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(Smallanthus sonchifolius)

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Yacon, Smallanthus sonchifolius

Yacon, Smallanthus sonchifolius


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  • Family: Asteraceae
    Taxon: Smallanthus
    Genus: sonchifolius
    Synonyms: Polymnia edulis, P. sonchifolia
    Common Names: aricoma, arboloco, aricona, arikuma, colla, chiriguano, ipio, jacón, jicama, jiquima, jikima, jiquimilla, leafcup, llacon, llacoma, mexican potato, polaco, poire de terre, potato bean, puhe, shicama, taraca, yacón, yacuma, yacumpi
    Part Used: root, leaves

    Yacon Leaves
    Main Actions Other Actions Standard Dosage
  • lowers blood sugar
  • kills bacteria
  • Leaves
  • fights free radicals
  • kills fungi
  • Decoction
  • protects liver
  •   1 cup 2-3 times daily
  • aids digestion

    Yacon is a perennial herb growing 1.5 to 3 m tall with dark green celery-like leaves. The plant produces both male and female daisy-like yellow to orange flowers that are pollinated by insects. Each plant forms a underground clump of 4 to 20 fleshy large tuberous roots. Each weighs, on average, about 500 g. The skin of the tuber when fresh is a tan to a light yellow in color but quickly turns dark brown to dark purple when exposed to air. Yacon is a member of the sunflower family and while it grows in the warm, temperate valleys of the Andes, it can be found at altitudes up to 3200 meters. It is native to the lower Andes regions and cloud forests of South America and can be found in Peru, Ecuador, Bolivia, and Colombia. It is now widely cultivated for its edible roots throughout Andean South America and has been exported into Japan, Taiwan, New Zealand, the Czech Republic, and even the United States as a novel edible root crop.

    Fresh yacon tubers are crisp and juicy with a delicate flavor reminiscent of apple or melon and a surprising sweetness that increases with storage. They are usually eaten raw, (fresh or sun-dried) or steamed, baked, roasted, or juiced into syrup. In the Peruvian Andes where yacon production is flourishing, one can find yacon processed into almost anything in the local markets. . . from pancake syrup, to soft drinks, jam, breakfast cereals, and pudding.


    In early evolutionary periods, Andean farmers had already recognized the value of yacon as a cultivated food crop. Yacon has been discovered in burial grounds from centuries before the Incas. The first written record of yacon was in 1615 when Felipe Guaman Poma de Ayala included it in a list of 55 native crops cultivated by the Andeans.

    In South American herbal medicine systems the tubers are taken raw as a diuretic for kidney and bladder problems while they decoct the leaves for cystitis, hepatosis, and nephrosis in Bolivia. In Peru, the leaves are prepared into a warm poultice and used externally for myalgia and rheumatism. In Brazil the leaves of the plant are brewed into a tea as a natural remedy for diabetes.


    The yacon root or tuber is a rich source (up to 67%) of fructooligosaccharides (FOS). These compounds helps gives the tuber its sweet flavor however most of these types of sugars are not readily digested or metabolized easily by humans. For this reason, yacon shows much promise as a food for diabetics and as a base for a low calorie sweetener. These oligofructans have been recently classified as “prebiotics.” Since they are not digested in the human gastrointestinal tract they are transported to the colon where they are fermented by a selected species of gut micro-flora (especially Bifidobacterium and Lactobacillus) and help to balance gut flora and aid digestion. One laboratory study suggests that the prebiotic effect of yacon tuber extracts during the fermentation process enhanced the natural production of beta-glucans which act as non-specific immunostimulants.

    In addition to these sweet compounds, yacon tubers are also rich in free fructose, glucose and sucrose as well as inulin and starch. Both the tuber and the leaves of the plant contain chlorogenic, ferulic and caffeic acids which are known to provide an antioxidant effect. Several sesquiterpene lactones can be found in the leaves of the yacon plants which have evidenced antibacterial and antifungal actions in laboratory tests.

    Other chemicals documented in yacon include: y-cadinene, caffeic-acid, 3-caffeoylquinic-acid, chlorogenic-acid, 2,4-dicaffeoylaltraric-acid, 2,5-dicaffeoylaltraric-acid, 3,5-dicaffeoylaltraric-acid, 3,5-dicaffeoylquinic-acid, enhydrin, ferulic-acid, fluctuanin, gallic-acid, gentisic-acid, inulin, melampolides, oligofructans, beta-pinene, protocatechuic-acid, rosmarinic-acid, sonchifolin, tryptophan, 2,3,5-tricaffeoylaltraric-acid, 2,4,5-tricaffeoylaltraric-acid, and uvedalin


    Leaves: The hypoglycemic action of yacon leaves has been demonstrated in a laboratory study with normal and diabetic rats by researchers in Argentina. A decoction of yacon leaves was reported to produce a significant decrease in blood sugar levels in normal rats when administered by injection or orally. In a glucose tolerance test, a single administration of the leaf decoction lowered the plasma glucose levels in normal rats. In contrast, a single oral or injectable administration of yacon leaf decoction produced no effect on the plasma glucose levels of laboratory-induced diabetic rats. However, the administration of a lower dosage of leaf tea instead of water for 30 days produced a significant hypoglycemic effect in laboratory-induced diabetic rats. The mechanism of action of these leaf extracts were insulin-like in the way they affected glucose metabolism. An in vitro study reports that the leaves also have antioxidant actions as well as a liver protective action by reducing free radical damage in rat liver cells (caused by alcohol).

    Tubers: In an 4 month oral toxicity with rats, researchers in Argentina reported that 340 mg and 6800 mg of yacon root given orally to rats twice daily evidenced no hypoglycemic or blood sugar lowering action, nor did it evidence any toxicity. They did note that both dosages lowered trigylcerol levels, but not cholesterol levels.


    While yacon root is currently being marketed to diabetics and dieters... no blood sugar lowering effects have been published in humans or animals for the tubers (only the leaves). Because it contains a type of sugar that isn’t metabolized (as well as being much lower in calories), it is certainly an appropriate sweetening substitute over regular sugar for diabetics and dieters. Consumers should be aware however, yacon root is not going to help diabetics lower or maintain blood sugar levels as some are trying to market it for (and the tuber actually does contain glucose and fructose).

    In local Andean markets today yacon root is considered a fruit and sold with other fruits like pineapple and apples (not in the very large and diverse potato section of the market). The tubers have a wonderful crispy sweet flavor which is enhanced with drying them in sunlight until the peels are slightly wrinkled. They are then peeled and eaten out of hand, chopped into salads, and steamed or fried. The tubers are also juiced and then concentrated into syrups and sweeteners (much like dark corn syrup) or further dried and concentrated to produce solid dark-brown sweet blocks called chancaca. Here in the U.S. several relatively new yacon root syrups are now available in health food stores and natural products markets as a low-calorie alternative to corn syrup or molasses. Try them... they’re great!

    Unfortunately, there are also one or two yacon root capsules on the market today which are making claims or pointing to the studies for blood sugar regulation, and/or antimicrobial actions which really only pertain to yacon leaves and not the root/tuber. If one takes yacon root in capsule form, about the only real benefit is as a prebiotic to help gut flora bacteria and possibly increase the natural production of immunostimulating beta-glucans (but it will certainly take much more than a 500 mg capsule or two... remember they eat the tuber by the pound in the Andes, and not by the gram). To aid blood sugar metabolism, look for yacon leaves in capsules or simply dried and cut up leaves sold in packages. There are a only a handful of products to choose from in the U.S. market place as this is a relatively new natural remedy for this country.

    Main Actions (in order):
    hypoglycemic, antioxidant, antibacterial, antifungal, liver protector

    Main Uses (leaves):

    1. for diabetes and high blood sugar
    2. as a liver tonic and for liver problems
    3. as an antimicrobial for kidney and bladder infections
    4. as an antioxidant (especially for the liver)
    Properties/Actions Documented by Research:
    antibacterial, antidiabetic, antifungal, antioxidant, hepatoprotective (liver protector), hepatotonic (liver tonic), immunostimulant,

    Other Properties/Actions Documented by Traditional Use:
    antidiabetic, stomachic (digesive aid)

    Cautions: The leaves will enhance the effect of insulin and diabetic drugs.

    Traditional Preparation: The tubers are simply just eaten like a fruit or they are juiced and boiled down to a syrup. The leaves are traditionally prepared as a decoction and taken in dosages of 1 cup two to three times daily.

    Contraindications: The leaves have demonstrated the ability to lower blood sugar levels. Diabetics should check with a practitioner before using the leaves and monitor their blood sugar levels accordingly as medications may need adjustment.

    Drug Interactions: The leaves will enhance the effect of insulin and diabetic drugs.

    Bolivia for bladder infections, cystitis, hepatosis, kidney infections, nephrosis
    Brazil for diabetes
    Peru for myalgia, rheumatism

    This text and plant database file has been authored by Leslie Taylor, copyrighted © 2006. All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, including websites, without written permission.

    * The statements contained herein have not been evaluated by the Food and Drug Administration. The information contained in this plant database file is intended for education, entertainment and information purposes only. This information is not intended to be used to diagnose, prescribe or replace proper medical care. The plant described herein is not intended to treat, cure, diagnose, mitigate or prevent any disease. Please refer to our Conditions of Use for using this plant database file and web site.

    Published Third-Party Research on Yacon

    All available third-party research on yacon can be found at PubMed. A partial listing of the published research on yacon is shown below:

    Hypoglycemic Actions:
    Valentova, K., et al. “The effect of Smallanthus sonchifolius leaf extracts on rat hepatic metabolism.” Cell Bio.l Toxicol. 2004 Mar; 20(2): 109-20.
    Aybar, J., et al. “Hypoglycemic effect of the water extract of Smallanthus sochifolius (yacon) leaves in normal and diabetic rats.” J. Ethnopharmacol. 2001; 74: 125-32

    Antioxidant Actions:
    Terada, S., et al. “The constituents relate to anti-oxidative and alpha-glucosidase inhibitory activities in Yacon aerial part extract.” Yakugaku Zasshi. 2006; 126(8): 665-9.
    Valentova, K., et al. “Radical scavenging and anti-lipoperoxidative activities of Smallanthus sonchifolius leaf extracts.” J. Agric. Food Chem. 2005 Jul; 53(14): 5577-82.
    Valentova, K., et al. “The effect of Smallanthus sonchifolius leaf extracts on rat hepatic metabolism.” Cell Bio.l Toxicol. 2004 Mar; 20(2): 109-20.
    Simonovska, B., et al. “Investigation of phenolic acids in yacon (Smallanthus sonchifolius) leaves and tubers.” J. Chromatogr. A. 2003 Oct; 1016(1): 89-98.
    Valentova, K., et al. “Antioxidant activity of extracts from the leaves of Smallanthus sonchifolius.Eur. J. Nutr. 2003; 42(1): 61-6.
    Yan, X., et al. “Extraction and identification of antioxidants in the roots of yacon (Smallanthus sonchifolius).” J. Agric. Food Chem. 1999; 47(11): 4711-3.

    Antimicrobial and Prebiotic Actions:
    Lin, F., et al.”Purification and identification of antimicrobial sesquiterpene lactones from yacon (Smallanthus sonchifolius) leaves.” Biosci. Biotechnol. Biochem. 2003; 67(10): 2154-9.
    Pedreschi, R., et al. “Andean yacon root (Smallanthus sonchifolius Poepp. Endl) fructooligosaccharides as a potential novel source of prebiotics.” J. Agric. Food Chem. 2003 Aug; 51(18): 5278-84.

    Non-Toxic Actions:
    Genta, S., et al. “Subchronic 4-month oral toxicity study of dried Smallanthus sonchifolius (yacon) roots as a diet supplement in rats.” Food Chem. Toxicol. 2005; 43(11): 1657-65.

    Plant Chemistry & Compounds
    Valentova, K., et al. “The biological and chemical variability of yacon.” J. Agric. Food Chem. 2006 Feb 22; 54(4): 1347-52.
    Adam, M., et al. “Comparison of three different solid-phase microextraction fibres for analysis of essential oils in yacon (Smallanthus sonchifolius) leaves.” J. Chromatogr. A. 2005 Aug 19; 1084(1-2): 2-6.
    Schorr, K., et al. “ Quantitative determination of enhydrin in leaf rinse extracts and in glandular trichomes of Smallanthus sonchifolius (Asteraceae) by reversed-phase high-performance liquid chromatography.” Phytochem. Anal. 2005 May-Jun; 16(3): 161-5.
    Valentova, K., et al. “Smallanthus sonchifolius and Lepidium meyenii - prospective Andean crops for the prevention of chronic diseases.” Biomed. Pap. Med. Fac. Univ. Palacky. Olomouc. Czech Repub. 2003 Dec; 147(2): 119-30.
    Takenaka, M., et al. “Caffeic acid derivatives in the roots of yacon (Smallanthus sonchifolius).”J. Agric. Food Chem. 2003 Jan; 51(3): 793-6.

    * The statements contained herein have not been evaluated by the Food and Drug Administration. The information contained in this plant database file is intended for education, entertainment and information purposes only. This information is not intended to be used to diagnose, prescribe or replace proper medical care. The plant described herein is not intended to treat, cure, diagnose, mitigate or prevent any disease. Please refer to our Conditions of Use for using this plant database file and web site.

    © Copyrighted 1996 to present by Leslie Taylor, Milam County, TX 77857.
    All rights reserved. Please read the Conditions of Use, and Copyright Statement for this web page and web site.
    Last updated 12-29-2012