Up to half a glass a day was found to have some benefits
Eating chocolate and drinking wine can improve people's memory, according to researchers from Oxford University.
A team of physiologists, anatomists and geneticists examined the dietary habits of more than 2,000 people in Norway.
Six different cognitive tests were used to test the participants on memory, planning, attention and visual and spatial co-ordination.
Those who regularly consumed modest amounts were found among the top scorers in the survey.
Professor David Smith, who led the research, said: "We found that those who ate chocolate did score higher in the test and the results also related to the amount of chocolate eaten.
We are not suggesting for a minute that eating a bit of chocolate will instantly improve your memory on the spot
"Ten grams a day - about four squares of chocolate - seems to give maximum results on these tests.
"More than that didn't have any additional benefits."
Other studies have shown chocolate is good for the vascular system and show it can protect from heart disease, to some degree.
The tests also showed wine to have similar benefits with people who drank wine showing higher results in all six tests.
Professor Smith added: "Wine, tea and chocolate are rich in substances called flavanoids, which have long been suspected to be good for health - they have several antioxidants.
"What was very striking was when we looked at people who said they consumed no wine, chocolate or tea - and compared them to those who had [consumed] one - this improved their result, two improved it further and all three - chocolate wine and tea, improved it quite markedly."
He added: "We are not suggesting for a minute that eating a bit of chocolate will instantly improve your memory on the spot - that is another, far more difficult test."