A substance found in red wine may improve people's memory, a study has found.
The paper, published in the Journal of Neuroscience, suggests that people who take resveratrol supplements, a red wine compound, have better short-term memory.
The study, conducted by a team of researchers from Charité University in Berlin, analysed the effects of resveratrol on overweight people.
The team tested 46 people for six months; half of the volunteers were given 200 milligrams of resveratrol daily, while the other half received a placebo.
Before and after the six-month period, the participants took a memory test, gave a blood sample and had their brains scanned.
"The study is the first to show a link between the red wine compound and cognition in overweight adults," said researcher Veronica Witte.
Those who took resveratrol had better short-term recall than their counterparts who took a placebo. The people who took the supplement also had more connections among brain areas involved in memory.
The blood tests showed reduced levels of a blood sugar marker, in the people who took resveratrol.
The findings suggest that sugar metabolism may be linked to brain connectivity and memory, the researchers said.
Fabienne Aujard, an anti-aging researcher at the National Center for Scientific Research in France who was not involved in the study, told Live Science: "Further studies should be performed in non-overweight subjects to extend the observed results."
According to Joseph Baur, a physiologist at the University of Pennsylvania's school of medicine in Philadelphia, who was also not part of the study, said the fact that the study involved overweight people "makes the detection of any benefit all the more impressive, but also suggests that the potential impact [of resveratrol] may be underestimated".
Aside from red wine, resveratrol is contained in dark chocolate, red grapes, peanuts and blueberries.
Previous studies have found that resveratrol could help improve mobility and prevent life-threatening falls among older people.
A November 2012 research showed that red wine and red grapes have positive effects in the reduction of prostate cancer.