The Decision Tree: Taking Control of Your Health in the New Era of Personalized Medicine

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Living by Numbers

How a Lot of Science and a Little Self-Awareness Can Give You Control of Your Health

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AVIATION HAS KITTY HAWK. Biology has the Galapagos Islands. And medicine, or more specifically preventive medicine, has Framingham, Massachusetts.

A small city of 65,000 people about 20 miles due west of Boston, Framingham appears at first an indistinct patch of New England suburbia. Take Exit 13 off the Massachusetts Turnpike, and you'll drive past the usual temples of American sprawl: a Shopper's World shopping center (among the first malls built in the United States), a Super Stop & Shop grocery store, and a Lowe's, all built in the same squat, stuccoed style and painted in the same tan-to-taupe palette that characterizes the rest of American consumerland. As you drive along Highway 9 toward Framingham's center, it's easy to miss the original town. Even the arrow on the sign that points toward "Downtown Framingham" makes only a half-hearted gesture in the right direction, as if it can't decide whether or not to recommend the place. But make the turn, and the town starts to hint at its more dignified origins; pass the requisite Revolutionary War statue, and you'll reach the stately brick and stone buildings of what must have once been a thriving town center. These days, though, like many neglected downtowns outdone by the interstate, Framingham's center is dotted with empty storefronts and tinged with sad neglect.

None of this hints at why Framingham actually matters. In the years after World War II, when the town was a far smaller place with a population of just around 28,000, Framingham became the epicenter of what would become one of the great experiments in medicine--an experiment that is still running quietly today. In 1948, the National Heart Institute chose Framingham as the place that would reveal the causes of heart disease.

At the time, the idea of studying a disease by studying a population was an altogether novel concept, and an urgent one. In the first decades of the 20th century, most infectious diseases were eliminated from the United States and other industrialized nations. Cholera, diphtheria, typhoid, malaria, tuberculosis--all the diseases that had plagued mankind for centuries were largely banished from our shores as vaccines, antibiotics, and sanitation did their work. The result was profound: The average life span for an American male increased from 46 years in 1900 to 61 by 1940, while the average for women increased from 48 to 65.

But as remarkable as the elimination of infectious disease was, it didn't eliminate disease entirely. In fact, it revealed a new, unknown sort of disease, one that seemed to fester beneath the surface until it struck. A stunning 36 percent of Americans died of just two conditions in 1940: heart disease and stroke. But unlike with tuberculosis, it wasn't possible to lay the blame on a single pathogen. Medicine in postwar America had almost no idea what caused heart attacks or strokes or the other fatal events related to heart disease. They just happened. It was as if by eliminating epidemics of infectious diseases, medicine had unwittingly allowed new epidemics to kill thousands of other people.

By singling out Framingham, the National Heart Institute (known today as the National Heart, Lung, and Blood Institute) was taking a bold step: It would investigate heart disease as thoroughly, ambitiously, and successfully as the nation had fought World War II. Framingham then was just as much an Everytown, USA, as it is today. It had a mix of ethnic backgrounds: Irish, Greek, Polish, Italian. Its inhabitants smoked, worked in factories (GM opened a new plant in town in 1948), and, like other Americans, considered meat and potatoes a balanced diet. And when television came to town in 1948, they began to watch TV as well. They were, in other words, entirely typical citizens of postwar America.

The Framingham Heart Study, as it's called, began by recruiting as many townspeople as possible until it had enrolled 5,209 citizens--half of all of Framingham's adults, and nearly 20 percent of the total population. These citizens filled out a long questionnaire about their lifestyle, habits, and health; they tried to remember what their parents and grandparents had died of. They stripped down to their underwear and were given a thorough physical, including measuring their blood pressure and their lung capacity. A blood sample was taken and sent to the lab for tests. And every 2 years, these 5,209 citizens were called back for more poking, prodding, and reevaluation. The study has continued ever since. In 1971, it expanded to begin tracking a second generation of Framingham citizens--5,124 sons and daughters and their spouses of the original subjects. And in 2002, a third generation was signed up, 4,095 grandchildren. In Framingham, being one of the cohort is a point of family pride.

The size, ambition, and duration of the Framingham study--calling on thousands of townspeople and tracking them and their children and their children's children for more than 60 years--makes Framingham not an Everytown at all, but an exceptional experiment in science. The resulting pool of data has yielded insights into the human condition that were, prior to the study, entirely mysterious. The Framingham data have led to more than 1,200 published research papers, science that has broken ground on cholesterol and smoking and heart failure. It's because of Framingham that we know cigarettes increase the risk of heart disease. It's because of Framingham that we know high blood pressure can lead to stroke. And if not for Framingham, we'd have no idea that some cholesterol is good for you and some is bad. And it's not just heart disease. The Framingham data have been used to study osteoporosis, breast cancer, Alzheimer's disease, arthritis-- even sleep and happiness.

Most of all, Framingham, more than any other piece of research, has created the concept of health risks, the idea that behind every chronic disease lies a certain chance of developing that disease. It has given us the idea that we can and should anticipate disease, and that we might be able to identify what leads to chronic disease just as we try to identify the bacteria or pathogens that lead to infectious diseases. Indeed, the very term risk factors comes out of Framingham. Blood pressure, body mass index, cholesterol, triglyceride level--all these metrics today reflect the essential research gathered in the Framingham study.

This concept of risk is integral to the way our society tries to improve health. On a population level, reducing risk is the cornerstone of public health, and in your doctor's office, identifying individual risk factors is the backbone of preventive care. The study has changed not only our understanding of heart disease but also our understanding of how science should be practiced. The Framingham approach--population research--is now standard practice in public health, the basic framework of the science of epidemiology.

The Framingham Heart Study itself is run out of a building about a mile from downtown, a squat, two-level complex painted in the same shade of taupe as the malls near the freeway. Aside from that building, the only public acknowledgments of the town's significance are street signs posted here and there that hail Framingham as the Town That Changed America's Heart. But it's no exaggeration to add that it's the town that changed our concept of health as well.

IT'S A PLEASANT SPRING EVENING in San Francisco, and a group of supremely self-obsessed people has gathered in a downtown office to compare notes-- very, very specific and thorough notes. This group tracks pretty much anything and everything that one can imagine measuring, counting, or calculating about the human body. Blood pressure, weight, exercise, sleep, mood, menstruation--these folks track it all, down to the gram, the second, the microliter. Welcome to the quantified Self monthly meet up, a group of people who believe that, in the future, our data will say more about us than anything. And they want to get to that future first.

The meeting begins with some chatting over beer and chips, and then the crowd of about 40 people grab seats and listen to a series of brief presentations. One by one, people stand up and chronicle their chronicling. One man recounts his struggle with sleep apnea and how tracking his sleep patterns has become, for him, a matter of great urgency. "I was having about 48 episodes a night," he tells the group. "That's classified as severe. That amount could be fatal." After surgery, he says, he's down to about 40 episodes--better, but still in the danger zone.

Next, a married couple steps forward to share how they've been tracking their relationship. "We can count the frequency of having sex," the woman says. "But we haven't been able to find another quantitative metric to assess our relationship." She notes that the frequency of intercourse goes up when her weight goes down, and vice versa.

Another woman, by her count, is tracking 40 metrics on a daily basis: her sleep, her weight, her caloric intake, her exercise quantity and duration, her supplements, her headaches and nausea, the length of time she works, the time she spends with her kids, and six separate factors that correspond to mood. In the data, she says, she finds order and some calm. "When I don't get anything out of it anymore, when it starts to be a net negative, then I'll stop. But for now I find it helpful, and I'm learning about myself," she says. "I've learned that weight is an issue for me, and that I should exercise more. And I've learned that I'm a pretty good mother. These are worthwhile insights."

To be fair, this crowd isn't really obsessed (at least not all of them). More accurately, they are passionate believers that there is real meaning, quantifiable meaning, to be found in everyday life. They believe that in our daily actions of living and breathing we are shedding data all the time, whether we're aware of it or not, and that by capturing this data stream and analyzing it, we might grasp some insight. In approaching life by the numbers, they have found some new way to engage with their lives.

It is, to say the least, an interesting group of people. Yes, this being San Francisco, many of them could be described as nerdy. There are beards and stickered laptops and discussions about experiment design and open- source software. This is perhaps to be expected. The Quantified Self folks are, in the jargon of technology, classic early adopters: people who throw themselves into an experiment with numbers and gadgets, a group that enjoys playing around with possibility and tinkering with what might be done. They are geeking out, in other words, just like the guys who stand in line for iPhones and then rush home and take them apart to see how they're made. Except in this case, the iPhones are their own bodies.

The iPhone, in fact, plays a significant part in the Quantified Self experiment. There are dozens of applications, or apps--little software programs--that can be loaded onto an iPhone to help you track your weight or your exercise or your glucose level or your nutritional intake. And there are dozens of other gadgets and Web sites that likewise offer to help track this number or quantify that variable. There is Fuelly, a Web site that lets any driver turn into a "hypermiler," wringing every possible mile from a tank of gas. There is Tweet What You Eat, a service that lets people Twitter about what they've consumed (the tweets are entered into a personal database). There's Wakoopa, which tracks certain Web sites you visit. And Garmin, the global positioning system (GPS) tools company, has MotionBased, a GPS-enabled mapping system and exercise calculator for bicyclists. The Quantified Self crowd uses all of these tools and more with an enthusiasm most of us save for our hobbies or our relationships.

The Quantified Self folks sense an opportunity at hand: the wide availability of tools and cheap technology to measure and save most anything you can think of. Not all of the data will have meaning, but the point, at this early stage, isn't necessarily to start drawing conclusions, it's simply to gather the information. They're turning everything into a possible input. And what are the outputs? They'll turn up in due time.

AROUND THE CORNER from Number 10 Downing Street, the British prime minister's residence, is Whitehall Street, the epicenter of the UK government. Whitehall is lined with offices; the Treasury building is just down from the Foreign Office, the Department of Health is across the street, and so on down the road. Every day, Whitehall Street is packed with workers--bureaucrats and diplomats, secretaries and sanitation workers-- going about the business of government. Indeed, in the United Kingdom, "Whitehall" is as synonymous with "government" as "Washington" is in the United States. And that explains the name given to the Whitehall studies, two landmark pieces of public health research that provide an unusual perspective on the variety of factors that result in our health.

In 1967, just as the Framingham study was turning up its early conclusions about heart disease, a team of researchers from the London School of Hygiene and Tropical Medicine and University College London arrived on Whitehall Street to take a different crack at the same problem. The scientists, led by Michael Marmot, PhD, and Geoffrey Rose, wanted to know not what caused heart disease, but who was most at risk for it. They recruited more than 18,000 men from the British civil service (the agency that employs all the workers of Whitehall Street) between the ages of 40 and 64, when most heart attacks seemed to happen. These were the bookkeepers and administrators, the janitors and messengers that kept the government humming along, as well as the higher-level ministers and officials.

At the time, Britain was still a highly stratified society, marked by finely measured and codified class distinctions. The civil service was an especially perfect microcosm of this structure; as Dr. Marmot described it, it was "exquisitely stratified," like a bank or an insurance company or any "big white-collar corporation, only more so." This Stratification made Whitehall an ideal place to examine what role status might play in health-- especially since everyone had equal access to health care, provided via the National Health Service.