Whole grains changing to fructose?

[knitone]

There are several posts on this board warning that whole grains turn into sugars/fructose during digestion. After searching the internet, I cannot find any mention of this. Would someone please let the group know more about this phenomenon? Many HFIers say they eat oatmeal without worry, but that is a whole grain. If anyone can provide further information about whole grains changing to fructose, please do!

[Stefanie (Ziba)]

This article out of New Zealand shows low-FODMAP and high-FODMAP grains. Clearly, HFI requires limiting even the low FODMAP grains, but I think sensitivity must vary even among HFI-ers. My son can eat oats to an extent, but too much will give him GI issues. He seems to do OK with white flour but I have not even tried whole wheat flour (all wheat is high FODMAP due to the fructans). He eats some white rice but not brown. 

www.healthyfood.co.nz/blogs/alana-scott/2015/december/09/what-flours-and-starches-are-low-fodmap

I looked on Google Scholar and had trouble finding articles that spelled out the fructose content in various grains.

[antonia]

It’s an interesting question I’ve wanted to answer for a long time. Unfortunately, it’s not the kind of data that readily exists, at least not via google search anyway, it’s pretty tough. You’d need to find a resource on cereal chemistry or talk to a cereal chemist I’m afraid.

I wish fodmap information was more helpful too. My daughter followed the low fodmap diet for over a year because before we found HFI we thought she had fructose malabsorption. So I’m pretty familiar with the diet. There are several problems with fodmaps as they relate to HFI. First is that low fodmap carbohydrates are low fructose not NO food fructose, as Ziba mentioned above. Another is that fodmaps are any sugar or carbohydrate that can be fermented in the gut, they may not have any fructose units at all. Lactose, for example, is a fodmap to be avoided if you’re on a low fodmap diet. However, since it contains no fructose it’s perfectly fine for HFIers. So avoiding certain high fodmap carbs may not be necessary at all, and we certainly don’t want to eliminate any more from a HFIers diet than is absolutely necessary. Lastly, fructose malabsorption is often related to an imbalance of microbes in the gut (SIBO, etc). Low fodmappers avoid even refined, white wheat because fructans, an oligosaccharide, can ferment in the gut. Fructans, as the name implies, contain fructose so why can HFIers eat refined wheat? I assume because in a gut with balanced microbes the fructans are not broken down and just pass on through without any fructose units being released. Or maybe the fructose that is released is actually being consumed by microbes if you’ve got the right kind in your gut? Being that all of our guts vary a bit in regards to natural floral or possibly by probiotics, if you take them, this could also be the reason some HFIers seem okay eating certain whole grains and others do not. This is the main reason I don’t give my daughter probiotics. She seems to do fine with whole grains like oats and sorghum, so I’m not going to mess with that. In other words, no need to fix what’s not broken, we’ll leave the probiotics on the shelf.

Of course I’m no doctor, these are just my rambling thoughts. There’s so many areas where more accurate and detailed data is needed to help HFIers determine what’s safe to the eat and what’s not.

[knitone]

Antonia, Those are some good ramblings, very logical. The fructans confused me too. I found I have no problem with white wheat and that is now a standby--pretzels, couscous, bread from a real bakery. I'm feeling much better on a no-added sugar diet. That said, according to cronometer I get more sugar than HFIers can have. I'm tallying about 5 or 6 grams a day because I allow myself 2 servings of vegetables  I don't eat the sweet ones, but I do allow cucumber, celery and broccoli. I tried popcorn and felt okay, which is why I started to think about the whole grains changing to sugar question. Perhaps they are changed further down in the intestine so that my small-intestine microbes, which theoretically cause problems, don't come in contact with them. It would seem to me that the whole grains would digest into glucose rather than fructose. More ramblings!

I don't think fodmaps are my problem, just any kind of sugar.

[antonia]

Yes, the mind really can spin when thinking about these kinds of things. I think we might need a whole team of doctors, food scientists and nutritionists, to get real answers. Wouldn’t that be nice?

It’s my understanding that in a balanced gut fermentation of non digestible fibers and such are suppose to take place in the large or lower intestine and that once you’ve gotten that far no more nutrients are being absorbed into the blood stream, they’re basically on their way out.

I do avoid foods with free fructose, sucrose or sorbitol, but when the sugars are (possibly) bound up into fibers or long chain carbohydrates, I might consider trialing to see how Palmera tolerates it. She seems to do okay with corn flour or cornmeal products in moderation as long as they’re not fortified or enriched. She’s not tried popcorn though. I try to rotate through all the grains so that she’s not eating a lot of any one in particular, everything in moderation, and she seems to do better this way. Interesting to think of other foods where tolerances seem to vary, like vegetables, nuts, seeds and legumes, but I’ve not been brave enough to try any of those with her yet. May have to wait until she’s older.

I also wonder about the effects of different methods of cooking and how that might change the structure of carbohydrates, sometimes for the good, sometimes for the bad, in regards to the release of fructose and HFI safety.

[antonia]

Also, knitone, have you ever looked into FBPase or FDPase Deficiency? This is often described as a cousin to HFI, but it is the lack of a different enzyme (not Adolase B) occurring in a different place in the metabolic cycle. Those with it are suppose to be able to tolerate larger amounts of fructose compared to HFIers when they are otherwise healthy. When ill or under strenuous exercise or fasting conditions it supposedly acts just like HFI though. Just a thought since you said you tolerate more fructose than HFIers do.

[knitone]

Antonia, I have not looked into that, but I never experience hypoglycemia. I was tested for sucrase deficiency and that test was negative. I don't tolerate vegetables or beans with raffinose, nothing with -ose or -ol at the end! I'm getting used to no sugar and enjoying carbs--also discovering teas have a lot of flavor variations when the diet is limited.

[knitone]

Update: Not doing well on popcorn and broccoli. Also, Dr. Pimental (an expert on irritable bowel syndrome and sibo) says this:

Fiber
Fiber is just indigestible long chains of sugar.
1. Do not go out of you way to eat fiber as in whole wheat bread or supplements such as Citrucel, Metamucil, etc.
2. Many products now have “added fiber.” Cheerios, for example, often has added fiber now to make it “healthier.” Watch for this.