Chris Kresser on RS

Is resistant starch useful?

Steve Wright: Yeah, sounds like a great protocol. OK, let’s roll on to the next question. This question comes from Joss. “Chris, what’s your take on resistant starch? Do you think it can be useful as a prebiotic? How about other uses such as hunger control, etc.?”
Chris Kresser: Yeah, I am pretty interested in resistant starch. I’ve been studying it quite a bit lately and using it in my practice. It’s a type of insoluble fiber that’s fermentable by gut bacteria. There are several different types of fiber. The two main categorizations are soluble and insoluble. Soluble fiber is fermentable by gut bacteria, and I consider it to be more beneficial for that reason. Insoluble generally isn’t, but resistant starch is a type of insoluble fiber that is fermentable, so it can be used as a prebiotic to increase the levels of beneficial bacteria in the gut, but it’s also – and I would say primarily – being used now for blood sugar management and metabolic issues. It seems to have a pretty significant impact on especially fasting blood sugar. I’ve seen 10-or-15-point drops and heard of even greater reductions in fasting blood sugar just by using resistant starch.
It’s difficult to obtain in food. One way to get it is in potatoes that have been cooked and then cooled for 24 hours. It’s the cooling that actually transforms the starch in potatoes to resistant starch, so cooked potatoes that haven’t been cooled don’t really have any resistant starch or very little, but potatoes that have been cooled for 24 hours do have a significant amount. Another way is eating green plantains. The only way to make green plantains edible without cooking them is dehydrating them into chips. Green bananas have some resistant starch, but I don’t find them to be very appetizing myself, so the way that most people are using resistant starch is by taking potato starch and mixing it with water. The Bob’s Red Mill variety is gluten free, and you can do 2 to 4 tablespoons a day. If you have a really high fasting blood sugar, doing maybe 3 to 4 tablespoons at night before you go to bed mixed with water is one way you can get the benefits of it.
So, yeah, I think it’s promising and it’s cheap. Potato starch is pretty darn cheap. There’s no risk to it really, and I’ve been hearing about some other interesting metabolic effects, like increases in body temperature with people who have thyroid or adrenal issues. Richard over at Free The Animal has been writing a lot about resistant starch, so if you want to learn more about it, you can go check out his blog, FreeTheAnimal.com. It’s not for kids, let’s just say! There is language. Yeah, but if you’re a consenting adult, you can head over there, and there’s some great information on resistant starch.
And be careful with resistant starch if you have SIBO or other gut issues, like IBS, because as a prebiotic, it can cause some pretty profound changes in the gut flora pretty quickly, and that can, in some cases, increase gas and bloating and lead to some digestive difficulty. The best way to mitigate that is just to go slowly. So, instead of starting with 3 tablespoons, start with a teaspoon and see how you tolerate that and go from there.