Only one animal has figured out how to cheat death: Turritopsis nutricula. This tiny hydrozoan resembles a jellyfish, and it is the only known animal that is virtually immortal. How does it escape death? T. nutricula is able to revert back to an immature stage after going through its reproductive stage. Once it completes its transformation from polyp to medusa, this hydrozoan has the ability to turn itself inside-out and revert back to a polyp, repeating the process indefinitely.
A distant second to the immortal T. nutricula are the long-lived turtles, which have reached ages of 250 years or more. Don’t be fooled by their wrinkles: turtles have the ability to virtually stop senescing, or growing old. Their organs do not break down or become less efficient over time, and they have the ability to almost stop their heart beat. Turtles also have an unusually long growth cycle: some sea turtles do not reach sexual maturity until 40 or 50 years of age. However, once they reach maturity, they can reprodce for the rest of their lives, in effect making up for their long developmental stage.
Humans still have a long way to go to achieve immortality, but improved health has led to more people living past 100 than ever before. The number of centenarians already has jumped from an estimated few thousand in 1950 to more than 340,000 worldwide today, with the highest concentrations in the U.S. and Japan, according to the latest Census Bureau figures. Their numbers are projected to grow at more than 20 times the rates of the total population by 2050, making them the fastest growing age segment.
The reason? Medical advances and improved diets have reduced heart disease and stroke, and more doctors who are willing to aggressively treat the health problems of people once considered too old for such care.
Japan, known for its low-fat diet of fish and rice, will have the most centenarians in 2050 – 627,000, or nearly 1 percent of its total population, according to census estimates. Italy, Greece, Monaco and Singapore, aided by their temperate climates, also will have sizable shares of centenarians, most notably among women. In the U.S., centenarians are expected to increase from 75,000 to more than 600,000 by 2050.
And while health care has become more expensive than ever, basic health is still as simple and low-tech as it’s always been. Studies of the longest living humans in Okinawa, Japan, found four keys to long life:
1) a low-fat diet of predominantly vegetables, fruits, and whole grains
2) outdoor exercise as part of daily life (the people of Okinawa rely on gardening, walking, martial arts, tai chi, and dancing)
3) sleep (at least eight hours for adults)
4) community (connecting with supportive social networks to encourage healthy living)
You may not be able to reverse your reproductive life cycle like T. nutricula or stop your internal organs from aging like a turtle, but these four healthy habits can help you live a longer—and happier—life.