The United States is currently experiencing the early stages of what is expected to be an epidemic of Alzheimer's Dementia. It is predicted that the current number of cases of Alzheimer's Dementia will double by 2020, and double again by 2040. Some unfortunate individuals are born with genes that strongly predispose them to developing Alzheimer's Dementia. However, this is true for only a minority of people. The familial, early onset form of Alzheimer's Dementia, which is so strongly linked to genetic abnormalities, is responsible for about five percent of cases of this illness. There is compelling evidence that the rest of us can escape, or at least postpone or diminish the severity of Alzheimer's, by improving our diets, maintaining our health and generally living healthier lifestyles. In most cases, it appears Alzheimer's Dementia can be avoided.
An underappreciated but scientifically substantiated fact is that getting a good education, challenging your mind, maintaining friendships and staying socially active can also help reduce the risk of developing Alzheimer's Dementia in later life. A new report in the American Medical Association journal, Archives of General Psychiatry, now compliments those findings in showing that simply having a sense of purpose in life can help to reduce this risk.
People who say their lives have a purpose are less likely to develop Alzheimer's disease or its precursor, mild cognitive impairment, a new study suggests. Purpose -- which the researchers define as a "psychological tendency to derive meaning from life's experiences and to possess a sense of intentionality and goal directedness that guides behavior" -- has long been thought to protect against adverse health outcomes. For example, it was recently reported to be associated with longevity, they noted. But there was little information on the association of purpose with Alzheimer's disease.
As the population ages and dementia becomes a more frequent diagnosis, there's increasing impetus to determine the causes of the disease, associated risk factors and how to prevent it, explained study co-author Dr. Aron S. Buchman, an associate professor in the department of neurological sciences at Rush University Medical Center in Chicago.
"There has been a lot of interest in psychosocial factors and their association with cognitive decline and dementia in later life," he said.
The study looked at the positive aspects of life and their possible effect on keeping dementia at bay, "looking at happiness, purposefulness in life, well-being and whether those kind of concepts are associated with a decreased risk of dementia," Buchman explained.
For the study, published in the March issue of the Archives of General Psychiatry, Buchman and his colleagues collected data on 951 older people without dementia who participated in the Rush Memory and Aging Project. The participants were asked to respond to statements such as: "I feel good when I think of what I have done in the past and what I hope to do in the future," and "I have a sense of direction and purpose in life."
After an average four years of follow-up, 16.3% of the people in the study developed Alzheimer's disease. Taking into account other factors that could account for Alzheimer's, the researchers found that people who responded most positively to statements about their lives were the least likely to develop the condition. Also, people who said they had more purposeful lives were less likely to develop mild cognitive impairment and had a slower rate of cognitive decline.
People who scored 4.2 out of 5 on the purpose-in-life measure were about 2.4 times less likely to develop Alzheimer's disease, compared with people who scored 3.0, the study found.
It's not known whether there is a biological reason for this finding, the researchers noted.
"One possibility is that, truly, somebody with high purpose in life might have a lower risk of developing dementia because of what's involved in purpose in life," Buchman said.
"The importance of the study," he added, "is this doesn't prove anything, but it points researchers in the direction of a link between purpose in life and cognition in late life. And now we have to find out what the biological basis is."
Still, the researchers think these findings could have implications for public health. "In particular, these findings may provide a new treatment target for interventions aimed at enhancing health and well-being in older adults. Purpose in life is a potentially modifiable factor that may be increased via specific behavioral strategies that help older persons identify personally meaningful activities and engage in goal-directed behaviors," the authors continue. "Even small behavioral modifications ultimately may translate into an increased sense of intentionality, usefulness and relevance."
"More social activity, more physical activity, higher cognitive activities, high purpose in life -- all these psychosocial factors seem to be linked with longer life, decreased mortality, decreased disability and provide important clues to a public health approach to try to increase independence in older people in later life," Buchman said.
Greg M. Cole, a neuroscientist at the Greater Los Angeles VA Healthcare System, wondered if the study is really measuring depression, not a purposeful life.
"I am unclear about how low scores on the purpose-in-life measures can be separated from mild depression," Cole said. "Depression has been repeatedly associated with increased Alzheimer's disease risk. So psychiatrists can make a distinction, but they seem likely closely related."
"One wonders whether this is a treatable psychiatric condition contributing to risk or an early symptom of decline," he added.
William H. Thies, chief medical and scientific officer at the Alzheimer's Association, said the new study "contributes to the literature that says there is a linkage between behavior and disease."
The study begs the question whether there is more Alzheimer's disease because more people have a lower sense of purpose, or is a lower sense of purpose an early, subtle, sign of dementia, he said.
"As we get better and better at having biological measures of the disease, we will shed a lot of light on these kinds of studies and whether these behaviors are simply a symptom or they are a place where you can intervene," Thies said.
Previous researches have shown that people that have long histories of Major Depression are twice as likely to develop Alzheimer's Dementia than those that do not. Reduction of stress further decreases the likelihood of dementia. Indeed, studies have shown that people who describe themselves as calm, relaxed, and self-satisfied can reduce their risk of Alzheimer's by one half. The East Boston study showed that every year of education after high school reduces the risk of Alzheimer's by 17 percent. A study at Duke University showed that having intellectually challenging work in adult life can reduce the risk of dementia even further beyond what a good education alone can do. In the Honolulu-Asia Aging Study it was found that maintaining friendships in later life significantly improves the likelihood of avoiding dementia. Another interesting study found that people already diagnosed with Alzheimer's Dementia who have large social networks of family and friends can maintain better cognitive function, even with higher levels of amyloid plaque damage in their brains, than can those without such social support. Scientific studies have also shown that people with deeply held religious beliefs and dedication to religious practices, regardless of the type, have a slower rate of cognitive decline when Alzheimer's dementia is already diagnosed. The current study now adds to this list of things we can do and ways we can approach life that can reduce our risk of dementia. Having a sense of purpose in life can reduce this risk.
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