(CNN) You don't have to be a Monty Python fan to whistle along with Eric Idle as he croons "Always Look on the Bright Side of Life" while contemplating death on a cross.
British satire aside, focusing on the upside of life could easily be the theme song for research focusing on a key component of longevity: optimism.
Optimism doesn't mean ignoring life's stressors. But when negative things happen, optimistic people are less likely to blame themselves and more likely to see the obstacle as temporary or even positive. They also believe they have control over their fate and can create opportunities for good things to happen in the future.
A new study published Monday finds men and women with the highest levels of optimism had an 11% to 15% longer life span on average than those who practiced little positive thinking. The highest-scoring optimists also had the greatest odds of living to age 85 or beyond.
The results held true, the study found, even when socioeconomic status, health conditions, depression, smoking, social engagement, poor diet and alcohol use were considered.
"This was the first study to look at the impact of optimism on exceptional longevity, which is defined as living to age 85 or more," said lead author Lewina Lee, assistant professor of psychiatry at Boston University's School of Medicine. The study was published in the journal Proceedings of the National Academy of Sciences.
The study found women with the highest levels of optimism had 1.5 greater odds of living to 85 or beyond, compared to those with the lowest levels of optimism. Highly optimistic men had 1.7 greater odds of living to that age over the more pessimistic. Again, those relationships remained true even after adjusting for health behaviors.
How would an optimistic attitude help you live a much longer life?
"Optimistic individuals tend to have goals and the confidence to reach them," Lee said. "Those goals could include healthy habits that contribute to a longer life."
Prior research has found a direct link between optimism and healthier diet and exercise behaviors, as well as better cardiac health, a stronger immune system, better lung function, and lower mortality risk, among others.
"Optimism is one important psychological dimension that has emerged as showing some really interesting associations with health," said neuroscientist Richard Davidson, professor of psychiatry at the University of Wisconsin-Madison and the founder and director of the Center for Healthy Minds.
"And I would add other positive attributes, such as mindfulness, compassion, kindness, and having a strong sense of purpose in life," Davidson added.
Studies of twins finds only about 25% of our optimism is programmed by our genes. The rest is up to us and how we respond to life's lemons.
If you tend to be a sour puss about the stresses in your life, don't worry. It turns out you can actually train your brain to be more positive.
"There is research which indicates that optimism can actually be enhanced or nurtured through certain kinds of training," Davidson said. "So, it does open the possibility that cultivating optimism and other positive attributes may lead to significant improvements in health-related outcomes, including longevity."
At Davidson's Center for Healthy Minds, researchers studied the brains of Tibetan Buddhist monks recruited by the Dalai Lama and found startling results: Tens of thousands of hours of meditation had permanently altered the structure and function of the monks' brains.
But you don't have to devote your life to meditation to see change, Davidson said. He pointed to the results of a randomized controlled trial of people who've never meditated before.
Using direct measures of brain function and structure, Davidson found it only took 30 minutes a day of meditation practice over the course of two weeks to produce a measurable change in the brain.
"When these kinds of mental exercises taught to people, it actually changes the function and the structure of their brain in ways that we think support these kinds of positive qualities," Davidson said. "And that may be key in producing the downstream impact on the body."
There are simple mental exercises that any person can do to nurture an optimistic outlook.
Imagine your best possible self
One of the most effective ways to increase optimism, according to a meta-analysis of existing studies, is called the "Best Possible Self" method. Interventions using this approach will ask you to imagine yourself in a future in which you have achieved all your life goals and all of your problems have been resolved.
One technique, for example, is to write for 15 minutes about a future day in your life in which you have accomplished everything you wish. Then spent five minutes imaging that reality. Practicing this daily can significantly improve your positive feelings.
In an 2011 study, students practiced the Best Possible Self exercise for 15 minutes a week for eight weeks. Not only did they feel more positive, the feelings lasted for about six months.
Keep a journal of positives
Many of us can easily recite a litany of negative things that have happened to us each day. But ask what went well, and we might stumble. That's why keeping a daily journal in which you list the positive experiences you had that day can help shape your outlook.
Be grateful
Taking a few minutes each day to write down what makes you thankful can improve your outlook on life. A number of studies have shown that practicing gratefulness improves positive coping skills by breaking the typical negative thinking style and substituting optimism. Counting blessings even lessened problem behavior in adolescents.
Practice mindfulness
One of Davidson's favorite mindfulness exercises cultivates appreciation.
"Simply to bring to mind people that are in our lives from whom we have received some kind of help," Davidson said. "Bring them to mind and appreciate the care and support or whatever it might be that these individuals have provided."
"You can spend one minute each morning and each evening doing this," he said. "And that kind of appreciation is something that can foster a sense of optimism about the future."
Like exercise, mindfulness will need to be practiced on a regular basis to keep the brain's positive outlook in good shape, Davidson said. But the effort is definitely worth it.
"This is really about nurturing the mind," he said. "And there is ample evidence to suggest that there are real psychological and physical health-related benefits."