- Cinnamon (Cinnamomum zeylanicum, C. cassia)
- Health Benefits
Re: More Human Trials Needed to Support Health Benefits of Cinnamon
J, Freder J, Armbruester N. Cinnamon and health. Crit Rev Food Sci Nutr. 2010;50(9):822-834.
has long been used for culinary uses, as well as for treating gastrointestinal
complaints and other ailments. The volatile oils from the bark, leaf, and root
bark of the two major species vary significantly in chemical composition. Each
oil has a different primary constituent: cinnamaldehyde in the bark oil,
eugenol in the leaf oil, and camphor in the root-bark oil. The major
constituents of the bark oils also differ between species: trans-cinnamaldehyde,
eugenol, and linalool in C. zeylanicum
and cinnamaldehyde, cinnamic acid, cinnamyl alcohol, and coumarin in C. cassia. This article provides a
comprehensive summary of the current scientific literature on the effect of
cinnamon bark on several physiological and health-related conditions.
conducted an extensive database search by using PubMed, MEDLINE, EMBASE,
BIOSIS, TOXLINE, and Google Scholar. Species of the genus Cinnamomum other than C.
zeylanicum and C. cassia were
excluded, as well as most studies on plant parts other than the bark, as it is
the only part used for medical purposes.
identified more than 200 articles relevant to the efficacy of the two herbs.
trials investigating the efficacy of cinnamon on health-related conditions have
been published. Among those trials, the treatment of type 2 diabetes mellitus
is the most documented health benefit associated with cinnamon. Of the seven
clinical studies cited in this review, four did not report statistically
significant beneficial effects; the other three did. The authors cite numerous
in vivo and in vitro studies supporting the efficacy of cinnamon in the
treatment of types 1 and 2 diabetes mellitus. "The available in vitro and
in vivo studies strongly suggest that cinnamon has hypoglycemic properties.
However, the available human data are less consistent and indicate that
cinnamon may have modest effects on blood glucose in subjects with type 2
diabetes," write the authors. While the ineffective outcomes were obtained
in studies using doses of 1-1.5 gm daily, the positive results were shown with
daily doses up to 6 gm daily.
evidence suggests that cinnamon may be effective in the supportive treatment of
cancer and infectious diseases because of its anti-inflammatory, antimicrobial,
antioxidant, and antihypertensive effects.
cite several in vitro studies supporting the anti-inflammatory properties of
the bark of C. cassia, "probably
due to its cinnamaldehyde content," and other in vitro studies showing
that cinnamon bark oil as well as cinnamaldehyde and eugenol has potent
antibacterial effects against a number of bacteria.
antifungal properties have also been demonstrated in vitro. Cinnamaldehyde has
been identified as the fungitoxic constituent of C. zeylanicum bark oil.1 The fungitoxic properties of
the oil vapors have been demonstrated against fungi involved in respiratory
tract infections. The authors cite a pilot study2 of five patients
with HIV infection and oral candidiasis to investigate the activity of cinnamon
against fluconazole-resistant and -susceptible Candida isolates. All patients had pseudomembranous candida
infection. After ingesting eight lozenges of a cinnamon candy daily for one
week, three of the five patients had improvement of their oral
data demonstrate that C. cassia bark
oil as well as aqueous and ethanolic extracts are effective antiviral
properties against HIV and influenza virus; however, those properties have not
been shown for C. zeylanicum.
"Further in vitro and in vivo research in addition to human data is needed
to confirm the antimicrobial properties of cinnamon in free-living
individuals," note the authors.
vitro studies are cited to support the antioxidant properties of both C. cassia and C. zeylanicum. Dhuley3 examined the antioxidant
properties of C. zeylanicum in vivo
by measuring hepatic and cardiac antioxidant enzymes, glutathione (GSH)
content, and lipid conjugated dienes in rats fed a high-fat diet containing 10%
cinnamon. The antioxidant enzyme activities were enhanced significantly,
whereas the GSH content was markedly restored in rats fed a high-fat diet
containing spices. According to the authors, these results suggest that
cinnamon exerts antioxidant protection through its ability to activate
antioxidant enzymes. "In conclusion, numerous in vitro studies and one in
vivo trial demonstrate the antioxidant potential of Cinnamomum cassia and C.
published in vitro and in vivo data, as evidenced by several cited studies,
suggest that cinnamon has antitumor properties that are probably related to its
C. cassia bark as 8% of the diet affects the
cardiovascular system as shown by lowering blood pressure in hypertensive rats,4
while an extract has been shown to have beneficial hypolipidemic properties on
triglycerides while also increasing high-density lipoprotein (HDL) cholesterol
in mice.5 A study with cinnamon bark in people with type 2 diabetes
found that after 40 days, 1, 3, or 6 gm daily reduced triglycerides 23-30%,
low-density lipoprotein (LDL) cholesterol 7-27%, and total cholesterol 12-26%
(P < 0.05 for each), but had no significant effect on HDL cholesterol.6
its potential gastroprotective properties following an in vitro finding of
effective Helicobacter pylori
inhibition, a pilot study7 tested the activity of an alcoholic
extract of cinnamon in patients infected with H. pylori. It found that cinnamon extract (at a dosage of 80 mg
daily taken as a single agent) was ineffective for eradicating H. pylori. The investigators concluded
that a combination with other antimicrobials, or a higher concentration of
cinnamon extract, may have an effect; further studies are needed to make these
No human data
are available to confirm the in vitro immunomodulatory properties of cinnamon.
preponderance of available in vitro and in vivo data suggests that cinnamon has
health benefits. However, controlled human studies will be necessary to
determine whether these effects have public health implications," conclude
1Singh HB, Srivastava M, Singh AB, Srivastava AK.
Cinnamon bark oil, a potent fungitoxicant against fungi causing respiratory
tract mycoses. Allergy. 1995;50(12):995-999.
2Quale JM, Landman D, Zaman MM, Burney
S, Sathe SS. In vitro activity of Cinnamomum
zeylanicum against azole resistant and sensitive Candida species and a
pilot study of cinnamon for oral candidiasis. Am J Chin Med. 1996;24(2):103-109.
3Dhuley JN. Anti-oxidant effects of
cinnamon (Cinnamomum verum) bark and
greater cardamom (Amomum subulatum)
seeds in rats fed high fat diet. Indian J
Exp Biol. 1999;37(3):238-242.
4Chen Y. Pharmacological studies of Cinnamomum cassia bark. Part I.
Effects on the blood and cardiovascular system. Zhong Yao Tong Bao. 1981;6(5):32-34.
5 Kim SH, Hyun SH, Choung SY.
Anti-diabetic effect of cinnamon extract on blood glucose in db/db mice. J
6Khan A, Safdar M, Ali Khan MM, Khattak KN, Anderson RA. Cinnamon
improves glucose and lipids of people with type 2 diabetes. Diabetes Care.
7Nir Y, Potasman I, Stermer
E, Tabak M, Neeman I. Controlled trial of the effect of cinnamon extract on Helicobacter pylori. Helicobacter.