Short men more likely to die from dementia, Edinburgh University finds
By Sarah Knapton, Science Editor
The University of Edinburgh has found that height is linked to the risk of death from dementia.
Short men are more likely to die from dementia than taller men, scientists have found, in the first ever study to link height with mental decline in old age.
Researchers at the University of Edinburgh found that men who were 5ft 5 inches or shorter were 50 per cent more likely to develop, and die from dementia, that those who were 5ft 8 inches or taller.
The academics think that height is an important indicator of developmental difficulties in childhood, such as stress, illness and poor nutrition.
They warn that lifelong damage can take place while the body is growing which may not be apparent until much later in life and suggest that breakfast clubs, vaccination programmes and improved parenting schemes could help tackle the growing dementia timebomb.
Lead author, Dr Tom Russ, of the University of Edinburgh’s College of Medicine & Veterinary Medicine, said: “This just shows the importance of intervening early to make sure children have proper nutrition and are not at risk. “We found that shorter adult height was associated with an increased risk of subsequent dementia death and that this association was stronger in men than it was in women.
“The association between height and dementia death remained when we took into account early life or adult socio-economic status and other relevant factors, including obesity, smoking, cardiovascular disease risk factors, and longstanding illness.”
The huge study of nearly 220,000 people across Britain, found men who were 5ft 5inches or shorter were 50 per cent more likely to develop dementia that those who were 5ft 8 inches or shorter.
A gap of 2.8 inches (7.3cm) between any height also raised the risk by 24 per cent. So, for example, a man who was 6ft or taller would be 24 per cent less likely to die from dementia than a man of 5ft 9 inches or shorter. For women the association was not as great, but there was still a 35 per cent increased risk of developing dementia for women who were 5ft 1ins (156cm) compared with those who were 5ft 4ins. (165cm) A gap of 2.6 inches (6.8cm) between any height raised the risk by 13 per cent.
The researchers speculate that women are less influenced by the effects of nutrition and stress in childhood. “Short height in itself of course does not ‘cause’ dementia. Rather, height captures a number of early life factors, including early-life illness, adversity, poor nutrition, and psychosocial stress, and so allows us to examine the effect of these factors on dementia more closely,” said co-author Dr David Batty, of the Department of Epidemiology & Public Health at University College London. One in six people aged 80 and over have dementia, and by next year it is thought that 850,000 will be suffering from the condition in Britain.
The disease claims 60,000 deaths a year and costs the UK £26 billion per annum. Earlier this year, David Cameron said that dementia is one of the “greatest enemies of humanity” and has pledged to accelerate progress on drugs, by increasing funding and making new medication more accessible. The new study suggests that tackling childhood poverty and nutrition in early life could help stop the disease developing.
The authors suggest the growth hormone levels are linked to the development of the hippocampus – a part of the brain which is first to show evidence of dementia damage.
British scientists and charities said that the research showed that a healthy lifestyle could lower the risk of developing dementia.
Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, said: “The findings of this well controlled research encourage us to focus on early life, which influences adult height, as a small contributing factor to later dementia risk, particularly in men. “Evidence is mounting for the potential to prevent dementia through lifestyle and environment, and this study will contribute to building our knowledge around the factors we might control to reduce disease risk throughout life.”
Prof Tim Frayling, Professor of Human Genetics, University of Exeter Medical School, said: “The authors are not claiming that height directly alters risk of dementia. They are actually claiming something more subtle and less controversial. That is that height is a marker of early life factors which predict death from dementia.
“Their results show that increased height is a marker of reduced risk of death from Dementia. This is not surprising because it is well known that taller height on average, especially those born 60-80 years ago, was a predictor of generally better health and wealth.
“And people of generally better health and wealth are likely to have access to better healthcare and therefore their decline from dementia may be less steep.” Dr. Doug Brown, Director of Research and Development, Alzheimer’s Society, added; “Once fully grown there is nothing we can do to change our height, however we do know that we may be able to reduce our risk of dementia by making changes to our lifestyle. Not smoking, taking regular exercise and eating a healthy diet are all things that could improve our brain health.”
The research was published in the British Journal of Psychiatry.