Raphael ThysTop highlight
The Dirty Little Secret of ‘Anti-Aging’ Research
Short-lived animal models exaggerate longevity intervention effects
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Published in
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5 min read
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2 days ago
Photo by Kristina Flour on Unsplash
Time & money
Science ain’t cheap.
It depends on what you’re doing, of course, but studying the mechanisms of aging is — generally — an expensive endeavor.
Ideally, you start an intervention trial with a clear outcome in mind. In the case of longevity: lifespan. Good luck running such a 50-plus-year trial with humans.
That’s why most of the anti-aging and longevity claims that make it into the popular made are from animal studies, with roundworms (C. elegans), fruit flies, or mice supplying most of the results. With these results, we can then try to infer the relevance of a certain mechanism or intervention in humans, either by looking at observational data or an intervention with specific biomarkers as endpoints. We can’t exactly wait until people drop dead to figure out what works and what doesn’t. Good luck getting that past the ethics board.
The point is that we have to combine different data sources to figure out which longevity-promoting things might work in humans. (Though, so far, common sense prevails. Move your body, eat nutritious foods, sleep well, and find a social tribe.)
So, most of the claims in the media — this drug adds years to your life! do this to reverse aging! — are based on animal studies.
But even those animal studies have a dirty, little secret.
The secret
A new preprint minces no words and the introduction immediately lays out the problem:
It is an open secret within the field of geroscience research that short-lived and metabolically unhealthy control animals can complicate the interpretation of lifespan studies. In addition, mouse lifespan studies are often small, limited to one sex, and fail to report potential confounding factors
I would add that lab animals are usually genetically impoverished (in terms of variation) compared to their wild cousins and that they are kept in very artificial conditions.
The dirty little secret behind the longevity headlines is this: driven by pressures…