From Naked Mole Rats To Dog Testicles: A Writer Explores The Longevity Quest : Shots - Health News "Nature knows how to let animals live a very long time," says Bill Gifford, whose latest book is Spring Chicken, a look at the history of anti-aging schemes and current ways people try to live longer.
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From Naked Mole Rats To Dog Testicles: A Writer Explores The Longevity Quest

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From Naked Mole Rats To Dog Testicles: A Writer Explores The Longevity Quest

From Naked Mole Rats To Dog Testicles: A Writer Explores The Longevity Quest

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DAVE DAVIES, HOST:

This is FRESH AIR. I'm Dave Davies, in for Terry Gross, who's off this week. When my guest, journalist Bill Gifford, turned 40, his friends gave him a cake shaped as a tombstone with the words, my youth rest in peace, on it. As he reflected on his creeping memory lapses and the weight he'd gained, Gifford got interested in the timeless quest to turn back the aging clock, or at least slow it down. The result is his book, "Spring Chicken," which explores everything from some wacky pseudo cures for aging you'll soon hear about, to fascinating research that points to causes of aging at the cellular level. And there are some interesting phenomena in the natural world, like an animal that lives long, shows no increase in mortality with age, never gets cancer and never experiences menopause. Bill Gifford is a contributing editor for Outside Magazine and has written on science, health and fitness for WIRED, Men's Journal, The New Republic and other publications. He's the author of a previous book, "Ledyard: In Search Of The First American Explorer."

Well, Bill Gifford, welcome to FRESH AIR. You have some great stories in here about things people have done to fight the aging process. One of them involves a British professor, Charles-Edouard Brown-Seguard, if I have the name right.

BILL GIFFORD: Sequard.

DAVIES: Sequard, OK. What was the treatment he came up with in the late 19th century?

GIFFORD: Right, so he was one of the great scientists of the 19th century. He's regarded as the founder of endocrinology, the study of glands. And when he got to be about 70 years old, he wasn't feeling so hot, and he started to wonder why. And he thought that the answer had to do with something produced in the gonads. So he mixed up a little mixture of crushed-up dog testicles, testicular blood and semen - mixed it all up and injected himself with it for a period of about three weeks. And then in 1889, he gave a triumphant address to the Society of Biology in Paris, describing this experiment and how it had miraculously rejuvenated him, an old man. You know, he could work through the night now. He could lift much more weight. He could urinate farther - all these fantastic things, and people were horrified.

DAVIES: Well, as they well might be. I mean, (laughter) distance urination might not be the first goal in medicine. Did he live long?

GIFFORD: Well, he was already 70 or 71, and he lived about another five years. So he did pretty well for the 19th century. But whether the treatment extended his life span, difficult to say. I mean, they now think it was pretty much of a placebo effect.

DAVIES: Did anybody try it after him?

GIFFORD: Oh, yeah, absolutely. It became a cultural sensation, and people were mail-ordering - it was called the Sequard elixir. And all kinds of quacks set up mail order businesses where you could get 10 syringes for $2.50. There were songs written about it. It was written-up in all the papers. People went crazy. And he never made a dime off it, so...

DAVIES: Do you happen to know any of the songs for this elixir?

GIFFORD: One of them went - well, here's a verse. It said, the latest sensation's the Sequard elixir. It's making young kids of the withered and gray. There'll be no more pills or big doctor bills or planting of people in churchyard clay.

(LAUGHTER)

DAVIES: OK. Now, he did inspire some other treatments after that, right?

GIFFORD: Well, in a way, Sequard's elixir was kind of a precursor of the testosterone replacement and estrogen replacement therapies that are extremely popular right now. So, you know, he was on to something.

DAVIES: And there was this guy, John Brinkley, who had a rather more extreme approach. Tell us about him.

GIFFORD: Right, so - right, in between the elixir and the testosterone, there was an unfortunate intermediate step where a salesman named John Brinkley, down in Texas, began implanting goat testicles in worn-out, middle-aged men. And he did similar surgeries in women, and obviously, not a good idea. And many people died on his operating table, but he became fabulously wealthy. He was one of the richest men in the pre-depression era. He actually had a radio station down there. He was just across the border in Mexico 'cause they kicked him out of the country. But he had this hugely powerful radio station that broadcast some of the early country music stars.

DAVIES: Yeah, Border Radio was a phenomenon.

GIFFORD: Border Radio, right.

DAVIES: I mean, lot of people...

GIFFORD: He started it.

DAVIES: ...Crossed the border and then broadcast all kinds of stuff that would be, well, questionable, if not illegal, in the states.

GIFFORD: And paid for by quack testicle implants.

DAVIES: Now, clearly there's a long-standing fascination with trying to reverse aging. You describe visiting the - a congress of the American Academy of Anti-Aging Medicine in Orlando, Fla. in 2012.

GIFFORD: Right.

DAVIES: Is this a recognized medical specialty?

GIFFORD: Well, it's not recognized by the Board of Medical Specialties, which sort of arbites these things. But, you know, it is a very fast growing area of medical practice. There are anti-aging clinics popping up everywhere - places like Florida, California. So it's a growing area of practice. It's not officially recognized, but that doesn't stop anybody.

DAVIES: So tell us a little bit about the conference. I mean, who were the stars?

GIFFORD: Well, it was founded by these two doctors in Chicago who basically pioneered the use of human growth hormone as a treatment for aging back in the '90s. And a study had come out in about 1990, saying that older men gained muscle mass when they were on an exercise program and human growth hormone. And so they kind of took this and ran with it. And now, you know, 20 years later, older Americans inject themselves with about $1.4 billion worth of human growth hormone per year. And it costs, you know - the system of injections costs about 12,000 bucks - $10,000 to $12,000 a year.

DAVIES: You describe a guy named Dr. Life - Jeffry Life, right? Tell us about him.

GIFFORD: Dr. Life - he's - yeah, great guy. He's the guy in the back of the airline magazines. The grandpa - he looks like Larry David from the neck up. And from the neck down, he looks like a Chippendales dancer. I mean, he's got the most incredible torso you've ever seen in your life. And it's real, you know, I squeezed his bicep. And he was a - he was kind of a schlubby 57-year-old family doctor in northeast Pennsylvania. And he realized that he wasn't heading in a good direction, you know? He had diabetes. He had heart disease. So he changed his life. He ate better. You know, he quit eating fast food and all that kind of stuff, and he started weightlifting. So in the space of about eight weeks, he went from the schlubby guy to winning a bodybuilding contest - like, a body transformation contest run by a weightlifting magazine. So that's all pretty good, right? But then, he's become sort of the leading spokesman for human growth hormone use. And he insists that the only way he can keep looking like Dr. Life is by taking testosterone to sort of get himself to the testosterone levels of a 20-year-old - and also, human growth hormone.

DAVIES: Right. Now, as you describe in this conference that you went to in Orlando for - this anti-aging conference, a lot of people talked about hormone therapy - estrogen for women, testosterone for men - and the use of human growth hormone, which athletes have used. I mean...

GIFFORD: Right.

DAVIES: A substance that's banned, but which athletes have used to get better performance. What does the science tell us about the effectiveness of these things?

GIFFORD: Right. Well, the jury is still out on testosterone. There's a big clinical trial that should be reported later this year. But the scientists I spoke to feel that human growth hormone, I mean, far from reversing aging, actually accelerates aging. It turns on these pro-growth, pro-aging pathways. And, you know, there aren't clinical trials of this stuff because it's technically illegal for this use. But let's just say that the longest-lived laboratory mice had zero growth hormone. Their cells had no growth hormone receptors. So you know, if - human growth hormone might make you feel better for a short time, but it's very doubtful that it will lengthen your life and may do the opposite.

DAVIES: And does it have side effects?

GIFFORD: It does, things like edema, pre-diabetic symptoms. It has some cardiac impacts. And you know, one of the great fears is that it fuels the growth of cancer. So if you have cancer cells in your body, they just gobble up - you know, they just really respond to the growth hormone.

DAVIES: I want to just briefly go back to the conference in Orlando. Suzanne Somers was there. What does she do to stay young?

GIFFORD: Right. So she's sort of the leading spokesperson for the anti-aging movement. And again, you know, she looks pretty good. She does a lot of things right. She exercises a lot. She eats a good diet. But I think - and I think the scientific consensus would back this up - but I think she, you know, goes a bit overboard with the hormone replacement. And again, you know, the studies and the consensus says that that is safe for short periods of time in women under about 65. When you're talking about long-term use in women older than 65 - you get to 70, 75 - then that starts to really increase the cancer risk.

DAVIES: And she takes a whole bunch of other - what? - pills, supplements, vitamins.

GIFFORD: Right. I think in one interview, she said she takes about 40 supplements in the morning, and then another 60 at night, or something like that. And, you know, the supplements are a whole other story. But there's very little evidence for most of these supplements that you see marketed to older people. You know, supplements are very poorly regulated in this country. And there just aren't the same evidentiary standards that you need for, say, a drug. And, you know, there was just a recent case where the attorney generals of several states found that supplements sold in places like Wal-Mart had things like grass clippings in them, you know?

DAVIES: (Laughter).

GIFFORD: So - at least grass clippings aren't harmful, so you might as well take them. But you're wasting your money.

DAVIES: Bill Gifford's book is "Spring Chicken: Stay Young Forever (Or Die Trying)." We'll talk more after a break. This is FRESH AIR.

(SOUNDBITE OF MUSIC)

DAVIES: This is FRESH AIR, and if you're just joining us, we're speaking with writer Bill Gifford. He's written a book about the quest to fight aging. It's called "Spring Chicken."

You know, a lot of your book is this odyssey through, you know, science and beliefs of people who think they've figured out something about fighting aging. So let's talk about some of this. One of the things you looked at was people who are over 100 - centenarians. Do they have something in common that gives us insight into what - how we can fight aging?

GIFFORD: Well, some scientists think that they do. There's a saying that if you want to become a healthy 80-year-old, you have to live a healthy lifestyle, but if you want to be a healthy 100-year-old, you need the right parents. And so I spent time with one scientist in particular, a guy named Nir Barzilai, at the Einstein College of Medicine. He studies Ashkenazi Jewish centenarians, and the theory is that they have genes that protect them from the diseases of aging that the rest of us get. So they get to 100, and they don't have diabetes, they don't have heart disease, they don't have cancer. They've been protected somehow.

So the question is, do they have genes that protect them from these diseases, and what are the genes? And number three - can we make a drug that can kind of imitate the action of those genes? And they found - for example, there's one that has to do with cholesterol processing. And that not only gives you, you know, great results on your cholesterol test, but it seems to protect people from Alzheimer's disease. And there's an effort to develop a drug based on that - on that particular gene.

DAVIES: And how's it going?

GIFFORD: Good, it's in stage three trials. I believe Merck is working on it. The gene is called CETP.

DAVIES: You talked to a number of scientists who suggest that the heart of aging really is at the cellular level. There's this concept of senescent cells. You want to explain kind of what they are and what its significance is?

GIFFORD: Right, so in high school biology, we pretty much learn that cells divide and divide and divide forever, and that's kind of what they thought up until about 1960. But now they know that cells actually have a kind of lifespan. They have a limit to the number of times they can divide. And then what happens after that is they enter a state called replicative senescence. So they go from being these lively, dividing cells to basically retiring, right? And they're sitting there and they're kind of grumpy. And they've since learned that these senescent cells are basically toxic and they emit all these sort of potent, toxic cytokines that affect all the cells around them. It's sort of like certain people, you know, kind of bring everybody down.

DAVIES: (Laughter).

GIFFORD: Senescent cells are kind of the same way. And some people think that senescent cells actually drive much of what we recognize as aging.

DAVIES: Right, and if I recall the research right, they think that maybe only 15 percent of an old person's cells are senescent. So if you can...

GIFFORD: Or less, or less.

DAVIES: ...So if you can identify them and kill them - do we beat aging?

GIFFORD: Right, and that's very, very hard to do. But a team of researchers at the Mayo Clinic in Minnesota created a very, very fancy genetically engineered mouse that you could tag their senescent cells and then flush them out with a special drug. And so they did this study and they, you now, they wiped out all the senescent cells and the mice were sort of miraculously rejuvenated by this. You know, their health problems - they had cataracts and stuff like that - all that went away. So if you could somehow get to the point where we could all flush our senescent cells out, we'd be golden, they think.

DAVIES: And how's research going on something that would actually do that?

GIFFORD: Well, that's a long, long way off. It's very hard to identify and isolate senescent cells in human bodies. But, you know, one place where senescent cells seem to congregate is in fat tissue. So you would think the less fat tissue you're carrying around, the less of these inflammatory cytokines your body is sort of suffering.

DAVIES: Well, that's consistent with what we know about a lot of good advice, right?

GIFFORD: Yeah, well it's actually quite interesting because, you know, you think, well, it's not good to be really overweight or obese, but it's actually worse than that. Some of the scientists I talk to feel that having that vast amount of fat tissue is really like almost like having a tumor because it's such a potent - it's like an endocrine organ - and it affects, you know, all the rest of your body. So it's almost like an accelerated aging kind of situation.

DAVIES: Let's talk about exercise in terms of longevity. You describe meeting some amazing athletes that are in their 60s and 70s. Tell us about these folks.

GIFFORD: Right, I went to the National Senior Games in Cleveland in 2013. And that's like a sort of Olympics for older people. And I didn't really know what to expect, but I was blown away. I saw 85-year-olds sprinting down the track in the hundred meter dash just going as hard as they could and pretty fast. And, you know, doing the pole vault. I saw an old, you know - I don't want to say old. She wasn't old; she was 89. This woman throwing a - heaving a javelin a pretty healthy distance, you know? And so these people were clearly extraordinary. And so I started looking at the science behind what they did. And why - you know, why could they do this? Why could they still sprint and long jump at their age? I mean, the idea of doing a long jump makes my knees throb. And basically I found that exercise is this incredibly - apart from being, quote, unquote, "good for you," right? It's this incredibly potent. It's almost like a drug. It's almost like a medicine itself.

DAVIES: And it works how? How is it a medicine?

GIFFORD: Well, in a variety of ways. They've found that, you know, when you're - just as your fat is this endocrine organ, a muscle works the same way. So when you're exercising, your muscles are sending out signals to other parts of your body that basically say, hey, you know, we're - we might be chasing a woolly mammoth or something, so you guys better be performing at your best, right? And it also - they've also found that it stops the aging of your mitochondria - the little power plants in your cells. And it reverses the patterns of gene expression that are associated with aging, so it sort of switches your gene expression back to a younger profile. It's very powerful. I mean, if you could put exercise in a pill, you'd make a zillion dollars.

DAVIES: And does it need to be - I mean, rigorous exercise as we get older? I mean, do I need to be pole vaulting, or is walking OK?

GIFFORD: It has to be pole vaulting.

(LAUGHTER)

DAVIES: Oh, damn.

GIFFORD: No, not really. I mean, anything really is better than nothing. Basically, we evolved to move around, to run, to walk, to use our bodies and not to just sit around the way most of us do for most of the day. So there's kind of an idea of like use it or lose it. And that's really kind of programmed into our biology. The more you use your muscles, the more you're walking around, the more you're going to hang on to your muscle as you get older. And that's really important because, you know, muscle wasting with age is the second-leading cause of admission to nursing homes after Alzheimer's disease. So these athletes, you know, I'm sure their kids think they're crazy for pole vaulting. Like, Mom, why do you got to do that? But they're going to stay in a better functional health for much longer than they would otherwise.

DAVIES: Yeah, I forget who it was in the book that says sitting is the new smoking in terms of harm to your health.

GIFFORD: Right, right, and it's really true. I mean, public health experts are beginning to view inactivity itself as - if not a disease, as a serious risk factor. And there was a study in The Lancet in 2013 that found that inactivity was responsible for more than 5.3 million premature deaths every year. So you're talking about heart disease but also things like colon cancer.

DAVIES: Bill Gifford's book is "Spring Chicken." After a break, we'll talk about what evolution tells us about aging, whether slightly starving yourself will extend your life and we'll meet the amazing ageless naked mole rat. Also, David Bianculli reviews the latest TV offering from "Breaking Bad" creator Vince Gilligan. He says it's a lot of fun to watch. I'm Dave Davies, and this is FRESH AIR.

(SOUNDBITE OF MUSIC)

DAVIES: This is FRESH AIR. I'm Dave Davies, in for Terry Gross who's off this week. We're speaking with journalist Bill Gifford, whose new book is about efforts to reverse the effects of aging and what modern science tells us about why we age and what we can do about it. It's called "Spring Chicken: Stay Young Forever (Or Die Trying)."

I wonder what evolution tells us about aging. I mean, you note for example that, like, bats live really old. Mice don't. And there is this species of opossum where a bunch of the opossum that lived in the jungles didn't live very long. The same species that lived on an island lived to ripe old ages. Does this tell us anything about kind of whether we are evolved to age specifically?

GIFFORD: Well, there is a debate over whether aging is, you know, somehow programmed into evolution. But what we do know is that, you know, evolution cares about reproduction. It wants to get you to the age of reproduction and get your offspring launched into the world so your genes can be continued. So what happens is after that age, natural selection basically checks out. So that's why we have all these genes for things like, you know, our hair falls out. We get cancer. We get fat. So aging occurs in this selection shadow, it's called, after the period of reproduction, and that's when things just kind of go haywire. But where that point occurs varies greatly from species to species. So - and it sort of has to do with how long you're likely to live in the wild. Our ancestors, hunter-gatherers, they lived to about 25. You would have had kids. And some of us lived to be, like, 45-year-old grandparents. But after that, it really kind of didn't matter, so - whether we died at 35, 45. After that, it was just all sort of gravy.

DAVIES: Right. So in other words, evolution says we want genes that will allow you to reproduce healthy kids.

GIFFORD: Right.

DAVIES: After that - doesn't matter.

GIFFORD: It doesn't care.

DAVIES: It doesn't matter except for the propagation of your species.

GIFFORD: You're on your own, yeah. All right.

DAVIES: You have a chapter called Starving for Immortality, about evidence that suggests that eating less - I mean, like a lot less - could promote health and longevity. And you talk about a guy you meet named Don Dowden. Tell us about him and this whole idea.

GIFFORD: So he's a member of something called the Caloric Restriction Society, and they are people who - basically, they make a great effort to eat anywhere from 15 percent to 30 percent less than most of us eat. So obviously they're very skinny, but they're doing this because research for decades has shown that feeding mice and other animals a lot less makes them - seems to make them live longer. And so they're taking this and putting this into practice. And, you know, he was an 82-year-old retired lawyer, and he really - he just sparkled with energy. He was quite a guy.

DAVIES: So you said there's scientific research that looks into why this might be. What do we know?

GIFFORD: Right. Well, back to evolution. When we were hunter-gatherers, we didn't get three meals a day, right? We might get three meals a week. So the people who survived or the critters who survived are the ones who could go for pretty decent periods without food and then - even then, not eating a lot of food. So our biology is kind of tuned to survive famines, to survive low-nutrient conditions. And what that does is that sort of puts ourselves in a stress-resistance state that ends up prolonging life.

DAVIES: Interesting. There's also research that suggests fasting - that is to say - maybe eating every other day or eating very, very little one day and then a regular meal the next day can be helpful, right?

GIFFORD: Well, it's a very hard thing to study anything aging-related in humans because you need a lifetime to finish the study, but they did two very interesting studies of caloric restriction in monkeys. And one of them found that the monkeys lived 30 percent longer if you fed them, like, 25 percent less. But the other one ended up finding that the monkeys would live just as long if you fed them a good whole-foods diet and fed them just about 10 percent less. They lived just as long as the calorically restricted monkeys. So if you eat a better diet and don't eat too much, you're doing pretty well.

DAVIES: Yeah. It was interesting because in the first study, where they fed them a lot less, when people looked back at what they were actually fed, there was some not-so-great stuff in there. There was processed food. There was sugar. And you have this picture of the two monkeys, Canto and Owen. Canto's lean, looking good. Owen? Not so good (laughter).

GIFFORD: Right. And he's basically diabetic because they had been fed this diet of processed, refined foods, a lot of sugar - 30 percent sugar. But then as one of the researchers pointed out to me, you know, it was like they were eating at the ballpark, but that's what most Americans eat.

DAVIES: So if you eat less at the ballpark, you're better off (laughter) than a lot.

GIFFORD: Eat less at the ballpark.

DAVIES: But better to eat well and eat a little less.

GIFFORD: Yeah.

DAVIES: There's also this idea that deliberately exposing oneself to hardship and stress - or at least some kinds of it - is good for longevity. There's this guy Todd Becker. Describe his routine. What does he do?

GIFFORD: Right. So he believes in small amounts of stress as a way of life, right? And it sounds completely crazy, but there's actually a scientific basis to it. Let me - I'll just describe some of the things he does. He wakes up in the morning every day, and he takes a freezing cold shower. That's how he starts off. And then he'll skip lunch, right? And then at the end of the day, he'll go -without having eaten all day - he'll go for a trail run in Palo Alto, which is where he lives. So it sounds completely nuts, right? So I started looking into the science. And, you know, cold-water exposure actually has some pretty interesting effects. They've done studies of cold-water swimmers, and they're healthier than people who don't go cold-water swimming. And he actually persuaded me to jump into Half Moon - the science was so good, he persuaded me to jump into Half Moon Bay with him outside San Francisco on about a 40-degree day...

DAVIES: How'd that go?

GIFFORD: ...Which I'm not going to do again.

DAVIES: (Laughter).

GIFFORD: I'm not doing it again, but it was great (laughter).

DAVIES: It was great? Really?

GIFFORD: Yeah, yeah, it was very exciting - for six minutes. But the idea is this concept of hormesis, right? And that's the stress response, and that's another thing we have hardwired into our biology. Organisms that are exposed to stress, in certain ways, respond to it and become stronger. And one obvious example is exercise, right? You stress out your muscles. You lift a weight or whatever. They're damaged, and then they come back stronger. But then on the cellular level, it also works. It has an effect of almost like cleaning up or reorganizing your proteins so that they're in better shape.

DAVIES: Now, does that go for all kinds of stress? I mean, like, you know, the cranky boss who harasses you or, you know, the...

GIFFORD: No.

DAVIES: ...Unrequited love for your girlfriend? No (laughter).

GIFFORD: Unrequited love might be good for you in the long run if it makes you a poet or something, but, no, chronic long-term stress and psychological stress is not good and, you know, bad for your heart and all the rest so - this is short-term controlled stress that we're talking about.

DAVIES: And we're kind of talking about physical discomfort, right? As opposed to...

GIFFORD: Yeah, yeah.

DAVIES: ...Depression or anxiety?

GIFFORD: Right, right.

DAVIES: You write about naked mole rats. Tell us about that.

GIFFORD: Right. So that is the most bizarre and weirdly cute animal I think I've ever encountered in my life. They're little critters. They live underground. They're from Africa, and they live in kind of a colony. And they're this - I held one in my hand. She was the size of about a mouse - between a mouse and a rat -and she was 28 years old, whereas a mouse lives to about 2 years old. So this was like a - you know, in human terms, a 600-year-old person? Woman? And she was pregnant.

DAVIES: Wow.

GIFFORD: So they have these tremendously long life spans. They have huge amounts of oxidative stress in their bodies, and it does not affect them at all. Somehow they can survive this.

DAVIES: What does that mean? What does that mean - oxidative stress?

GIFFORD: Well, so that's a chemical thing. You know, you hear about antioxidants and free radicals. Free radicals are like unpaired oxygen molecules and they rampage around, and they're very reactive, and they cause all kinds of chemical damage. And it used to be thought that this drove the aging process. This was the first real theory of aging - oxidative stress. And it's since, over the decades, it's been sort of discredited or it's faded away because of things like the naked mole rat, which can survive to a very, very old age with huge amounts of oxidative stress.

DAVIES: And what's remarkable about them, if I have this right, the females do not get menopause. They continue to reproduce into old age. They don't get cancer even if you smear them with a carcinogen and - I think you've heard...

GIFFORD: Right.

DAVIES: ...It's like suntan oil.

GIFFORD: Right. They paint them with toxic chemicals, and they're just fine. So they - so I think it goes down to the cellular level again. They have these mechanisms in their cells that just - it's like a repair mechanism, right? So they survive a lot more damage and they live a lot longer.

DAVIES: Is there anything we can learn from their cellular mechanics and structures that will help us?

GIFFORD: Well, they recently sequenced the mole rat genome, so they're looking pretty hard for whatever that might be. On the other hand, they might just be an anomaly. It might just be one weird critter. We don't know. But what the point is that nature knows how to let animals live a very long time, but it all has to do with - back to this age of reproduction thing. There's no point in creating a mouse that's going to live for 20 years when your typical mouse lives for about six months before it gets eaten.

DAVIES: And the mole rats really have no predators where they are.

GIFFORD: No, they live underground. It's dark. It's safe. There's nobody else down there.

DAVIES: We're speaking with Bill Gifford. His book about fighting the aging process is called "Spring Chicken." We'll continue our conversation in just a moment. This is FRESH AIR.

(SOUNDBITE OF MUSIC)

DAVIES: This is FRESH AIR. And if you're just joining us, we're speaking with journalist Bill Gifford. He has a new book about efforts to fight aging called "Spring Chicken."

You describe an operation that people use in research called parabiosis. Let's explain what that is and then some of the - and we'll go into some interesting things we've learned about it. What is it?

GIFFORD: Right. So this dates from the testicular injection era of science. But there is another enterprising French scientist who sewed two rats together as, like, Siamese twins to see what would happen. So about 100 years later, somebody thought of using this to study aging. And you'd sew an older animal to a younger animal and see what happened.

DAVIES: So the idea is you make an incision say in the left side of one animal, and then on the right side of the other.

GIFFORD: Right.

DAVIES: And then what?

GIFFORD: They're kind of joined at the elbows and the torso.

DAVIES: And then what? Do their kind of blood vessels align? Do they start sharing organs, or...

GIFFORD: Right. Their circulatory systems will kind of intertwine. And within a few weeks, they'll be sharing the same blood, essentially. And so what happens is the older animal will be sort of miraculously rejuvenated in multiple tissues. So, like, muscles will be in better shape. Heart - it reverses the aging of hearts.

DAVIES: This is in the case where an older animal is joined with a young animal?

GIFFORD: Yeah. Yeah, and even neurons, I mean, it restores the connectivity of neurons, which is something that we lose and lose and lose and lose with age.

DAVIES: Yeah.

GIFFORD: It was quite phenomenal.

DAVIES: This was fascinating. It was fascinating because there were these mice that - I forget. They had forgotten something that they were supposed to do about finding some board so that they don't get wet.

GIFFORD: Right. They put them in a water maze. And the older ones would get lost and fumble around, you know, make all these mistakes. And it was sad. And then they were injected with young blood plasma. And they were - boom - they solved the maze quickly.

DAVIES: Wow. If we extrapolate that to humans, if someone's aging and losing, you know, brain function or getting forgetful, whatever, younger blood in the circulatory system could reverse it?

GIFFORD: Right. Well, there's clearly some factors or several factors in young blood that are missing when we get older. So if you can restore them, you can go back to sort of a more youthful state. And it's particularly interesting and exciting in the area of Alzheimer's, which, you know, there's no really good treatment for Alzheimer's yet. So they're hopeful. There's a team at Harvard that's found one of these factors, something called GDF11, and there's various others. And they're kind of hopeful that this will yield some sort of treatment for Alzheimer's, and then maybe even for heart failure.

DAVIES: So the idea would be to identify that factor rather than just doing blood transfusions?

GIFFORD: Right. No, you don't want to be doing blood transfusions from your interns.

DAVIES: (Laughter).

GIFFORD: You know, you want to find what the protein is or the factor is and then make that and somehow turn that into some sort of medication.

DAVIES: In the book, you describe a lot of things, some of which are really kooky and some of which are interesting, but kind of a long way off from any practical implementation. But in the appendix, you list some things that you might want to try that might just work. You want to give us a few?

GIFFORD: Well, I'm an English major. So nobody should try anything based on my say-so.

DAVIES: (Laughter).

GIFFORD: No, I'm not advising anybody to do anything. But there are a few medications that are in common use right now that have shown promise and may actually delay aging and diseases of aging. So one of them is a diabetes drug called metformin. It's been around for decades; millions of people take it. They did a study that found that diabetics on metformin were actually living longer than non-diabetics who were matched in every way. So normally diabetes takes five to seven years off your life, but the diabetics on metformin seemed to be living longer. So that was interesting.

DAVIES: And do we know why - how it works?

GIFFORD: Metformin's been around for decades, and they still pretty much don't know how it works, just that it does work. And then there's another one called rapamycin, which is - it's a transplant drug. It was actually found in the soil of Easter Island, and they've found that that extends the lifespan of mice. And they're beginning to work on - there's a clinical trial in dogs that's about to start. It turns out that this weird microbe found in the dirt of this remote island sort of unlocks one of the key metabolic pathways in all our cells, not just our cells but going all the way down to yeast. And it's a thing that they named target of rapamycin. So it's the key sort of growth pathway and rapamycin turns it down. And it's really interesting because by turning it down that's how it kind of slows the aging process because when you're in this growth mode, when it's turned up, you're also aging. When it's turned down, you go into this stress-resistant kind of recycling, cleaner, cleaner way of operating. So that's a very promising medication also.

DAVIES: Aspirin?

GIFFORD: Yeah. Aspirin's an interesting thing. So inflammation is a major part of aging. And as we get older, there's more and more of this inflammation in our bodies, and it seems to correlate with mortality. And aspirin is an anti-inflammatory, ibuprofen also. So - and they've also - they've found that that does have a mild effect on the lifespan of mice. So that's promising too, and it's safe.

DAVIES: Did doing this reporting change your own lifestyle in any ways that have lasted?

GIFFORD: I knew I was going to get this question.

DAVIES: Moment of truth.

GIFFORD: (Laughter). Actually yeah, it did. You know, I spent several years hanging around with these scientists and visiting them in their labs and going to conferences and getting to know them. And I started observing their habits, like what did they actually do? And they would do things like, you know, I'd push the elevator button and they'd look at me like - what? We're taking the stairs. So they would take the stairs. They would, you know, they would go running at lunchtime. They would almost never eat dessert. Very few of them were overweight or obese. And so I started looking at their lifestyle going, I think they know something. So even though I was, you know, neck-deep in writing this book, I made it a point to get out and try and exercise every single day, you know, on my bike. I'm a big bike rider - or go running or, you know, in the winter go skiing or skating or whatever and also being more conscious of what I eat, you know. At a certain point I quit eating hamburgers, French fries, any kind of fast food. And just trying to, you know, eat a diet based on fresh food, less processed food. All that kind of stuff that Suzanne Somers talks about.

DAVIES: (Laughter).

GIFFORD: She's right.

DAVIES: And you've stayed with it pretty much?

GIFFORD: Yeah. You know, I lost 10 pounds. I feel good. I'm in pretty good shape. I have a group of guys I go out mountain biking with every week and got to stay in shape for that.

DAVIES: OK. Well, Bill Gifford, it's been interesting. Thanks so much for speaking with us.

GIFFORD: Thank you.

DAVIES: Bill Gifford's book is "Spring Chicken: Stay Young Forever (Or Die Trying)." Coming up, TV critic David Bianculli reviews "Battle Creek," a cop show from "Breaking Bad" creator, Vince Gilligan.

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