July 22, 2011— -- Looking on the brighter side of life just may save your life, according to new research from the University of Michigan. In a study of 6,000 adults over 50 with no history of stroke, optimism was associated with significantly reduced risk of stroke, even when controlling for stroke risk factors such as high blood pressure, heart disease, hypertension and body mass index.
"Past research has linked optimism with a range of health benefits, including cardiovascular outcome," says lead author Eric Kim, a doctoral student in clinical psychology at the University of Michigan. The study was published Thursday in the journal Stroke.
Kim and colleagues drew on data from the National Institutes of Health Health and Retirement Study, analyzing the relationship between how participants scored on an 15-point optimism scale and how likely they were to suffer a stroke during a two-year follow-up period. Optimism was gauged by how stronlgy patients agreed with statements like: ""In uncertain times, I usually expect the best." They found that for each point increase in optimism rating, patients were 9 percent less likely to suffer a stroke. The reduction in risk is on par with the reduction seen in those making dietary changes, such as increasing fruits and vegetables in the diet.
Previous studies have linked antagonistic and disagreeable personalities with increased risk of heart attack and stroke, and a lack of pessimism with better heart outcomes and optimism in decreased mortality in those who have had heart attacks.
Given the mounting evidence that ties an optimistic attitude to a better outcome, these results hardly came as a surprise to researchers. What remains a mystery is exactly how a sunny attitude affects heart health.
Optimism could be working by reducing blood pressure, or the extent to which blood pressure spikes when stressed out, or it could be that those who are optimistic are more likely to engage in healthy behaviors such as good eating and exercise, says Dr. Redford Williams, a professor of psychology and neuroscience at Duke University who has studied the connection between personality traits and health extensively.
"We can't say for sure which thing is responsible for reduction in stroke, or as we have found in a recent study, a reduction in mortality among those with heart disease. It's pretty clear though, that something in optimism and related psychological characteristics is protective," he says.
Optimism Makes for Health, or Good Health Makes You Optimistic?
What's difficult to parse in all this optimism research is how optimism directly acts on either biological functions or health behavior. Because research hasn't yet confirmed a direct cause and effect with, say, an "optimism intervention" program, some doctors question whether these studies are perhaps capturing some other variable that goes along with optimism, such as adhering to medical advice.
Kim notes that previous research found that those who are higher in optimism are more likely to take vitamins and are more likely to adhere to a health program in cardiac rehab following a heart attack or stroke.
"People who are optimistic are more likely to listen to other people's advice and plan for the future and think they can change the outcome," says Dr. Joseph Broderick, professor and chairman in the department of neurology at the University of Cincinnati, but this doesn't mean that all optimistic people will have a lower risk of stroke. Broderick cautions that saying point blank that optimism reduces stroke risk is a "huge generalization" that hides a lot of the other factors that play into who does and who doesn't suffer from stroke or other health problems.
"Some people think that ornery, cranky people survive things in spite of it all because of a will to endure on, but these people are certainly not optimistic. Optimism can also work against making healthier decisions -- you can be optimistic and feel like everything will work out, and so you don't change your behavior for the better," he says.
Dr. Wendy Wright, medical director of the Neuroscience Intensive Care Unit at Emory University Hospital Midtown in Atlanta, agreed that morestudy is needed to parse out what's going on in the optimism-stroke relationship.
"It would be valuable to know ... if the results will be different if people try to 'manipulate' their levels of optimism to improve stroke risk," she says, especially considering that optimism is a medicine with no negative side effects: "Encourage optimism for its health benefits. It has no downside. Optimism is free!"