The Boston Globe kindly rounded up three reputable studies suggesting that thinking old can make us old. And sick. In one study, a Yale researcher who tracked 440 adults found that
those who expressed gloomy views about elders when they were younger
were much more likely to suffer a heart attack, stroke, or other cardiac
problem 30 years later. Twenty-five percent of those in the negative
age-stereotype group had a heart problem, compared to just
13 percent in the positive age-stereotype group. The same researcher found that people older than 50 with more
positive self-perceptions of aging
lived 7.5 years longer than those with less positive views.
In another study, the Globe reports, a North Carolina State psychologist told people aged 60 to 82 that the researchers were trying to
understand why younger and older adults perform differently on memory
tests  and then asked each to write down his or her age. These elders
did not do as well as those who were simply told that adults of various
ages performed similarly on the test.
Finally, the Globe reports, a University of Kansas researcher found that baby boomers who thought of
themselves as older tended to have poorer recall on memory tests than
those who identified with younger people.
I think the reasoning is flawed. People know how they feel. Wouldn’t the results be the same if these people were right in their self assessment. A healthy person is more likely to give a more optimistic self appraisal while a less healthy person would be more pessimistic.
The reasoning is actually “scriptual” because God even says in His word that as a man thinketh in his heart, so is he”. The reason is what you believe, you will speak. Our words have that much power in shaping our destiny. A right perspective about yourself will inevitably change how you feel.
There are enough medical studies to prove that depression, stress, bitterness and unforgiveness releases toxins into our bodies causing sicknesses of all sort.
I’m not trying to teach “mind over matter” here. Just a right perspective goes a long way for your well being.