The comedian George Burns once quipped, “If I knew I was going to live this long, I’d have taken better care of myself.” What if we could not only live longer but live like we were younger? Here are some of the most promising studies on ways to reverse aging.

Reversing Aging in the Brain

Inflammation is at the root of many disorders, and it makes cells age poorly. Cells damaged by inflammation can’t recharge themselves properly, and they lack the energy to clear debris. Cellular debris can harm neurons in the brain. A Stanford University study published in Nature (January 2021) may have found a way to prevent this. “Our study suggests that cognitive aging is not a static or irrevocable condition,” said the authors. The researchers used drugs to block the receptors for a prostaglandin that causes inflammation. When drugs reduced inflammation in elderly mice with symptoms similar to Alzheimer’s disease, the mice’s memories improved. The researchers concluded that reducing inflammation reversed age-related cognitive decline in mice. See Abby Olena’s story in The Scientist.

Longevity Drug

The drug rapamycin came from a compound found in soil on Easter Island many years ago. For decades, people thought it was only good for suppressing the immune system. In 2014, a study showed that mice lived about 25 percent longer on rapamycin. Not only that, but the mice were sleek, glossy, and youthful, well into the mouse equivalent of old age. Their memories worked better, and they performed better on tasks of strength and endurance. See my 2018 story in The Scientist.

Muscle Mass

When we age, we lose muscle size and strength, even when we exercise. Researchers at the University of Basel in Switzerland found that long-term use of the drug rapamycin prevented this. Rapamycin was “overwhelmingly beneficial for skeletal muscle aging in mice, preserving muscle size and strength,” according to a press release from the University of Basel in September 2020.

Making DNA Age Backwards

As reported in the last issue of The Pragmatic Idealist, scientists have been able to reverse the aging of DNA itself. DNA aging is related to chromatin, which functions as a switch to turn genes on or off. Harvard researchers performed a “factory reset” of chromatin—restoring DNA to an earlier version before so many switches were flipped. When they did this, elderly mice re-grew their optic nerves, restoring their eyesight. See the study in the December 2020 issue of Nature, and this essay in Science.

Curing Macular Degeneration

Stem cells show some promise in reversing age-related macular degeneration. It’s even better if those stem cells are made from reprogrammed adult skin cells—with the patient’s own DNA. In Japan, the first human clinical trial showed that such reprogrammed stem cells can halt age-related macular degeneration. See the 2019 story by Jef Akst in The Scientist.

A Fish That Extends its Own Lifespan

The killifish can live much longer by pausing its development as an embryo. “If humans could do something similar, an 80-year-old person might instead have a life span from 160 to more than 400 years,” said a Stanford geneticist who studies killifish. The embryos temporarily stop growing organs and other tissues, possibly in response to environmental stress. As a result, they extend their lives. It’s unknown whether this could be applied to other species. See the story in Science News by Erin Garcia de Jesus.