Ginkgo biloba extract may benefit people who have experienced ischemic stroke.
The treatment was significantly more effective than aspirin alone.
Study co-author Qi Fang — from the Department of Neurology at The First Affiliated Hospital of Soochow University in Suzhou, China — and colleagues have reported their results in the journal Stroke & Vascular Neurology.
More than 795,000 people in the United States have a stroke each year, which is the equivalent to one stroke every 40 seconds.
Around 87 percent of strokes are ischemic, wherein the artery that supplies blood to the brain becomes blocked — most commonly due to a blood clot.
This blockage deprives the brain of oxygen and nutrients carried by the blood, which can cause damage to brain cells. Side effects, such as memory and thinking problems and loss of motor function, may arise as a result of this.
Tissue plasminogen activator is currently the gold standard treatment for ischemic stroke. It works by dissolving the blood clot that is blocking blood flow to the brain, thereby limiting brain damage.
However, this treatment must be administered within 3 hours of the initial stroke symptoms, and a lot of patients do not get to the hospital in time to receive it.
As such, there is a need for new treatments that can help to reduce the cognitive damage caused by ischemic stroke. Fang and colleagues investigated whether ginkgo biloba extract could be a possible candidate.
Ginkgo biloba extract and stroke
Ginkgo biloba extract is an herbal supplement that derives from the ginkgo tree, or the maidenhair tree, which is native to China.
It has been used in medicine for thousands of years, from healing wounds to alleviating anxiety and depression. That said, the National Institutes of Health (NIH) claim that there is "no conclusive evidence that ginkgo is helpful for any health condition."
The new study, however, suggests that it might be helpful for individuals who have experienced ischemic stroke.
To reach their findings, Fang and team enrolled 348 adults from five hospitals in China Jiangsu Province. The adults were aged 64, on average, and they had all experienced ischemic stroke within the past 7 days.
The subjects were divided into two groups. One group received 450 milligrams of ginkgo biloba extract and 100 milligrams of aspirin every day for 6 months, while the other group received 100 milligrams of aspirin only. Aspirin is often used in stroke treatment and prevention, as it can stop blood from clotting.
The researchers note that the ginkgo biloba extract used in their study consisted of fewer harmful chemicals and more protective chemicals than EGb761, which is a form ginkgo biloba extract that has been used in previous research.
At study baseline and at 12, 30, 90, and 180 days later, all participants completed a test called the Montreal Cognitive Assessment score (MoCA), which was used to assess their cognitive functioning.
Combined therapy better than aspirin alone
The final analysis included a total of 330 participants, as 18 subjects dropped out during the 6-month study period.
Compared with participants who received aspirin only, those who received ginkgo biloba extract plus aspirin had higher MoCA scores at all assessment points, particularly for memory and executive function.
Also, at 12 and 30 days after treatment, participants treated with both ginkgo biloba extract and aspirin demonstrated better functional capacity than those who received aspirin only, indicating fewer neurological impairments such as speech problems and muscle weakness.
The scientists found no differences in vascular events between subjects treated with ginkgo biloba extract plus aspirin and those treated with aspirin only, and the combination treatment led to few side effects.
Commenting on their study results, the researchers write:
"The study demonstrated that patients with stroke who received GBE [ginkgo biloba extract] and aspirin manifested better memory function, executive functions, neurological function, and daily life. Additionally, the safety data analysis demonstrated that GBE did not increase the incidence of adverse events."
Fang and colleagues admit that there are some limitations to their study. For example, it was not double-blind, meaning that the researchers and participants knew which treatments they were receiving. This could have affected the results.
Additionally, they note that the follow-up period was short, and that further studies are needed to assess the long-term effects of ginkgo biloba extract among people who have had a stroke.