NEW YORK - An individual's personality and outlook on life may affect their risk of developing dementia, according to a new study from Finland.
Cynical distrust, anger or hostility have been linked to heart problems and inflammation in past research, and dementia may be another potential consequence of a bad attitude, researchers say.
"This makes sense, as previous studies have linked cynical distrust to e.g. lower socioeconomic position which itself is related to worse health outcomes," Anna-Maija Tolppanen told Reuters Health in an email.
Tolppanen, a researcher in neurology at the University of Eastern Finland in Kuopio, is the study's senior author.
It's also possible that health problems and behaviours associated with cynicism are contributing to dementia risk, the study team notes.
For their analysis, they defined cynicism as a person's belief that others are motivated by selfishness.
They looked at data on 1,500 Fins between the ages of 65 and 79 in 1997. The participants were examined for basic characteristics, attitudes and dementia in 1997 and again eight to 10 years later.
The researchers measured cynical distrust using an eight-question survey that scores cynicism levels on a scale from zero to 24, with higher numbers representing greater cynicism. They only had complete data on screening and diagnosis of dementia for less than half of the participants.
People who scored highest on the cynicism scale, between 15 and 24 points, tended to be heavier and were more likely to smoke, according to the findings published in the journal Neurology.
The highly cynical group was also the smallest one, containing 164 people, compared to 246 in the group that scored moderate cynicism and 212 in the least-cynical group.
But there were 14 dementia diagnoses in the most cynical group, compared to 13 in the moderately-cynical group and nine in the least-cynical group. That works out to the most cynical group having a risk of developing dementia more than three times that of the least cynical group.
This study does not prove that having a bad attitude causes health problems, Tolppanen said.
"But together with the previous research it strongly suggests that our personality may affect our health," she said.
When her team adjusted for socioeconomic position, age, sex, health status and smoking, those factors did not explain the difference in dementia risk between the most cynical and those who were less so.
She and her coauthors did not take into account individuals' engagement in social activities, which is beneficial for cognition, she noted, and might at least partly help to explain the association between dementia and personality.
The study was also unable to assess whether cynicism might represent a symptom, rather than a cause, in the earliest stages of dementia.
More research, with a larger group of people, is needed to better identify the role cynicism may play in dementia risk, Tolppanen's team writes in their report. But what's important, they say, is that attitudes and lifestyle can be modified - if doing so leads to better health and quality of life, it's worth a try.
Cynicism is not pessimism, rather it is a type of anger and mistrust directed at others, Dr. Hilary A. Tindle of the University of Pittsburgh School of Medicine told Reuters Health by email.
Tindle wrote the book "Up: How Positive Outlook Can Transform Our Health and Aging" in 2013.
Cynical people tend to smoke more, weigh more and exercise less, which can affect health, and they are less likely to follow medical advice or treatment regimens, she said.
They also tend to have higher stress responses and inflammation, which can accelerate heart disease, which in turn contributes to dementia risk, as small blood vessels in the brain are damaged, she said.
"I think in the near future cynicism and other psychological attitudes will be incorporated medically," as risk factors for dementia or other health problems, she said. But for now, there are other things people can do to decrease dementia risk.
"Some risk factors can't be changed, such as age, family or genetic history," H. Shellae Versey told Reuters Health by email. Versey is a postdoctoral trainee at the Institute for Health, Health Care Policy and Aging Research at Rutgers University in Camden, New Jersey.
But alcohol use, blood pressure, cholesterol, diabetes, obesity, depression and smoking are things that can be changed or controlled, she said.