Before you worry about the amount of cholesterol in a pat of butter or jog that extra mile, suggests a professor at the Johns Hopkins University School of Public Health, consider these suggestions for prolonging life:
Fasten your seat belt. Wear a helmet when bicycling. Store a gun and its bullets separately.
While most Americans realize that a healthy diet and regular exercise may postpone death due to illness, hundreds of thousands never reach old age because they fail to take such precautions against injury, according to Hopkins professor Susan P. Baker.
She is the principal author of the just updated "Injury Fact Book," an exhaustive study of injuries based, among other things, upon eight years of U.S. death certificates.
For more than four decades of life -- from ages 1 to 44 -- injuries are the leading cause of death among Americans, according to the public health statistics. Injuries claim more than 153,000 lives each year. Two-thirds of that toll results from unintentional causes -- motor vehicle crashes or falls, for example. One-third is a result of suicide or homicide.
While the death toll from injury has fallen throughout the 20th century, progress has been far more rapid against dangerous illnesses, such as typhoid, polio, influenza and measles.
Many of the more than 100,000 Americans who die of unintentional injuries each year could be saved through such simple acts as fastening safety belts.
"Injuries are not accidents. Injuries are not random. They are not chance events," Professor Baker said.
"They are predictable, they are preventable."
Among the study's findings:
* Seat belt use is least common among people who are at greatest risk of being in crashes: teen-age drivers, those who drink and drive, those who exceed the speed limit and run red lights.
* Cigarettes are the leading cause of fatal house fires.
* The number of children from birth to age 4 who die of poisoning each year has fallen dramatically, from 445 in 1960 to 59 in 1988. (Child-proof caps, poison control centers and reformulation of pain remedies to remove aspirin are credited for the decline.)