The high blood pressure drug rilmenidine has been found to slow the aging of worms – an effect that, if translated to humans, could one day help us live longer and stay healthier in old age.
Rilmenidine appears to mimic the effects of caloric restriction at the cellular level, and reducing available energy while maintaining nutrition has been shown to extend lifespan in several animal models.
Whether this translates to human biology or is a potential risk to our health is a subject of ongoing debate. Finding ways to get the same benefits without the costs of extreme calorie reduction could lead to new ways to improve health in old age.
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In a study published in 2023, young and old Caenorhabditis elegans worms treated with the drug – which is normally used to treat high blood pressure – lived longer and showed higher measures in a variety of health markers, in the same way that calorie restriction did, as scientists had hoped.
Watch the video below for a summary of the research:
“For the first time, we have been able to show in animals that rilmenidine can increase lifespan,” said molecular biogerontologist João Pedro Magalhães of the University of Birmingham in the UK.
We are now keen to explore whether rilmenidine may have other clinical applications.
The C. elegans the worm is a favorite for study because many of its genes have similarities to counterparts in our genome. However, despite these similarities, it is still quite distantly related to humans.
Other tests showed that gene activity associated with caloric restriction could be seen in the kidney and liver tissues of mice treated with rilmenidine.
In other words, some of the changes that caloric restriction produces in animals that are thought to confer certain health benefits also occur with a high blood pressure medication that many people already take.
Another discovery was that a biological signaling receptor called nish-1 was crucial in the effectiveness of rilmenidine. This particular chemical structure could be targeted in future attempts to improve lifespan and slow aging.
“We found that the lifespan-extending effects of rilmenidine were abolished when nish-1 was deleted,” the researchers explain in their paper.
“Critically, rescue of the nish-1 receptor restored increased lifespan after rilmenidine treatment.”
Low-calorie diets are difficult to follow and have a variety of side effects, such as thinning hair, dizziness and brittle bones.
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It’s still early days, but it’s thought that this hypertension drug could provide the same benefits as a low-calorie diet while being easier on the body.
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“This research makes a novel case for rilmenidine to be considered a potential caloric restriction mimetic through its long-lasting and health-preserving effects,” the authors write.
What makes rilmenidine a promising candidate as an antiaging drug is that it can be taken orally, is already widely prescribed, and its side effects are rare and relatively mild (including palpitations, insomnia, and drowsiness in a few cases).
Recently, observational research has suggested that the drug metformin, which is already used to manage type 2 diabetes, may also give older women a better chance of living into their 90s.
Scientists from the US and Germany analyzed data from a long-term US study of postmenopausal women. Records were selected for 438 people – half of whom were taking metformin to treat diabetes and half who were taking another diabetes medicine called a sulphonylurea.
Those in the metformin group were calculated to have a 30% lower risk of dying before age 90 than those in the sulfonylurea group.
The study cannot demonstrate cause and effect like a randomized controlled trial (RCT) because the participants were not randomly assigned to one treatment or another—rather, they followed professional medical advice. Furthermore, there was no placebo group.
A key strength was the median follow-up period of 14 to 15 years, extending far beyond the length of a standard RCT. This is important to understand how any intervention influences lifespan.
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We’ll need a lot more research to figure out whether rilmenidine could also work as an anti-aging drug for humans, but early signs in worms and mice are promising. Scientists now know more about what rilmenidine can do and how it works.
“With an aging global population, the benefits of delaying aging, even slightly, are immense,” Magalhães said.
“The repurposing of drugs capable of extending life and health has huge untapped potential in translational geronscience.”
The research was published in Aged cell.
An earlier version of this article was published in January 2023.