Diet is vital in prevention of Alzheimer's

Each year, September 21st marks World Alzheimer’s Day. An estimated 55,000 Irish people currently have dementia, with about 60% of them having Alzheimer’s disease (AD). And due to our ageing population, figures are expected to rise exponentially.

AD is characterised by the formation of amyloid ‘tangles’ and ‘plaques’ in the shrinking brain. These clumps destroy brain cells and interfere with its chemical messaging functions, particularly of acetylcholine, which deals especially with memory. Age is of course the primary risk factor, but others are equally important – diabetes, cardiovascular issues, genetics, infections, stress and nutritional deficiencies. An overview of more than 300 studies last August found that the number one protective factor was a healthy diet.  

One consideration is that cognitive health is directly linked to heart health, and that both are strongly determined by blood levels of a toxic compound called homocysteine. Reducing those levels, by taking high strength B vitamins, would therefore be the first plan of action. Research has shown between 30% and 90% less brain shrinkage in people with early signs of AD when given B6, B12 and folic acid, which boost the conversion of homocysteine into that vital acetylcholine in the same way as the drugs given to people with AD do.

Inflammation (partly as a result of poor gut bacterial balance) is a central feature, as is oxidative damage to the cells, so taking a good probiotic and eating plenty of antioxidants in brightly coloured plant foods is the second prong of attack, along with exercising regularly (in the sunshine for important vitamin D). Inactivity raises the risk of AD by 70%, while sex has been shown to light up the relevant areas of the brain. And be sure to visit your dentist regularly – a strong connection has been established between gum disease and amyloid clumping.  

Eating plenty of anti-inflammatory omega 3 and vitamin D-rich oily fish, and the healthy oils in olive oil, avocadoes, nuts and seeds is of proven benefit to those most at risk, but avoid trans/hydrogenated fats altogether, as they markedly accelerate cognitive decline. While research shows that a diet high in healthy fats reduces risk by 44%, a diet high in sugar and refined (white) grains increases the risk by a staggering 89%. Another study showed accelerated shrinkage in the part of the brain involved in memory in those on a Western diet of processed and fried meats, crisps and soft drinks.

The latest research on diet includes: a moderate coffee intake can reduce risk by 18%, broccoli slows the degeneration of acetylcholine while egg yolks help to make it; avocado boosts blood flow to the brain, and the antioxidants in kale make your brain ‘younger’. A chemical called resveratrol, in red wine, raspberries and dark chocolate, can strengthen the barrier that blocks harmful molecules from accessing the brain. 

 An anti-inflammatory and antioxidant Indo/ Mediterranean diet, based on colourful vegetables and fruit, greens, oily fish, beans and lentils, nuts and seeds, olive oil, green tea and a little red wine, is widely accepted by as the very best model for the prevention and control of AD (figures are lower in Mediterranean countries). Olive oil contains compounds that can halt the build up of those plaques.     

A connection has long been made between AD and exposure to aluminium. This is disputed, but it might be wise to eat foods rich in silicon, which counteracts aluminium. More recent research has pointed to high levels of copper in the blood of AD sufferers, and we know that copper makes it harder for the brain to get rid of amyloid proteins. It is, however, in a great variety of foods and necessary for health, so the answer is to take a supplement of zinc, which is antagonistic: the higher your zinc levels, the lower those of copper.  

This January it was suggested that BMAA, a toxic compound produced by algae in Irish lakes and reservoirs and so present in some seafood and plants, is contributing to our Alzheimer’s ‘epidemic’, so this will doubtless be the focus of further research. As will the revelation that the brains of sufferers contain unusual yeasts and fungi. In more practical terms: while some studies show that being slightly overweight is far more protective than being underweight, it’s just been shown that the inflammation associated with obesity causes the brain to age ten years faster, so it really is a balancing act. Also in January, Canadian scientists found that chronic exposure to anxiety and stress hormones—also inflammatory--damage and shrink the relevant parts of the brain. And finally, a study out this April involving 5,000 people with insomnia found them to be 43% more likely to develop dementia in later life; there’s no doubt that lifestyle issues are key.   

• For more information, contact the Alzheimer Society of Ireland on 1800 341341, or go to www.alzheimer.ie.