Thousands of pet dogs are part of a citizen science project aimed at understanding memory and cognition in older people — maybe old dogs can teach us some new tricks.
Dr. Matt Kaeberlein leads the Dog Aging Project and says his research into dog longevity could reveal some key mysteries about the biology of aging and what we can do about it.
The project began 8 years ago, collecting data over a dog’s lifetime and so far 40,000 dogs have participated, making it the largest longitudinal study of aging in animals. .
About a decade ago, Kaeberlein realized that the science he had been working on since grad school might actually be useful in helping his own dogs live longer.
Kaeberlein has a 12-year-old German Shepherd, Dobby – named after the Harry Potter character because of the big ears he had as a puppy.
“He’s a great dog, I love Dobby, he’s one of those special dogs – although of course everyone says so – I’d say he’s the best dog in the world.”
Dogs age biologically faster than humans, but Kaeberlein says it’s a bit more complicated than the old adage that one human year equals seven dog years.
“Both because different sizes of dogs age at different rates, so large dogs age faster than small dogs, and because it’s not exactly what we would call a linear relationship.”
When dogs are young, Kaeberlein says, they age more like 10 years for every human year. As they get older it slows down and it feels more like three years than a human year.
As they age, dogs can contract almost the same range of illnesses as humans, he says. “Importantly, they are associated with age in dogs.”
Because dogs age much like we do but age faster, that means understanding the biological aging process in dogs can be studied in a reasonable amount of time, he says.
“The last 20 years have been truly remarkable in the field of the biology of aging, learning what it means at the cellular level. We know a lot about the types of changes, and most people would call it damage, which accumulates with age at the cellular level.
There are nine hallmarks of aging representing most of what we know about the conserved molecular processes that occur during aging, he says.
“That includes things that people may have heard of before, like telomere shortening, cellular senescence, or mitochondrial damage.”
We don’t know everything about the biological aging process, but Kaeberlein says scientists know enough to start doing something about it.
This is what excites him the most.
Most of the dog aging study is observational and covers dogs of all ages and sizes living in the United States.
Owners complete a survey of their dog’s home environment, diet, previous disease diagnosis, and provide a veterinary medical record.
Ten thousand of these dogs will have their genomes sequenced. A thousand dogs have annual large-scale datasets recorded.
Kaeberlein was excited about the first set of data that arrived. These data come from a single moment, before the start of the longitudinal phase.
“We learned a lot of interesting things.”
“[These include] the impact of inbreeding on different diseases such as cancer, the relationship between how often a dog is fed and its risk of developing future diseases, the relationship between its sex and the risk of disease.
“It was exciting, and I would say we’re really at the tip of the iceberg in terms of diving and data analysis.”
Another part of the project is a clinical trial testing rapamycin, a drug used in humans to treat cancer and prevent organ rejection in transplant patients.
“It was first approved to prevent organ transplant rejection, by the FDA, it’s also used clinically for a variety of other indications, a rare form of cancer. Kind of alongside that clinical use , about… 14 years ago, a published study on mice showed that treatment with rapamycin, beginning in middle age, could significantly increase lifespan.
Since that study, Kaeberlein’s lab and others have shown that not only has lifespan increased, “even from transient treatments in middle-aged mice, you can delay or, in some cases, reverse the functional declines that accompany aging.
Kaeberlein argues that biological age is the greatest risk factor for nearly all major causes of death and disability in developed countries.
“So if we can understand this biology of aging, we really have the potential to have a much greater impact on healthy longevity – which is what we’re all looking for, not just in dogs but also in humans.”
At 51, Kaeberlein says that over the years the study of aging has become more personal for him.
“Still at this point, most of what we know that works to target the biology of aging is the obvious things like exercise and nutrition and trying to live a healthy life. Hopefully in the near future we we will be able to do better than that.
“And in addition to these lifestyle factors, [we] some really promising interventions that can have a significant impact – probably first in dogs, but I don’t think it’s too far past that for us to be able to make recommendations for people as well.