Resistant starch
Yesterday a reader sent me a film clip from ABC news about resistant starch. (Click here to view the video) In this film clip a young woman who is a registered dietitian (RD) spoke about the virtues of a “type of fiber” that she referred to as resistant starch. According to her, this substance can cure a multitude of ills.
There is a type of fiber called resistant starch that’s naturally found in some high carbohydrate foods.
And it’s amazing, the benefits. It ranges from helping us burn fat, helping us boost our immune system, control blood sugar, reduce the risk of type II diabetes and reduce the risk of cancer.
She’s really excited because, as she points out, there are over 160 studies showing the benefit of resistant starch.
Wow! Where do I sign up to get some? It sounds great. Or does it?
There are probably over 1600 studies showing the purported benefits of statin drugs, but we all know what those are. The 160 studies purporting to show benefit for resistant starch are probably in the same mold. Let’s forget about the studies right now and focus more on what we really know about starch and resistant starch to see how well this lady’s claims hold up to scientific scrutiny.
When asked about how resistant starch works, she claims that
it basically gets fermented in the digestive tract, and it creates beneficial fatty acids. One is called butyrate. And what that does is it helps to shut off the burning of carbohydrates. So carbohydrates are the preferred source of fuel, but if they can’t be burned, your body is going to turn to body fat and recently consumed fat instead.
All fiber goes through the digestive tract unabsorbed until it reaches the colon where it is acted upon by colonic bacteria (I suppose you could loosely call it fermented) that convert it to short chain fatty acids, one of which is butyrate (a four-carbon fat). These short chain fatty acids can be absorbed through the colon and used for energy just like any other fat.
So if butyrate “shuts off the burning of carbohydrates,” as our RD says it does, then wouldn’t it make sense to get as much of it as we can? And what happens to all that carbohydrate we don’t burn? Does it just continue to circulate in the blood running our blood sugar sky high? Or does it get stored as glycogen? Does butyrate encourage carbohydrates to head into storage? These are all questions she doesn’t address. Let me help clarify.
The list of foods containing resistant starch she mentions specifically are the following:
- Beans
- Potatoes
- Barley
- Corn
- Brown rice
- Under ripe bananas
She claims that these foods contain about 5 percent of their starch as resistant starch (which prety much agrees with other similar claims I’ve seen in the medical literature). If true, this means that 95 percent of the starch is not resistant starch and breaks down in the GI tract to glucose.
One half cup of any of these foods – so she says – contains all the resistant starch one needs to provide all the above benefits. Let’s take a look.
According to the USDA database if we consume a half cup of cooked potato we’ll end up with 12.9 grams of carbohydrate (almost three teaspoons), of which 10.5 grams are starch. If we go by our RD’s estimate that 5 percent of the total starch is resistant starch, we calculate that our half cup of potato contains about half a gram of resistant starch (0.5265 g to be exact). If we then convert this starch to butyrate we find that we have about 2.3 grams of butyrate (assuming 100 percent conversion to butyrate, which isn’t the case because some is converted to other short chain fatty acids).
So, we eat our half cup of cooked potato, and what do we get? We get almost three teaspoons of sugar and carb that convert almost immediately to glucose and head directly into the bloodstream. The blood volume of a person with a normal blood sugar contains about a teaspoon of sugar, which means that consuming the potato almost quadruples the amount of sugar in the blood. The pancreas then secretes insulin to drive this excess sugar into the cells. This extra insulin then does all the things excess insulin is famous (or infamous) for doing.
But what about the butyrate from the resistant starch? Oh yeah, the 2.3 grams of butyrate. I don’t see how the butyrate is going to do much to stop the insulin spike resulting from the ingestion of the sugars and starch from the non-resistant starch part of the potato. And even if butyrate really does all it is cracked up to do, we wouldn’t really need the potato with all its accessory easily absorbed carb because we can get the equivalent amount of butyrate from a single pat of butter. (Or almost the same – a pat of butter contains 1.45 g butyrate. Two pats of butter contain 3 g or about 1.5 times the amount generated by the resistant starch component of the potato.)
If the benefits of the resistant starch come from its conversion to butyrate as our RD avers, and if it requires the amount per day found in only one half cup of potato (or of the other foods she lists) as she also avers, then why not provide ourselves with one and a half times as much by eating a couple of pats of butter per day, which come without the extra three teaspoons of sugar? We get the butyrate without having to convert and we don’t get the extra carbs. Makes perfect sense to me.
Amazingly, our RD recommends adding the half cup of one of the resistant-fat-containing foods to the rest of whatever you’re eating that day. So, if you’re already on a ‘normal’ diet, i.e., one pretty high in carbs already, she is recommending that you add, say, a half cup of cooked potato to the mix so that you will ‘lose fat, reduce blood sugar, and lower insulin levels.’ Hmmm. Sounds a little snake oily. Sounds like she’s telling porkies.
While I’m at it, I have to mention one other little porky she tells during the interview. Says she
…and because resistant starch doesn’t get digested or absorbed it fills you up but you don’t get any calories from it.
Okay. Let me get this straight. First, she tells us that it converts to butyrate, a fat, which is absorbed and works miracles once it is absorbed. Second, she tells us that we don’t get any calories from it. Have I got that right?
She is correct in saying that resistant starch (as well as any other type of fiber) gets converted to short-chain fatty acids. And she is correct in saying that the short-chain fatty acids get absorbed. But when they do get absorbed, they contain 9 kcal per gram, just the same as any other fat. So they are not free of calories. That’s why fiber is counted in the total calorie count on nutritional labels. Fiber does make it’s way through the upper digestive tract without being absorbed, but it does get converted to fat and absorbed in the lower GI tract, i.e., the colon. So, I guess we could say she’s a fibber when it comes to fiber. At least in terms of its calorie content.
This brief discourse should put you off of resistant starch even without knowing what anti-nutrients are (resistant starch is an anti-nutrient), why they’re there and what they do. We’ll save that for a later post.
Now that you know the real story behind resistant starch, go back and watch the video to see how filled with misinformation it really is. Which also goes to show why you should never believe anything like this you see in a short spot on a news program without checking it out first.
Hat tip to Terry for sending me the video clip
I understand the purpose ofthe 6WC is for those who have the last 10-20 lb to lose (around the middle). Do the 6WC tactics have any place in a LC (PP) weight loss plan when the end goal is further away? Say 40-50 lb? (I’m guessing there are a lot of us loyal PP’ers who are in that position and interested in the buzz around 6WC.)
Sure. You can stay in the first couple of phases longer or you can cycle through them again until you get near your goal then head off onto the last two week phase. We know that people can’t lose 40-50 lb in 6 weeks, but people needing to lose 50-60 lb can make a huge dent in their visceral fat in those 6 weeks.
im interested to know, what is the range or percentage of resistant starch that are normally found in starch.
how many percent of resistant starch to call it as high? i mean what’s the range?
Correction, a pat of butter contains 161mg of butyrate, per our standard nutrition tables, 1/9th of the amount you mention. Is your pat 9x the size of the one in the database?
http://www.nutritiondata.com/facts/dairy-and-egg-products/133/2
Stephan Guyenet has a post up about butyrate, always a good read.
http://wholehealthsource.blogspot.com/2009/12/butyric-acid-ancient-controller-of.html
Dr. E,
This may have been mentioned already, but in case not, I just tried to see the clip you linked to at the beginning of this article (I’m slowly but surely getting through as many posts as I can and even try to read many of the comments because there’s so much information in them) and it “has been removed. Please go on to the next clip.” Hmmmm. Maybe the comments there were too on-point?
Love your stuff!
Marcia
“it looks like she is a vegetarian, which would explain some of her hostility and narrow mindedness.”
Pot meet kettle…
I was pretty engaged up until that, it was good to read someone trying to take an open-minded approach to assessing the validity of yet another quick fix diet solution
Your bigotry towards anyone who doesn’t eat meat means is disgusting and unprofessional – was such a petty, mean jibe really necessary on what is otherwise an excellent post?
And no, I’m not a vegetarian
I think you should avail yourself to the numerous studies indicating exactly the opposite of what you propose here.
The lady interviewed may have been from a company that makes a product called Hi-maize. according to the Resistent starch website, Hi-maize is the only supplement that can be added to food to increase or add resistent starch to food. There was an effort to hide the source of the website so I searched the two product names mentioned in the article, Hi-Maize and Novelase and discovered that they are manufactured by National Starch and Chemical a multinational company headquartered in New Jersey. They also make starch paper and biomedicals.
Something you did not mention was, and according to the Resistant Starch website was that supposedly the natural resistant starch in potatoes and rice for example increases during the cooling process and makes the the amount of resistant starch higher than by eating the food hot, therefore recommending sushi and cold macaroni dishes.
There is a bit of marketing going on with some of the info. on TV.
How about some potatoes with two pats of butter. Mmmmm. Some cheese and bacon added in would be even better!
I just read an article posted on FB “8 reasons carbs help you lose weight-healthy living on shine” …. I read it feeling optimistic about adding some resistant starch to my diet… then I researched some more.
I started eating very low carb after running out of my Humalog insulin (i was a type II diabetic with poor control on all meds) I tried to eat things to not raise my blood sugar and came upon atkins like eating … I started losing weight and got scared … I had an extra 40 pounds to spare so it wasn’t a problem.
2 months after feeling good and not spiking any blood sugars (a new thing for me) I had blood work done. My A1C was in normal range … not just for a diabetic … but actually ‘normal’ … my cholesterol had dropped into normal range (it had been high for 20 years and I didn’t want to take meds for it)
I had my food log and my results of blood sugar testing (I did 10 a day to see what reaction to the food I was eating had)
My doctor who had told me to not eat eggs, red meat, etc. because of the high cholesterol said after we went over my blood tests and I told her what I’d been doing …. “That works for some diabetics”
I had NEVER been told about this way to control my blood sugar … in 25 years of type II diabetes … the dieticians I was sent to seen always had the standard diabetic pyramid and I followed it and took my meds and my A1C was always between 8 & 9. I was 100 pounds overweight off and on throughout those years. I was basically not believed that I measured my portions and took my pills/then insulin as directed.
The other benefit I got from the low carb eating is that the neuropathy in my lower legs and feet that I was told was permanent but we could keep it from getting worse … is gone… I have full feeling in my legs and toes and never want to get the little pin prick toe test again .. because I feel it now.
Thanks for your article … I was thinking I could add some things to my diet but I realize that I need to research more and be careful or I’ll be back on meds and out of control again.
think atkins sounds more and more like the really best diet for me, having diabeties, oh yeah pass the butter, cheese, steak and raw milk,if i had a cow.
Glycerin is good in homemade lotion recipes
any thoughts recipes or info on konjac flour, also known as glucomannan and shiriake miracle noodles? High in fiber & zero calories?
oops I spelled it wrong! shiritake noodles!
Or Konjac Angel Hair Pasta etc
Good to know! I have also heard about resistant starch from cooked potatoes that are allowed to cool, so I eat a lot of potato salad using low fat Mayo. Guess I better give it up.
Wow…my head is spinning…but luckily my need for technical support for new and progressive “fad” diets led me here…
I bought the book…Carb Lovers Diet…it is all about that resistant starch…but they were treating it like a snake oil salesman would.
Ironically, I bought your South Beach diet book also…same day…kind of freaky…
anyway…I’ll light my wood stove with the Carb Lovers book…at least I’ll get “burn some good carbon” with it…lol
Now I need to really get down to it and re-vamp my health correctly…Thank You Doctor.
I’ve seen many articles lately on resistant starch foods. This article explains it well. Most resistant starch foods are a good choice. Here is a complete list of Resistant Starch Foods.