Most people expect to suffer a degree of decline as they age.

Noel Coward said it's "foolish to think that one can ever slam the door in the face of age. Much wiser to be polite and gracious and ask him to lunch in advance".

True, there is no point in denying the aging process, but positive eating habits and regular exercise do much to delay it.

There is even new evidence to suggest that a diet rich in vitamins can protect against the devastating mental illness Alzheimer's.

Alzheimer's disease was only discovered a century ago but has since become one of the most common forms of dementia in the elderly.

It is characterised by progressive mental and physical deterioration which includes a decline in memory, disordered perceptions of space or time, delusions, personality changes and, eventually, a loss of bodily functions.

Many people worry they may be suffering from Alzheimer's. If you can't remember where you put your glasses, you are merely forgetful. However, if you can't remember you wear glasses, this may indicate dementia.

Microscopic examinations of the brain of Alzheimer's patients reveal tangled nerve fibres and plaques consisting of abnormal protein fragments.

Messages can no longer be transmitted correctly and memories can't be retrieved.

Apart from genes, environmental factors may have a part to play - toxic metals such as aluminium and mercury have been found in the brains of some patients.

The number of cases is expected to rise as babyboomers age, putting a huge strain on healthcare resources. Strategies for preventing or delaying the onset of the disease are, therefore, urgently required.

Research from Holland and the US shows people with a high intake of four antioxidants, vitamins C and E, flavonoids and betacarotene, are less likely to develop Alzheimer's.

Vitamin E, in particular has been found to strengthen overall antioxidant defences and may slow its progression.

There is new evidence that elevated levels of homocysteine are common among Alzheimer's patients.

Homocysteine is an amino acid found in small amounts in the blood but it can increase and cause trouble if a person is deficient in folic acid and the vitamins B6 and B12. High levels cause deterioration of blood vessels and have been linked to heart disease and stroke.

Now scientists are suggesting the build-up of homocysteine could also be a risk factor in Alzheimer's and that adequate dietary or supplementary intake of B vitamins may be protective.

Some forms of medication are known to raise homocysteine levels and deplete nutrients.

As vitamin and mineral deficiencies are common in the elderly, diet and lifestyle factors must be key in the war against dementia. Take regular exercise and follow a healthy-eating plan with plenty of fresh vegetables.

A daily supplement of vitamins, minerals and essential fatty acids is highly recommended. Other protective supplements include lecithin, lipoic acid and ginkgo biloba. Avoid mercury fillings as well as fluoridated water (it helps to transport aluminium into the brain) and smoking which increases susceptibility to Alzheimer's.

Martina is a qualified
nutritionist at the Crescent Clinic of Complementary Medicine, 37 Vernon Terrace, Brighton. Tel: 01273 202221 or e-mail: martina_watts@compuserve.com