The reduction in performance on these tasks associated with a 25-decibel hearing loss (classified as "mild") was equivalent to an ageing effect of seven years in cognitive abilities.

BBC: Viewpoint: Does deafness contribute to dementia?

Although he accepts some neuroscientists (and the journalists who report their work), may have been guilty of overestimating the power of their findings, the Director of UCL's Institute for Cognitive Neuroscience Professor geraint Rees believes Ray Tallis is also guilty of exaggerating for effect.

BBC: Brain research's 'golden age'

In particular, he pointed out that those who drank sake tended to eat larger quantities of raw fish, which is thought to have possible benefits to cognitive function, while wine drinkers tended to eat more cheese, which may have a similar effect.

BBC: Alcohol 'improves IQ'