Recently, researchers at Massachusetts General Hospital and other academic centers set out to re-analyze 30 clinical studies involving more than 14,000 patients with heart disease to see whether having a positive psychological outlook affected their health outcomes.

One study after another in the medical literature had already drawn links between depression, anxiety, and stress and poor outcomes in such patients. Indeed, the data on depression were so demonstrably clear that, in 2014, the American Heart Association labeled it a “risk factor for poor prognosis” following acute coronary syndrome (a heart attack or unstable angina, for example).

But the question here was whether the flipside was true: Did “positive psychological constructs”—an optimistic outlook on life or a general sense of well-being—correlate with reduced mortality and even hospitalizations in those with established cardiovascular disease?

The short answer? Yes. In about two-thirds of the studies, the team found, the optimists fared better overall. Their report, published last year in the International Journal of Cardiology and available here in digital commons, is worth reading for both its careful analysis and clarity.

Optimism may even help prevent progressive heart disease to begin with, according to some research. One mechanism for this may be that it favorably changes a person’s lipid profile—it was associated with higher HDL (“good”) cholesterol and lower triglycerides, according to a 2013 study. Likewise, optimism and emotional well-being have been tied to improved immune function and better pulmonary function.

Which brings me to today. Believing the future will be better than either the present or the past is healthy. Believing that we can meet the challenges that life throws at us with ingenuity and resolve, with creativity and fortitude, with collaboration and good will, is healthy.

Taking the time to cast a vote in our already-great republic is a statement of optimism—a manifestation of the belief that our voices matter. And that, without question, is healthy.

Go out and vote. It will be the kindest thing you do for yourself today.

Clifton Leaf
@CliftonLeaf
clifton.leaf@fortune.com