The study reported in the Journal of Neuroscience mainly focused on resveratrol. For the study, a team of researchers from the Charité -- Universitätsmedizin Berlin, in Germany, looked at 46 healthy but overweight people. For a period of six months, half of the participants received 200mg of resveratrol supplements daily, and the rest took placebo.

Using functional magnetic resonance imaging (fMRI), researchers scanned participants' brains. They also collected blood samples from the participants and sent them for testing. The participants also gave memory tests that included memorizing certain words on a list 30 minutes after going through them.

Regular intake of the resveratrol supplements was associated with improvements in short-term memory. Participants who took the resveratrol supplements remembered more words than people who received placebo. The resveratrol group had better communication within the hippocampus or the brain region related to memory. People who took the chemical supplement also had comparatively lower levels of a blood sugar marker.

"From a clinical point of view, our findings suggest that regular, high-level intake of resveratrol in the elderly may convey protective effects on cognitive functions, a hypothesis that now needs to be evaluated in large-scale clinical trials," the researchers explained.