I know. It sounds like some spammy email subject line. I’d normally avoid something like this like the plague. Let me explain.
I probably spend an inordinate amount of time looking for viable sources of fermentable prebiotic fiber, preferably from whole foods. And so I stumbled upon yacon, a South American tuber related to jicama that’s slightly sweeter and exceptionally high in short-chain fructooligosaccharides (up to 70%), one of the more potent and beneficial prebiotic fibers. And then the assault began: yacon syrup everywhere. I was barraged by a ton of ad spam, claims about weight loss, and a bunch of Dr. Oz references. What on earth? So I looked into it.
It looks like it all stems from a segment on the Dr. Oz show called “The Yacon Syrup Project.”
The project seems to be based on a 2009 Argentina study that had 55 obese women with insulin resistance consume yacon syrup for 4 months. The study seems to have yielded impressive results:
Daily intake of yacon syrup produced a significant decrease in body weight, waist circumference and body mass index. Additionally, decrease in fasting serum insulin and Homeostasis Model Assessment index was observed. The consumption of yacon syrup increased defecation frequency and satiety sensation. Fasting glucose and serum lipids were not affected by syrup treatment and the only positive effect was found in serum LDL-cholesterol levels.
And it attributes the effects to the bacterial fermentation of FOS and the resulting production of short-chain fatty acids:
The major products of FOS metabolism in the intestine are short-chain fatty acids (SCFA). The data presented in this study demonstrate that yacon syrup is an excellent source of FOS with favorable health effects on pre-menopausal obese women and that these effects would be probably modulated via SCFA produced during FOS fermentation in the colon. Much has been investigated concerning SCFA production in the gut and the different metabolic significance of the individual acids. It is known that butyrate serves as fuel for the mucosa, whereas acetate and propionate enter the portal blood and may influence systemic carbohydrates and lipids’ metabolism. Therefore, the pattern of fermentation of syrup-containing FOS might be important when predicting their metabolic effects.
It’s also worth mentioning that these results were achieved with not all that much FOS — 0.14 grams per kg of body weight.
And so it looks like “America’s doctor” conducted his own experiment, asking 60 women to take one teaspoon with each meal for 4 weeks, and change nothing else about their diet or lifestyle. It, too, seems to have yielded impressive results: 73% of women lost weight, 14 of them lost five pounds or more, and the average amount of weight lost was 2.9 pounds. With nothing more than a healthy dose of short-chain fructooligosaccharides. Sadly, many who are taken in with this stuff will think yacon syrup is some special elixir with magical properties, when it’s really just an effect of prebiotic fermentable fiber.
So why am I writing about this?
Well, first I’ll say why I’m NOT writing about this: I’m not suggesting that people should go out and grab a bottle of yacon syrup. There seems to be a whole industry that’s sprouted up as a result of this segment. While the syrup is indeed a potent source of FOS, it’s pretty pricey and not all that economical. I certainly wouldn’t recommend it as a staple — maybe something to keep around for an occasional prebiotic boost and to foster some fiber diversity? Or maybe something to try if you are keen on doing a little experimentation just for the heck of it. On the upside, it seems to have a not offensive taste — similar to molasses, apparently. And most options seem to be organic and GMP-certified. But again, as a major staple, I don’t think it makes sense.
Here’s why I AM writing about this: it’s further proof of the prebiotic fiber effect. The effects line up pretty well with what people are experiencing with Resistant Starch/Potato Starch, and here we have those effects corroborated with a completely different type of prebiotic fiber. Significant reduction in body weight. Significant increase in insulin sensitivity. Improved bowel function. Lowered LDL cholesterol. Nothing about sleep improvement, but maybe if they measured it they would have found something.
And it also underlines, again, the primary reason why I think the Resistant Starch experiment has been so successful: it has found a cheap, high-dosable, and accessible source of a potent prebiotic fiber in the form of potato starch. But I don’t mean to discount the unique effects of RS — there’s just more to figure out on that front.
Anyway, it’s too bad there was no gut analysis involved in either of these experiments. Am I the only one dying to know their before and after Actinobacteria? Clostridia? SCFA production levels?
Or do I just need to get out more?