Five...

Americans could add years to their lives with just a handful of healthy habits, new study suggests.

The typical 50-year-old American can expect to live another 30 to 33 years. Based on the new study, those who maintain five lifestyle habits could add roughly a decade to that life expectancy.

The key factors include the usual suspects:

not smoking; eating healthy; exercising regularly; maintaining a normal weight; and drinking only in moderation.

"Our findings have significant public health implications, because they demonstrate the great potential of diet and lifestyle changes in improving life expectancy," said  Dr. Frank Hu,  chair of nutrition at the Harvard School of Public Health.

The habits are also realistic. For example, moderate exercise  such as brisk walking for 30 minutes a day -- was enough.

"That isn't a crazy amount of exercise." "It doesn't require you to join a gym."

So do something to help yourself.