Being the life of the holiday party may actually shorten your own lifespan. That’s the upshot of new research that has calculated the impact of even a single day’s overindulgence — in food, drink, tobacco, and other unhealthy habits — on how long you will live.
The study, published in the online version of the British Medical Journal, BMJ.com, found overdoing it with alcohol, smoking, eating red meat, as well as watching too much TV — during the holidays or any other time of year — can knock at least 30 minutes off your life for every day you indulge.
By contrast, each day you spend having just one alcoholic drink, eating plenty of fruit and vegetables, and exercising can add up to two hours to your life.
Lead researcher David Spiegelhalter, a statistician at the University of Cambridge, said his calculations are based on the idea that unhealthy lifestyles cause us to age more quickly, while healthy behaviors can slow down the impacts of growing older.
For the BMJ.com study, he expressed the daily effect of lifestyle habits in terms of "microlives" — half-hours of life expectancy — using health information and biostatistics from studies of the longevity of smokers and other people who engage in unhealthy activities.
For instance, he calculated lifelong smokers lose a single “microlife” — a half-hour of lifespan — for every two cigarettes they smoke. Similarly, being more than 11 pounds overweight, having a second or third alcoholic drink in one day, watching two hours of television or more daily, or eating a burger can shave an additional 30 minutes from your life.
On the other hand, microlives can be "gained" by sticking to just one alcoholic drink a day, eating fresh fruit and vegetables, exercising, and taking statins, he said.
Spiegelhalter acknowledged that his statistical calculations aren’t exact or applicable to everyone. They don’t, for instance, take into account an individual’s overall health, genetics, or other lifestyle factors that can affect longevity.
But he said his research allows the average person to make rough, but fair comparisons between the risks and benefits of certain behaviors, based on “a metaphor of speed of aging," which has been effective in encouraging cessation of smoking.
"[The calculations] bring long-term effects into the present and help counter temporal discounting, in which future events are considered of diminishing importance," he said. Despite his study’s limitations, he added, "a reasonable idea of the comparative absolute risks associated with chronic exposures can be vividly communicated in terms of the speed at which one is living one's life."