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Neurology - Alzheimers

Houston, Texas

The Cullen Building at Baylor College of Medicine.
Department of Neurology
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DHA (Docosahexaenoic Acid) in Slowing
the Progression of AD

Enrollment — Closed

What is the purpose of this study?

The purpose of this study is to determine if daily DHA supplementation slows the progression of cognitive and functional decline over 18 months in mild to moderate Alzheimer's disease.

Who sponsors this clinical trial?

This study is being sponsored by the National Institute on Aging, through a grant to the Alzheimer's Disease Cooperative Study.

What is DHA?

Docosahexaenoic Acid (DHA) is an omega-3 fatty acid that is found throughout the body. DHA is a major structural fat in the brain and eyes and a key component of the heart. It is a nutrient that is found in fish, algae, and human breast milk. Previous studies suggest that DHA is the key component of fish oil that protects the brain.

Why is DHA being studied in Alzheimer's disease?

Previous studies have shown that a high intake of DHA was associated with a reduced risk for developing Alzheimer's disease. DHA is the most abundant omega-3 fatty acid in the brain. It is now considered so important to brain and eye development that DHA is included in most infant formula. DHA is also important for maintaining brain, eye, and heart health throughout life.

What is the design of this study?

This is a randomized, double-blind, placebo-controlled study. Participants will be randomly assigned (by chance) to one of two groups: 60% of the subjects will be given DHA (2 g daily) for 18 months while 40% will receive a placebo (inactive substance or "sugar pill") daily for 18 months. Neither the participants nor the research team will know to which group each subject has been assigned ("double-blind").

What is involved for individuals who wish to participate?

At an initial screening visit (to determine eligibility), medical history will be reviewed and the following evaluations performed: vital signs, physical examination, brief memory assessment, lab work (blood and urine tests), and an electrocardiogram (ECG). If accepted into the study, subjects will be asked to return to the clinic for seven study visits over an 18-month period.

Who is eligible to participate?

Men and women (age 50 and older), with mild to moderate Alzheimer's disease, scoring between 14 and 26 on the Mini-Mental Status Exam may be eligible for the study. Individuals already taking DHA-containing supplements will not be allowed to participate. Also, people who eat fish more than twice a week may not be able to join the study (researchers would not be able to tell if adding DHA was making a difference for those individuals whose DHA levels are already high through dietary intake). At the screening visit, potential subjects will complete a Food Frequency Questionnaire to estimate dietary DHA intake.

Can subjects continue their current AD therapy?

Yes, subjects may continue taking their currently-prescribed approved AD medication (Aricept, Exelon, Reminyl, Namenda), provided that the dose has been stable for at least 3 months. Other medications must be at stable dose for at least one month prior to study enrollment.

Is DHA safe? Are there any risks associated with this study?

This study will use a pure form of Docosahexaenoic Acid (DHA) made from algae - not from fish oil, which can sometimes contain mercury or other contaminants. DHA is generally recognized as safe by the FDA. The most common side effects associated with DHA are mild GI symptoms of belching, gas, upset stomach, and diarrhea. None have been serious.

Where is this study being held?

Baylor College of Medicine is one of about 40 sites participating in this trial, which will enroll approximately 400 subjects nationwide.

For more information

Contact: Aline Hittle at Baylor College of Medicine
Tel: 713-798-5325
E-mail:

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