Stress is a killer -- for both the body and the brain.
Over time, chronic stress can contribute to a host of negative health outcomes, including heart disease, depression, diabetes and obesity. And according to new research, high stress levels late in life can contribute significantly to the development of Alzheimer's disease.
Neurologists at Albert Einstein College of Medicine and Montefiore Health System in New York found that older adults who reported experiencing high stress levels were twice as likely to develop the memory problems that tend to precede full-blown Alzheimer's.
"Our study provides strong evidence that perceived stress increases the likelihood that an older person will develop MCI," Dr. Richard Lipton, a neurologist at Einstein and Montefiore and senior author of the study, said in a statement. (MCI, or mild cognitive impairment, is a known precursor of Alzheimer's.)
Since we can change the way that we perceive stress, Lipton explained, stress management could be an effective treatment option.
For the study, the researchers collected data from 507 adults aged 70 or older living in New York who were participants in the Einstein Aging Study. They analyzed 10 years' worth of data on each participant's perceived stress levels, memory function and other cognitive skills.
The participants were also screened for mild cognitive impairment, which is diagnosed based on recall tests and self-reports of forgetfulness. Of the participants, 71 were diagnosed with MCI.
The higher the participants' stress levels, the more likely they were to develop MCI: For every 5-point increase in their perceived stress level rating, their risk of developing MCI increased by 30 percent.
The findings were published online Dec. 11 in the journal Alzheimer Disease and Associated Disorders.
Previous studies have shown that stress has a negative effect on memory, but the findings are the first to demonstrate a dramatic effect of later-life stress on Alzheimer's risk.
"In response to stress, blood pressure goes up and stress hormones are activated," Lipton explained. "These stress hormones... may interfere with brain structures involved in memory, including the hippocampus."
Additionally, Lipman said, stress may activate pathways in the brain that involve toxic proteins that play a significant role in the development of Alzheimer's.
In the mounting public health battle against Alzheimer's, these findings suggest that stress reduction may be a powerful means of delaying or even preventing the disease.
The next step for the researchers is to determine whether stress management interventions -- including cognitive behavioral therapy, meditation, yoga, massage or other methods -- reduce an individual's risk of later developing mild cognitive impairment.
"There is no way to escape stressful life events and daily hassles," Lipton said. "What may matter is how we perceive and manage those events."