The Resilience Project’s Founder, Hugh van Cuylenburg, says “An optimist is less likely to die from infection, cancer, heart disease, stroke and respiratory disease. Optimists are also likely to enjoy better levels of mental health. Science shows optimists are significantly more successful than pessimists in aversive events and when unforeseen circumstances get in the way of achieving important life goals.”
Professor Dianne Vella-Brodrick puts it well, “When it comes to health, positive psychology goes beyond the idea that wellness is simply the absence of illness and instead looks at the body as a complete system. Along with being disease-free – indeed, research shows that being optimistic is linked to improved heart health, – positive health is defined by less frequent and briefer ailments, greater recuperative ability and rapid wound healing. What’s more, people who experience positive emotions are more likely to live longer than people who are less happy (but not depressed)."
Professor Karen Hooker wrote, “We know that personality makes a difference in life outcomes, but the interesting questions are getting at how this works and under what conditions personality and outcomes, such as finding satisfaction with life or using health care services, are linked. One example is how personality affects coping with illness. We have known for some time that optimism is important for coping with and even recovering from serious illnesses, such as cardiovascular disease. High levels of optimism lead one to believe that there are things one can do to improve, and of course if you believe your actions will have positive health consequences, you are more likely to engage in positive health behaviors such as sticking to dietary guidelines, exercising, taking medications as prescribed and so forth. You are also more likely to be pleasant to be around and may, therefore, have a stronger social support system than someone who is not so optimistic.”
Norman Vincent Peale in The Tough Minded Optimist, wrote, "A thoughtful physician once told me, “If you want to contribute to the public health, I suggest you speak and write often on the necessity for hopefulness, optimism and expectancy. Put some real up-beat into people’s minds.” He explained how important is a happy and optimistic spirit in healing, and went so far as to say that pessimism in a patient reduces the natural healing processes by ten per cent. I asked how he could pinpoint a particular percentage figure and found him vague on this; but the idea is that when your mind is filled with optimism your natural re-creative forces are stimulated.
“Another physician, in reviewing his practice of some forty years, said that many patients would not have been ill and forced to consult him if they had simply practiced optimism, faith and joy. He said, “Quite apart from medication, if I can get them to lift themselves mentally for ten minutes every day into an area of pure joy—meaning undiluted optimism, I can get them well and keep them well.” So it seems that medically, also, optimism is important."