2009-09-10 Are Your Friends Making You Fat
Are Your Friends Making You Fat?
In the reunion photos, there is only one person who visibly degrades in health as the years pass: a boyish-faced man sporting mutton-chop sideburns. When he was younger, he looked as healthy as the rest of the crowd. But each time he showed up for the reunion, he had grown steadily heavier, until the 2003 photograph, when he looked straightforwardly obese, the only one of his size in the entire picture. Almost uniquely among the crowd, he did not remain friends with his old classmates. His only point of contact was the reunions, which he kept attending until he didn’t show up last year. It turned out he’d died.
The man’s story struck me as particularly relevant because Eileen and Joseph are part of a scientific study that might actually help explain his fate. The Bellolis are participants in the Framingham Heart Study, the nation’s most ambitious project to understand the roots of heart disease. Founded in 1948 by the National Heart Institute, the study has followed more than 15,000 Framingham residents and their descendants, bringing them in to a doctor's office every four years, on average, for a comprehensive physical. Each time the Bellolis are examined, every aspect of their health is quantified and collected: heart rate, weight, blood levels and more. Over the decades, the Framingham study has yielded a gold mine of information about risk factors for heart disease; it was instrumental, for instance, in identifying the positive role of "good" cholesterol.
But two years ago, a pair of social scientists named Nicholas Christakis and James Fowler used the information collected over the years about Joseph and Eileen and several thousand of their neighbors to make an entirely different kind of discovery. By analyzing the Framingham data, Christakis and Fowler say, they have for the first time found some solid basis for a potentially powerful theory in epidemiology: that good behaviors – like quitting smoking or staying slender or being happy – pass from friend to friend almost as if they were contagious viruses. The Framingham participants, the data suggested, influenced one another’s health just by socializing. And the same was true of bad behaviors – clusters of friends appeared to "infect" each other with obesity, unhappiness and smoking. Staying healthy isn’t just a matter of your genes and your diet, it seems. Good health is also a product, in part, of your sheer proximity to other healthy people. By keeping in close, regular contact with other healthy friends for decades, Eileen and Joseph had quite possibly kept themselves alive and thriving. And by doing precisely the opposite, the lone obese man hadn't.
- 2009-09-14 On Norms (OMB Blog): the Obama administration's Office of Management and Budget pays attention to science. This seems good. -W.
 shorter text
“...they have for the first time found some solid basis for a potentially powerful theory in epidemiology: that good behaviors – like quitting smoking or staying slender or being happy – pass from friend to friend almost as if they were contagious viruses.”