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Anti-aging drugs for dogs may be developed before anti-aging drugs are developed for humans. Our best friend, the dog, has become a popular animal model of human aging, and multiple clinical trials are currently underway to test potential anti-aging compounds in dogs. Fido is also a potentially huge market.
This science has the potential to benefit both species, but premature claims are already raising credibility issues.
Recently, Harvard biologist David Sinclair began selling a life-extending supplement for dogs, touting unpublished clinical trial data that other researchers in the field found completely unconvincing. did. In March, Mr. Sinclair did not respond to interview requests, but he changed the wording in a press release that had originally promised the chewy treat would “reverse aging.” It is now claimed to reverse the effects of age-related decline.
Sinclair’s trial used dog owners’ subjective assessments of cognitive changes in their aging pets, but other scientists argue that even with this modest claim, the trial showed no consistent results. It is said that sufficient efficacy has not been shown. (Sinclair rose to fame in the 1990s after making headlines for several papers linking aging to proteins called sirtuins.) This idea, which is now widely debated, suggests that red wine has an anti-aging effect. This led to the idea that there is.)
Although the FDA has the authority to regulate veterinary drugs, it does not approve supplements for pets or humans, so they may be sold without being tested for safety and effectiveness.
Arthur Caplan, an ethics professor at New York University, said anti-aging supplements for dogs will be in demand regardless of whether they work. In the past, desperate dog owners have cloned dead or dying dogs, hoping that the clones are essentially the reincarnation of their dead pets.
Some researchers who study aging believe that the sight of high-level professors touting canine longevity supplements has already been overshadowed by self-styled experts pushing fad diets and unproven anti-aging treatments on people. I am concerned that this will further tarnish the reputation of this sector, which has been dragged into it.
There is much to be gained by understanding aging scientifically. Aging is a risk factor for all major killer diseases, including heart disease, cancer, and even severe coronavirus. And as the U.S. population ages 70 and older increases rapidly in the coming years, the number of people suffering from dementia and other age-related problems will increase significantly.
But scientists have yet to agree on what causes aging or what approaches are best to slow it down. Attrition ultimately affects all living things, but even among closely related species, some live many times longer than others. Some researchers believe that the rate of aging in animals is controlled by specific genes.
Other experts point to the shrinking of the caps at the ends of chromosomes called telomeres. Some blame degeneration of the packaging around DNA, so-called epigenetic markers, which activate or repress specific genes. Some scholars blame the damage caused by chronic inflammation. In addition, accumulation of cellular waste products is also considered.
Some of these possible aging mechanisms can be modified using drugs in ways that confer long life in C. elegans, Drosophila, and mice. Which drugs should be tried in humans? Clinical trials examining their effects on human longevity can take decades, long enough for study subjects to survive the rest of their lives.
One way to identify more likely candidates is to see which ones also work for dogs. Dogs are long-lived enough to be a better model of human aging than mice, but short-lived enough that treatments can be tested within a few years.
Matt Kaeberlein, CEO of Optispan and an affiliated professor at the University of Washington, has been one of the most vocal critics of Sinclair’s dog longevity claims. He is also competing as co-director of The Dog Aging Project. The project involves collecting data on thousands of dogs and conducting canine clinical trials with a drug called rapamycin. It is currently approved for people who have received an organ transplant. Although high doses cause canker sores and other nasty side effects, it can extend the lifespan of mice, he acknowledged, and lower doses could have similar effects in dogs and humans.
He says biohacker-type groups are already taking rapamycin off-label in hopes of extending life. He is trying to get data from there because there might be useful information there. Although it’s messy. (Caplan, an ethicist at New York University, said he believes it is unethical for doctors to prescribe the drug off-label for longevity.)
Kaeberlein said the biological data they are collecting from all of the thousands of dogs could lead to an explanation for the fact that large dogs don’t live as long as small dogs. “If you compare, on average, a Great Dane and a Chihuahua, the life expectancy is at least twice as different,” he says.
But his project could fall victim to broader credibility issues in the field. The grant was funded by the National Institutes of Health, but he and his colleagues recently learned that the five-year grant, created in 2018 and extended for one year, likely will not be renewed. He is currently working to earn personal money.
Charles Brenner, a biochemist at City of Hope National Medical Center in Los Angeles, has also been a vocal critic of Sinclair’s claims about dogs and humans. (Like most researchers on the front lines of aging, he has his own supplement connection as chief scientific advisor for a bioscience company called ChromaDex.)
Brenner is also skeptical of those who claim that various treatments and drugs can reverse a person’s “biological age,” which is calculated through proxies measured in the blood, such as telomeres and epigenetic markers. It is true. None of these measure aging or walking speed, he says.
When I asked him about the rapamycin study in dogs, he said it was “worth a shot” because the test measures actual lifespan, not a proxy. But he’s not betting on this particular drug. He is more optimistic about the efforts of a company called Loyal, which Bloomberg Businessweek profiled in 2021.
Brenner said Royal has been secretive about the drug, but believes the one it is currently testing inhibits the production or action of growth hormone. According to him, growth hormone is associated with faster aging in large dogs compared to small dogs.
In addition to dogs, shellfish can live up to 500 years old, rockfish can live up to 200 years old, and whales can live up to 80 years old, so there is promise in studying how and why animals age. Once scientists understand the mechanisms of aging, they will be better able to find ways to do it. To help us and our furry friends live longer and healthier lives.
But first, investors and the public need to take it seriously.
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