The Dog Aging Project, launched in 2014, is a collaborative effort to understand the biological and environmental factors that influence aging in dogs. With over 44,000 dogs enrolled, the project gathers data on lifestyle, lifespan, and age-related diseases, including those affecting heart and brain health. Researchers hope the project will provide insights into aging processes shared by dogs and humans, while also helping pets live healthier, happier lives.
Rapamycin's Potential in Promoting Healthy Aging
One of the project's key initiatives is exploring the potential of rapamycin to extend lifespan in healthy older dogs. Rapamycin, initially studied for its antifungal and anticancer effects, inhibits the protein mTOR, a central regulator of growth, development, and reproduction. Matt Kaeberlein, a biogerontologist at the University of Washington and co-founder of the Dog Aging Project, noted that rapamycin is "the most effective and reproducible small molecule for increasing lifespan and healthspan in laboratory animals."
Early Trial Results Show Promise
Early trials of rapamycin in dogs have shown promising results. A ten-week, double-blind, randomized, placebo-controlled trial tested the safety of two different doses of rapamycin. Researchers measured heart function using echocardiographic parameters and found statistically significant improvements in two of the three parameters in dogs treated with rapamycin. Importantly, the study found no evidence of side effects, and owners reported increased activity in dogs receiving rapamycin.
A subsequent six-month clinical trial at Texas A&M University, using half the lower dose from the first trial, did not show changes in echocardiograms but still reported an increase in activity levels among the dogs, with no significant side effects observed.
The TRIAD Study: A Large-Scale Lifespan Assessment
The project is currently conducting the Test of Rapamycin in Aging Dogs (TRIAD), a large-scale study involving 580 dogs. Half of the dogs will receive rapamycin for one year, while the other half will receive a placebo, with a two-year follow-up period. The primary endpoint of the TRIAD study is lifespan. Kaeberlein stated that the study's size and duration will provide the statistical power to detect a nine percent change in lifespan.
Mechanisms of Action and Immune Homeostasis
Rapamycin's potential benefits in promoting healthy aging may stem from its ability to re-establish immune homeostasis in aged animals. According to Kaeberlein, rapamycin is effective at reducing sterile inflammation, a common feature of aging. By reducing this inflammation, the immune system can restore balance, potentially contributing to improved healthspan.
Future Implications for Human Longevity
The Dog Aging Project's findings could have significant implications for human longevity. Given the parallels between aging in dogs and humans, insights gained from studying rapamycin's effects on canine healthspan could translate to interventions that promote healthy aging in humans. The project's comprehensive approach, combining observational data with clinical trials, offers a unique opportunity to unravel the complexities of aging and develop strategies to extend lifespan and improve quality of life for both dogs and their human companions.
