Yacon
Smallanthus sonchifolius
Vegetables. Latin American & Amazon and Native American.
Also called Peruvian ground apple, Bolivian sunroot
Spanish: Yacón
Can cause gas and bloatingYacon is a sweet, crisp root from the Andes, eaten fresh or as syrup, mainly for the fiber-like sugars that feed gut bacteria.
Did you know? Yacon roots store much of their sugar as fructooligosaccharides, chains of fructose that human digestive enzymes cannot break down. They reach the large intestine intact and feed friendly gut bacteria.
What it may help, and how strong the proof is
- Digestion & gut health. Its fructooligosaccharides feed friendly gut bacteria. Trials of yacon syrup and root found more frequent bowel movements, and a 2025 meta-analysis of root trials reported the same. The trials are small and short.See the research: 10 studies in peoplePromising proof
- Blood sugar. Short trials did not find a change in fasting blood sugar. One placebo-controlled trial in obese women found lower fasting insulin, but blood sugar did not change, so the results are small and mixed.See the research: 12 studies in peoplePromising proof
- Weight. One placebo-controlled trial in obese women found lower body weight, waist size and BMI after 120 days, and people reported more fullness. Other trials are few and small, so this needs confirmation.See the research: 13 studies in peoplePromising proof
Parts of the body
Gut & intestines, Stomach, Pancreas & blood sugar, Energy & metabolism
Traditional use
Andean farmers in Peru, Bolivia and Ecuador have grown yacon for centuries. They eat the crisp roots raw and brew the leaves into a tea.
How it is classified
How people take it
Most people eat the root raw or cooked, or take it as syrup or powder. Trials used yacon syrup or powder for weeks to months, and doses varied, so there is no set amount. In one 120-day trial, the lower dose, about 0.14 g of fructooligosaccharides per kg of body weight a day, caused no stomach upset. Start small, since large amounts cause gas.
Food, syrup, powder and tea.
Where to get it
Grown as a root crop in the Andes and in a few other countries. Fresh roots are sold in some farmers' markets and specialty stores, and syrup and powder are sold in health stores and online.
Be careful
Fructooligosaccharides are fermented in the colon, so large amounts often cause gas, bloating and loose stools. People with irritable bowel syndrome or fructan sensitivity may react more. Yacon may affect blood sugar, so people on diabetes medicines should check with a doctor and watch for low blood sugar. Few studies have looked at pregnancy or breastfeeding, so stick to food amounts then.
Avoid if: pregnancy (medicinal amounts); irritable bowel syndrome; diabetes medicines.
Mixing with other things
- Use cautionDiabetes medicine (metformin, insulin, glipizide, Ozempic)
Yacon may add to the effect of diabetes drugs on blood sugar, although blood sugar did not clearly fall in trials. Check blood sugar more often if you use them.
Adds up with others that may lower blood sugar: , , , , , , , , , , , , , and 54 more.
The honest take
Yacon is a crisp, naturally sweet root that feeds friendly gut bacteria, so it is a good food to enjoy. Human trials are small and short, and they most consistently show more frequent bowel movements, with weight and insulin results that need confirming. Blood sugar did not change in the trials that measured it, so claims of diabetes control go beyond the research.
Sources
Each “See the research” link opens PubMed, the U.S. National Library of Medicine's index of medical studies, showing only trials and reviews done in people. The number tells you how much a use has been tested, not whether it worked. The proof rating tells you that.
Study counts checked October 2026.