Dear Doctor: Does outlook really matter when it comes to lifespan, as a recent study suggested? I'm not a wet blanket, but I don't have a relentlessly sunny disposition either.
Dear Reader: Let's say it's a gray, cloudy Monday morning. You're stuck in traffic, listening to the news of another atrocity in some distant land. Such a scenario would not in itself arouse feelings of optimism. Instead, an optimistic person might focus on feeling excited about his or her job, realize that the traffic is going to get better, and take solace in the fact that humanitarian efforts will be made to stop further atrocities.
In my own experience, I've seen pessimistic, unhappy people lead very long lives, and I've seen optimistic people's lives cut short by illness. That doesn't mean that, in the aggregate, optimism has no effect on lifespan.
Specific studies have looked for correlations between an optimistic outlook and cardiovascular disease, finding mortality benefits among those who had a more optimistic attitude. These studies used different scales to judge a person's level of optimism, with one common approach using a questionnaire about a person's approach to life. Some, for example, asked people to respond in either agreement or disagreement to statements such as, "Overall, I expect more good things to happen than bad."
A combined evaluation of many studies assessing the connection between optimism and physical health was reported in the Annals of Behavioral Medicine in 2009. Researchers measured physical health outcomes by rates of cancer, heart disease, infection rates, pain, diabetes and kidney failure. In the combined evaluation, the authors found a small correlation between better physical health and optimism, and an even smaller correlation between lower death rates and optimism.
A more recent study published in 2016 in the American Journal of Epidemiology followed 70,000 nurses and judged levels of optimism by how they responded to a questionnaire called the Life Orientation test. The women responded to 10 different statements such as, "In uncertain times, I usually expect the best," "I rarely count on good things happening to me," and "I'm always optimistic about my future."
The researchers ranked women into four quartiles, from lowest to highest, and found that those who were most optimistic had a 26 percent decrease in the death rate over the study period compared to those who were the least optimistic. This was after adjusting for depression, because some people who aren't optimistic may actually be depressed. The decrease in death rates was seen for deaths caused by cancer, strokes, heart attacks and infections.
One problem with the study is that women who were the most optimistic had lower smoking rates, were more physically active, had more education and were more likely to be married. Each of these factors is associated with greater longevity. The authors say they adjusted for these factors, but fully adjusting for them is difficult. Another problem with the study is that the study might not reflect correlations within the general population, in that 97 percent of the women identified themselves as white.
Overall, the study found what appears to be a correlation between optimism and a better cholesterol level, higher blood levels of antioxidants and improvements in one's immune system.
My own feeling is that optimism is less about sunniness than about hopefulness. This hopefulness helps people get through the bad times, because they realize that good times are ahead. And, overall, such people seem to have healthier habits that can help lead to greater longevity.
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