Nobody likes feeling stressed, but a new study provides even greater reason to practise relaxation techniques and try to reduce the amount of anxiety we feel – especially as we get older.
Researchers in the US have found that stress increases the likelihood that elderly people will develop the mild cognitive decline that often precedes Alzheimer's disease. The findings aren't saying that stress itself causes Alzheimer's, but rather that it's a risk factor for amnestic mild cognitive impairment (aMCI), a less severe but still noticeable decline in cognitive abilities that sometimes develops into Alzheimer's.
"Our study provides strong evidence that perceived stress increases the likelihood that an older person will develop aMCI," said Richard Lipton, a neurologist at the Albert Einstein College of Medicine and Montefiore Health System in New York. "Fortunately, perceived stress is a modifiable risk factor for cognitive impairment, making it a potential target for treatment."
Amnestic mild cognitive impairment, sometimes called isolated memory impairment, is a pre-dementia condition that progresses to Alzheimer's disease in about 10 to 15 percent of individuals with aMCI per year.
The researchers examined data on 507 people who were enrolled in the Einstein Ageing Study, a community-based cohort of adults aged over 70 who live in Bronx County, New York.
Starting in 2005, when none of the participants exhibited aMCI or dementia, the researchers began testing them on the Perceived Stress Scale (PSS), which measures psychological and chronic stress due to ongoing life circumstances, possible future events and other causes.
During the course of the study (3.6 years), 71 of the 507 participants were diagnosed with aMCI, and the researchers found that the greater the participants' stress levels, the greater their risk for developing the impairment.
For every 5 percent increase in their PSS scores, the risk of developing aMCI increased by 30 percent, and participants in the highest-stress segment (considered 'high stress') were nearly 2.5 times more likely to develop the impairment than those in the other four 'low stress' segments combined. The findings are published in Alzheimer's Disease & Associated Disorders.
Further research will be needed to verify the nature of this relationship and pre-dementia and confirm the results in a wider setting. But as scary as it sounds – after all, everybody experiences stress sometimes – the good news is that now we know about this link between stress and aMCI, it could help us to focus efforts on reducing stress as we get older and perhaps figure out ways that can better reduce the incidence of this occasional precursor to full-blown Alzheimer's.
"Perceived stress reflects the daily hassles we all experience, as well as the way we appraise and cope with these events," said Mindy Katz, one of the researchers. "Perceived stress can be altered by mindfulness-based stress reduction, cognitive-behavioural therapies and stress-reducing drugs. These interventions may postpone or even prevent an individual's cognitive decline."