December 18, 2012
Expert Uses ‘Microlives’ To Highlight Link Between Lifestyle And Longevity
redOrbit Staff & Wire Reports - Your Universe Online
While overindulgence is an almost inescapable part of the holiday season for even the strongest of wills, a new study uses a concept known as "microlives" to help understand how those gluttonous indiscretions can shave hours off of your life expectancy.
In a Christmas article published online in the British Medical Journal (BMJ), researchers say that activities like smoking, having one too many drinks or gorging on red meat can trim the length of your life by a half hour each time. And on the flipside, they say that curbing alcohol intake, consuming lots of fresh produce and exercising can help tack on additional hours to your sojourn on planet Earth.
In an effort to simply and directly communicate the relationship between rapid ageing and lifestyle choices , statistics guru Professor David Spiegelhalter of the University of Cambridge invented a concept that he calls “microlives,” or half-hour increments of life expectancy. Each microlife represents 30 minutes — or about one-millionth — of the life expectancy for adults after the age of 35.
By collecting statistics from a range of population-based studies, Spiegelhalter has calculated that we can lose one microlife every time we indulge in more than one alcoholic drink or cigarette, eat a greasy fast-food meal or lazily lounge in front of the television for two hours. However, he also says that we can reclaim these lost microlives by limiting ourselves to one drink per day, loading our plates with fresh veggies, exercising or even taking cholesterol-lowering medications like statins.
Spiegelhalter also points out that there are a number factors that affect our microlife count which are outside of our control. For instance, simply being born a female can earn you an additional four microlives per day, while factors like nationality and year of birth can add or subtract tens of microlives each day.
The Cambridge professor believes that the concept of microlives could prove to be a valuable tool for helping the general, non-academic population to understand how chronic health risk factors affect our longevity. He says that he borrowed the idea of the microlife from the “speed of aging” concept that has been successful in helping smokers to kick the habit.
"So each day of smoking 20 cigarettes (10 microlives) is as if you are rushing towards your death at 29 hours rather than 24," he explained.
Spiegelhalter admits that this method has a number of limitations. They are based on a number of assumptions that are not always correct, and they represent very rough approximations that cannot be simply plugged in to a calculator to figure out how long you can expect to live.
Still, he believes that the idea of microlives can help people to gain a general understanding of the long-term consequences of their lifestyle choices in the here and now. Almost all humans, Spiegelhalter explains, have a tendency to engage in what is known in economics and psychology as “temporal discounting,” whereby we treat future events as less important because they are far away. Thinking in terms of microlives, he believes, is just one way to counteract the effects of temporal discounting.
As to whether the microlife concept will have any practical effect on the way people live, Spiegelhalter says: "Of course, evaluation studies would be needed to quantify any effect on behaviour, but one does not need a study to conclude that people do not generally like the idea of getting older faster."