Nov. 4, 2005 -- New research shows that a compound in red wine and grapes may counter a hallmark of Alzheimer's disease.
But don't count on wine to ward off Alzheimer's.
"Going now to the public and telling them, 'You should drink wine and you won't have Alzheimer's disease' is totally wrong," researcher Philippe Marambaud, PhD, tells WebMD.
"We don't know yet and we have to be very careful," he continues. "What we have seen is just, maybe, the tip of the iceberg."
Still, he says the findings are "strongly supportive [of] the fact that there is something in red wine that may be protective" and could lead to the development of new Alzheimer's drugs.
Marambaud is a senior research scientist at New York's Litwin-Zucker Research Center for the Study of Alzheimer's Disease and Memory Disorders. He's also an assistant professor at the Albert Einstein College of Medicine.
His study appears in The Journal of Biological Chemistry.
The compound that attracted the attention of Marambaud's team is resveratrol. It's found in red wine, grapes (especially black ones), peanuts, and some berries.
Resveratrol is an antioxidant, a group of plant-based chemicals being widely studied for their health benefits.
Marambaud's interest was sparked by observational studies (done by other experts) showing that Alzheimer's is rarer in populations that consume moderate amounts of red wine.
In Marambaud's lab tests, resveratrol hampered beta-amyloid protein. That protein is a key ingredient in plaque found in the brains of people who die with Alzheimer's disease.
Resveratrol didn't stop the protein's production. Instead, it encouraged beta-amyloid's breakdown.
That's a "very attractive mechanism for therapy" against Alzheimer's, says Marambaud.
He and his colleagues also tested a handful of other antioxidants against beta-amyloid. Only resveratrol stood out.
Why Not Just Eat and Drink It?
It would probably be impractical, Marambaud says, to try to get the levels of resveratol used in his study from food or drink.
Natural resveratrol is unstable, Marambaud says. That makes it hard to get protection from eating grapes or drinking wine.
Plus, resveratrol doesn't have the compound market cornered. It's got lots of chemical company in a glass of wine or a bunch of grapes.
It's difficult to know if those compounds team up when they're together -- working differently than in isolation -- and how that might affect Alzheimer's and other forms of dementia, Marambaud says.
"Maybe if you drink wine for 20 years, you may have a beneficial effect," Marambaud speculates. "But people want to hear something in the short term."
Marambaud and colleagues want to tweak resveratrol to make it a drug.
"We're going to take this natural compound as a scaffold and modify [it] chemically to make it more active and ... more stable," Marambaud says.
"It is known from previous studies that if you isolate, purify, or produce the compound directly and you inject it in mice, the compound is very rapidly degraded, mostly by the kidney system," he explains. "To use it as a drug like that is difficult."
Marambaud says his team has already developed a series of molecules that are 20 times more active than natural resveratrol in terms of reducing beta-amyloid protein.
Those molecules are already being tested on mice; tests will take six months to a year and will check for toxicity, Marambaud says.
He adds that resveratrol has been shown to have some "very interesting pharmacological effects" against herpes, some cancers, and possibly neurodegenerative diseases such as Huntington's.
Black grapes are nature's best source of resveratrol, Marambaud notes.
Red grapes have more resveratrol than green grapes, and red wine is richer in resveratrol than white wine.
Peanuts and some berries also have some resveratrol, says Marambaud.
He explains that plants generally make resveratrol as a defense against infection. "Some specific grapes were found to be very good at this ... especially black grapes," Marambaud says.