Researchers have found that a naturally occurring compound found in dark chocolate and red wine might be able to halt the progress of Alzheimer’s disease.

Resveratrol, which is also contained in red grapes and various berries, was taken in its purified form by a number of participants with mild to moderate dementia due to Alzheimer’s disease; meanwhile, a control group took a placebo.

After a one-year study, the group taking resveratrol supplements showed little or no change in the levels of amyloid-beta40 (Abeta40) in their blood and cerebrospinal fluid, while those in the control group saw their levels diminish as usually occurs with the worsening of the disease. The build-up of amyloid proteins in the brain are thought to be one of the key causes of Alzheimer’s disease.

While the results are promising, the researchers involved are cautious to not label resveratrol a wonder drug just yet. The findings, published in Neurology, may be “very interesting” according to the study’s principal investigator, R. Scott Turner from Georgetown University in the US, but they don’t yet prove that resveratrol halts the development of Alzheimer’s disease in the brain.

“This is a single, small study with findings that call for further research to interpret properly,” said Turner in a press release. “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.”

Nor would you easily be able to replicate the effects of resveratrol supplements by simply snacking on same after-dinner choccies and sipping a good shiraz. In the experiment, dosages of purified, pharmaceutical-grade resveratrol ranged up to 2 grams daily – which the researchers note is equivalent to the amount you’d find in approximately 1,000 bottles of wine.

The experimental drug is not yet commercially available, although other pure forms of the compound are available from health food shops and pharmacists.

Resveratrol is of interest to scientists because it activates sirtuin proteins, which are also activated by caloric restriction. With studies in animals indicating that eating fewer calories may slow down genetic ageing, the current thinking is that restricting your food intake to two-thirds the normal caloric intake may help to stave off age-related neurological diseases.

If that sounds too hard, this new research suggests you might be able to take a short cut to brain health, simply by artificially bumping up your resveratrol consumption.

This isn’t the first time the compound has been found to have beneficial effects. Research announced earlier in the year showed that resveratrol may prevent memory loss in rodents.

The latest study found that resveratrol supplements were safe and well-tolerated by the participants who consumed them, although nausea and diarrhoea were reported by some patients. Also, some patients on resveratrol lost weight, while some in the control group gained weight.

“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,” Turner said.

One unexpected result was that MRI scans revealed that resveratrol-treated patients lost more brain volume than those in the control group. The researchers theorise that resveratrol may reduce brain swelling in patients who have Alzheimer’s disease, which could account for the lower volume.