The number of people with neurodegenerative diseases is increasing rapidly. A 2022 analysis estimated that by 2050, around 153 million people will be living with dementia worldwide. Parkinson’s disease, the second most common neurodegenerative disorder, now affects over twice the number it did in 1990, with more than 6 million people living with the condition in 2016.Now, a study using data from the UK Biobank has found that it is not only extra weight but where that weight is carried on the body that may influence the risk of neurodegenerative conditions.
In the study, published in Neurology, the medical journal of the American Academy of Neurology, the researchers suggest that extra belly and upper arm fat may increase the risk of these conditions, whereas increased muscle mass could decrease the risk.
Higher risk with both belly and upper arm fat
Researchers analyzed data from 412,691 people, who were followed for an average of nine years. During the study, 8,224 people developed neurodegenerative diseases. The most common diagnosis was Alzheimer’s disease, with some people developing other dementias, or Parkinson’s disease.
At the start of the study, participants had an average age of 56. The researchers assessed body composition by measuring waist and hips, grip strength, bone density, and fat and lean mass.
They found that people with more belly fat (central obesity), or more upper arm fat (arm-dominant fat distribution) had an increased risk of developing neurodegenerative disorders.
Higher bone density and leg-dominant fat distribution decreased the risk, while high muscle strength appeared to protect against neurodegeneration.
These results are in line with previous research, which has suggested that people with central or abdominal obesity are at increased risk of developing dementia.
This study highlights the potential to lessen people’s risk of developing these diseases by improving their body composition. Targeted interventions to reduce trunk and arm fat while promoting healthy muscle development may be more effective for protection against these diseases than general weight control.
