Dr Anthony Mander explores the tender issue of cognitive decline and gives his advice on how to reduce the risk.

Minimal cognitive impairment is a condition that affects at least half a million people in the UK. It involves a loss of brain function which can start with memory loss, which steadily progresses over the years and can end in Alzheimer’s disease or other forms of dementia. Up to 700,000 people in the UK are affected by Alzheimer’s.

WHO IS AT RISK?

Unfortunately, research tells us that the most significant risk factors are those we cannot change. Age is the principal known risk factor for dementia. Dementia affects one in twenty people over the age of 65 and one in five over the age of 80. But dementia is not restricted to older people - there are over 18,000 under the age of 65 with dementia in the UK. It is not a normal part of ageing.

Genetic inheritance influences our risk of developing many diseases. The role of genetics in the development of dementia is still not fully understood. However, in the vast majority of cases, the effect of inheritance seems to be small. A person’s chances of developing Alzheimer’s disease if his or her parent or other relative has it are only a little higher than if there are no cases in the immediate family. Women are two to three times more likely to develop Alzheimer’s than men, even if we discount their longer life expectancy.

CAN COGNITIVE IMPAIRMENT BE PREVENTED OR TREATED?

Although there are no prescription drugs as yet there are practical steps that can be taken to help slow cognitive decline. They involve avoiding the factors that can potentially damage memory - smoking, drinking, eating a poor diet - and encouraging factors that are good for it - including dietary and nutritional factors as well as the old adage ‘use it or lose it’.There is a large study looking at age-related memory loss - the Oxford Project To Investigate Memory and Ageing (OPTIMA) - where by the cognitive function of hundreds of both healthy volunteers and those with some impairment has been intensively studied since the late eighties.

We know that ways of alleviating or postponing age-related memory loss centre around maintaining a robust hippocampus (the part of the brain that controls memory) and crucially, holding on to as much of it as possible. While normal ageing involves shrinking of the hippocampus by 1% a year from our forties onwards, it can become as much as 15% for Alzheimer’s sufferers.

POSTPONING AGE-RELATED MEMORY LOSS

Scientists agree that challenging your memory and regular physical exercise can help postpone age-related memory loss. Tango dancing is an activity that reduces the risk of developing Alzheimer’s by an astonishing 75% - the same is true of playing either chess or the piano. These, it seems, demand an unusual combination of multi-tasking - mixing mental and physical activities - thereby helping to maintain a robust hippocampus. Nutritional supplements can also help.

There is particular focus on the research behind the herb ginkgo biloba. Systematic reviews of the clinical evidence suggest ginkgo biloba has beneficial effects on cognitive impairment and dementia. One clinical trial looked at the effects of treatment with ginkgo on cognition and mood in women. Researchers from King’s College London studied 34 postmenopausal women (age 53-65) who were randomly given seven days of treatment with either 120mg ginkgo biloba or an inactive placebo. A battery of cognitive tests and measurements of mood and menopausal symptoms was administered before and after treatment. The group taking gingko showed significantly better performances in memory tests1. Ginkgo biloba extracts appear relatively safe, with most reported adverse events being mild and benign.

The role of oily fish containing omega 3 fatty acids - which help the brain send messages between cells - is very important in brain function. We should aim for a minimum of oily fish or its equivalent twice a week. It is interesting that fish oil is being given to children with learning and behavioural problems. Folic acid is important (yeast extracts, black-eyed beans, soya, wheatgerm, liver, asparagus and broccoli are good food sources) as are vitamin B supplements. Antioxidants may also be of value in helping brain health.

LIFESTYLE CHANGES THAT CAN HELP POSTPONE COGNITIVE DECLINE

Research evidence increasingly suggests that there are strong links between a healthy heart and a healthy brain.

High levels of homocysteine (a breakdown product of protein metabolism) are associated with cognitive impairment (interestingly they are also linked with heart disease and bone fracture). Excess homocysteine in the blood is associated with low levels of folic acid and vitamins B12 and B6 are also thought to be important in regulating homocysteine levels. It has been suggested that folic acid supplements may be of benefit in this situation.

Anyone can develop dementia, including those who follow a "low-risk" lifestyle. It is not possible to guarantee that you won′t develop dementia if you change your way of life. Keeping your mind and body active and healthy is the best way of protecting your brain. Other factors, such as education and good nutrition habits from an early age, are a good idea for everyone.

DEFINITION

Minimal or early cognitive impairment: The slowing-up of the system in the brain that processes and stores recent memories and events and relates them to earlier past memories in a meaningful way.

MY TOP TIPS FOR STAYING MENTALLY ALERT

• Don′t smoke
• Reduce your intake of salt and saturated fat
• Take regular exercise - especially tango dancing!
• Drink alcohol only in moderation
• Eat plenty of fruit and vegetables
• Eat oily fish at least once a week
• Check your blood pressure and cholesterol levels (with your GP)
• Check your homocysteine level - ask your GP - strangely not used as much in the UK as in the rest of Europe
• Avoid head injuries (wear a helmet for cycling or motorcycling; don’t box)
• Enjoy an active social life and pursue interests and hobbies that allow you to multi-task or to challenge your brain.

¹ Hartley et al; Pharmacol Biochem Behav. 2003 Jun; 75 (3): 711-20.

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