Being fat can cause dementia: How your lifestyle can pose a threat to your mind that's just as serious as Alzheimer's
00:48 GMT, 27 March 2012
For a man who used his mental arithmetic skills as a tool of his trade for years, it was a perplexing moment.
Tom Mitchell and his wife Liz, from Bootle, Merseyside, were at the checkout in their local supermarket and, as she’d done hundreds of times before, Liz handed Tom the money to pay for the groceries.
‘Tom looked at the money then at me,’ recalls Liz.
‘Then he shook his head and I could see the confusion in his eyes. “What do I do with this” he asked me. “What are these things for” ’
Changing your lifestyle can greatly reduce your risk of vascular dementia, this includes losing weight, reducing alcohol intake and stopping smoking
This was more than out of character for Tom: until his retirement four years earlier, he’d made his living as a scrap metal merchant.
‘His ability to calculate weights and prices in his head was amazing,’ says Liz.
‘Yet there he was by the checkout, seemingly unable to even work out what the coins in his hand were for.’
Back at home, a concerned Liz tried to discuss the matter with her husband.
‘The strangest thing of all was that he didn’t seem at all bothered by what had just happened,’ she explains.
‘He just seemed to be quietly confused.’
Worried, Liz took Tom, then 62, to their GP. He carried out a basic memory test and pronounced there was nothing wrong.
‘I was relieved and more than happy to believe the GP, although deep down I knew something wasn’t right,’ says Liz.
‘A month or so after that visit I found him eating grapes off the floor, because he had mistaken the carpet for the table.
‘We’d lived in our house for 20 years, but suddenly Tom couldn’t remember where the toilet was and I’d find him wandering from room to room looking for it.
‘Again, he wasn’t distressed by this. In fact, he used to look puzzled if I mentioned it.’
Vascular dementia is the second most common cause of dementia after Alzheimer's disease
Tom’s personality was also changing: ‘He had always been a very kind family man, but he was now regularly bad tempered and often unreasonable, and he seemed to be having trouble sleeping.’
After a few months of this, Liz decided to take Tom back to the GP.
This time he was referred to a memory clinic at their local hospital, where he was also given brain scans. The diagnosis: vascular dementia.
‘To say I was devastated was an understatement,’ recalls Liz, now 60.
‘Tom was my first and only boyfriend; we were the perfect match and for our entire married life we had been content just being together, raising our boys, Thomas (now 38) and Mark (35), and enjoying our home life.
‘And now Tom was being taken away from me in the cruellest possible way.
'But Tom either didn’t or couldn’t seem to understand what I was telling him. All he said was: “We’ll just have to get on with it then.” ’
Vascular dementia is the second most common cause of dementia after Alzheimer’s disease.
It affects around 200,000 people in the UK and, unlike Alzheimer’s, where experts have yet to pinpoint the cause, the origins of vascular dementia are very well understood.
‘Vascular disease is caused when the blood supply — the vascular system — to and within the brain is disrupted or damaged,’ explains Dr Karen Horsburgh, a neuroscientist at Edinburgh University who specialises in the causes of vascular dementia and Alzheimer’s disease.
‘If blood cannot reach the brain cells, the cells will eventually die. This can lead to the onset of vascular dementia.
'It can happen suddenly — for example, with a significant stroke, or over a long period of time due to an ageing process which is not yet fully understood.’
Vascular dementia is also often triggered when people suffer from mini strokes.
‘This can cause imperceptible damage, but over a series of months of years, this can build up to a significant disruption of brain function,’ says Dr Horsburgh.
There are, however, several key differences between Alzheimer’s disease and vascular dementia, she adds.
‘The brain of someone with vascular dementia will show evidence of blocked blood vessels and general damage to the vascular system, and you can actually test the reduced blood flow using a special angiograph in the same way you can test the blood supply to the heart.’
This involves injecting a dye into the bloodstream that shows up on an X-ray to reveal how well the blood is flowing into certain areas.
‘With Alzheimer’s disease, a brain scan will show more general brain cell death and a build-up of amyloid plaque — a protein associated with Alzheimer’s disease.
'This tends to affect the neurons first, the grey matter in the brain — the part of the brain associated with, among other things, memory.
‘However, vascular disease can damage any part of the brain — wherever the blood flow blockage occurs.
'So depending on which part of the brain is damaged, you may lose cognitive function such as perceptions, physical functions or memory.’
Yet there is another, more crucial difference between the two types of dementia, a difference experts are desperate for people to understand and be made aware of.
While there is not yet any known cause of Alzheimer’s disease, the causes of vascular dementia are not only known, but in many cases preventable.
‘Vascular dementia is caused by broadly the same things that will cause cardiac disease,’ explains Dr Horsburgh.
This means anything that clogs up or damages the arteries and stops the blood supply from flowing adequately.
‘So if you smoke, have high cholesterol, suffer from hypertension or fail to take regular exercise, then you are increasing your risk not just of a heart attack, but also of suffering from dementia as well,’ she says.
Indeed, someone who smokes doubles their risk of getting vascular dementia, according to the Alzheimer’s Society.
If you have high blood pressure, your risk is up to three times higher than the average person, and someone who has survived a stroke (which suggests they have existing blocked arteries) has a one in three chance of succumbing to dementia.
Being a diabetic also increases your risk, though experts are unsure why.
However, perhaps rarely for dementia, there is some good news.
According to experts, lifestyle changes may reduce your risk, postpone and maybe even prevent altogether the onset of vascular dementia.
‘For too long people have thought getting dementia was just bad luck — in fact, you can actively reduce your risks,’ says Jessica Smith, of the Alzheimer’s Society.
‘We say that what is good for the heart is good for the head.
'Certainly some people may have genetic predisposition towards vascular dementia. But changing your lifestyle can greatly reduce your risk.’
This includes losing weight, reducing alcohol intake, taking exercise and stopping smoking.
It is a message Liz wishes she’d known about earlier.
‘Tom was very overweight and he was diagnosed with type 2 diabetes in his 40s,’ she explains.
‘He also chain smoked, though he gave up after he developed blocked arteries in his legs.
‘Doctors were always telling him he was at risk of heart disease, but if he’d known he was at risk of dementia because of his lifestyle, I’m sure he would have taken more notice.’
At the moment, the best hope of treatment for the condition lies in working out how the disease occurs — this is something that Dr Horsburgh and her colleagues are working on in a project funded by Alzheimer’s Society.
Another project paid for by the charity is trying to work out a way of standardising the diagnosis and care of vascular dementia.
‘Lack of awareness of vascular dementia, both within the public and, to a certain extent, the health care professions, is a real problem,’ says Jessica Smith.
‘Some patients will get good care; others will be left to cope as best they can.’
That has certainly been Liz’s experience. Since her husband’s diagnosis she’s not heard back from the hospital, nor is he receiving treatment for his dementia from his GP.
Five years since Tom was diagnosed, Liz is now his full-time carer.
At the age of 67, the once-independent businessman is frightened if Liz leaves him for a even a few minutes and during his bad times he can shout at his wife for up to ten hours at a time.
Their friends have melted away and, save for visits from their sons and journeys to a support group, Liz lives a lonely and isolated life.
‘It is only my deep love for my husband that keeps me going,’ she says.
‘Living with dementia is hell, and I wouldn’t wish it on anyone else.
‘I know that if either Tom or I had known that his smoking and being overweight could be the cause of dementia, then we would have changed his lifestyle in an instant.’