Aloe Vera
Background
Aloe
vera’s use can be traced back 6,000 years to early Egypt, where the
plant was depicted on stone carvings. Known as the “plant of
immortality,” aloe was presented as a funeral gift to pharaohs.
Historically,
aloe vera has been used for a variety of purposes, including treatment
of wounds, hair loss, and hemorrhoids; it has also been used as
a laxative.
Two substances from aloe vera, the clear gel and
the yellow latex, are used in health products today. Aloe gel is
primarily used topically (applied to the skin) as a remedy for skin
conditions such as burns, frostbite, psoriasis, and cold sores, but it
may also be taken orally (by mouth) for conditions including
osteoarthritis, bowel diseases, and fever. Aloe latex is taken orally,
usually for constipation.
How Much Do We Know?
There’s not enough evidence to show whether aloe vera is helpful for
most of the purposes for which people use it.
What Have We Learned?
Aloe
latex contains strong laxative compounds. Products made with aloe were
at one time regulated by the U.S. Food and Drug Administration (FDA) as
over-the-counter (OTC) laxatives. In 2002, the FDA required that all
OTC aloe laxative products be removed from the U.S. market or
reformulated because the companies that manufactured them did not
provide the safety data necessary for continued approval.
There’s
some evidence that the topical use of aloe products might be helpful
for symptoms of certain conditions such as psoriasis and
certain rashes.
There’s not enough high-quality scientific evidence to show whether
topical use of aloe helps to heal wounds.
There’s not enough scientific evidence to support aloe vera for any of
its other uses.
What Do We Know About Safety?
Use of
topical aloe
vera is likely to be safe.
A 2-year National Toxicology Program study on
oral consumption
of nondecolorized whole leaf extract of aloe vera found clear evidence
of carcinogenic activity in male and female rats, based on tumors of
the large intestine. Another study in rats showed that decolorized
whole leaf aloe vera did not cause harmful effects. This suggests that
a component called aloin, most of which is removed by the
decolorization process, may be responsible for the tumors seen in rats
fed nondecolorized whole leaf aloe vera. More information, including
what products are actually in the marketplace and how individuals use
different types of aloe vera products, is needed to determine the
potential risks to humans.
Abdominal cramps and diarrhea have
been reported with oral use of aloe latex. Also, because aloe latex is
a laxative, it may reduce the absorption and therefore the
effectiveness of some drugs that are taken orally.
People with
diabetes who use glucose-lowering medication should be cautious if also
taking aloe orally because aloe may lower blood glucose levels.
There
have been a few reported cases of acute hepatitis in people who took
aloe vera orally. However, the evidence is not definitive.
Keep in Mind
Tell
all your health care providers about any complementary or integrative
health approaches you use. Give them a full picture of what you do to
manage your health. This will help ensure coordinated and
safe care.
Key References
- Aloe.
Natural Medicines Web site. Accessed at
naturalmedicines.therapeuticresearch.com on March 27, 2015.
[Database subscription].
- Boudreau
MD, Mellick PW, Olson GR, et al. Clear
evidence of carcinogenic activity by a whole-leaf extract of Aloe barbadensis Miller
(aloe vera) in F344/N rats. Toxicological Sciences. 2013;131(1):26-39.
- Dat
AD, Poon F, Pham KBT, et al. Aloe vera for
treating acute and chronic wounds. Cochrane Database of Systematic
Reviews. 2012;(2):CD008762.
Accessed at http://www.thecochranelibrary.com(link
is external) on
March 30, 2015.
- Rodriguez
S, Dentali S, Powell D. Aloe vera. In: Coates PM, Betz JM, Blackman MR,
et al., eds. Encyclopedia of Dietary
Supplements. 2nd
ed. New York, NY: Informa Healthcare; 2010:7-14.
- Shao
A, Broadmeadow A, Goddard G, et al. Safety
of purified decolorized (low anthraquinone) whole leaf Aloe vera (L)
Burm. F. juice in a 3-month drinking water toxicity study in F344 rats. Food and Chemical Toxicology. 2013;57:21-31.
- Yang
HN, Kim DJ, Kim YM, et al. Aloe-induced
toxic hepatitis. Journal of Korean Medical
Science. 2010;25(3):492-495.
-NIH