Eat well and be smart

You are what you eat has taken on a new meaning. Your brain is what you eat.

At a neurology conference held in San Diego this week, 300000 doctors from across the world discussed the brain and health.

One overriding theme, according to conference moderator Fernando Gomez-Pinilla from the University of California, Los Angeles, was "that we cannot separate the nutritional benefits of food for the body from that of the mind. What we put into the body shapes the brain, for better or for worse".

The studies included a presentation showing that naturally impulsive rats binged on more food than calmer rats . Their inclination to be impulsive and overeat were both linked to serotonin levels in the brain. So researchers have suggested that treating the brain may help people who binge eat.

In another study, the children of parents who had used marijuana were more likely to be obese.

Scientist Samantha Gardener from Edith Cowan University in Australia presented evidence that older people who ate a Western diet had greater cognitive decline than those who ate a Mediterranean diet with more fruit and vegetables.

The study, "Dietary patterns and their association and cognitive decline", monitored the eating patterns of elderly Australians over three years.

The Western diet was high in red and processed meat, potatoes, high-fat dairy products and sweets. The Mediterranean diet was high in vegetables and fish.

The people on the Western diet were found to have a greater decline in visual-spatial functioning - one's ability to see, perceive depth, give directions and draw.

The study linked poor diet to a greater risk of cognitive decline and Alzheimer's disease.

Gardener said: "Our findings are in agreement with previously published work on dietary patterns and cognitive decline."

She said it had already been shown in US populations that diets high in fish, olive oil, fruit and vegetables were associated with a lower risk of Alzheimer's. It was significant that the Australian study showed the same.

"As Alzheimer's increases as the populations ages, diet represents a potential intervention strategy accessible to all."

Current research is shifting from understanding and diagnosing Alzheimer's to preventing it.

The September edition of the journal Epidemiology showed that nine out of 12 studies linked a Mediterranean diet to a lower risk of mental decline and Alzheimer's.