LYNN NEARY, HOST:
This year in London, there was a one of a kind birthday celebration. It brought together people who had never met but have shard an experience for their entire lifetimes. Sixty-five years ago in 1946, thousands of British babies, all born within a single week, were selected to be part of a study, a lifelong study. They've been under the microscope ever since.
Reporter Geoff Brumfiel was there at the anniversary event.
GEOFF BRUMFIEL, BYLINE: It's a very civilized evening here at the British Library in central London. Silver-haired men and women mingle, making polite conversation over wine and hors d'oeuvres. You wouldn't know it to look at them, but they all have something special in common.
How old are you?
UNIDENTIFIED WOMAN #1: Sixty-five on Sunday.
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UNIDENTIFIED WOMAN #2: Sixty-five.
UNIDENTIFIED MAN #1: Well, we're both 65.
UNIDENTIFIED WOMAN #3: Sixty-five today.
UNIDENTIFIED WOMAN #4: Well I'm 65 too, by coincidence.
BRUMFIEL: Actually, it's no coincidence. Almost everyone in the room turned 65 this week. They were all born in 1946 and they're all part of the world's longest continuous study of human health. It began with their birth, which coincided with the birth of another great British institution: the National Health Service.
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UNIDENTIFIED MAN #2: This new health service will be organized on a national scale as a public responsibility.
BRUMFIEL: And it was in the spirit of public health for the public good that the study was set up. The new study would follow children with the help of a doctor who didn't like sick people.
RACHEL DOUGLAS: He found they became self-centered, whiney, moany(ph), demanding, really not terribly pleasant.
BRUMFIEL: That's Rachel Douglas, the widow of James Douglas who founded the study.
DOUGLAS: So he decided, what he'd like to do, rather than trying to cure them when they got ill, was to keep them from getting ill in the first place.
BRUMFIEL: And thus began the first British birth cohort - as these things came to be known. Over 5,000 babies were enlisted with their mothers' consent. As the children grew up, most stayed in the study. Participant Nicole Barnston says it just seemed natural.
NICOLE BARNSTON: This is something that I've always accepted. It's been all my life, you know, every so often you'll have a questionnaire or you have a medical or something. And so, I've never really thought about it in a way. It's just something that happens.
BRUMFIEL: So what do you learn following people over a lifetime? Diana Kuh is the third generation of researchers to lead the study for Britain's Medical Research Council. She sums it up this way.
DIANA KUH: The most significant of findings for me is that we were the first national birth cohort study to actually have evidence that childhood really matters for adult health.
BRUMFIEL: In fact, it mattered a lot. One of the first big results was that study members born into a poor households tested worse than equally bright children born into middle-class families. The finding reshaped British education and built the case for programs like Head Start in the United States. But it doesn't stop there.
As the cohort ages, more and more correlations are appearing between early life and later health.
KUH: So, one surprising one was how well women had done on the cognitive test, even at age eight had this quite robust association with when they reached menopause. It was, it seemed to be, either an early genetic or an early hormonal effect. And that's one of the puzzles that we're still actually trying to explain.
BRUMFIEL: Now, as the cohort reaches retirement, things are starting to get really interesting. Study members like Douncan Boulton are undergoing a battery of medical tests.
DOUNCAN BOULTON: Found out a number of things like all my heart valves leak or, you know, my bone density is perhaps not as good as it should be. But, hey, the guy said it doesn't matter, so I believe him.
BRUMFIEL: The information being gathered could help scientists to better understand the aging process and governments to manage their aging populations. It's such a unique opportunity that American researchers, like Emily Murray, have traveled here just to study the cohort even though the U.S. has plenty of cohort studies of its own.
DR. EMILY MURRAY: When they're 65, you know, that's when it starts to get interesting where if you started a cohort in the 1960s, they're not old enough to have things interesting to us.
BRUMFIEL: It may seem a little macabre to be studied as you grow old and die, but many feel like Sheila Lucas.
How do you feel about being followed to the grave here?
SHEILA LUCAS: I think its fine. I'm happy to be part of the piece of research, really. It's extremely important. Oh, saying it's a duty is rather heavy handed. But it's something you said you would do and then so you do it.
BRUMFIEL: In fact, 13 percent of the cohort has already passed away and others have left the study. But plenty more remain. Again, Douncan Boulton.
BOULTON: It's nice to know there are quite a lot of people still left. You know, you might think you were the last survivor.
BRUMFIEL: Reassuring, huh?
BOULTON: Yeah, very reassuring.
BRUMFIEL: And together with researchers, they're having a great party.
(SOUNDBITE OF SINGING, "HAPPY BIRTHDAY SONG")
BRUMFIEL: For NPR News, I'm Geoff Brumfiel in London.
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