The team from Oxford’s Department of Physiology, Anatomy and Genetics and Norway examined the relation between cognitive performance and the intake of three common foodstuffs that contain flavonoids (chocolate, wine, and tea) in 2,031 older people (aged between 70 and 74).

Participants filled in information about their habitual food intake and underwent a battery of cognitive tests.Those who consumed chocolate, wine, or tea had significantly better mean test scores and lower prevalence of poor cognitive performance than those who did not. The team reported their findings in the Journal of Nutrition.

The role of micronutrients in age-related cognitive decline is being increasingly studied. Fruits and beverages such as tea, red wine, cocoa, and coffee are major dietary sources of polyphenols, micronutrients found in plant-derived foods. The largest subclass of dietary polyphenols is flavonoids, and it has been reported in the past that those who consume lots of flavonoids have a lower incidence of dementia.

The latest findings seem to support the theory, although the researchers caution that more research would be needed to prove that it was flavonoids, rather than some other aspect of the foods studied, that made the difference.The effect was most pronounced for wine.

However, say the researchers, those overdoing it at Christmas should note that while moderate alcohol consumption is associated with better cognitive function and reduced risk of Alzheimer’s disease and dementia, heavy alcohol intake could be one of many causes of dementia – as well as a host of other health problems.