What Is Resistant Starch?
Starch is one type of carbohydrate in your diet — the other two being sugars and fiber, according to MedlinePlus. When your body digests starchy foods, it typically breaks them down into glucose (sugar) in the small intestine. Resistant starch, however, is a type of carbohydrate that doesn’t break down into sugar and is not absorbed by the small intestine, according to the National Cancer Institute. Instead, resistant starch passes to the colon (large intestine) to be fermented, says Nancy Cooper, RDN, CDCES, at the Molly Diabetes Education Center at Hackensack University Medical Center in New Jersey. As the starch ferments, it acts as a prebiotic, feeding the good bacteria in your gut, Cooper says. Plus, resistant starch is lower in calories than other types of starch — about 2.5 calories per gram (g) compared with 4 calories per g of wheat starch, per a review published in June 2022 in the Journal of Functional Foods
Type 1 Starchy foods coated with seeds or germ. Examples include unprocessed whole grains and legumes such as beans and lentils.Type 2 Naturally resistant starchy foods, such as uncooked potatoes and green banana flour.Type 3 Known as retrograded starch, this is starchy food that’s been cooked and then cooled, which increases its resistant starch content. Examples include potatoes or pasta that’s been cooked and allowed to cool.Type 4 Starchy foods that have been chemically modified so they resist digestion. Typically, the products are food additives derived from corn, potatoes, or rice.Type 5 This is a newer category. It entails resistant starches that have been created through a process that involves heating and cooling starchy foods with specific lipids, such as fats or waxes.
Plantains and green bananasBeans, peas, and lentilsWhole grains, such as oats and barleyCooked and cooled rice, pasta, and potatoes
Keep Blood Sugar Stable
Because resistant starch is slow to digest, it keeps blood sugar levels stable. This can help reduce blood sugar spikes after a meal, which is especially beneficial for people with diabetes. What’s more, resistant starch has a second-meal effect: Eating resistant starch at breakfast can lower your blood sugars at lunch, per the results of one small study. According to a review published in January 2022 in Frontiers in Nutrition, adding resistant starch to your diet is a simple lifestyle tweak that can aid diabetes management. “We’re still learning more about this topic, but it’s been suggested that the blood sugar-lowering effect may be related to improved insulin sensitivity or the action of short-chain fatty acids [or both],” says Amanda Sauceda, RD, a registered dietitian in Long Beach, California, who specializes in gut health. As she explains, short-chain fatty acids are produced when your good gut bacteria ferment fibers, like those found in resistant starch foods.
Support Gut Health
Resistant starch acts like fiber, and that fiber gets fermented by healthy bacteria in your gut. “Those good gut bugs can produce short-chain fatty acids, which can have wide implications for your gut health,” Sauceda says. For example, short-chain fatty acids can help keep your intestinal lining strong and assist with mucus production and inflammation, she explains. The short-chain fatty acids from resistant starch may also help reduce the risk of colorectal cancer, according to the review published in June 2022 in Journal of Functional Foods.
Boost Heart Health
Resistant starch has been shown to benefit heart health by lowering cholesterol levels, per findings from a meta-analysis published in June 2018 in Nutrition Research. It also improves blood sugar control, as demonstrated in a small study of overweight adults published in 2017 in Nutrition Journal. “It does this by promoting the growth of healthy bacteria in the gut, which produce the short-chain fatty acids that have these beneficial effects,” Butler says. According to a review published in March 2022 in the International Journal of Molecular Sciences, short-chain fatty acids help regulate the sympathetic (fight-or-flight) nervous system. In this way, resistant starch may help treat heart diseases that are aggravated by an overactive nervous system, such as chronic heart failure, high blood pressure (hypertension), and coronary artery disease. While early research suggests that resistant starch may play a role in weight loss, further research is needed to confirm any such benefits. Research published in 2017 in the Nutrition Journal reveals that eating 30 g of resistant starch per day for six weeks decreased hunger hormones and mindless snacking in 18 overweight adults, but didn’t create changes in body composition. You can find resistant starch in powdered form to use as a supplement, however. If you choose to supplement your diet with resistant starch, it’s a good idea to discuss it with your primary care provider first. When choosing a supplement, find one that is made from a natural source of resistant starch, like green bananas, Butler says. choosing a supplement that’s third-party tested by independent testing organizations that evaluate dietary supplements for quality and safety purposes. The three primary agencies that test dietary supplements include NSF International, ConsumerLab, and U.S. Pharmacopeia (USP). Check the supplement label for a seal of approval from one of these three agencies. “I would also recommend trying food-based sources of resistant starch before supplements, because you’ll get other nutrients in addition to the starch,” Sauceda says. Begin by adding resistant starch in small amounts. For example, include a somewhat-green banana to your breakfast and a quarter-cup of lentils to your lunch, suggests Hunnes. Here are a few other ways to add resistant starch to your diet, per Johns Hopkins University:
Cook rice, potatoes, beans, and pasta a day in advance. Let them cool in the refrigerator overnight and reheat when you’re ready to eat.Instead of cooking oatmeal, soak uncooked oats in yogurt, milk, or nondairy milk in the refrigerator overnight.Use green banana flour, plantain flour, cassava flour, or potato starch when baking or cooking.
Also, try one these recipes that feature resistant starch:
Potato Salad With Green Beans and AsparagusNo-Bake Green Banana Resistant Starch CookiesOvernight OatsGreen Banana and Sweet Pepper Rice SaladCrispy Resistant Starch Potatoes
