Yacon is a tasty, potato-like root vegetable found in Peru. Historically, yacon has been used in South America to lower blood sugar in those with diabetes and improve digestion. Yacon roots are a rich source of fructooligosaccharides (FOS) and have a long use tradition as food in the Andean region. Yacon has several flavonoids including protocatechuic, chlorogenic, caffeic and ferulic acids.
What does the research say?
It appears that substances in yacon have
antioxidant, anti-microbial,
blood sugar lowering, and liver protecting properties. However, this research,
thus far,
has only been in the laboratory and animals. Yacon syrup use may lead to weight
loss. Other herbs that have a benefit for
blood sugar control include
Bitter-Melon, prickly pear cactus extract,
Fenugreek, and cinnamon.
Human studies
As of 2016 few studies in humans are published with this plant.
Crit Rev Food Sci Nutr. 2015. Yacon (Smallanthus sonchifolius): a food with multiple functions. The present review aims to broaden the discussions of the functional properties attributed to yacon (Smallanthus sonchifolius), considered a food with multiple functions since it possesses bioactive compounds (antimicrobial, antioxidant, and probiotic substances) that exert beneficial effects on the body. Although some studies have already demonstrated several of these functions, clinical evidence is scarce, making it necessary that more studies are conducted in this area. Still, since the availability of this food in the market is relatively new, its popularity depends on publications aimed at consumer education and development of new products by the food industry.
Eur J Nutr. Jan 8 2014. Freeze-dried powdered yacon: effects of FOS on serum glucose, lipids and intestinal transit in the elderly. Freeze-dried powdered yacon (FDY) can be considered a prebiotic product due to its fructooligosaccharides (FOS) content. The effect of 9 weeks of daily intake of FDY containing 7.4 g of FOS on glucose, lipid metabolism and intestinal transit in a group of elderly people was investigated. Seventy-two elderly (mean age 67 ± 6.11) men and women were studied for 9 weeks in a double-blind, placebo-controlled experiment. They were randomly assigned to the supplement group (which received 7.4 g of FOS as FDY) or the control group. At the beginning and end of the study, anthropometric measurements, blood sampling, clinical analyses and dietary intake were assessed. A daily intake of FDY containing 7.4 g of FOS for 9 weeks was associated with a mean decrease in serum glucose (p = 0.013), but supplementation did not reduce serum lipids in the study group. The administered dose did not adversely affect intestinal transit. It did not cause bloating, flatulence or intestinal discomfort. Freeze-dried powdered yacon is a good source of FOS, and daily consumption can have a favourable effect on serum glucose in the elderly. It is also practical, easy and safe to use and store.
Yacon syrup: Beneficial effects on obesity and insulin
resistance in humans.
Clin Nutr. 2009. Genta S, Cabrera W, Habib N, Pons J, Carillo IM,
Grau A. Instituto Superior de Investigaciones Biológicas (INSIBIO),
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET),
Universidad Nacional de Tucumán (UNT), Chacabuco, San Miguel de Tucumán,
Tucumán, Argentina.
Syrup obtained from yacon roots could be well positioned as a nutraceutical
product due to its high fructooligosaccharides content. We examined the
beneficial effects and tolerance of yacon syrup on human health. Obese and
slightly dyslipidemic pre-menopausal women were studied over a 120-day period in
a double-blind placebo-controlled experiment. We used two doses of yacon syrup,
0.29g and 0.14g fructooligosaccharides/kg/day. At the start and end of the
study, anthropometric measurements, blood glucose, calcium, lipid and insulin
concentrations were determined. The recommended daily consumption of yacon syrup
with no undesirable gastrointestinal effects is 0.14g fructooligosaccharides/kg.
Daily intake of yacon syrup produced a significant decrease in body weight,
waist circumference and body mass index. Additionally, decrease in fasting serum
insulin 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. Yacon syrup is a good source of fructooligosaccharides and its long-term
consumption produced beneficial health effects on obese pre-menopausal women
with insulin resistance.
Sperm health
Toxicol Mech Methods. September 2013. A mixture of extracts from Peruvian
plants (black maca and yacon) improves
sperm count and reduced
glycemia in mice with streptozotocin-induced diabetes.
Availability
Yocon is found in a variety of ways, including dry root slices, powdered
root, cut leaves for tea, yacon syrup, and in the form of various concentrations of
extracts. Yacon capsules are available for sale.
Yacon syrup for diabetes,
glycemic index
Q. We are a magazine working on a story about alternative sweeteners and I was
hoping Dr. Sahelian could tell me whether or not yacon syrup is a safe
alternative sweetener for people with diabetes.
A. Although some websites selling yacon syrup claim it has a low
glycemic index and does not raise blood sugar, as of February 2009 I have not
seen studies regarding the influence of yacon syrup on blood sugar levels. I
suspect yacon syrup, when used in low amounts, should be okay to use those who
are diabetic, but until formal studies are done with yacon syrup in terms of
determining its glycemic index effects, I would suggest keeping intake to a
minimum. Diabetics can safely use stevia, the no calorie natural sweetener.
Yacon benefit review
At this point it is difficult to make any firm recommendations regarding
yacon herb since
human studies are lacking, but there is a possibility yacon supplements could be helpful in
blood sugar control. Yacon capsules are sold as supplements.
Yacon root composition
Many substances are found in the root including tryptophan, caffeic
acid, chlorogenic acid, protocatechuic and ferulic acids. Roots contain
beta-1,2-oligofructans as the main saccharides.
Essential oils in yacon herb
Three compounds--beta-pinene, caryophylene and y-cadinene have been found
as the predominant essential oils.
Yacon leaves composition
Many chemicals are found in this
herb
including melampolide-type sesquiterpene
lactones including sonchifolin, uvedalin, enhydrin and fluctuanin.
Yacon leaves are used traditionally for blood sugar control.
Side effects, safety, toxicity
Kidney yacon side effects have been reported thus far.
J Ethnopharmacol. 2011. Renal toxicity caused by oral use of medicinal plants: the yacon example. Yacon [Smallanthus sonchifolius (Poepp. & Endl.) H. Robinson, Asteraceae] is an Andean species that has traditionally been used as an anti-diabetic herb in several countries around the world, including Brazil. Its hypoglycaemic action has recently been demonstrated in normal and diabetic rats. However, studies about the safety of prolonged oral consumption of yacon leaf extracts are lacking. Thus, this work was undertaken to evaluate the repeated-dose toxicity of three extracts from yacon leaves: the aqueous extract (AE) prepared as a tea infusion; the leaf-rinse extract (LRE), which is rich in sesquiterpene lactones (STLs); and a polar extract from leaves without trichomes, or polar extract (PE), which lacks STLs but is rich in chlorogenic acids (CGAs).MATERIALS AND METHODS:The major classes of the compounds were confirmed in each extract by IR spectra and HPLC-UV-DAD profiling as well as comparison to standard compounds. The toxicity of each extract was evaluated in a repeated-dose toxicity study in Wistar rats for 90 days. The PE was rich in CGAs, but we did not detect any STLs. The AE and LRE showed the presence of STLs. The polar extract caused alterations in some biochemical parameters, but the animals did not show signs of behavioural toxicity or serious lesions in organs. Alterations of specific biochemical parameters in the blood (creatinine 7.0 mg/dL, glucose 212.0 mg/dL, albumin 2.8 g/dL) of rats treated with AE (10, 50 and 100 mg/kg) and LRE (10 and 100 mg/kg) pointed to renal damage, which was confirmed by histological analysis of the kidneys. The renal damage was associated with increased blood glucose levels after prolonged oral administration of the AE. This observation suggested that the hypoglycaemic effect observed after treatment for 30 days in an earlier study is reversible and was likely the result of renal injury caused by the toxicity of yacon. Because STLs were detected in both AE and LRE, there is strong evidence that these terpenoids are the main toxic compounds in the leaves of the yacon. Based on our results, we do not recommend the oral use of yacon leaves to treat diabetes.
Yacon Plant Research studies
The constituents relate to anti-oxidative and alpha-glucosidase
inhibitory activities in Yacon aerial part extract
Yakugaku Zasshi. 2006. Research Laboratory, Zenyaku Kogyo
Co. Ltd., Tokyo, Japan.
Hot water extract of the aerial part of Yacon (Smallanthus sonchifolia,
Compositae) showed potent free radical-scavenging activity and inhibitory
effects on lipid peroxidation in rat brain homogenate. The most potent
antioxidative activity was
identified as 2,3,5-tricaffeoylaltraric acid (TCAA). The antioxidative activity
of TCAA is superior to that of natural antioxidants such as catechin,
alpha-tocopherol, and ellagic acid,. As the hypoglycemic activity of yacon
extract was described in a previous report, the present results showing that the
aerial part of yacon has strong antioxidative activity may encourage its
potential use as a food supplement to prevent type II diabetes.
Radical scavenging and anti-lipoperoxidative activities of Smallanthus
sonchifolius - yacon - leaf extracts.
J Agric Food Chem. 2005.
Radical scavenging and anti-lipoperoxidative effects of two organic fractions
and two aqueous extracts from the leaves of a neglected Andean crop- yacon (Smallanthus
sonchifolius Poepp. & Endl., Asteraceae) were determined using various in vitro
models. The extracts' total phenolic content was 10-24%. These results make yacon leaves a good candidate for use as a food supplement in the prevention of
chronic diseases involving oxidative stress.
Subchronic 4-month oral toxicity study of dried
Smallanthus sonchifolius (yacon) roots as a diet supplement in rats.
Food Chem Toxicol. 2005.
The aim of this study was to analyze the effects of subchronic (4-months)
oral consumption of dried yacon root flour as a diet supplement using normal
Wistar rats. Two daily yacon intake levels were used, equivalent to 340 mg and
6800 mg FOS/body weight, respectively. Yacon administered as a diet supplement
was well tolerated and did not produce any negative response, toxicity or
adverse nutritional effect at both intake levels used. Yacon root consumption
showed no hypoglycemic activity in normal rats and resulted in significantly
reduced post-prandial serum triacylglycerol levels in both doses assayed.
Conversely, serum cholesterol reduction was not statistically significant. Cecal
hypertrophy was observed in rats fed only the high dose. Our results indicating
lack of yacon toxicity and a certain beneficial metabolic activity in normal
rats warrant further experiments with normal subjects and patients suffering
metabolic disorders.
The effect of Smallanthus sonchifolius leaf extracts on
rat hepatic metabolism.
Cell Biol Toxicol. 2004.
Smallanthus sonchifolius, originating from South America, has become
popular in Japan and in New Zealand for its tubers which contain
beta-1,2-oligofructans as the main saccharides. The yacon plant is also successfully
cultivated in Central Europe in the Czech Republic in particular. Its aerial
part is used in Japan and in Brazil as a component in medicinal teas; while
aqueous leaf extracts have been studied for their hypoglycemic activity in
normal and diabetic rats. We have already demonstrated the high content of phenolic compounds in yacon
leaf extracts and their in vitro antioxidant activity. In this paper, we present
the effects of two organic fractions and two aqueous extracts from the leaves of
yacon on rat hepatocyte viability, on oxidative damage and on glucose metabolism and their insulin-like effect on the expression
of cytochrome P450 (CYP) mRNA. All the extracts tested exhibited strong
protective effect against oxidative damage to rat hepatocyte primary cultures , reduced hepatic glucose
production via gluconeogenesis and glycogenolysis. Moreover, the effects of the
organic fractions and to a lesser extent, the tea infusion on rat CYP2B and CYP2E mRNA expression,
were comparable to those observed with insulin. The combination of radical
scavenging, cytoprotective and anti-hyperglycemic activity predetermine yacon leaves for use in prevention and treatment of chronic diseases
involving oxidative stress, particularly diabetes.
Suppression of glucose absorption by various
health teas in rats
Yakugaku Zasshi. 2004.
The inhibitory effects on the intestinal digestion and absorption of
sugar of health teas that claim beneficial dietary and
diabetes-controlling effects were compared in rats.
The measured durations were the times during which the elevation of portal
glucose levels resulting from continuous intragastric infusion of sucrose
or maltose was suppressed by concentrated teas. The teas investigated
included salacia oblonga, mulberry, guava, gymunema, taheebo, yacon, and
banaba. The duration of the inhibitory effect on the sucrose load of
salacia oblonga, mulberry, and guava were 110 min, 20 min, and 10 min,
respectively. In contrast, gymunema, taheebo, yacon, and banaba had no
significant effect on the continuous infusion of sucrose. These results
suggest that there is considerable difference in the efficacy of
commercial health teas in influencing glucose absorption.
Smallanthus sonchifolius and Lepidium meyenii (maca) -
prospective Andean crops for the prevention of chronic diseases.
Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2003.
Smallanthus sonchifolius (yacon) and Lepidium meyenii (maca) were the
traditional crops of the original population of Peru where they are also still
used in folk medicine. These plants are little known in Europe and Northern
America although at least yacon can be cultivated in the climatic conditions of
these regions. This article deals with the botany and the composition, the
structure of main constituents, biological activity of maca and the cultivation
of yacon in the Czech Republic. The potential of yacon tubers to treat
hyperglycemia, kidney problems and for skin rejuvenation and the
antihyperglycemic and cytoprotective activity of its leaves seems to be related
mostly to its oligofructan and phenolic content, respectively. Maca alkaloids,
steroids, glucosinolates, isothicyanates and macamides are probably responsible
for its aptitude to act as a fertility enhancer, aphrodisiac, adaptogen, and
immunostimulant. Yacon and maca are already on the European market as
prospective functional foods and dietary supplements, mainly for use in certain
risk groups of the population, e.g. seniors, diabetics, postmenopausal women
etc.
Investigation of phenolic acids in yacon (Smallanthus
sonchifolius) leaves and tubers.
J Chromatogr A. 2003.
Thin-layer chromatographic screening of crude extracts of dried
leaves and tubers of yacon (Smallanthus sonchifolius, Asteraceae) revealed the
presence of chlorogenic, caffeic and ferulic acid.
Purification and identification of antimicrobial
sesquiterpene lactones from yacon (Smallanthus sonchifolius) leaves.
Biosci Biotechnol Biochem. 2003.
The extraction of yacon [Smallanthus sonchifolius (Poepp. and Endl.) H.
Robinson; Asteraceae] leaves and chromatographic separation yielded two
new antibacterial melampolide-type sesquiterpene lactones,
8beta-tigloyloxymelampolid-14-oic acid methyl ester and
8beta-methacryloyloxymelampolid-14-oic acid methyl ester, as well as the
four known melampolides, sonchifolin, uvedalin, enhydrin and fluctuanin.
The newly identified compound, 8beta-methacryloyloxymelampolid-14-oic acid
methyl ester, exhibited potent antimicrobial activity against Bacillus
subtilis and Pyricularia oryzae, while 8beta-tigloyloxymelampolid-14-oic
acid methyl ester showed lower activity. Fluctuanin exhibited the
strongest antibacterial activity against B. subtilis among these six
sesquiterpene lactones.
Andean yacon root (Smallanthus sonchifolius Poepp.
Endl) fructooligosaccharides as a potential novel source of prebiotics.
J Agric Food Chem. 2003.
The ability of three known probiotic strains (two lactobacilli and one
bifidobacterium) to ferment fructooligosaccharides (FOS) from yacon roots
(Smallanthus sonchifolius Poepp. Endl) was compared to commercial FOS in
this study. Results indicate that Lactobacillus acidophilus NRRL-1910,
Lactobacillus plantarum NRRL B-4496, and Bifidobacterium bifidum ATCC
15696 were able to ferment yacon root FOS.
Antioxidant activity of extracts from the leaves of Smallanthus
sonchifolius.
Eur J Nutr. 2003.
The leaves are used
in folk medicine as a medicinal tea for hypoglycemia. This paper
describes the antioxidant activity of various extracts from yacon leaves for their content of phenolic
components. The presence of protocatechuic, chlorogenic, caffeic and ferulic (traces) acids were determined in
the two fractions. Both fractions showed potent antioxidant activity in
DPPH and xanthine / XOD
superoxide radical scavenging
equivalents tests, they inhibited the lipoperoxidation of rat
liver subcellular membranes and they protected rat hepatocytes against
oxidative injury. Our results may predetermine the use of yacon
leaves in human diet as a potential remedy in the prevention of chronic
diseases caused by radicals, e. g., arteriosclerosis.
Caffeic acid derivatives in the roots of yacon (Smallanthus
sonchifolius).
J Agric Food Chem. 2003.
Five caffeic acid derivatives were found in the roots of yacon,
Smallanthus sonchifolius (Poepp. and Endl.) H. Robinson, Asteraceae, as
the major water-soluble phenolic compounds. Two of these
were chlorogenic acid (3-caffeoylquinic acid) and 3,5-dicaffeoylquinic
acid, common phenolic compounds in plants of the family Asteraceae. Three
were esters of caffeic acid with the hydroxy groups of aldaric acid,
derived from hexose. The compounds were novel caffeic acid esters of altraric acid: 2,4-
or 3,5-dicaffeoylaltraric acid, 2,5-dicaffeoylaltraric acid, and 2,3,5- or
2,4,5-tricaffeoylaltraric acid.
Hypoglycemic effect of the water extract of
Smallantus sonchifolius leaves in normal and diabetic rats.
J Ethnopharmacol. 2001.
The hypoglycemic effect of the water extract of the leaves of
Smallantus sonchifolius was examined in normal, transiently
hyperglycemic and streptozotocin (STZ)-induced diabetic rats. Ten-percent
yacon decoction produced a significant decrease in plasma glucose levels
in normal rats when administered by intraperitoneal injection or gastric
tube. In a glucose tolerance test, a single administration of 10% yacon
decoction lowered the plasma glucose levels in normal rats. In contrast, a
single oral or intraperitoneal administration of yacon decoction produced
no effect on the plasma glucose levels of STZ-induced diabetic rats.
However, the administration of 2% yacon tea ad libitum instead of water
for 30 days produced a significant hypoglycemic effect on STZ-induced
diabetic rats. After 30 days of tea administration, diabetic rats showed
improved body (plasma glucose, plasma insulin levels, body weight) and
renal parameters (kidney weight, kidney to body weight ratio, creatinine
clearance, urinary albumin excretion) in comparison with the diabetic
controls. Our results suggest that yacon water extract produces an
increase in plasma insulin concentration.
Extraction and identification of antioxidants in the roots of yacon (Smallanthus
sonchifolius).
J Agric Food Chem. 1999.
Yacon, Smallanthus sonchifolius (Poepp. & Endl.) H. Robinson,
Asteraceae, an important economic species grown for its juicy tuberous
root, is potentially beneficial in the diet to diabetics. The
antioxidative activity of yacon root was studied. Two of the major antioxidants were
identified as chlorogenic acid and tryptophan.
Traditional use
Traditionally, Yacon has been used in South America both as food and to help
control blood sugar and improve digestion. The fructooligosaccharide (FOS) in
Yacon is an indigestible sugar that is low in calories and does not appear to
have a significant effect on increasing blood sugar levels. Not only that, this
product is a prebiotic, feeding friendly bacteria and boosting the immune
system.
About the plant
Yacon (Smallanthus sonchifolia) is a showy, perennial plant that can reach
several feet high. It is commonly grown from Venezuela to Argentina, and is
believed to have originated in the mountains of Peru. It grows best in climates
that have little or no frosts, and has been found to grow well in the
Philippines, New Zealand, and Australia.
questions
Q. Can yacon herb be taken the same day as
serrapeptase or
the herbal extract curcumin?
A. Probably. Curcumin should be fine, serrapeptase is an enzyme
which still needs to have more studies to determine its interactions with
other herbs and supplements.