Podcast Episode 51 Transcript – Resistant Starch

Aidan

Hello, and welcome back to the Ideal Nutrition podcast. This is episode 51 and today we’re going to be talking about resistant starch.

I am Aidan Muir and I’m here with my co-host Leah Heigel, and we’re going to be talking about resistant starch in terms of what it is, why we should care about it a little bit, and then also how much we should care about it and what kind [00:00:30] of action we should take in relation to that.

So, starting off with a bit of background resistant starch is a form of starch slash fiber that passes through both the small intestine and large intestine, mostly undigested. It acts as a prebiotic fiber, even though it passes through mostly undigested, it is still a food source for bacteria into large intestine and that’s where a lot of the benefits come from.

It can increase the amount of short-chain fatty acids in the gut too and typically that is [00:01:00] a good thing. And in particular, it increases butyrate which is often linked with positive outcomes and good gut health. So that’s why we really care about it.

Leah

Yeah, in terms of where you can actually find resistance starch. So you’re going to find it in most foods that are quite starchy, but particularly in things like legumes, bananas, particularly unripe or green bananas and green banana flour. As well as potato, pasta, and rice [00:01:30] that has been cooked and cooled.

So things that you’ve cooked, you’ve put in the fridge and it’s come down to a lower temperature is going to have resistance starch in it. I find with my clients, that’s probably the thing that people tend to eat the most of in terms of resistant starch is they’ll get it from there.

But the average person eats about three to nine grams of resistant starch per day. But we know that in terms of gut health, what would be optimal and where we really start to see the benefits [00:02:00] is around that 15 to 20 gram per day mark.

Aidan

Yeah. So people are clearly getting it incidentally and stuff like that, but a conscious effort could potentially get a bit more out of it, right?

Leah

Yeah. So there’s been a lot of benefits associated with that higher intake of resistant starch. So, obviously we’ve touched a little bit on gut health and diversity of the gut microbiome.

So we’ll go into that a little bit, but also it’s been linked to things like reduction in insulin resistance, IBS [00:02:30] symptoms, potentially things like weight loss and a few other things. So we might just go through them one by one and go through it.

Aidan

Yeah, for sure. So starting with insulin and insulin resistance, blood glucose levels, putting that all together. It very clearly helps with blood glucose levels, just the same way as regular fiber would, in terms of it slows down digestion, which therefore allows insulin a longer opportunity to take blood glucose levels down.

[00:03:00] In terms of insulin resistance specifically though, there is according to the research, a 33 to 50% reduction in insulin resistance when people have that kind of high intake of resistant starch that we’re talking about, and there’s a lot of proposed mechanisms, but the main one is that it seems to stem from some downstream effects of having increased short-chain fatty acids. Which as I was saying, typically, they’re a good thing, and they can lead to a decrease in circulating fatty acids in the blood, which therefore leads to a decrease [00:03:30] in insulin resistance.

That seems to be the most common reason or explanation for that happening. And then a side thing is we’re going to talk about, this as one of the benefits later, but weight loss. It potentially helps with weight loss and if people do get leaner, that should also help decrease insulin resistance as well.

Leah

Second one we’ll touch on is IBS. So this is a bit of a mixed bag in that resistant starch, like we said, does increase this production of short-chain fatty acid. So things like butyrate, which we know is great for gut health, [00:04:00] also increases the amount of bifido bacteria in the gut, which again is really good for gut health and people that have IBS usually have five times lower levels of bifido bacteria in a lot of cases.

So having that kind of deficiency in that particular kind of bacteria, and then using your resistant starch to increase it could potentially help manage your IBS symptoms. But where this is a mixed bag is that obviously sometimes when you increase fiber [00:04:30] intake really quick, or you’re just putting a lot of plant based foods in your diet that are maybe high in FODMAPs, that could actually lead to an exacerbation of your IBS symptoms. So whilst it’s really good for gut health, it doesn’t mean it’s always going to cure everyone’s IBS symptoms.

I think whenever it comes to gut health stuff and IBS, it’s always best to work with a professional because it’s so hard to see what is actually causing your IBS symptoms or to know what that is. [00:05:00] And whether resistant starch will fix it, probably not, but it can contribute to good gut health, which might help lessen your symptoms.

Aidan

Yeah, I completely agree and it’s one of those areas where there’s not really research being like, “Hey, let’s get a hundred people with IBS, increase their resistant starch intake and see what happens,” because ideally we’d have that research and it show benefit. But we don’t have that research, it’s just theoretical at this stage. And because it’s one of those things, that if you make a massive jump in that, it probably makes symptoms worse.

But if you start low and go slow, you increase it very slowly over time or whatever, it has potential benefits. The theoretical mechanism makes sense and there’s a lot of reasons why it potentially, or likely would contribute in some way.

But you also aren’t risking these downsides if you take that approach.

Because if you do notice your symptoms getting worse, you can just cut back if you do that.

Leah

That’s true. You’re not doing any long term damage, and I guess with IBS, I always like to say just because someone has IBS doesn’t necessarily mean they have [00:06:00] poor gut health to begin with.

But those two things they don’t always go hand in hand. So just doing things that are good for gut health may not always fix your IBS.

Aidan

Yeah, for sure. And I like that bifido bacteria stack because it’s hey this is clearly a difference, on average in gut health.

But once again, we don’t have research being like, “Okay, let’s address that bifido bacteria.”

Get higher levels of that and then a resolution symptoms happens. We don’t really have research on that.

Leah

Yeah, so likely a good thing, but may not be the cure all.

Aidan

Yeah, definitely [00:06:30] worth discussing that.

Aidan

The next one we’re talking about is the effects on weight loss, and this is another one where we don’t have research specifically on it in terms of being increased resistant starch leads to this. It’s more of something that a lot of people just see in practice and talk about and everything like that, and there’s a few reasons why this might potentially happen.

One is that carbs normally have four calories per gram, that’s just a nutrition fact that I think a lot of people would benefit from knowing. I never changed anybody’s life by telling them that but [00:07:00] it’s a useful piece of information, and resistant starch has two calories per gram, so it has half the amount. So, that could be a small factor, it’s like you’re consuming less calories for the same amount of food you’re eating.

But probably the bigger picture or the bigger factor here is that people who have higher resistant starch intake typically consume fewer calories per day. And it’s likely just due to appetite management, it fills people up more than lower resistant starch foods. So you can see how that could contribute [00:07:30] to weight loss.

Leah

Resistant starch also has early links to things like potentially reductions in bowel cancer, inflammatory bowel disease, diverticular disease. So it may be helpful outside of the things we have touched on already.

But again, this is a mixed bag. We’re so early in the research, we can’t make any hard claims about any of that. But overall, I think it’s not a bad thing to just know about and add in if you’re [00:08:00] not already doing it, because what’s the harm.

Aidan

Yeah, exactly. Which I guess leads into, do we do anything with resistant starch with our clients? Do we focus on anything with that?

Leah

I rarely ever talk about this stuff. I think just because I’ve said this many times, but I work with predominantly vegans.

Who are more health conscious, so they’re likely already doing this. They’re already eating all these high starch foods, they’re already eating legumes. So it’s pretty rare that I’ll ever bring this up because it’s already being done.

Aidan

Yeah, and [00:08:30] I’m similar. Obviously the clientele I work with probably would benefit from it a little bit more, but I don’t bring it up unless people ask me, and a lot of people do ask me about it and we do talk about it. But in practice, from that side of things, like focusing on things like legumes, seeds, whole grains, all of those things, what we talked about in terms of like that cooked and cooled potato, rice, pasta, those things, a lot of people incidentally do that.

I don’t recommend people go out of their way to do that, but if you’re doing it, this is a nice bonus. [00:09:00] The unripe bananas that’s hit and miss with the green banana flower.

Leah

Yeah, you can bake stuff with that. So, that’s always an option. I know it’s pretty expensive, so I don’t think it would be my first port of call.

I’m probably just going to eat some legumes and nuts and seeds and stuff, but it’s an option.

Aidan

Yeah. Once again, not an option I often recommend, but it is an option, which is all we’re getting at. And one thing I actually have recommended a little bit over the years is there’s [00:09:30] a product called Barley Plus made on the grain Barley Max, which I believe is a human made grain that just happens to be really high in resistant starch.

So it’s developed by the CSIRO is my understanding, and in Woolworth’s, Cole’s, just general supermarkets, they have Barley Plus muesli bars that are high in this. And also Barley Plus cereal that’s high in this, and there’s one called Barley Plus Protein and often when I recommend cereal for people, oftentimes I’ll say like, “X grams of cereal.” And [00:10:00] I might say a higher fiber cereal or whatever, and then because people love specifics.

Whereas I’m like, “Hey, just choose the one that you like that fits this criteria,” because people like specifics, sometimes I will put in there, “Have Barley Plus Protein” or whatever it is.

Because even though it’s not super, super high protein, it ticks a few boxes being okay, say they have that with milk for example, they might combine that to get above the 20 grams of protein magical number of getting enough lutein and stuff like that. If they have a decent serving [00:10:30] size.

So that’s a nice thing, it’s not what we’re looking at for, but that’s one thing, but then it’s also relatively high fiber and they also might reap the benefits of having this kind of resistant starch as well.

Leah

Yeah, and for people that don’t have much of a plant-based diet or anything along those lines, these products that are jam packed full of these kinds of gut friendly things. Always a positive.

Aidan

Yeah, for sure. And it is one of those things as well that, again, start low and go slow.

Because I [00:11:00] got a weird thing, a bit of a photographic memory for food labels, and one of the things I noticed about these Barley Plus products is that their fiber decreased over the years. To the best of my knowledge, from memory, they came out super high fiber and then took away about 30% or something like that. Don’t quote me on the 30% number, but like…

Leah

A pretty big, a significant decrease.

Aidan

A significant decrease, and I’m like, “I think I know what happened.” I think people…

Leah

Everyone got upset stomach.

Aidan

Yeah, exactly. Particularly, because it could be easy to overeat those or people might have multiple muesli bars but that could be an easy introduction [00:11:30] or an easy win for something that we don’t consider a top priority, but there are some nice bonuses to having this higher intake of resistant starch.

Leah

This has been episode 51 of the Ideal Nutrition podcast. As always, we’d love it if you could leave a rating and review, if you can do so, but otherwise thanks for tuning in this week.