A sweet-tasting syrup that can help you lose weight?
Seems almost too good to be true...
But this is exactly what they're saying about Yacon syrup, which recently became popular as a weight loss aid.
In contrast to most weight loss supplements, it does have some actual human research to back up the claims.
This article takes an objective look at Yacon syrup and reviews the studies behind it.
Yacon syrup is extracted from the roots of the Yacon plant.
The Yacon plant, also called Smallanthus sonchifolius, grows natively in the Andes mountains in South America.
This plant has been eaten and used for medicinal purposes for hundreds of years in South America.
People there believed it to have powerful medicinal properties, leading to improvements in diabetes and helping with kidney and digestive disorders (1).
The juices from the roots are extracted, then filtered and evaporated in a chemical-free manufacturing process that resembles the way Maple syrup is made. A very natural process (2).
The final product is a sweet-tasting syrup, with a dark color and a consistency similar to molasses.
Yacon syrup became popular after it was featured by Dr. Mehmet Oz, a famous TV doctor in America. He called it a "metabolism game changer" and seemed very excited about it.
Keep in mind that Dr. Oz has a history of recommending things that don't work (like the ineffective Garcinia Cambogia) so his endorsement should be taken with a grain of salt.
Bottom Line: Yacon syrup is extracted from the roots of the Yacon plant. It is a sweet-tasting syrup with a look and consistency similar to molasses.
Yacon syrup is one of the best dietary sources of fructooligosaccharides (FOS).
The exact amount may vary between batches, but Yacon syrup contains roughly 40-50% fructooligosaccharides.
Fructooligosaccharides are sugar molecules that are connected in a way that makes them unrecognizable by the digestive system.
Even though these sugars can stimulate the taste buds, humans can not digest them.
Because a large part of Yacon syrup isn't digested, it has only a third of the caloric value of sugar, about 133 calories per 100 grams, or 20 calories per tablespoon.
For this reason, it can be used as a low-calorie alternative to sugar.
The fructooligosaccharides eventually reach the large intestine, where they feed the friendly bacteria in the digestive system. This is where Yacon syrup works its magic... in the gut.
The friendly bacteria in the gut are actually incredibly important for the health of our bodies. Having the "right" types is associated with a lower risk of diabetes, better immunity and improved brain function... to name a few (4, 5, 6, 7, 8).
Keep in mind that Yacon is not the only food that contains fructooligosaccharides. They are also found in smaller amounts in artichokes, onions, garlic, leeks and various other plant foods.
Bottom Line: The active ingredients in Yacon are Fructooligosaccharides (FOS), which feed the friendly bacteria in the intestine and lead to various beneficial effects on metabolism.
Pretty much all of the claims behind Yacon syrup rest on this one study:
This study was a double-blind, placebo-controlled clinical trial. The participants were 55 obese women with cholesterol problems and a history of constipation.
The women were split into two groups... 40 women took Yacon syrup, while 15 women took another type of syrup with no active ingredients (placebo).
All of them were advised to eat a low-fat diet and mildly restrict calories. The study went on for 120 days, about 4 months.
These are the results:
After a study period of 120 days, the women in the Yacon syrup group had lost 33 pounds (15 kg) on average.
At the same time, the placebo group gained an average of 3.5 pounds (1.6 kg).
They also saw reductions in waist circumference:
The women in the Yacon syrup group lost 3.9 inches, or 10 centimeters, off of their waist. No significant change in the placebo group.
There were several other effects noted in the Yacon syrup group:
- Their Body Mass Index (BMI) went from 34 to 28 (From obese to overweight).
- Their stool frequency increased from 0.28 per day to 0.99 per day, effectively curing them of constipation.
- Fasting insulin levels went down by 42%.
- Insulin resistance, a major risk factor for diabetes and heart disease, went down by 67%.
- LDL (the "bad") cholesterol went from 137 mg/dL to 97.5 mg/dL (a 29% decrease).
Overall, the women taking the Yacon syrup had dramatic improvements in both body weight and metabolic health, while the women taking the placebo stayed pretty much the same.
However... before you start jumping up and down of excitement, keep in mind that this is just ONE fairly small study. It is highly likely that other studies will lead to different results.
Anyway, the study was fairly small and had a number of flaws.
Although I personally believe that Yacon syrup can work, the skeptic in me finds it hard to believe that a syrup could have such a strong effect.
It's also important to keep in mind that even if Yacon syrup truly works this well... it is still a short-term effect. Lots of things can make people lose weight, it's keeping it off that is the real challenge.
Bottom Line: In one study, women taking Yacon syrup lost 33 pounds over a period of 120 days. They also saw dramatic improvements in metabolic health.
Due to the high amount of fructooligosaccharides, Yacon syrup has various other health benefits (15).
This includes reduced symptoms of constipation, which is a very common health problem.
In one study, Yacon syrup reduced the transit time through the digestive tract from 60 to 40 hours and increased stool frequency from 1.1 to 1.3 per day (16).
There is also some evidence that it can lower blood sugar, although this needs to be studied a lot more.
Bottom Line: Yacon syrup is effective against constipation and may lower blood sugar levels. It is also high in antioxidants and potassium.
Yacon syrup can have some side effects if you eat too much at a time.
It is very similar to the side effects you get by eating more soluble fiber than you're used to.
When a lot of it reaches the intestine, it can cause excess gas production.
This can lead to flatulence, diarrhea, nausea and digestive discomfort.
For this reason, it is best to start out with a small amount and then work your way up.
If you have problems with diarrhea, then you might want to avoid Yacon syrup altogether. It can make things worse.
The dosage used in the study was roughly 10 grams of fructooligosaccharides per day, which amounts to about 20-25 grams of Yacon syrup per day (about 4-5 teaspoons per day).
In the study, they took the syrup about 1 hour before meals. An effective dosage may be 1-2 teaspoons (5-10 grams) before breakfast, lunch and dinner. Start with 1.
You can also use Yacon syrup as a sweetener, but keep in mind that you can NOT cook or bake with it, because a high temperature (anything over 248°F or 120°C) will break down the structure of the fructooligosaccharides (18).
It is possible that the timing matters. Taking it 30-60 minutes before a meal may be a more effective way to reduce appetite than eating it with a meal.
If you want to try it out, then make sure to get 100% pure Yacon Syrup, there shouldn't be anything else added to it.
It is also possible to get other supplements with fructooligosaccharides, most of which are much cheaper than Yacon syrup. Whether these supplements will have the same effect is not known.
A sweet-tasting syrup from the Andes that can help you lose as much weight as an extreme weight loss diet?
You know what they say... if it seems to good to be true, then it probably isn't true.
That being said, the results of that one study are promising. Although Yacon syrup is far from being scientifically proven to work, I suppose it is worth a shot if you're curious about it.
It might turn out to be an effective tool for short-term weight loss, but don't get your hopes up and expect some syrup to be a permanent solution to your weight problem.
If experience has taught us anything, it is that most weight loss "gimmicks" don't work... at least not in the long term.