Jan. 8 (HealthDay News) -- What if one therapy could help ward off addiction, depression, stress and even Alzheimer's, all the while keeping you slim and feeling great?

That mental-health "treatment" is as close as your own two feet -- exercise.

"Exercise improves blood flow to the brain, it helps the body detoxify, it puts you on a better cycle of physical behavior, and it leads to decreased stress. It also improves thinking and mental function and decreases your tendency toward addiction," said Dr. Marc Siegel, an internist at New York University Medical Center and an associate professor of medicine at the NYU School of Medicine in New York City.

With each new study, experts are getting a better understanding of the intimate connection between the health of the body and that of the mind. And exercise -- the body's key method of staying healthy -- appears to be crucial to mental health, too.

For example, "there's evidence that exercise is maybe the best non-pharmacological antidepressant we have -- studies have shown that it works better than some drugs. It's also a great anti-anxiety intervention," said James Maddux, a professor of psychology at George Mason University in Fairfax, Va., and an expert on the mind-body health connection.

Aerobic exercise such as running or swimming can lead to a healthy release of the body's natural opiates, neurochemicals called endorphins. These are natural stress-busters, Siegel said, but exercise's impact on stress goes "way beyond endorphins."

"Exercise is a ritualistic activity that redirects your energy," said Siegel, who is also the author of a book on worry and stress called False Alarm: The Truth About the Epidemic of Fear. "Stress is a build-up of inactivity, of over-thinking without release," he said. "But exercise gives you a physical release that diminishes that psychic frustration."

For many people, exercise also provides a valuable sense of control over their physical health. "It's that sense of a loss of control that can lead to stress," Siegel said. And physical activity -- especially when individuals join sports clubs, teams or have workout partners -- also increases socialization, which has been proven to boost mental and physical health and increase lifespan.

Regular workouts may even help smokers beat their addiction, researchers say.

For example, one study from Brown University found that women looking to quit smoking who engaged in a vigorous exercise program were more than twice as likely to have stayed away from cigarettes for at least one year, compared to women who simply took part in a smoking-cessation program without exercise.

The Brown team believes that exercise may have helped smokers deal with the stress of quitting. As an added bonus, the study also found that exercising ex-smokers were able to stave off much of the weight gain typically associated with quitting smoking.

A fit, active body may even help reduce risks for Alzheimer's disease by improving cerebrovascular blood flow, experts say.

"There's no question that exercise improves blood flow to the brain," Siegel explained. One recent U.S. study found that seniors who engaged in some form of minimal exercise at least three days a week cut their risk of developing Alzheimer's and other forms of dementia by as much as 30 percent to 40 percent.

So, the advice from experts: Get out there, and get active.

"Exercise is clearly a discipline or ritualistic activity that you can use to break your cycle of worry and get on a path toward better health," Siegel said.