Participants in the study received either a placebo or a daily dose of resveratrol equivalent to the amount found in 1,000 bottles of red wine.
The study, published in Neurology, was a randomized, phase 2, placebo-controlled, double-blind study to establish the effectiveness of the supplement.
"Given safety and positive trends toward effectiveness in this phase 2 study, a larger phase 3 study is warranted to test whether resveratrol is effective for individuals with Alzheimer's - or at risk for Alzheimer's," reports principal investigator Dr. R. Scott Turner, director of the Memory Disorders Program at Georgetown University Medical Center in Washington, D.C.
Resveratrol is a naturally occurring compound that can be found in red grapes, red wine, chocolate, peanuts and other foods. For the study, the researchers utilized a pure synthetic form of resveratrol with a daily dosage equivalent to the amount found in 1,000 bottles of red wine.
This compound was selected for further study due to its capacity to activate a group of proteins known as sirtuins. These proteins are also activated by caloric restriction, which previous animal studies have demonstrated can prevent or delay age-related diseases. Aging is the biggest risk factor the development of Alzheimer's disease.
In the study, a total of 119 participants were recruited to participate in the 1-year trial. Half of the participants received resveratrol and the other half received a placebo.
The researchers noted that the patients treated with resveratrol experienced little or no change to the levels of amyloid-beta40 (Abeta40) in the blood and cerebrospinal fluid. In contrast, the participants who received the placebo experienced a decline in their Abeta40 levels over the 12 months of the trial.
Definitive phase 3 trial to follow
Dr. Turner explains their findings:
"A decrease in Abeta40 is seen as dementia worsens and Alzheimer's disease progresses; still, we can't conclude from this study that the effects of resveratrol treatment are beneficial. It does appear that resveratrol was able to penetrate the blood-brain barrier, which is an important observation."
The researchers also observed that those receiving resveratrol experienced some benefit in the participation of routine activities in the home. Alongside this was a more surprising discovery: those who received resveratrol experienced a decrease in brain volume in comparison with those who received a placebo.
"We're not sure how to interpret this finding," Dr. Turner admits. "A similar decrease in brain volume was found with some anti-amyloid immunotherapy trials." The researchers suggest that this finding could be explained by the treatment reducing inflammation and swelling in the brain.
While the findings of the study are not enough for the researchers to be able to start advising patients to commence taking the compound, they enable the team to move on to a more definitive phase 3 trial of resveratrol, to see just how effective it is for patients with Alzheimer's disease.
Previously, Medical News Today reported on a study indicating that a chemical called IRL-1620 could represent a novel therapeutic target for Alzheimer's disease after it was used to treat the condition in rats.