A new study has found tantalizing evidence that a highly concentrated form of a compound found in red wine and dark chocolate might be able to slow the progression of Alzheimer’s disease.
But it’s likely that it’s because the compound is tricking the body into acting as if it’s not eating at all.
Scott Turner, director of the Memory Disorders Program at Georgetown University Medical Center who was the study’s principal investigator, emphasized caution in interpreting the results of the Phase 2 clinical trial, saying further research is needed to determine whether the compound has a beneficial effect. He also said people should not interpret the results to mean that they should up their consumption of wine or begin taking over-the-counter supplements.
But Turner said researchers were excited to find that resveratrol produced a measurable effect on an important biomarker of the disease’s advance in people who have mild or moderate Alzheimer’s: the level of an abnormal protein known as beta amyloid became stabilized in patients who consumed two grams of resveratrol a day.
Normally, the level of beta amyloid, which can be found in the bloodstream and in brain and spinal fluids, declines and changes in composition as Alzheimer’s advances, because the protein instead forms toxic beta amyloid plaques in the brain.
But in the patients taking resveratrol, the rate of decline in beta amyloid levels slowed. The reason is not clear, Turner said. But he said the study - which was published online Friday in the journal Neurology - lent further credence to the idea that resveratrol stimulates enzymes that slow down metabolism and age-related changes in the cell.
“So it’s really targeting what we think are regulators of aging,” Turner said. “And of course aging is the No. 1 risk factor for Alzheimer’s.”
More than 5 million people in the United States have Alzheimer’s, which is the leading cause of dementia. As demographics shift the country further to the gray, and the number of Alzheimer’s patients is on a pace to nearly triple by 2050, researchers are in the hunt for ways to slow or halt its onset.
Resveratrol is found in dark chocolate, red wine, grape skins, peanuts and other plants. Plants produce the compound when exposed to stressors. Exposed to cold or infected with fungus, plants create more of the stuff.
Scientists believe the compound stimulates the activity of enzymes known as sirtuins, which play an important role in aging and metabolism. Sirtuins [sir-TOO-ins] have been described as “guardians of the cell”; in particular, they appear to enhance a cell’s ability to withstand stress and survive damage, especially when the cell is deprived of food. Other studies have shown, for example, that sirtuins are also activated by calorie restriction.
“Resveratrol is sort of a mimic of caloric restriction, a pharmacological mimic. It’s a way of getting the effects of caloric restriction without actually restricting calories,” Turner said.
The one-year study involved 119 people recruited from 26 sites around the country. The youngest was 49 years old. All had a diagnosis of probable Alzheimer’s disease. Some consumed as much as one gram of resveratrol twice a day - the equivalent of 1,000 bottles of wine - of a form of the compound that is not available on the market. Others were given a placebo.
Although some participants experienced nausea and diarrhea, and others lost weight, while taking the compound, the study found no signs of serious side effects. Those who took the compound lost weight, while those on the placebo gained weight.
Oddly, patients who took the compound also experienced a decline in brain volume, as detected by MRI scans — a finding that could be explained by a reduction in the inflammation that often accompanies Alzheimer’s disease, Turner said. He said the next step would be to move to a Phase 3 trial.
The study was funded by the National Institute on Aging and conducted with the Alzheimer’s Disease Cooperative Study.