This popular science article focuses on the study of negligibly senescent species in the context of work aimed at adjusting the course of human aging. There is at least one negligibly senescent mammal, the naked mole-rat, but it seems to me that attempting to mine benefits from other species and port them to humans is just another way to say we should re-engineer human metabolism to age more slowly. The past twenty years have demonstrated that this is enormously expensive and enormously challenging. Billions have been spent on trying to safely change just a few genes and proteins, and to try to better understand the modestly slowed aging of calorie restriction, with no practical result other than to add thin slices to our knowledge of metabolic processes. We should have similar expectations for the results of trying to obtain benefits from the biochemistry of another species - and going far beyond that in scope to produce a whole new human metabolism is very far from being a plausible project today.
The only way today to make practice, cost-effective progress towards very large gains in human longevity is to follow the SENS model of damage repair. The damage that causes aging is very well understood, and we don't need a full explanation of how exactly at the detail level that damage multiplies and interacts to contribute to every facet of aging. We don't need to adjust those facets or integrate them into a new working model of human biochemistry. All we have to do is periodically repair the damage, maintaining the youthful version of human biochemistry that we know works. It is an engineering approach in which we can bypass our ignorance of the details in order to produce working rejuvenation therapies here and now. Repair of the first form of damage is already in the clinical development pipeline: clearance of senescent cells. Others might follow soon, if there was just more support and funding.
The naked mole rat is the superhero of the animal kingdom. Similarly sized rodents usually live for about five years. The naked mole rat lives for 30. Even into their late 20s, they hardly seem to age, remaining fit and healthy with robust heartbeats, strong bones, sharp minds, and high fertility. They don't seem to feel pain and, unlike other mammals, they almost never get cancer. "It's not a ridiculous exaggeration to suggest we can one day manipulate our own biochemical and metabolic pathways with drugs or gene therapies to emulate those that keep the naked mole rat alive and healthy for so long. In fact, the naked mole rat provides us the perfect model for human aging research across the board, from the way it resists cancer to the way its social systems prolong its life."
Over the centuries a long line of optimists, alchemists, hawkers and pop stars have hunted various methods of postponing death, from drinking elixirs of youth to sleeping in hyperbaric chambers. The one thing those people have in common is that all of them are dead. Still, the anti-aging industry is bigger than ever. In 2013, its global market generated more than $216 billion. By 2018 it will hit $311 billion, thanks mostly to huge investment from Silicon Valley billionaires and Russian oligarchs who've realized the only way they could possibly spend all their money is by living forever. Even Google wants in on the action, with Calico, its $1.5 billion life-extension research center whose brief is to reverse-engineer the biology that makes us old or, as Time magazine put it, to "cure death." It's a snowballing market that some are branding "the internet of healthcare." But on whom are these savvy entrepreneurs placing their bets? After all, the race for immortality has a wide field.
British biomedical gerontologist Aubrey de Grey is enjoying the growing clamor about conquering aging, or "senescence," as he calls it. His charity, the SENS Research Foundation, has enjoyed a bumper few years thanks to a $600,000-a-year investment from Peter Thiel ("Probably the most extreme form of inequality is between people who are alive and people who are dead"). Though he says the foundation's $5.75 million annual budget can still "struggle" to support its growing workload. According to de Grey, the fundamental knowledge needed to develop effective anti-aging therapies already exists. He argues that the seven biochemical processes that cause the damage which accumulates during old age have been discovered, and if we can counter them we can, in theory, halt the ageing process. He says traditional medicines won't wind back the hands of our body clocks - we need to manipulate our makeup on a cellular level, like using bacterial enzymes to flush out molecular "garbage" that accumulates in the body, or tinkering with our genetic coding to prevent the growth of cancers, or any other disease. "If you look at the maths it is very straightforward. All we are saying here is that it's quite likely that within the next 20 or 30 years, we will develop medicines that can rejuvenate people faster than time is passing. It's not perfect yet, but soon we'll take someone aged 60 and fix them up well enough that they won't be 60 again, biologically, for another 30 years. In that period, therapies will improve such that we'll be able to rejuvenate them again so they won't be 60 for a third time until they are chronologically 150, and so on. If we can stay one step ahead of the problem, people won't die of aging anymore."
Of course, the naked mole rat isn't the only animal scientists are probing to pick the lock of long life. With a heart rate of 1,000 beats a minute, the tiny hummingbird should be riddled with rogue free radicals, the oxygen-based chemicals that contribute to aging by gradually destroying DNA, proteins, and fat molecules... but it's not. Then there are pearl mussel larvae that live in the gills of Atlantic salmon and mop up free radicals, and lobsters, which seem to have evolved to have more of a protein which repairs the tips of DNA, allowing for more cell divisions than most animals are capable of. And we mustn't forget the 2mm-long C. elegans roundworm. Within these 2mm-long nematodes are genetic mechanisms that can be picked apart like cogs and springs in an attempt to better understand the causes of aging and ultimately death.