Stanford researchers seek volunteers with Alzheimer's disease for study on omega-3 fats
STANFORD, Calif. - Researchers at the Stanford University School of Medicine are seeking local residents with mild to moderate Alzheimer's disease to participate in a clinical trial to test whether an ingredient found in some fish, omega-3 fatty acid, can help slow the progression of the disease.
Because people with Alzheimer's often must rely on caregivers, those helpers would have to accompany eligible study participants. "It is very hard to find participants for studies like this," said J. Wesson Ashford, MD, PhD, senior research scientist at the Stanford/VA Aging Clinical Research Center. "But if we do not have people to participate in research studies, we will never have a cure for Alzheimer's disease."
Ashford will lead the local study at the Stanford/VA Aging Clinical Research Center, a joint project of Stanford University and the Veteran Affairs Palo Alto Health Care System, working with Jerome Yesavage, MD, professor of psychiatry and behavioral sciences. The Stanford-VA effort is one of about 53 sites around the nation participating in the nationwide study coordinated by UC-San Diego.
Other preliminary studies have shown that people who eat more fish naturally high in one omega-3 fatty acid, called DHA for docosahexaenoic acid, appear to have a lower risk for dementia, the mental decline that can be caused by Alzheimer's.
Alzheimer's disease was the seventh-leading cause of death in 2004, according to the Centers for Disease Control. The illness is also one of the most costly diseases in the United States, with an annual expense of $100 billion. Risk factors for the disease include advancing age, head injury and poor vascular health. Some studies have found a healthy diet helps reduce the risk of Alzheimer's, along with regular exercise, social interaction and intellectual stimulation.
Ashford said research suggests DHA, a specific type of omega-3 polyunsaturated fat principally obtained from eating such fatty fish as wild salmon and sardines, may help the brain's structural components. DHA is the main omega-3 fatty acid found in the human brain, and studies in the 1990s revealed DHA is essential for neurocognitive development.
DHA may be the critical component in fish, Ashford said. "We want to find out whether DHA slows the progression of Alzheimer's disease."
DHA is often concentrated in brain regions with high metabolic activity, where the long-chain structure of the omega-3 fatty acid lends itself to the fluidity required in such an environment, Ashford said.
"The areas of the brain that have the highest metabolic activity are areas of the brain that are undergoing remodeling," he said. "Basically they are the areas that are being restructured to form new memories and they are the areas most likely to be vulnerable to Alzheimer's disease."
The nationwide study is funded by the National Institute on Aging and by Martek Biosciences Corp., headquartered in Columbia, Md. Martek manufacturers a concentrated form of DHA from an algae source that is free from possible contaminants, such as mercury, found in fish. Ashford said the algae extract is identical to the DHA in fish, which ultimately obtain DHA in part by consuming small animals that eat similar algae.
The nationwide trial seeks 400 participants at least 50 years old with mild to moderate Alzheimer's disease who are not residents in a long-term facility. Applicants who consume fish more than once per week or with a recent daily DHA intake greater than 200 milligrams per day are not eligible for the study.
The 18-month study requires a friend or relative to accompany the volunteer to all clinic visits. Approximately 60 percent of participants will be assigned to take 2 grams of DHA per day, while the remaining 40 percent will receive placebo pills. Neither researchers nor participants will know who is receiving DHA. Both groups will be closely monitored and regularly assessed by a team of doctors and nurses.
Over eight visits, participants will take several cognitive assessment tests and receive a complete physical and neurological examination. Specific visits will include a magnetic resonance imaging scan and a lumbar puncture to collect cerebrospinal fluid to determine the status of the patient's Alzheimer's disease in the brain.
Ashford said Stanford has already started to enroll patients, and he hopes the results provide clues about possible ways to stall the progression of Alzheimer's disease. "We are going to have so many older people in the coming 30 years with Alzheimer's disease that we have to find ways to prevent it now," he said.
Those interested in participating can call the Stanford Veterans Affairs Aging Clinical Research Center at (650) 852-3287, visit http://alzheimer.stanford.edu or call the Alzheimer's Disease Education and Referral Center at (800) 438-4380.
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