University Health System Blog

Dr. Eric Farbman answers the question, “Is there any evidence in the medical literature to support the use of gingko biloba for dementia?”

Ginkgo biloba is a large shade tree. It was thought to be extinct, but it was rediscovered in China in the 1700s. Today it is used with varying degrees of evidence for many different medical conditions. It is probably the most commonly used herbal product for the prevention of memory loss. Sales of this herb exceed $249 million annually.

Alzheimer’s disease is a devastating disease and the most common dementing illness. It affects more than five million people in the U.S. and this number is expected to rise as the population ages. It is a leading cause of disability in the elderly and one of the primary causes of long-term care placement.

Many people take gingko biloba in an effort to reduce their risk of developing Alzheimer disease. Many health food stores and Web sites market it to that effect. There are no FDA guidelines for the marketing of supplements. Is there any evidence in the medical literature to support the use of gingko biloba for dementia?

Some early studies with gingko biloba seemed to suggest that there might be a mild benefit. These studies may have shown benefit on one of many memory tests. These were also very short-term studies.  Because of these early studies, more extensive studies were then performed.

In 2002 a study was published to determine whether there was any memory enhancement in non-demented individuals who took gingko biloba. This study looked at nearly 230 people and there was no benefit seen in any of the many different domains of memory tested. The study authors noted that “gingko biloba provides no measurable benefit in memory or related cognitive function to adults with healthy cognitive function.”

A small study was published in 2008 to determine the feasibility of doing a large gingko biloba trial. It did suggest it was feasible and it also suggested that there might be benefit of taking this herb to slow Alzheimer disease, but it only looked at one area within cognition and feasibility studies by their nature are very small.

Recently the gingko evaluation of memory study was published. This was a very large, well-designed trial that included 3,069 people that was conducted over many years to look at the effect of gingko biloba on slowing the rate of decline of Alzheimer disease. The results, unfortunately, were negative. That is, there was no benefit on gingko biloba either on reducing cognitive decline in normal older adults or in those with mild Alzheimer disease.

These results support other smaller trials that were done around the same time. As a result of this and other trials, gingko biloba cannot be recommended for patients with dementia or for individuals trying to prevent the emergence of dementia. It is natural for patients to be desperate for a cure, but this herb is not the answer.

Eric Farbman, M.D. is a neurologist practicing in Las Vegas, Nevada. He is clinical associate professor of neurology at the University of Nevada School of Medicine.

Have a question? University Health System doctors answer select questions from readers like you.

Dr. David Ginsburg answers the question: Alzheimer’s disease: What are the possible early warning signs?

While it may be difficult to diagnosis Alzheimer’s disease with relative certainty early in the disease process, the diagnosis typically becomes more firmly established over time.

Patients initially presenting to a physician with complaints of memory loss may have early Alzheimer’s disease, or may alternatively have a less serious condition called “benign forgetfulness.” As symptoms gradually progress to involve other aspects of cognition, such as problems with word-finding, writing, drawing and calculating, the likelihood of Alzheimer’s disease increases.

These problems become particularly concerning when they interfere with daily functioning, such as working, cooking, self-grooming and balancing the checkbook.

When evaluating a patient with memory impairment, a physician will likely screen for a variety of possible causes, including stroke, tumor, epilepsy, depression, vitamin B-12 deficiency, hypothyroidism and hydrocephalus.

The work-up will likely include a brain CT or MRI, electroencephalography (EEG) and a variety of blood tests. A brain PET scan is also occasionally useful to evaluate for regional areas of metabolic disturbances.

If the diagnosis remains unclear, occasionally the patient will undergo a detailed cognitive evaluation by a neuropsychologist. The neuropsychological evaluation may subsequently be repeated after six to 12 months in order to monitor for worsening of the various subtests, which in turn might suggest a progressive neurodegenerative disorder such as Alzheimer’s disease.

The only way to diagnosis Alzheimer’s disease with absolute certainty is with a brain biopsy, which is not typically performed for this condition.

On the other hand, a diagnosis of Alzheimer’s disease is generally confirmed or excluded to a high degree of accuracy on the basis of the patient’s history, examination and a variety of ancillary tests as previously discussed. The importance of early diagnosis cannot be overstated, as a variety of medications are currently available to treat this condition.

David Ginsburg, M.D. is a neurologist practicing in Las Vegas, Nevada. He is an associate professor of neurology at the University of Nevada School of Medicine.

Have a question? University Health System doctors answer select questions from readers like you.

Dr. David Ginsburg answers the question: “Can a head injury increase my risk for developing Alzheimer’s disease?”

Although head injury has not been clearly proven as a risk factor for Alzheimer’s disease, several studies have suggested an association—particularly in men.

In at least one study, there was evidence that the observed time from traumatic brain injury to onset of Alzheimer’s disease was less than the expected time to onset of Alzheimer’s disease.

In addition, several studies evaluated the correlation between head trauma, the ApoE4 gene, an independent risk factor, and Alzheimer’s disease.

Upon reviewing the medical literature, no uniform conclusions could be determined. The association between head trauma and Alzheimer’s disease remains an active area of research.

David Ginsburg, M.D. is a neurologist practicing in Las Vegas, Nevada. He is an associate professor of neurology at the University of Nevada School of Medicine.

Have a question? University Health System doctors answer select questions from readers like you.

Dr. David Ginsburg answers the question: “Is there a way to detect the onset of Alzheimer’s disease in its early stages?”

While it may be difficult to diagnosis Alzheimer’s disease with relative certainty early in the disease process, the diagnosis typically becomes more firmly established over time.

Patients initially presenting to a physician with complaints of memory loss may have early Alzheimer’s disease or may alternatively have a less serious condition called benign forgetfulness.

As symptoms gradually progress to involve other aspects of cognition, such as problems with word finding, writing, drawing and calculating, the likelihood of Alzheimer’s disease increases. These problems become particularly concerning when they interfere with daily functioning, such as working, cooking, self-grooming and balancing the checkbook.

When evaluating a patient with memory impairment, a physician will likely screen for a variety of possible causes, including stroke, tumor, epilepsy, depression, vitamin B-12 deficiency, hypothyroidism and hydrocephalus. The work-up will likely include a brain CT or MRI, electroencephalography (EEG) and a variety of blood tests. A brain PET scan is also occasionally useful to evaluate for regional areas of metabolic disturbances.

If the diagnosis remains unclear, occasionally the patient will undergo a detailed cognitive evaluation by a neuropsychologist. The evaluation may subsequently be repeated after 6 to 12 months in order to monitor for worsening of the various sub-tests, which in turn might suggest a progressive neurodegenerative disorder such as Alzheimer’s disease.

The only way to diagnosis Alzheimer’s disease with absolute certainty is with a brain biopsy, which is not typically performed for this condition.  On the other hand, a diagnosis of Alzheimer’s disease is generally confirmed or excluded to a high degree of accuracy on the basis of the patient’s history, examination and a variety of ancillary tests as previously discussed.

The importance of early diagnosis cannot be overstated, as a variety of medications are currently available to treat this condition.

David Ginsburg, M.D. is a neurologist practicing in Las Vegas, Nevada. He is an associate professor of neurology at the University of Nevada School of Medicine.

Have a question? University Health System doctors answer select questions from readers like you.