When it comes to living longer, your perception of your health may trump the digits on that blood pressure cuff.
What does it take to get a cake with 100 candles? As you age, your responses to global questions (subjective ones such as "How's your health?") are significantly better predictors of mortality than hard data, such as your blood pressure or blood sugar levels, notes a new study published in Current Gerontology and Geriatrics Research.
Even genetics have only limited influence on longevity—their impact maxes out at about 30 percent, says lead author Leonard Poon, a gerontologist at the University of Georgia. Factors like exercise and diet matter too, but subjective info—often ignored by researchers in favor of quantitative medical data—makes up a sizable slice.
Attitude frequently interacts with health factors, Poon says: If you think your body is in top shape, for example, your immune system will more effectively fight back when a bug attacks. There's no magic ticket to the centenarians club, but some characteristics—powerful yet tough to measure—seem to hold special weight in maintaining vigor.
Four to Score (More Birthdays)
Are you open to new experiences?
Personality traits such as being receptive to the unfamiliar may directly explain why life for some centenarians is still as enjoyable and independent as it was in their younger years, Poon's study finds. Having a wealth of experiences may give you the skills to adapt to new problems.
Are you optimistic?
"If you're more optimistic, you're more likely to make changes" that contribute to good health, explains John Santrock, a longevity researcher at the University of Texas. "Say I'm overweight. If I'm pessimistic, I'll think, 'Why should I change my behavior? I'll just fail.'" Sunnier types believe success is possible.
Are you conscientious?
Centenarians who are more conscientious—i.e., more organized, more careful, and less impulsive—consistently report better health. Cautious qualities naturally affect well-being, Santrock adds: If you think things through, you're less likely to pick up damaging habits such as smoking, and you may take better care of yourself, say, by watching your diet.
Do you have close relationships?
Social support means a larger network of caregivers when you need them, Poon says. But even before you reach old age, relationships abet health. Isolation ups stress levels, and "as people age, stress hormones stay elevated in their bloodstream longer," Santrock says. "High stress levels are associated with a range of diseases." Maintain ties, and your hundredth birthday party may be a blowout.