Health experts have warned that rising levels of obesity in middle age – a condition recently linked to increased risks of Alzheimer’s disease in later life – could result in a major increase in numbers of dementia sufferers by 2050.
“We know dementia levels are going to rise because our population is growing older and Alzheimer’s disease is an illness of old age,” said Tim Marsh. “But it is clear that obesity is another factor that is putting more and more members of the public at risk. Recent research by several groups has indicated that individuals who are obese in their 40s and 50s have twice the average risk of getting dementia in their 70s."
The evidence follows previous research that found that obesity had an increasingly negative impact on performance in a series of memory and reasoning tests spanning over a decade. Another study found that people who are obese in middle age are nearly twice as likely to develop dementia in later life.
The roots of this link are not fully understood. One theory suggests that excess fatty tissue in the body releases proteins that travel through the bloodstream affecting the cells in the brain. Not every scientist agrees, but most accept there is a connection between obesity and dementia.
"Research shows that obesity in midlife is a significant risk factor for dementia and these projections suggest that rising obesity could contribute to growing levels of dementia over the coming years," said Simon Ridley, of Alzheimer's Research UK. "Dementia already has an enormous impact on individuals, families and communities and it is concerning to see that this could become even greater than previously predicted."
It has been estimated that around 5% of adults over 65 years in the UK will be suffering from dementia by 2050. With the impact of rising obesity levels, that figure could rise to 7%.
While the short-term impact of obesity is apparent, these findings are evidence of the long term damage that obesity can cause. Pursuing a healthy lifestyle throughout our lives will contribute to better health as we grow older.
Researchers in the US have found that families with exceptional longevity also appear to have later onset of Alzheimer’s disease.
While the same percentage of people in families surviving to the age of 90 and beyond is prey to Alzheimer’s disease as others, the progressive brain disorder tends to develop later in life, researchers say.
The research team looked at more than 1,800 participants (1,510 family members and 360 spouses as ‘controls’) in the US-Danish Long Life Family Study, which evaluated genetics and non-genetic factors associated with extreme longevity.
The researchers, led by Stephanie Cosentino, assistant professor of neuropsychology at New York’s Columbia University Medical Center, found that older family members, with an average age of 88, had similar rates of mental decline as their spouses. However, sons and daughters, with an average age of 70, of exceptionally long-lived people had less than half the risk of Alzheimer’s disease than their similarly aged spouses.
“Overall, a higher proportion of family members than their spouses were dementia-free until age 90,” said Stephanie Cosentino. “After 95 years of age, however, exceptionally long-lived individuals had a high preference of dementia, pointing to a delayed onset of mental impairment in families with exceptional longevity.”
So, this protection only delays the onset of Alzheimer’s disease rather than preventing it. Individuals from long-lived families are therefore just as likely to suffer from Alzheimer’s disease as the rest of the population, just at a later age.
A recent announcement by a UK police force that it plans to fit dementia patients with GPS tracking devices has received a mixed response from campaigners.