect how blood sugar levels will respond.