Dr. Amy Nett: Great question, and if you look on the blog, I wrote an article about resistant starch. Gosh, I think that was two years ago now, but it goes into some of the detail. I think most of that detail is actually covered in the presentation, but it just talks about the four different types of resistant starch, and I think I mention that once you go up to about… I would have to review it. I think once you go up to 120 degrees, the conformation of the carbohydrate changes so that it’s no longer resistant starch.
Green plantains, when they’re raw, they have resistant starch. Once you cook them, the conformation of the carbohydrate structure actually changes and it’s no longer resistant starch. Plantains are a popular source of carbohydrate in the Paleo world because, remember, we’re not only eating carbohydrates for resistant starch. We’re eating carbohydrates because carbohydrates are an important macronutrient, and they’re still nutrient dense. The one and only reason to eat plantains is not because of the resistant starch. That’s certainly an added benefit if you’re eating green plantains, and the best way to get resistant starch from green plantains is just to dehydrate them and turn them into plantain chips. What you can do there is cook them and cool them and then dehydrate them and turn them into chips and get the resistant starch. I like plantains for my patients because it’s a great carbohydrate source. A lot of people tolerate plantains really well, especially if they’re already having GI issues. Some people are going to have issues with potatoes because those are a nightshade, and then sweet potatoes and yams have … I think it’s polyols, but they have some FODMAPs in them, so plantains tend to be a really well-tolerated carbohydrate source. They’re great for turning into something like plantain tortillas or pancakes. There are a lot of things you can do with plantains. They’re a great carbohydrate source, but for reasons other than them being resistant starch.
And, yes, as bananas and plantains ripen, the amount of resistant starch in them does decrease. The greener they are, the more resistant starch they have. So there’s certainly a balance there between having a green banana or green plantain that you find edible or tolerable and the amount of resistant starch in there. That’s why I think a lot of times Chris and I will talk about variety and rotating different prebiotics. Including some green plantains or green bananas is a potential source, but, yeah, if you’re eating any of the food sources that contain resistant starch, if you’re eating them hot, heated above about 120 degrees, it’s going to decrease or remove the resistant starch in those. You can cool them down, put them in the fridge, but again, they have to be pretty cool to get that resistant starch back in them. Hopefully that answers that question.