*Corresponding Author: Seyed Adel Moallem, Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of
Medical Sciences, Mashhad, Iran. Tel: +98 51 38823255 , Fax: +98 51 38823251, E
Sciences, March 2015, 20, 163-168
Effect of Apple Cider Vinegar on Blood Glucose Level in Diabetic
Maryam Iman1, Seyed Adel Moallem2,3,4*, Ahmad Barahoyee4
1Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
2Pharmaceutical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
3Medical Toxicology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
4Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
Apple cider vinegar is an acidic solution produced by
fermenting apples. It contains vitamins, minerals and
many trace elements.1 It contains a potent supply of
potassium. Potassium is essential for soft tissue repair
and the replacement of worn-out tissues within the
body. Cider vinegar improves the health and function
of the vital organs of the body by preventing
excessively alkaline urine. It is a strong detoxifying and
purifying agent. It breaks down fatty, mucous and
phlegm deposits within the body. It also oxidizes and
thins the blood, which is important in preventing high
blood pressure. Cider vinegar has been found to
neutralize any toxic substances that enter the body. It
neutralizes harmful bacteria that may be found in
certain foods, promotes digestion, assimilation and
elimination.2,3 Toxic build-ups with the body can cause
boils, blisters, acne, etc. Cider vinegar detoxifies and
helps with the cleansing and clotting processes of the
blood, by helping along the blood oxidation process.
When a mixture of cider vinegar and water is taken
before a meal (particularly food served in restaurants or
at picnics where the preparation or duration of food left
uncovered and not refrigerated is questionable), it
seems to prevent diarrhea or digestive upsets.4,5 Cider
vinegar can be taken alone or used in cooking. The best
method of using apple cider vinegar is in its natural
liquid form. Cider vinegar is thought to be beneficial in
the treatment of arthritis, asthma, nose bleeds,
osteoporosis, cancer, Candida, high cholesterol, colds,
constipation, muscle cramps, colitis, diabetes, diarrhea,
depression, dizziness, ear discharge, eczema, fatigue,
gallstones, kidney stones, hay fever, headaches,
heartburn, hiccups, indigestion, insomnia, kidney and
bladder problems, metabolism, nasal congestion, sore
throats, stiff joints, ulcers and weight loss.6 Some
reports showed that vinegar effect the glucose and
insulin responses to a sucrose or starch load. It is near
25 years that several in vivo and in vitro studies have
analysed the effect of vinegar on glucose metabolism in
In recent years, apple cider vinegar has been singled out as an especially
helpful health remedy. It has been widely used in various dosage forms in alternative
medicine for several conditions such as diabetes and obesity. In this study, the effect
of apple cider vinegar on blood glucose level has been evaluated. Methods:
Intraperitoneal (IP) injection of streptozocin 40 mg/kg/day for 4 days was used to
induce diabetes in mice. The mice were divided in six groups (n=10). Two
concentrations of 0.16% and 1.6% of apple cider vinegar were used in drinking water
for 21 days. Normal saline and acetic acid were used as negative controls and
glibenclamide by IP injection (5mg/kg) as positive control. For studying any possible
combination effects, 0.16% apple cider vinegar and glibenclamide were used together.
Also, the effects of apple cider vinegar on glucose tolerance test and amylase serum
concentration were evaluated. Results: Our results indicated that apple cider vinegar
in both concentrations was not effective after 3 days of the start of its administration.
However, on day 7 it reduced blood glucose levels significantly and this was
maintained on days 14 and 21. Glucose tolerance test showed that apple cider vinegar
was effective in lowering blood glucose level after 60 minutes of glucose
administration and this was maintained up to 120 minutes. Also, in both
concentrations significantly reduced serum amylase levels 21 days after the start of its
administration. Conclusions: Therefore, in this study it has been revealed that apple
cider vinegar has considerable reducing effect on blood glucose levels in diabetic
mice. The mechanism of this action and its significance remain to be elucidated in
A R T I C L E I N F O
A B S T R A C T
Received: 22 Dece mber 2014
Accepted: 4 February 2015
Apple Cider Vinegar
Apple cider vi negar in diabetes
healthy subjects and in subjects with diabetes
One of the major worldwide health problems is
diabetes. Diabetes appears to be increasing in most
countries, due to increasing population growth, aging,
urbanization, and increasing prevalence of obesity and
physical inactivity. Diabetes is a metabolic disease
which affects not only the glucose metabolism but also
lipid and protein metabolism. Diabetes can lead to
increased cardiovascular mortality, nephropathy,
neuropathy and retinopathy.9
There are mainly two types of diabetes–Type 1 and
Type 2. In Type 1 diabetes, the hormone insulin is not
produced while Type 2 diabetes mellitus (T2DM) is
characterized by a relative decreased sensitivity of
target tissues to the action of this hormone and
progressive impairment of insulin secretion.
Approximately one T2DM patients are treated with oral
hypoglycemic agents to stimulate insulin secretion.10,11
T2DM is managed through a program that consists of
lifestyle modifications including appropriate diet and
exercise programs and addition of oral
antihyperglycemic agents.12,13Although oral
hypoglycemic agents (insulin) are the mainstay of
treatment of diabetes and are effective in controlling
hyperglycemia, they have prominent side effects and
fail to significantly alter the course of diabetic
The common side effects associated with the main
classes of drugs used for the treatment of T2DM are
hypoglycemia, weight gain, gastrointestinal disorders,
peripheral edema and liver disease.14 The present study
investigates the hypoglycemic effects of apple cider
vinegar and its combination effects with
antihyperglycemic agents. It is thought to be beneficial
for decreasing uses of antihyperglycemic agents and
their side effects.
Methods and Materials
Apple cider vinegar with 16% concentration was
obtained from Septiko Co. (Mashhad, Iran) and
streptozosin (Zanosar®) from Pharmacia & Upjohn
(Mich, USA). Amylase kit was obtained from Zist
Chimi Co. (Iran). Glibenclamide (Daroupakhsh Co,
Iran) was used. Accu-chek Glucometer (Roche,
Canada) was used to determine blood glucose levels.
All reagents were of analytical grade.
Mice at 6-8 weeks of age, weighing 25-30 g were
obtained from Avicenna Research Institute (Mashhad,
Iran). The mice were housed in a standard environment
at a constant temperature of 25˚C under a 12-h
light/dark cycle with free access to food and drinking
Intraperitoneal (IP) injection of streptozocin 40
mg/kg/day for 4 days was used to induce diabetes in
mice. Two weeks after streptozosin injection, blood
glucose levels were measured and those with fasting
glucose levels above 11.1 mmol/l were included in the
Treatment regimens with apple cider vinegar
Mice could not tolerate gavage of 8% and 16% of apple
cider vinegar, probably due to the high acidity of these
concentrations. Various experiments showed that
concentrations of 0.16% and 1.6% of apple cider
vinegar in drinking water up to 21 days are well
Streptozocin-diabetic mice were divided randomly into
6 groups (n=10). The method of treatment was
“drinking water”. Two concentrations of 0.16% and
1.6% of apple cider vinegar were used in drinking
water for 21 days.17 Normal saline and acetic acid were
used as negative controls and glibenclamide by IP
injection (5mg/kg) as positive control. For studying any
possible combination effects, 1.6% apple cider vinegar
and glibenclamide were also used together. Also, the
effects of apple cider vinegar on glucose tolerance test
and amylase serum concentration were evaluated. The
glucose levels in the plasma were determined in groups
after 3, 7, 14, 21 days from drug administration. All of
samples were obtained after 4h of fasting. The plasma
glucose levels were expressed in mmol/l.
Blood collection for measurement of blood glucose
Stressful methods of blood collection can affect blood
parameters such as glucose levels. To decrease stress,
the mice were acclimated to the restraining device and
were warmed and placed in the restraining tube. After 4
hour of fasting, a 2 mm distal section of the mouse
sterilized tail is scratched using a syringe needle and
gently squeezed to obtain two drops of blood, the first
of which is discarded. The second drop is applied
directly to the test strip to obtain blood glucose
measurement. In our experience, one reading per time
point was sufficient to obtain an accurate reading,
however additional readings per time point were
performed randomly for results validation.
Glucose tolerance test
The test is usually used to diagnose prediabetes and
diabetes, insulin resistance, and sometimes reactive
hypoglycaemia. The glucose is most often given orally
to determine how quickly it is cleared from the blood.
The test may be performed as part of a panel of tests,
such as the comprehensive metabolic panel in medical
In the last day of treatment, after the fasting plasma
glucose was tested, all groups received 5 g/kg of
glucose by gavage. The glucose levels in the plasma
were determined in groups after 30, 60 and 120 minutes
of glucose administration.
Iman et al.
Measurement of blood α-amylase
Amylase is an enzyme that its catalytic function is t o
hydrolyze sugar and starch. It digests polysaccharides
into smaller disaccharide units, eventually converting
them into monosaccharaides such as glucose. α-
Amylase is the major form of amylase found in humans
and other mammals. It is produced by the pancreas t o
help digestion. An amylase test measures the amount of
this enzyme in a sample of blood. In the last day of
treatment, mice were sacrificed and 1.5-2 ml blood
samples were obtained by cardiac Puncture. Amylase
activity was determined by using a diagnostic kit. The
substrate was ethylidene-p-nitrophenyl maltoheptaoside
(EPS-G7). Absorbance, which is directly related to α-
amylase activity, was measured at 405 nm and 37 ºC
using an auto analyzer (Alcyon 300® Plus, Molecular
Devices Corporation, Sunnyvale, CA). Before
application, the auto analyzer was calibrated with the
control sera N and P (TrueLab N and TrueLab P®,
respectively; Zist Chimi., Iran) and a calibrator solution
(TrueCal U®, Zist Chimi Co., Iran). After calibration,
the auto analyzer mixes 6 μl of enzyme sample with
300 μl of substrate solution, automatically and
calculates the enzyme activity (IU/L).
One-way ANOVA and t-student statistical tests were
used to assess the significance of the differences. In
case of significant F value, multiple comparison Tukey-
Kramer tests were used to compare the means of
different treatment groups. Results with p<0.05 were
considered to be statistically significant.
Results and discussion
Measurement of blood glucose
The effect of apple cider vinegar on glucose levels in
the plasma was determined in mice after 3, 7, 14, 21
days of drug administration. Glucose blood levels in
diabetic mice treated with normal saline and acetic acid
were increased during 21 days (Fig. 1). Apple cider
vinegar in both concentrations was not effective after 3
days of the start of its administration. However, on day
7 it reduced blood glucose levels significantly and this
was maintained on days 14 and 21 (p < 0.05) (Fig. 1).
Comparisons of treated groups showed no significant
difference in their glucose levels at days 7, 14 and 21 (p
> 0.05), indicating that apple cider vinegar at both
doses has antihyperglycemic effects comparable to
Figure 1. Glucose blood l evels during 21 days.
Glucose tolerance test
In the last day of treatment after determining the fasting
blood glucose, all groups received 5 g/kg of glucose by
gavage. The glucose levels in the plasma were
determined in groups after 30, 60 and 120 minutes. The
results showed that apple cider vinegar in both
concentrations significantly reduced blood glucose
level after 60 minutes of glucose administration in
comparison to its level after 30 minutes (p < 0.05) and
this was maintained up to 120 minutes after the start of
its consumption by diabetic mice (p < 0.05) (Fig. 2).
This was also apparent in the positive control group.
There was no dose-dependent effect as no significant
difference was observed between the two apple cider
vinegar groups (p > 0.05).
As the glucose level did not rise significantly after
glucose administration after 30 minutes in the
combination treated group (apple cider vinegar +
glibenclamide), there was no significant reduction in
the glucose levels after 60 and 120 minutes as
compared t o glucose level at 30 minutes (p > 0.05).
However, the glucose levels in this group were the
lowest among all treated groups (Fig. 2).
Apple cider vi negar in diabetes
Figure 2. Glucose blood levels after administrations of 5g/kg glucose in diabetic-mice at day 21.
Measurement of blood α- amylase
In the last day of treatment, α-amylase was determined.
Apple cider vinegar in both concentrations significantly
reduced α-amylase levels in serum after 21 days (p <
0.05) (Fig. 3). The higher concentration of apple cider
vinegar has more effect on reducing α-amylase serum
levels compared t o the lower concentration of apple
cider vinegar (p < 0.05). Interestingly, glibenclamide
administration did not affect α-amylase serum levels
alone or in combination to apple cider vinegar,
compared to normal saline and apple cider vinegar,
respectively (Fig. 3).
Figure 3. Amylase blood l evels after 21 d ays of treatment.
In previous studies, it was demonstrated that vinegar
affect glucose metabolism in healthy or in patients with
diabetes mellitus, improves insulin sensitivity in
healthy or in patients with insulin-resistant and could
further delay gastric emptying, so do postprandial
hypoglycaemia. But some studies showing no
beneficial effect on glucose metabolism that show
several factors affect vinegar effects.19-21 There is much
interest in identifying diet patterns that could possibly
reduce hyperglycemia. The aim of this study was to
investigate the effect of apple cider vinegar on blood
glucose level. Our results indicated that apple cider
vinegar on days 7 and 14 reduced blood glucose levels
significantly (p<0.05) and was effective in lowering
blood glucose level after 60 minutes of glucose
administration and this was maintained up to 120
minutes. Also, apple cider vinegar in both
concentrations significantly (p<0.05) reduced serum
amylase levels 21 days after the start of its consumption
by diabetic mice. So these results showed the favorable
effects of apple cider vinegar on glucose level and it
can be used in patient with diabetes type 2.
Our results indicated that apple cider vinegar in both
concentrations was not effective after 3 days of the start
Iman et al.
of its administration in diabetic mice. However, on day
7 it reduced blood glucose levels significantly (p<0.05)
and this was maintained on days 14. A slight rise in
blood glucose levels was observed on day 21 that was
not significant (p < 0.05). The findings of the present
investigation showed that blood glucose levels in the
acetic acid group were comparable to the normal saline
group at days 3, 7 and 14. However, they were higher
than the normal saline group at day 21 suggesting that
continuous consumption of acetic acid probably due to
its acidic property might induce stress in treated mice.
This increased stress can lead to a rise of glucose blood
levels. Although the cider vinegar has acidic property,
probably its “therapeutic” effect in lowering glucose
levels was able to overcome this property.
Glucose tolerance test showed that apple cider vinegar
was effective in lowering blood glucose level after 60
minutes of glucose administration and this was
maintained up to 120 minutes. Also, apple cider
vinegar in both concentrations significantly (p<0.05)
reduced serum amylase levels 21 days after the start of
its consumption by diabetic mice.
In this study it has been revealed that apple cider
vinegar has considerable reducing effect on blood
glucose levels in diabetic mice suggesting a useful
outcome in reducing the risk diabetes due to its
antihyperglycemic effect in diabetic mice.
Although the full mechanism of this effect is unclear,
one probable mechanism could be the effect of apple
cider vinegar α-amylase. Reduction of α-amylase in
liver cells can suppress the conversion of carbohydrates
(polysaccharides) into smaller saccharide units such as
glucose leading to a reduction in blood glucose levels.
Whether apple cider vinegar has any effect on insulin
action in peripheral tissues, such as skeletal muscles
and adipocytes any other probable mechanisms are
unclear that can be further studied. More work is
needed to determine the exact nature of the active
MI conceived of the study and helped to draft the
manuscript, SAM is head of study and participated in
its design and coordination and helped to draft the
manuscript. AB participated in the taking result and
performed the statistical analysis.
We appreciate the technical assistance support of
Mashhad University of Medical Science.
1. Banna AA, Kawar NS. Behavior of parathion in
apple juice processed into cider and vinegar. J
Environ Sci Health B 1982;17:505-514.
2. Vijayakumar C, Wolf-Hall CE. Evaluation of
household sanitizers for reducing levels of
Escherichia coli on iceberg lettuce. J Food Prot
3. Hlebowicz J, Darwiche G, Bjorgell O, Almer LO.
Effect of apple cider vinegar on delayed gastric
emptying in patients with type 1 diabetes mellitus: a
pilot study. BMC Gastroenterol 2007;7:46.
4. Ryu JH, Beuchat LR. Influence of acid tolerance
responses on survival, growth, and thermal cross-
protection of Escherichia coli O157:H7 in acidified
media and fruit juices. Int J Food Microbiol
5. Bjornsdottir K, Breidt F, Jr., McFeeters RF.
Protective effects of organic acids on survival of
Escherichia coli O157:H7 in acidic environments.
Appl Environ Microbiol 2006;72:660-664.
6. Wolman PG. Management of patients using
unproven regimens for arthritis. J Am Diet Assoc
7. Ebihara K, Nakajima A. Effect of acetic acid and
vinegar on blood glucose and insulin responses to
orally administered sucrose and starch. Agric Biol
8. Johnston CS, Kim CM, Buller AJ. Vinegar
Improves Insulin Sensitivity to a High-
Carbohydrate Meal in Subjects With Insulin
Resistance or Type 2 Diabetes. Diabetes Care
9. Kaushik G, Satya S, Khandelwal RK, Naik SN.
Commonly consumed Indian plant food materials in
the management of diabetes mellitus. Diabetes and
Metabolic Syndrome: Clinical Research and
Reviews.In Press, Corrected Proof.
10. Wild S, Roglic G, Green A, Sicree R, King H.
Global Prevalence of Diabetes Estimates for the
year 2000 and projections for 2030. Diabetes Care
11. Hannan JM, Rokeya B, Faruque O, Nahar N,
Mosihuzzaman M, Azad Khan AK, et al. Effect of
soluble dietary fibre fraction of Trigonella foenum
graecum on glycemic, insulinemic, lipidemic and
platelet aggregation status of Type 2 diabetic model
rats. J Ethnopharmacol 2003;88:73-77.
12. Rubio MA, Arrieta JL, Ruiz M, Garrido J, Rubio
JA, del Llano J, et al. Design and validation of a
scale to assess preferences of type 2 diabetic
patients towards different nutritional supplements.
Nutr Hosp 2008;23:253-262.
13. Bethel MA, Califf RM. Role of lifestyle and oral
anti-diabetic agents to prevent type 2 diabetes
mellitus and cardiovascular disease. Am J Cardiol
14. Esposito K, Ciotola M, Maiorino MI, Giugliano D.
Lifestyle approach for type 2 diabetes and
metabolic syndrome. Curr Atheroscler Rep
15. The institutional animal care and use committee
(IACUC). IACUC / LARC standard procedures
Diabetes induction in mice. 2011.
16. Graham M L, Janecek JL, Kittredge JA, Hering BJ,
Schuurman HJ. The Streptozotocin-Induced
Diabetic Nude Mouse Model: Differences between
Apple cider vi negar in diabetes
Animals from Different Sources. Comp Med
17. Shirwaikar A RK, Kumar CD, Bodla R.
Antidiabetic activity of aqueous leaf extract of
Annona squamosa in streptozotocin-nicotinamide
Type 2 diabetic rats. J Ethnopharmacol
18. A service of the National Institute of Diabetes and
Digestive and Kidney Diseases (NIDDK), National
Institutes of Health (NIH).
19. Brighenti F, Castellani G, Benini L, Casiraghi MC,
Leopardi E, Crovetti R, Testolin G. Effect of
neutralized and native vinegar on blood glucose and
acetate responses to a mixed meal in healthy
subjects. Eur J Clin Nutr 1995;49: 242-247.
20. Johnston CS, Kim CM, Buller AJ. Vinegar
improves insulin sensitivity to a high-carbohydrate
meal in subjects with insulin resistance or type 2
diabetes. Diabetes Care 2004;27:281-282.
21. Liatis S, Grammatikou S, Poulia KA, et al. Vinegar
reduces postprandial hyperglycaemia in patients
with type II diabetes when added to a high, but not
to a low, glycaemic index meal. Eur J Clin Nutr