Mental exercise, low-fat diet and vitamins can delay Alzheimer's

Diet and exercising the brain with mental puzzles can reverse the effects of ageing, says a series of studies that are beginning to explain the causes of Alzheimer's disease.

Diet and exercising the brain with mental puzzles can reverse the effects of ageing, says a series of studies that are beginning to explain the causes of Alzheimer's disease.

Separate teams of scientists have found that vitamin supplements, a low-fat diet and mental games can play a critical role in delaying the onset of senile dementia, and that dietary fats in particular are intricately involved in triggering Alzheimer's.

One of the studies identified a link between the damaged brain cells of Alzheimer's patients and higher levels of cholesterol and ceramide - another fatty compound - in the brain. Both fats could be reduced with the aid of dietary supplements, said Mark Mattson of the US National Institute on Ageing. He said: "We found that we could block the increase in ceramide by increasing levels of antioxidants. Finally we found that increases in ceramide levels in the nerve cells may play a role in dysfunction and degeneration.."

Another study, involving more than 70 dogs of varying ages, found that feeding them vitamins and antioxidants enabled older dogs to learn tricks that they could only do when they were much younger and more alert. Carl Cotman, a neurochemist at the University of California at Irvine, used the dogs to test the theory that a diet rich in vitamins and antioxidant supplements could slow down or reverse mental decline in old age.

The dogs were divided into those fed a basic diet and those given extra supplements of vitamin E and other antioxidants. He tested their performance over several years in distinguishing between certain unfamiliar objects; a recognised test of mental ability in animals. He said: "The really remarkable finding is that ... they learnt to do tasks they could only do when they were younger and they'd lost as a function of age," he said."The data show that those animals that have lost it can be rejuvenated by this long-term diet.

The findings support the view that brain cells are constantly trying to repair themselves and need antioxidants to help them mop up destructive chemicals.