Exercise may ward off Alzheimer's and slow down its progression
Being physically fit could hold back the advance of Alzheimer's disease, US researchers have suggested.
Their study, published in the journal Neurology, looked at 121 people aged over 60, around half of them in the early stages of the disease.
Those with Alzheimer's who were less fit had four times more signs of brain shrinkage than those who were fit.
The Alzheimer's Research Trust said other research showed exercise reduced the risk of dementia.
People with early Alzheimer's disease may be able to preserve their brain function for a longer period of time by exercising regularly
Dr Jeffrey Burns
University of Kansas School of Medicine
Well over 700,000 people today in the UK are living with dementia, with this number predicted to grow quickly over the next two decades, as the proportion of older people in the population increases.
Other studies looking at the relationship between dementia and exercise tend to focus on whether being active can reduce the risk of the condition developing in the first place.
Dr Jeffrey Burns, from the University of Kansas School of Medicine, said his was one of the first to look at whether exercise could affect the progress of the illness.
His volunteers underwent a treadmill test to see how fit they were and then their brains were scanned for shrinkage, which is one way of measuring the severity of their Alzheimer's.
Enriched environment
Exercise offers an impressive array of health benefits. It helps prevent heart disease and type 2 diabetes; lowers the risk for high blood pressure, colon cancer, and breast cancer; and helps relieve insomnia, anxiety, and depression. But that's not all. Several studies suggest that exercise might also help ward off Alzheimer's disease and other forms of dementia.
One study of 2,000 people, published in 2005 in Lancet Neurology, found that those who exercised during midlife for 20 to 30 minutes twice a week were at least 50% less likely to develop Alzheimer's disease or another dementia in the following decades than people who were sedentary. Earlier, a Canadian study involving 9,000 people over age 60 found that regular exercise cut the risk for cognitive impairment by 37%. Studies of seniors in the United States and the Netherlands have yielded similar results.
Just how exercise may prevent Alzheimer's disease is unclear, but research on mice offers a clue. A 2005 study in the Journal of Neuroscience reported that mice that used their treadmills most often not only proved better able to learn how to get around test mazes than others, but also had fewer deposits of beta-amyloid in their brains. And in the environmental enrichment study described previously, the lowest levels of beta-amyloid and amyloid deposits were found in the most active mice, who spent the most time running and climbing on the toys placed in their cages.
Singles 'face Alzheimer's risk'
Social interaction may be key
Being single when you reach middle age could mean more than having the house to yourself - it could increase your risk of dementia.
Swedish research, presented at a US conference, found that marriage or having a partner halved the risk of developing dementia.
Scientists believe social interaction between couples may ward off illness.
The Alzheimer's Research Trust said the results were worrying, given the high divorce rates in the UK.
These findings are particularly worrying for the UK - a society with a high divorce rate, marriage at an all-time low, and aging population
Rebecca Wood,
Alzheimer's Research Trust
The study by the Karolinska Institute suggested that the problem might be even greater for some people.
Divorcees who remained single, they noticed, had a trebled risk of dementia, while those widowed at a young age who stayed single faced a six times greater chance.
The research looked at 1,449 people from a Finnish database, who were asked about their relationship status in mid-life, then revisited 21 years later to see if they had developed dementia.
In total, 139 of them had some sort of cognitive impairment, and Alzheimer's had been diagnosed in 48 of these.
Even after other factors which might have an impact on dementia were adjusted for, the study consistently showed people with partners as less prone to the illness.
Advice for the single
Dr Krister Hakansson, who led the study, said: "Living in a couple relationship is normally one of the most intense forms of social and intellectual stimulation.
"If social and cognitive challenges can protect against dementia, so should living as a couple.
Singletons shouldn't worry - there are many other ways to reduce your risk of dementia that don't involve popping the question
Susanne Sorenson,
Alzheimer's Society
"This study points to the beneficial effects of a married life."
Rebecca Wood, from the Alzheimer's Research Trust, said that more research along these lines was urgently needed.
"These findings are particularly worrying for the UK - a society with a high divorce rate, marriage at an all-time low, and aging population.
"This is the first study of its kind to examine the link between midlife marital status and dementia, adding to previous research suggesting that social interaction reduces dementia risk."
However, Susanne Sorenson, from the Alzheimer's Society, had some words of cheer for partnerless people.
She said: "Singletons shouldn't worry - there are many other ways to reduce your risk of dementia that don't involve popping the question.
"The best evidence is around eating a Mediterranean diet, exercising regularly and not smoking."
She also said that the findings were consistent with other research showing social interaction could be beneficial.
She added: "Whether it's reaching for the vacuum cleaner or going for long romantic walks, lifestyle factors associated with being married may also help."
Inactivity link to mental decline
Lack of exercise could lead to dementia in later life
Being a slob puts you at risk of mental health problems, experts have warned.
A lack of physical activity leads to depression and dementia, evidence presented at the British Nutrition Foundation conference shows.
It comes as new research from the University of Bristol found that being active cuts the risk of Alzheimer's disease by around a third.
Currently only 35% of men and 24% of women reach the recommended weekly amount of physical activity.
Professor Nanette Mutrie, an expert in exercise and sport psychology at the University of Strathclyde, told the conference that mental health was not a trivial issue.
It's only recently that people have begun to see the link between physical activity and mental health
Professor Nanette Mutrie
"It's only recently that people have begun to see the link between physical activity and mental health.
"It's important for increasing people's self esteem, general mood, coping with stress and even sleeping better.
"And we now have very strong evidence that physical activity can prevent depression."
She said inactive people had twice the risk of becoming depressed and there was also very good evidence that exercise is a useful treatment for depression.
Dementia risk
Researchers at the University of Bristol carried out an analysis of 17 trials looking at the effects of physical activity on dementia and Alzheimer's disease.
They found that in both men and women physical activity was associated with a 30-40% drop in the risk of Alzheimer's.
It is unclear why there is such a great effect but it could be associated with benefits to the vascular system as well as release of chemicals in the brain.
Professor Mutrie added: "It could be a simple case of use it or lose it.
"It is estimated that over 700,000 people in the UK currently suffer from dementia and more research is needed to determine how this condition can be prevented."
Professor Judy Buttriss, director general at the BNF, said with people living longer the implications of such studies were "enormous".
"There has already, justifiably, been a lot of emphasis on good nutrition but we must also find ways of helping people to be more physically active to ensure that they maintain health and quality of life in later years."
Department of Health figures show the majority of adults do not do the recommended 30 minutes of moderate activity at least five times a week.
Children are also leading increasingly inactive lives.
Around 30% of boys and almost 40% of girls fail to reach the recommended hour of moderate intensity activity per day.
Professor Chris Riddoch, expert in sport and exercise science at the University of Bath, said: "We have half a Century of evidence showing active people have lower levels of disease.
"We also have a very good handle on how much exercise people should take."
But he added efforts to get people to be more active had not been very successful to date.
Mary Joseph Foundation a non-profit organization for Alzheimer's disease