America in the 1950s: the average life expectancy of a baby born in 1955 was 69 years old.

Forty years later -- in 1995 -- longevity in the United States was up to 76 years of age. 

The latest numbers from the National Center for Health Statistics put life expectancy at a new high.  A baby born in 2005 -- the latest year for records compiled in the U.S. -- can now expect to live at least to 78 years.

Robert Anderson of the National Center for Health Statistics says it is part of a decades-long trend. "Over a century, life expectancies [have] increased and I don't really have any reason to expect that it won't continue to do so."

Americans are living longer

Dr. Bruce Johnson is with the Dana-Farber Cancer Institute in Boston, Massachusetts. He says, "People are listening. They are getting themselves screened.  They are having their cancers identified at an earlier stage, when more effective treatments are available, and they are also seeking treatments to prevent it from coming back."

Americans also seem to have gotten the message that exercise is good for the body and brain, says dance teacher Lynne Osborne. "Use it or lose it.  [exercise often].  And that is very, very true."

While many Americans are living longer, they are not living as long as people in some other countries.  The United States is way behind Japan, Singapore, much of Europe and Jordan.  Researchers say socialized medical care, available to all in many countries, is a major factor.  In the United States, there are still a number of Americans who cannot afford the cost of private health insurance.

Those babies born a half century ago -- who are part of the baby boom generation born after World War Two -- are now getting old.  Experts say that may be why there has been an increase in Alzheimer's and Parkinson's, two diseases that often occur among the elderly.