There’s long been an anecdotal link between optimism and better health, but it’s only been a correlation, nothing that proves cause and effect.

Now there is new biological evidence to suggest that optimism can have a direct effect on health, including leading to a lower risk of developing cardiovascular disease and other chronic ailments and to fostering “exceptional longevity,” a category that a team of researchers used for people who live to 85 and beyond.

According to Dr. Alan Rozanski, one of the field’s primary researchers, “It’s never too early and it’s never too late to foster optimism. From teenagers to people in their 90s, all have better outcomes if they’re optimistic.”

Rozanski, a cardiologist at Mount Sinai St. Luke’s Hospital in New York, became interested in optimism while working in a cardiac rehabilitation program early in his career.

“Many heart attack patients who had long been sedentary would come into the gym and say, ‘I can’t do that!’ But I would put them on the treadmill, start off slowly and gradually build them up,” he said. “Their attitude improved, they became more confident. One woman in her 70s said her heart attack may have been the best thing that had happened to her because it transformed what she thought she could do.”

In a major analysis of 15 studies involving 229,391 participants published in JAMA Network Open, Rozanski and colleagues found that people who ranked high in optimism were much less likely to have a heart attack or other cardiovascular event and had a lower mortality rate from any cause than did pessimistic participants in the studies.

“The data are very consistent,” he said. “In every case, there was a strong relationship between optimism and a lower risk of disease. Optimists tend to take better care of their health. They’re more likely to exercise and eat better and are less likely to smoke.”

He added, “There’s also a biological effect. Pessimists bathe their bodies in damaging stress hormones like cortisol and norepinephrine all day long. Pessimism increases inflammation in the body and fosters metabolic abnormalities like diabetes. Pessimism is also on the way to depression, which the American Heart Association considers a risk factor for cardiovascular disease.”

A rosy outlook

Another researcher, Julia K. Boehm, a psychologist at Chapman University in Orange, Calif., said: “Optimism promotes problem-solving. It helps people deal with challenges and obstacles in more effective ways. Optimists tend to pursue strategies that make a rosy future a reality. Their hearts are not constantly pounding.”

Boehm was part of a research team whose findings were published in Circulation Research. They found that optimistic individuals were more likely to engage in healthier behaviors.

In contrast, she said, “Pessimists tend not to be open to the possibility of favorable outcomes, and the fight-or-flight response they experience amps up bodily systems that over a long period of time wear the body down.”

Lewina O. Lee, an assistant professor of psychiatry at Boston University School of Medicine, was in a group that analyzed several decades of data from women in the Nurses’ Health Study and men in the Veterans Affairs Normative Aging Study.

They found that, on average, those with higher levels of optimism, as measured by an assessment tool called the Life Orientation Test, lived longer. Among the most optimistic study participants, the women had a 50% greater chance and the men a 70% greater chance of surviving to age 85.

Facing challenges

Lee said that optimists are better able to reframe challenging circumstances and react to them in less stressful ways. They’re also more likely to embrace a can-do attitude toward life and persist in trying to overcome obstacles rather than think there’s nothing they can do about a bad situation, she said.

But is it possible for chronic pessimists to change their outlook? Rozanski said it is, and he cited the tenets of cognitive behavioral therapy, which can help people develop better coping skills and counter negative thoughts.

“Our thinking is habitual, not conscious, so the first step is to learn to catch yourself when thinking negatively and make a commitment to change how you look at things,” he advised. “Recognize that the way you’re thinking is not necessarily the only way to think about a situation. Just that thought alone can decrease the toxic effect of negativity.

“Step 2 is to substitute a better thought that is credible.” Rozanski likened the practice to increasing muscle strength, “gradually building a ‘muscle’ of positive thinking, for example, by trying to feel more grateful.”

The advice comes with a caveat, however: Don’t overdo it. Taken to the extreme, undue optimism can prompt people to ignore potential threats and take foolish chances.

How do you determine in which camp you fall? In simple terms, you’re an optimist if you expect more good things to happen to you than bad. On the other hand, no matter how good things are going at the moment, pessimists figure that if something can go wrong, it will.