You may have come across the term “resistant starch” and have an idea that it is a good thing to have. But, if you have IBS, you may wonder whether you should include it in your diet. In this blog post, I will explain what resistant starch is, what its health benefits are, which foods are rich in resistant starch, and the implications for people with IBS.
What is resistant starch?
Resistant starch literally “resists” digestion by our small intestine. Hence, its name. There are several reasons why this may happen. It may not be accessible to our digestive enzymes because it is “protected” by a thick plant cell wall (as in some grains and legumes). Or because the starch does not have enough exposed area (as in green bananas). Or, it is harder to break down (as in starchy foods such as rice or potatoes that are cooked and cooled).
Regardless of the reason why, this starch travels to our large intestine (the colon). There, our gut bacteria use it as fuel and ferment it. You may be wondering: isn’t this how FODMAPs work? Will eating resistant starch trigger bloat, distention, or cramps in people with IBS?
Resistant Starch and IBS
To begin with, both FODMAPs and resistant starch are fermented by the bacteria. However, whereas FODMAPs are rapidly fermented and result in a fast increase in intestinal gas, the fermentation of resistant starch is slow. Consequently, the gas is released slowly and it you won’t get the same degree of distention and discomfort as with FODMAPs.
Although some studies have shown that high intakes of resistant starch can cause some discomfort in sensitive people, you are unlikely to reach such high amounts if you eat a variety of healthy foods. Each person will have a different level of tolerability. If you have IBS and have a very sensitive gut you can start with small portion sizes of resistant starch. After a while, as your symptoms improve and your gut bacteria strengthen your tolerability should increase.
Resistant starch is a prebiotic because it is food for our gut bacteria. However, its benefits go beyond its property as a prebiotic. Resistant starch may contribute to the prevention of chronic diseases like heart disease and diabetes. That’s because it can decrease cholesterol and triglyceride levels, and lower the rise in blood sugar after eating. In addition, as we don’t completely digest resistant starch, it provides only half the calories of other carbohydrates. Resistant starch can also improve satiety. As a result, foods high in resistant starch can play a role in maintaining a healthy weight.
Foods High in Resistant Starch
Both high and low-FODMAP foods can contain resistant starch. High-FODMAP foods that are high in resistant starch are whole wheat pasta, rye bread, and many types of beans. You will need to temporarily exclude these during the low-FODMAP diet.
On the other hand, there are many low-FODMAP food choices that are high in resistant starch. If you have IBS, you may benefit from eating more of them. These may help you keep your good gut bacteria happy and prevent the decrease in the diversity of gut bacteria that happens during the elimination phase. Some low-FODMAP foods rich in resistant starch are:
- Canned chickpeas, lentils, cannellini, and red kidney beans
- Cooked buckwheat groats
- Cooked millet
- Cooked and cooled rice (white or brown)
- Cooked and cooled potatoes
- Corn tortillas
- Uncooked oats
- Under-ripe bananas
You can check the appropriate portion sizes in the Monash FODMAP App. If these foods are new to you, start adding one portion at a time. Then, increase your intake gradually to minimize potential gut symptoms. Among these, uncooked oats are the richest source of resistant starch. Try my delicious Easy Overnight Oats as a start.
In summary, resistant starch is a prebiotic with has many health benefits, and people with IBS can find many low-FODMAP choices that can keep their gut bacteria happy. Once you have reintroduced high-FODMAP foods and discovered your triggers, you may expand the variety and quantity of resistant starch-rich foods you can eat without experiencing gut symptoms.