Short People Are More Likely To Die From Dementia, Scientists Say

Why Short People Are More Likely To Die From Dementia

Being short increases your chances of dying from dementia, according to a new health study.

Scientists analysed 18 population studies with more than 180,000 participants and compared the risk of dying from dementia for the tallest and shortest men and women.

They found that men under 5ft 6in in height were 50% more likely to suffer death from Alzheimer's or other forms of dementia than those taller than 5ft 10in.

Meanwhile, women were less at risk, but those shorter than 5ft 1in were still 35% more likely to have their lives ended by the disease than those taller than 5ft 5in.

Scientists stressed that there was no evidence that lack of height triggered the brain-deteriorating condition, the most common form of which is Alzheimer's.

But height could be a marker of other factors that might influence dementia risk, even early in life.

Senior author Dr David Batty, from University College London, said: "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."

Men and women taking part in the studies had average heights of 5ft 8in and 5ft 3in respectively.

The risk of dying from any form of dementia was examined over an average period of 9.8 years. Of the total, 426 men and 667 women died as a result of developing the disease.

Participants were divided into four groups ranging from the tallest to the shortest. The study found that, for men, every 7.3 centimetre reduction in height was associated with a 24% increased risk of dementia death.

For women, each 6.8 centimetres of height loss coincided with a 13% increase in risk.

Study leader Dr Tom Russ, from the University of Edinburgh, said: "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 long-standing illness."

Writing in the British Journal of Psychiatry, the researchers concluded: "We have demonstrated a dose-response association between height and later dementia death which was robust to adjustment for a series of covariates.

"We propose the hypothesis that the mechanism driving this association may be early-life circumstances and thus add to the growing evidence of the role of pre-adult factors in later dementia risk."

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Early Symptoms of Dementia

They called for continuing public health policies "on a broad front" to improve early-life conditions, taking into account pre-school education, parenting schemes and vaccination programmes.

An estimated 850,000 people in the UK are thought to be suffering from dementia, 60% of whom have Alzheimer's.

Commenting on the findings, Dr Doug Brown, director of research and development at Alzheimer's Society, said: "The data suggests that very short people are at increased risk of dying with dementia.

"While the study was robust and detailed, because a very small number of people actually had dementia when they died it is very difficult to conclude that height is one of the most important risk factors for dementia," he added.

"Future work in this area needs to understand exactly which factors that contribute to our height are important - whether that be childhood nutrition or genetic inheritance - and use that information to help us understand more about how dementia develops.

"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."

Dr Simon Ridley, from the charity Alzheimer's Research UK, said: "Separating cause from effect is a big challenge of observational studies. However, 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, and 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."