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- Cinnamon (Cinnamomum spp., Lauraceae)
- Review
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Date:
03-31-2016 | HC# 081546-541
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Re: Review of the Health Benefits of Cinnamon
Kawatra P, Rajagopalan R. Cinnamon: mystic
powers of a minute ingredient. Pharmacognosy
Res. June 2015;7(Suppl 1):S1-S6.
Historically, the use of cinnamon (Cinnamomum spp., Lauraceae) dates back
to about 2800 BCE in China. It was used in Biblical anointing oils and to
embalm Egyptian mummies. Its desirability and scarcity were major drivers of
European exploration in the 15th century CE, motivating the voyages of
Christopher Columbus and Vasco da Gama. True or Ceylon cinnamon (C. verum syn. C. zeylanicum), found in Ceylon (now Sri Lanka), made that nation
extremely desirable to Europeans seeking trade supremacy. It was ruled
successively by the Portuguese, Dutch, and British before gaining independence
in 1948.
Cinnamon is now well known to have several
potential health benefits. The authors conducted a systematic review of online
publications on health benefits of cinnamon species, including true or Ceylon
cinnamon, Saigon cinnamon (C. loureirii),
and cassia (C. aromaticum syn. C. cassia). Indonesian cinnamon (C. burmanni) and pseudocinnamon (C. osmophloeum) also are mentioned.
While cinnamon bark, rich in cinnamaldehyde, is most commonly used, pseudocinnamon's
leaves contain its cinnamaldehyde component. Cinnamon leaf oil contains eugenol;
root-bark oil, camphor; leaves and flowers, trans-cinnamyl acetate. Cassia
cinnamon has the highest levels of hepatotoxic, carcinogenic coumarin; true
cinnamon and pseudocinnamon have low levels.
Cinnamon may be useful in managing diabetes.
While results of several small trials have been conflicting, a meta-analysis of
ten randomized, controlled trials (RCTs) including 543 patients found that 120
mg/d to 6 g/d cinnamon taken for approximately four months produced a
statistically significant decrease in fasting plasma glucose and an improved
lipid profile. Cinnamon is thought to be an insulin-mimetic and insulin-sensitizing
agent. Cassia affects phosphorylation of signaling proteins and enhances
insulin-sensitive glucose transporter expression. Cinnamon extracts have been
shown to increase expression of peroxisome proliferator-activated receptor
(PPAR) α and γ, as do thiazolidinediones in type 2 diabetes. Lipid profiles,
important in cardiovascular health and diabetes, improved upon exposure to
cinnamon extracts in vitro, but were not affected in an animal study. Further
studies using human subjects are needed. Cinnamaldehyde and cinnamic acid are thought
to be cardioprotective due to their ability to produce nitric oxide.
Cinnamaldehyde also inhibits L-type calcium channels in vascular smooth
muscles, contributing to vasodilation.
Cinnamon also has antimicrobial, antioxidant,
and anti-inflammatory properties. It is used to inhibit growth of Listeria spp. and Escherichia coli in foods. Cinnamon oil's antimicrobial action is
in the range of 10-150 µg ml−1. Cinnamon can alter expression of the
gene icaA, important in formation of bacterial biofilms. While literature on
the effects of cinnamon on viruses is limited, it is thought to inhibit viral protein
synthesis and was shown to improve survival in mice infected with influenza. A
trial of true cinnamon in commercially available preparations against
fluconazole-resistant oral candidiasis in five people with HIV found
improvement, highlighting a need for additional trials. In combination with
clove (Syzygium aromaticum,
Myrtaceae) oil, cinnamon was effective against the fungus Aspergillus flavus.
Lipid oxidation, a challenge during food
processing, may be prevented or slowed with the use of cinnamon extracts; a
methanolic extract had higher antioxidant properties than either water or
ethanolic extracts. In vitro, the eugenol component inhibited
peroxynitrite-induced nitration and lipid peroxidation. Cinnamon's antioxidant
effects are now being studied in liver diseases, where an ethanolic extract has
shown the ability to reduce carbon tetrachloride-induced lipid peroxidation and
oxidative stress. A water extract of cinnamon showed anti-inflammatory
properties in vitro, reducing levels of tumor necrosis factor-α and interleukin-6.
Several compounds in pseudocinnamon also are known to be anti-inflammatory.
Cinnamon's antibacterial activity may also be
important in cancer prevention and treatment. Stomach cancer and other serious
conditions are often attributed to gram-negative Helicobacter pylori; initial research indicates that cinnamon may
inhibit this microorganism. In vitro, a cassia extract inhibited the survival,
viability, and proliferation of cancer cells without affecting healthy cells.
The extract also induced apoptosis in tumor cells and inhibited nuclear factor-kappa
B. Two of its derivatives induced apoptosis by raising levels of reactive
oxygen species in cancer cells; one of them also made cells more susceptible to
oxidative stress by inhibiting proteasome activity. In melanoma cells, cinnamon
impeded angiogenesis and increased activity of CD8(+) T cells. The polyphenol
components of cinnamon potently inhibited vascular endothelial growth factor.
Finally, cinnamon may also benefit mental cognition
by boosting the brain's ability to use glucose. Its ability to reduce oxidative
stress and improve insulin resistance are also important mechanisms in brain
health.
Highlighting the understudied health effects
of one of mankind's most-used spices, this review is marred by its early use of
a few words that may be off-putting to some readers; the title offers two
examples in mystic and minute. "The surplus health benefits of this clandestine
ingredient" is also cited in the abstract. (Italics added.) However, the
remainder of the report is relatively straightforward.
—Mariann
Garner-Wizard
Peer Reviewer
Comments:
Data
support that C. verum has very low
coumarin levels, and C. cassia the
highest, but C. burmanni and C. loureirii have quite low levels too,
as long as they are not adulterated with C.
cassia. The paper actually says that only C. verum has low levels (Table 1).
The authors refer to particular plants as
"indigenous" but then fail to identify where the plant is indigenous.
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