In 1997, A Jeanne Calment, a French woman, died at the age of 122. According to the Gerontology Research Group, she was the oldest verified person in the world. Her daily habits included drinking a glass of port and smoking a cigarette after meals (she also ate 2.5 pounds of chocolate a week). “No one else has lived to be 120 since her death,” says Venki Ramakrishnan, a Nobel Prize-winning biologist and author of the book Why we die. Indeed, while the number of centenarians increases year by year, the number of people living beyond the age of 110 does not. “This suggests that perhaps there is a natural limit to the length of human life.”
If there is such a constraint, it is imposed by biological evolution. “Evolution wants to make sure that your genes have the maximum probability of being passed on,” says Ramakrishnan. “It doesn’t care how long you live.” This explains, for example, why there seems to be a correlation between the size of animals and their life expectancy—in general, the larger the species, the longer it will live. Most mayflies live for one to two days. Monarch butterflies can live for months. Bowhead whales live to be over 200 years ancient. Bowhead sharks can live to be over 500 years ancient. “If you’re a smaller species, it doesn’t make sense to spend a lot of resources maintaining and repairing your body, because the likelihood of you being eaten or starved to death is high,” says Ramakrishnan. “On the other hand, larger species will have the advantage of having more time to find mates and have offspring.”
However, a few species appear to be exempt from this rule. Hydra, a petite freshwater animal with 12 tentacles, does not seem to age at all. The immortal jellyfish can even age backwards. “This suggests that aging is not inevitable and that we can bypass our natural limitations if we change our biology,” Ramakrishnan says.
That’s why understanding the biology of aging and death is such a heated topic of research right now. Scientists are trying to figure out how to manipulate the aging processes of cells—for example, how to destroy senescent cells (ancient cells that cause inflammation) or how to reprogram cells to return them to an earlier state of development. More than 300,000 scientific papers have been published on aging in the past decade, and billions of dollars have been poured into more than 700 longevity startups, including Altos Labs, Human Longevity, Elysium Health, and Calico.
One of the most promising avenues of research is the discovery of compounds that can mimic the effects of a low-calorie diet, which is considered one of the best-known ways to sluggish down aging. One such compound is rapamycin, first discovered in the soil of Easter Island for its antifungal properties. “It was later found to be a powerful anti-cancer and anti-inflammatory agent as well,” says Ramakrishnan. “It is also immunosuppressive, so it can also make people more susceptible to infections and slow wound healing. We need to find a balance between having no side effects and having [anti-aging] benefits.”
Longevity researchers also know of a body of research that shows that young blood can rejuvenate old bodies — at least in mice. The discovery came when scientists first surgically linked the circulatory systems of a young and old mouse — a technique called parabiosis — and observed that the procedure slowed the signs of aging, extending the life of the older animal by 10 percent. Ramakrishnan notes that while scientists are still trying to identify the factors in young blood that cause this effect, “there are companies that have rushed out and started offering young plasma to billionaires.”
“While we wait for all this to happen, there is something we can do.” Ramakrishnan’s notes. “It’s probably similar to the advice your grandparents gave you. Eat moderately, eat a healthy diet, get enough sleep and exercise. It turns out that each of them influences the other two, so it’s a really positive cycle. If you take them all at once, it works better than any drug on the market, has no side effects and is free.”
The article was published in the July-August 2024 issue WIRED Magazine UK.