Ginkgo
Background
Ginkgo,
one of the oldest living tree species in the world, has a long history
in traditional Chinese medicine. Members of the royal court were given
ginkgo nuts for senility. Other historical uses for gingko were for
asthma, bronchitis, and kidney and bladder disorders.
Today,
the extract from ginkgo leaves is used as a dietary supplement for many
conditions, including dementia, eye problems, intermittent claudication
(leg pain caused by narrowing arteries), tinnitus, and other
health problems.
Ginkgo is made into tablets, capsules, extracts, tea,
and cosmetics.
How Much Do We Know?
There have been a lot of studies on the possible health effects and
risks of people using ginkgo.
What Have We Learned?
There’s no conclusive evidence that ginkgo is helpful for any
health condition.
Ginkgo
doesn’t help prevent or slow dementia or cognitive decline, according
to studies, including the long-term Ginkgo Evaluation Memory Study,
which enrolled more than 3,000 older adults and was funded in part by
the National Center for Complementary and Integrative
Health (NCCIH).
There’s no strong evidence that ginkgo helps
with memory enhancement in healthy people, blood pressure, intermittent
claudication, tinnitus, age-related macular degeneration, the risk of
having a heart attack or stroke, or with other conditions.
Ongoing NCCIH-funded research is looking at whether a compound in
ginkgo may help with diabetes.
What Do We Know About Safety?
For many healthy adults, ginkgo appears to be safe when taken by mouth
in moderate amounts.
Side
effects of ginkgo may include headache, stomach upset, and allergic
skin reactions. If you’re older, have a known bleeding risk, or are
pregnant you should be cautious about ginkgo possibly increasing your
risk of bleeding.
In a 2013 research study, rodents given
ginkgo had an increased risk of developing liver and thyroid cancer at
the end of the 2-year tests.
Ginkgo may interact with some conventional medications, including
anticoagulants (blood thinners), research reviews show.
Eating fresh (raw) or roasted ginkgo seeds can be poisonous and have
serious side effects.
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
- Brinkley
TE, Lovato JF, Arnold AM, et al. Effect
of Ginkgo biloba on
blood pressure and incidence of hypertension in elderly men and women. American Journal of Hypertension. 2010;23(5):528-533.
- DeKosky
ST, Williamson JD, Fitzpatrick AL, et al. Ginkgo biloba for
prevention of dementia: a randomized controlled trial. JAMA. 2008;300(19):2253-2262.
- Evans
JR. Ginkgo biloba extract
for age-related macular degeneration. Cochrane Database Systematic
Review. 2013;(1):CD001775.
Accessed at http://www.thecochranelibrary.com(link
is external) on
April 10, 2015.
- Ginkgo.
Natural Medicines Web site. Accessed at
naturalmedicines.therapeuticresearch.com on on April 8, 2015.
[Database subscription].
- Hilton
MP, Zimmermann EF, Hunt WT. Ginkgo biloba for
tinnitus. Cochrane Database of Systematic
Reviews. 2013;(3):CD003852.
Accessed at http://www.thecochranelibrary.com(link
is external) on
April 10, 2015.
- Kuller
LH, Ives DG, Fitzpatrick AL, et al. Ginkgo
Evaluation of Memory Study Investigators. Does Ginkgo biloba reduce the
risk of cardiovascular events?Circulation. Cardiovascular
Quality and Outcomes. 2010;3(1):41-47.
- Laws
KR, Sweetnam H, Kondel TK. Is
Ginkgo biloba a cognitive enhancer in healthy individuals? A
meta-analysis. Human Psychopharmacology:
Clinical and Experimental. 2012;27(6):527-533.
- Stramgaard
K, Vogensen SB, Steet J. Ginkgo. In: Coates PM, Betz JM, Blackman MR,
et al., eds. Encyclopedia of Dietary
Supplements, 2nd ed. New York, NY: Informa
Healthcare; 2010:332-338.
- Vellas
B, Coley N, Ousset PJ, et al. Long-term
use of standardized Ginkgo biloba extract
for the prevention of Alzheimer’s disease (GuidAge): a randomized
placebo-controlled trial. Lancet Neurology. 2012;11(10):851-859.
-NIH