Work Your Brain, Live Longer

More than 2,000 years ago, Greek physician Hippocrates explored the mind-body connection and determined that our state of mind greatly influences our physical health. Since then, a growing body of scientific evidence has supported his claims. It turns out that those who see the glass half-full live longer, healthier lives.

"A positive attitude and laughter increase the neurotransmitters dopamine and serotonin. These neurotransmitters cause us to feel good, get things done, resist sugar and other carbohydrate temptations and sharpen our minds," said neurologist Vincent Fortanasce, author of "The Anti-Alzheimer's Prescription: The Science- Proven Plan to Start at Any Age" ($26, Gotham Books).

On the converse, those who see the glass as perpetually half-empty are at a greater risk for long-term illness and serious health problems.

"Anxiety and depression have been linked to poorer health and shorter lives," said Kate Flanigan Sawyer, co-author of "Longevity Made Simple: How to Add 20 Good Years to Your Life" ($14, Williams Clark Publishing) and director of the Heart and Health Prevention Center in Denver, Colo.

"Personality traits such as anger, hostility, irritability and gloominess increase the amount of stress in our lives, which can lead to a higher incidence of hypertension and heart disease," Sawyer explained.

When anxious or stressed, the nervous system releases hormones like adrenaline, which raises blood pressure and increases heart rate, and Cortisol, a stress hormone that suppresses the immune system.

"Even though the exact mechanism connecting the mind and physical health is not completely understood, we do know it's just as important to pay attention to the health of your mind as it is your body for a long, happy life," Sawyer said.

So find your happy place. Frequent mental stimulation, a strong social network and regular stress-reducing exercise are the keys to maximum joy -- and maximum health.