Tall people may be less at risk of dementia, research suggests.
Dementia is an “umbrella term” for disorders that affect brain functioning, leading to memory loss, slower thinking and mood swings.
With no single cause, many forms of the condition come about when proteins accumulate in the brain, eventually “killing” nerve cells.
While it has been linked to age and a family history of the illness, dementia’s onset is poorly understood.
Scientists from the University of Copenhagen are suggesting height may influence an individual’s risk.
The team looked at more than 666,000 men born in Denmark between 1939 and 1959, of which over 70,000 were brothers and 7,000 twins.
More than 10,500 of the participants developed dementia down the line.
After looking at their heights, the scientists found the risk of the disease went down by around 10% for every 6cm (2.3 inches) in men above the average 5ft 9inches (175cm).
This remained true when the team analysed brothers of different heights, suggesting genetics alone may not be to blame for dementia.
They also adjusted for education level and intelligence scores, which have been shown to protect against the condition.
It is unclear whether the same results would occur in women, with past studies finding an inconclusive link between a female’s height and her dementia risk.
“We cannot say for sure if our results apply to women,” study author Professor Merete Osler told Yahoo.
“But we find it likely the mechanism described above would be the same for women.”
Dementia affects 850,000 people in the UK.
Alzheimer’s is the most common form of the disease, impacting 62% of patients.
In the US, 5.8 million Americans live with Alzheimer’s.
There is no cure, with treatments focusing on slowing and managing symptoms.
Does height influence a person’s dementia risk?
While it may sound farfetched a 2014 study by the University of Edinburgh looked at the height of more than 181,000 people across 18 trials.
They found the taller participants were significantly less likely to die from dementia.
As to why this may occur, Dr Terese Sara Høj Jørgensen - lead author of the Copenhagen study - told Yahoo: “Height is an expression of growth early in life, and a taller body height may express the body has had an optimal development.
“At the same time, a shorter height may be an indicator of harmful exposures early in life.
“Thus, the association between body height and dementia may exist because body height expresses early life circumstances that are linked to later risk of dementia.”
Height can be genetic, but is also linked to childhood diseases and nutrition.
Not everyone is convinced, however.
Dr Douglas Scharre, from Ohio State University, told Yahoo he does not think height is “all that important”.
Genetics, age, diet and exercise may play a bigger role in dementia’s onset.
Studies also suggest socialising, and staying sharp with crosswords and board games could ward off the condition.
“In clinical practice, I have lots of patients above five foot nine inches with dementia and plenty below five foot nine inches,” Dr Clifford Segil - from Providence Saint John's Health Center in Santa Monica, California - told Yahoo.