Growing Young

by Marta Zaraska

Women Ahead

  That women and men differ in terms of longevity is certainly not news to anyone. Just take a stroll through your local graveyard. My grandma keeps joking that Grandpa likes to visit the graves of our relatives so that he can flirt with all these widows he meets at the cemetery. After all, he is a rare sight there: a Polish gentleman in his late eighties. Admittedly, Poland has quite a large spread between the female and male life expectancies—it’s eighty-one for women and seventy-three for men. Lithuania is even worse, with a ten-year gap, and Russia tops the world’s charts with 11.6 years of difference between the sexes (the male penchant for vodka certainly plays a role). On the other end of the scale are countries such as Iceland (a 3.0 year gap in favour of women), Sweden (3.4 years), or the UK (3.6 years). Curiously, in the past, men and women could look ahead to living for a comparable amount of time. In the 1800s in Sweden the life expectancy at birth was thirty-three years for women and thirty-one years for men, and other places were likely similar. Fate simply cut everyone’s existence short: birthing kids, infections, and wars.

  Once birthing kids, infections, and wars stopped flattening the playing field for everyone, however, the gap between men and women widened, reaching its largest between the 1970s and 1990s. Nowadays, with men starting to take better care of themselves, they are once again catching up—but not quite. Somehow women always seem ahead in terms of longevity, whether we are talking nineteenth-century Scandinavia or contemporary India or Canada. What’s going on, then? Is it still all due to healthier female lifestyles? Less gun-shooting, less show-off driving, and more broccoli? Not exactly. Scientists now believe that the female-male longevity gap is actually imprinted into our bodies, and one of the clues comes from how women and men survive catastrophic conditions.

  On the night of November 3, 1846, heavy snow coated the eastern slopes of the Sierra Nevada. A group of Midwestern farmers and businessmen, their wives, children, and family pets in tow, got stranded around Truckee Lake (later renamed Donner Lake), a large, whale-shaped body of water at the foot of the mountains. In the morning of November 4, the eighty-one members of the group woke up surrounded by ten-foot-high drifts of snow. Impassable.

  The Donner party, as it is now known after the name of their leader, George Donner, had set off from their homes in the Mississippi valley in search of a better life in California. But they’d made a mistake. Instead of taking the usual route through present-day Idaho, they chose what was supposed to be a shortcut crossing the Great Salt Lake Desert. The shortcut proved harder than the original route. The group didn’t make it in time to cross the Sierra Nevada before winter. With the new, heavy snow, they were stuck.

  Cut off from the world, with dwindling food supplies and close to no outdoor skills, the Donner party started suffering “maniacal cravings for food.” They ate their dogs. They cooked animal hides into jelly they could swallow. And by February they began eating their own dead. Once the rescue finally came, thirty-five out of eighty-one had died, by and large from hunger and hypothermia. Curiously, most of the dead were men.

  Researchers have calculated that among the Donner party, the male mortality risk was almost double the female one. They attributed this to the fact that women in general tend to survive starvation better, which came up in data from many historical famines, including the Ukrainian famine of 1933 and the Irish one of 1845 to 1849. The reason for this, scientists argue, is that women tend to be smaller than men, have a lower basal metabolic rate and a larger proportion of subcutaneous fat—the jiggly type right under the skin. This allows them to survive on less food, while the fat keeps them warm. It’s ironic that the very thing that’s the bane of so many women’s existence (belly fat!) is the same thing that’s keeping them alive over men.

  Although in the modern-day West starvation is rarely an issue, men still live shorter lives than do women, even in strictly controlled conditions. When German researchers looked at over eleven thousand Catholic nuns and monks from Bavarian cloisters, they discovered that there still remained about a year of difference in favour of the sisters. Females of other mammal species, from chimpanzees and lions to American beavers and European rabbits, have a similar advantage. In a comparison of fifty-nine species inhabiting zoos, only four had males that outlived the females. Certainly smoking and vodka were not to blame.

  One key to the mystery of the male-female longevity gap may lie in our chromosomes. Since women have two X chromosomes, they basically have a spare copy of every gene in their bodies to replace a defective one in case of need. Second, women tend to be shorter than men, so they have fewer cells to go awry in the first place (it’s like with mice and elephants and their million-fold higher cancer risk). Yet another hypothesis suggests that because each woman’s heart rate goes up during the second half of the menstrual cycle, their tickers get exercised in a similar way to how joggers exercise theirs—which could explain why women tend to get cardiovascular disease later in life than men do.

  And then, there are the hormones. An analysis of lifespans of eunuchs living in nineteenth-century Korean courts revealed that they survived on average twenty years longer than did other men in the court, including the kings. What eunuchs are short on, of course, is testosterone, which, studies show, tends to suppress the immune system, making men more susceptible to viruses and bacteria. On the other hand, female hormones such as estrogens give a boost to the immune system while also helping the cleanup of bad cholesterol from the arteries.

  Since cutting off their male parts does not seem to appeal to most contemporary men, a search for other potential boosts to longevity is in full swing. In a way, that’s nothing new—conquistador Ponce de León supposedly hunted for the fountain of youth way back in the sixteenth century. Yet these days the search happens mostly in biotech labs, and its focus is on pills and injections, not magic water sources.

  Magic Pills and Plasma Infusions

  In an interview for The New Yorker back in 2017, the futurist Ray Kurzweil admitted to downing as many as ninety pills a day in an effort to keep himself young and boost his centenarian potential. One of these pills was metformin, a diabetes drug which, Cox tells me, is currently taken by nearly everybody she knows from the US who is working on aging. There is growing evidence that metformin may indeed prolong life and delay aging—it does so in mice and in C. elegans. At a cellular level it reduces production of reactive oxygen species and decreases DNA damage (among other effects). But Cox herself does not take metformin. “Any pharmaceuticals will have side effects. And we don’t really know the long-term effects of metformin in people who don’t have a clinical need to take it,” she says.

  Many of the therapies currently hyped in Silicon Valley as the next fountain of youth haven’t undergone rigorous testing on humans and are, at best, just “promising.” A molecule called NAD+, which could potentially rejuvenate the mitochondria, was just entering clinical trials at the time of writing. Rapamycin, an immunosuppressant commonly used to prevent rejection of transplanted organs, could help regulate cellular suicide and growth—but there are already reports of serious side effects including toxicity to kidneys and decreases in blood platelets.

  Other proposed longevity therapies are even more disturbing. You could, for instance, get an infusion of blood from a younger person. In rather creepy experiments, scientists sewed together the circulatory systems of two rats, an old one and a young one, so that the elderly rodent would get an infusion of young blood, and discovered that this boosted the senior’s lifespan. Some companies in the US are already preparing to run clinical trials on elderly humans (don’t worry, no one will sew them to teenagers—it would be done by blood transfusions). But many scientists are wary of the whole idea. In an interview for Scientific American, one University of California molecular biologist said it “just reeks of snake oil.” To me, it brought to mind a warning Stephen Colbert gave to American youth on The Late Show: that President Trump was going to replace Obamacare with m
andatory blood exchanges from teens to rejuvenate the aging population: “He’s going to stick a straw in you like a Capri-Sun,” he said.

  If vampire-style longevity remedies don’t appeal to you, you could always go for stem cell treatments instead. Several biotech companies in North America now offer banking of stem cells derived from a variety of sources, including umbilical cord blood, menstrual blood, and baby teeth. The hope here is that we will be able to use these cells to rejuvenate tissues. Yet stem cell therapies are still in infancy. At best, their anti-aging effects are just uncertain. At worst, they may be dangerous. When one Florida company tried to treat age-related macular degeneration with stem cells, three women ended up blind.

  When I think of a longevity pill, the idea seems really appealing at first. No need to exercise, eat well, or take care of my social life. Just swallow and be young forever, my mitochondria rejuvenating, my DNA fixing itself, my proteins folding correctly. If all promises of stem cells, senolytics, and organ replacements pan out, maybe some of us could become immortal, regenerating over and over. Many in Silicon Valley are certainly banking on that. But assuming hydra-like immortality is attainable for humans, would pursuing it actually be a good idea? First of all, if we were immortal, our lives could lose their meaning. Nothing would matter anymore if you had all the time in the world to get anything you wanted. One study, aptly titled “The Scrooge Effect,” revealed in a series of experiments that people derive more pleasure from donating money if they are reminded of their own mortality. How much pleasure in living would we lose by living forever?

  Then there is the ethical side of the immortality question. Around the world there are children dying of starvation by the thousands—should we really be spending so much research money on finding some miraculous longevity pill? Our planet is already overpopulated and its resources stretched to the limit. How many immortal humans could the earth withstand? Certainly not everyone that is born, right? So how do we pick who lives forever and who degenerates and dies? And what if immortality or extreme longevity was indeed achievable, and dictators could stay in power in perpetuity? Imagine if Stalin never died or Castro never aged.

  A better idea than chasing the holy grail of ridiculously long lifespans may be focusing on something far more attainable: prolonging average health-spans, which usually has the neat side effect of upping our chances of becoming centenarians anyway. Instead of the few wealthiest one-percenters living to 150 or 200, we could have societies where many reach their hundredth birthdays in good health. We know from research on supercentenarians that the longer people live, the longer they tend to stay in good shape. Instead of occupying hospital beds and draining health care budgets, these seniors would still be productive members of the community. Giving instead of taking. And, of course, suffering less, too.

  Ethical questions aside, we are unlikely to discover one magic longevity pill any time soon. Our bodies are complicated, far more so than those of hydras, C. elegans, or mice. What works for rodents won’t necessarily work for humans. And then there are the potential side effects to consider. Metformin, for instance, has been shown to cause diarrhea, cold sweats, coma, seizures, and racing heartbeat.

  There are no easy fixes no matter how much we would love them, so instead of hoping for the fountain of youth, we should embrace solutions that do work. Eating right, exercising, and above all, taking care of our minds and social lives. Changing our mindsets, not our medicine cabinets. Living in a community where neighbours care about one another means, for women, cutting the risk of coronary heart disease by a third. Chronic loneliness, on the other hand, can up your mortality risk by 83 percent—which is worse than cigarettes. Longevity pills may be tempting, but volunteering or improving friendships won’t give you seizures or a racing heartbeat (unless we are talking romantic friendships, that is).

  Jeanne Calment might have lived long due to her genes, but perhaps also due to her have-no-regrets personality. Optimism can prolong life by as much as ten years, while lack of rumination on past mishaps boosts the immune system in the elderly. What’s more, Calment was happily married for decades, and studies shows that married people live longer, are more likely to survive heart attacks, and even respond better to flu vaccines. For cancer, marriage may be sometimes better than chemotherapy.

  Jeanne Calment may have also gained a year or two simply by being a woman—perhaps because of her double X chromosomes, but maybe also because women tend to be more empathic and socially integrated, which helps longevity, too (more on that in chapters 6 and 7). Such links between sociality and health are hardly surprising. After all, our bodies and minds are connected in myriad ways: through our stress axes, our immune systems, and even the three pounds of microbes that reside in our guts.

  A FEW SUGGESTIONS TO BOOST YOUR LONGEVITY

  Don’t trust anyone who tells you they’ve discovered a secret to longevity.

  Don’t waste your money on genetic predict-your-lifespan tests or banking your own stem cells—their efficacy is doubtful at best. Don’t obsess about your telomeres. If you do have a few hundred spare dollars, and really want to test something, measure your epigenetic clock. Forget miracle longevity pills—many of them are simply dangerous. If you want to live longer, try to find a romantic partner or work on your current relationship—being happily married can lower your mortality risk even by 49 percent. Or volunteer, which may lower your risk of death by about 22 percent.

  2

  HOW YOUR MIND TALKS WITH YOUR BODY

  Mortgage Worries, Stress-Resistant Nazis, and a Few Trillion Microbes

  IN THE 1979 MOVIE Manhattan Diane Keaton asks Woody Allen to let out his anger so that they can finally get things “out in the open.” “I don’t get angry,” he replies, “I grow a tumour instead.”

  Woody Allen might have been on to something. Our bodies and minds are amazingly interconnected. In experiments, people who merely imagine exercising their hand muscles end up with improved strength. Others get real rashes from exposure to fake poison ivy. Placebo treatments, meanwhile, are so effective that 42 percent of balding men maintain or increase hair growth after such “cures.” Hypnosis can even be used to reduce pain during lumbar punctures and heart surgeries.

  There is nothing magical or New Agey about body-mind connections. Instead, very measurable neural, hormonal, and immunological pathways link our thoughts and feelings to other physiological processes in our bodies. William Paul Young, a Canadian novelist, once wrote that “emotions are the colors of the soul”—a sublime statement, but rubbish from the perspective of modern biology. Emotions are not fairy-dust clouds floating around in our heads. They are evolved signals inside the body that exist as much in humans as they do in other animals, from cows and dogs to birds and reptiles.

  If you take an animal and apply electrical stimulation to its brainstem, that ancient structure at the base of the brain, you will elicit behaviours suggestive of emotions. The same thing works with humans too, indicating that emotions are very old in evolutionary terms and that besides inspiring poetry they must serve some very down-to-earth purposes, like helping you not get eaten by predators. Emotions inform us about the state of our environment and our bodies and help us prepare an adequate response. Fear? A lion may be approaching. Anger? You may soon get punched. Disgust? Don’t touch! Parasites could be lurking. Satisfaction? All is well in your body.

  Emotions may also facilitate learning—things that are emotionally loaded simply get better ingrained in our memory. You may well remember to avoid nighttime strolls through the savanna if you were once scared there by a predator. In lab experiments, people are best at recalling memories that are emotionally intense, regardless how much time has passed since the experience. The idea that emotions serve as guides to bodily sensations and the environment is further supported by the fact that people paralyzed from the neck down often complain that their emotions are blunted.

  Of course, eve
n if lizards and ducks do have emotions, our inner lives are likely more complicated than are theirs. That’s why neuroscientists tend to distinguish emotions from feelings, the latter being the mental experiences of emotions—yet still very much planted in our biology (the cerebral cortex is involved). Emotion is basically that thing that stirs in your gut or your chest. Feeling is what your brain does with that stir, how it experiences it. Emotions are our guide to the environment. Feelings are how we interpret the signs. Emotions are automatic, while feelings are more conscious.

  Just like emotions and feelings, our thoughts aren’t ethereal vapours, either. Researchers are still arguing over where exactly in the brain self-generated thoughts arise, but some patterns are beginning to emerge. A region called the default network seems particularly vital—that’s a network of brain regions that activates when you are not doing anything in particular, kind of like a computer on standby.

  If you wonder how, exactly, scientists find thoughts inside human skulls, here are some examples: they zap brains with electricity during surgeries (with patients’ permission, of course), they use implanted electrodes to record electrical activity produced by neurons, or they place experienced meditators in magnetic resonance imaging scanners. Such studies show, for example, that if you stimulate parts of the default network of someone’s brain — so the regions of the cortex that activate when you think about the past or envision the future — you may cause that person to daydream and spontaneously recall memories. And if you run one-millisecond electrical pulses through the almond-shaped amygdala, you can cause déjà vécu—kind of like déjà vu on steroids—an illusion of having lived a whole sequence of events already, one that is longer, less fleeting, and less easy to dismiss than déjà vu. The amygdala, the region that is very likely involved in thinking, is also one of the main brain structures that can help explain how our minds and bodies are interconnected. The keyword here is fear.