Nasal spray extends lifespan and healthspan in aged mice

And it works if started late in life

It’s not easy to administer a nasal spray to a mouse, but it’s worth the hassle

What's the news: A nasal spray activates immunity and extends life in old mice.

Why should we believe it: This news is based on a new study published two weeks ago by scientists in South Korea and Spain. They treated 21-month-old mice, equivalent to 50-60-year old humans with a nasal spray designed to stimulate a specific type of pathogen receptors known as toll-like receptors (TLRs). Result:

  • Lifespan extension of 8% for males and 11.9% for females (equivalent to an extra 5.8 years of human life for men and 9.4 years for women)

  • Improvements in bone density, brain glucose uptake, behavioral tests, locomotor activity, eye function, and hair quality

  • Overall results comparable to rapamycin administration, which is one of the best currently known longevity interventions in mice

Why this is a big deal: First off, this study identifies another possible target for longevity interventions. It highlights how compromised immunity and chronic low-grade inflammation contribute to or might be the primary cause of many age-related conditions.

Second, this study is interesting because the intervention was started so late in life, with mice that were already showing significant signs of aging. And yet, it had a significant impact both on healthspan and lifespan.

So what's next: Scientists will have to study the connection between TLR and longevity in other strains of mice to see whether it's reproducible and deserves being tested in humans.

While we wait for that research, keep reading The Longevity Newsletter, because I regularly write about other interventions that can also positively impact your immune system, and that might increase your lifespan too.