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- Açai (Euterpe oleracea)
- Phytochemistry
- Pharmacology
- Health Claims
| Date:
04-29-2011 | HC#
041131-423
|
Re: Phytochemical and Pharmacological Assessment of Açai's Health Claims
Heinrich
M, Dhanji T, Casselman I. Açai (Euterpe
oleracea Mart.)―a phytochemical and pharmacological assessment of the
species' health claims. Phytochem Lett.
2011;4(1):10-21.
Açai
(Euterpe oleracea) berries are
marketed for health benefits such as promoting rapid weight loss, improving
digestion, fighting cardiovascular disease, and preventing the aging process.
Such claims are based on "an alleged special phytochemical
composition" of the berries and their antioxidant properties, say the
authors. Many studies suggest that high levels of antioxidants such as
polyphenols, phenolic acids, flavonoids, and carotenoids may reduce the risk
for cardiovascular diseases and some cancers. These authors, from the
University of London in England and Southern Cross University in Lismore,
Australia, reviewed the evidence on the use of açai in the treatment and
prevention of specific diseases, focusing on the phytochemical data on the
species.
Açai,
a multi-stemmed, monoecious palm, is abundant in the Amazonian estuary
floodplains. With a strong history of use as a medicinal plant, it has been
used to treat fevers, skin complications, digestive disorders, and parasitic
infections.
With
the emergence of the Internet has come the online availability of numerous
herbal products and different information sources about herbal medicines and
nutraceuticals. Açai is among the products advertised widely on the Internet in
recent years.
For
this review, the authors used Google Insight for Search, which shows search volume and regional
search interest, to assess the global as well as regional interest in açai from
2004 to the present.
The
predominant chemical constituents in açai are polyphenols, most notably
anthocyanins and flavonoids. Cited in this review are reports of anthocyanin
levels in açai pulp ranging from 88 mg/L to 211 mg/L. The major anthocyanins
are cyanidin 3-glucoside and cyanidin 3-rutinoside. Other reported
anthocyanins, in minor quantities, include peonidin 3-rutinoside and peonidin
3-glucoside.
The
major flavonoids found in açai are quercetin, orientin and its derivatives, as
well as proanthocyanidins.
"Data
concerning the species' antioxidant potential are conflicting," note the
authors. One cited report concluded that anthocyanins were the predominant
contributing factor to the antioxidant capacity of açai, which was found to be
higher than that of muscadine grape juice and that of several berries
(high-bush blueberries, strawberries, raspberries, blackberries, and
cranberries).1 One report adds that açai has been shown to have
large contents of chlorophyll, as well.2
Also
reported to be present in açai are fatty acids, amino acids, and nutrients, as
well as small amounts of lignans. The main polyunsaturated, monounsaturated,
and saturated fatty acids include linoleic acid, oleic acid, and palmitic acid.
Other minor fatty acids and a range of lignans have also been reported.
In
vivo studies on the bioavailability of both flavonoids and anthocyanins are
limited. "The forms in which proanthocyanidins are absorbed or metabolized
are not well understood and therefore their in vivo capacity is still open for
interpretation," state the authors.
Açai
extracts have exhibited a spectrum mostly of in vitro pharmacological
properties; however, say the authors, the overall pharmacological findings
relating to antiproliferative, anti-inflammatory, antioxidant, and
cardioprotective activities are unclear and inconclusive. The quality of the
studies varies, with most focusing on the antioxidant effects. "In general
terms, such in vitro studies are very limited and in vivo studies practically
absent. Overall, açai does not seem to have superior antioxidant levels based
on current literature, and the evidence points to variable antioxidant
capacities," the authors state.
Regarding
its cardioprotective properties, açai supplementation led to better lipid
profiles and appetite suppression in hypercholesterolemic rats.3
In
two in vitro studies,4,5 açai demonstrated strong antiproliferative
activity; however, both studies failed to demonstrate any possible protective
mechanisms of açai. Further investigation is needed.
The
authors suggest that more rigorous intervention studies and clinical trials are
needed on açai and other food supplements to assess their potential health
benefits. Epidemiological studies should also be conducted on the incidence
rates of coronary heart disease, obesity, and diabetes in people whose
principle diet includes açai.
The
authors recommend the establishment of strategies to prioritize lesser studied
herbal medicines or nutraceuticals distributed or popularized on the Internet
to assess their benefits and risks and to evaluate the health benefit claims
made. The authors do not include the human trial that found açai to demonstrate
an increase in antioxidant capacity (See HC 110682-373).6
―Shari Henson
References
1Del Pozo-Insfran D,
Brenes CH, Talcott ST. Phytochemical composition and pigment stability of açai
(Euterpe oleracea Mart.). J Agric Food Chem. 2004;52(6):1539-1545.
2Rufino MDM, Alves RE,
de Brito ES, Pérez-Jiménez J, Saura-Calixto F, Mancini-Filho J. Bioactive
compounds and antioxidant capacities of 18 non-traditional tropical fruits from
Brazil. Food Chem. 2010;121(4):996-1002.
3de Souza MO, Silva M,
Silva ME, Oliveira Rde P, Pedrosa ML. Diet supplementation with açai (Euterpe
oleracea Mart.) pulp improves biomarkers of oxidative stress and the serum
lipid profile in rats. Nutrition. 2010;26(7-8):804-810.
4Hogan S, Chung H,
Zhang L, et al. Antiproliferative and antioxidant properties of
anthocyanin-rich extract from açai. Food
Chem. 2010;118(2):208-214.
5Ribeiro JC, Antunes
LM, Aissa AF, et al. Evaluation of the genotoxic and antigenotoxic effects
after acute and subacute treatments with açai pulp (Euterpe oleracea Mart.) on mice using the erythrocytes micronucleus
test and the comet assay. Mutat Res.
2010;695(1-2):22-28.
6Mertens-Talcott SU,
Rios J, Jilma-Stohlawetz P, et al. Pharmacokinetics of anthocyanins and
antioxidant effects after the consumption of anthocyanin-rich açaí juice and
pulp (Euterpe oleracea Mart.) in human healthy volunteers. J Agric
Food Chem. Sep 10, 2008;56(17):7796-7802.
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