Drugs that allow humans to live longer may seem like the stuff of utopian science fiction.
However, the recent discovery of a drug that can extend the life of mice by 25 percent has rekindled hopes of discovering a true anti-aging elixir.
An international team of researchers found that by inhibiting an inflammatory protein called IL-11, mice stayed healthier for longer into old age.
Scientists say the promising treatment is already being tested in humans for other age-related conditions, but caution that it is too early to know whether it will be safe in the long term.
Dr Cathy Slack, an expert in ageing biology at the University of Warwick, told MailOnline: “The functions of IL-11 in mice and humans are very similar, so the possibility that the treatment might work in the same way is exciting.”
Drugs that allow humans to live longer may seem like the stuff of utopian science fiction. But the recent discovery of a drug that can extend the life of mice by 25 percent has rekindled hopes of discovering a true anti-aging elixir.
As our bodies age, we accumulate more damaged proteins and chemicals, which our immune system can mistake for an infection.
This causes our bodies to overreact to the natural signs of aging and produce inflammation, which can have long-term detrimental effects on our health.
Inflammation is linked to cancer, fibrosis, and many of the other diseases we associate with aging.
While testing a method to detect IL-11, researchers at the UK Medical Research Council Laboratory of Medical Sciences (MRC LMS) found that older mice had significantly higher levels of the protein.
In 2016, they had already discovered that IL-11 was responsible for activating immune cells and ‘fibroblasts’ that cause the inflammatory response.
This gave the team the first clue that IL-11 levels might play a role in producing the negative effects of aging.
Researchers have discovered a potential anti-aging elixir that extended the life of mice (pictured) by 25 percent in laboratory tests
The Office for National Statistics predicts that life expectancy for men born in the UK in 2070 will reach 85 years on average, while women will be almost 88 when they die. However, researchers hope that this life expectancy could be extended even further with a range of new anti-ageing drugs.
To test this theory further, the scientists turned off the gene that produces the IL-11 protein in mice to see if they lived longer.
They found that mice that had the degraded gene lived 25 percent longer than those that did not have it.
In a second experiment, lead researcher Professor Stuart Cook of Duke-National University in Singapore and his team developed an antibody that eliminated the IL-11 protein in mice that still had the gene.
Professor Cook injected the antibodies into 37 mice, giving them one dose every three weeks from 75 weeks of age (the equivalent of 55 years in humans).
Compared with the 38 mice that did not receive the treatment, those that received IL-11 antibodies lived more than 20 percent longer.
A key aspect is that the mice not only lived longer, but they also stayed healthy longer (a measure known as health expectancy).
The 75-week-old animals, equivalent to a 55-year-old human, that received the drug (right) lived an average of 155 weeks, compared with 120 weeks for those that received no treatment (left).
Professor Cook said: ‘The treated mice had fewer cancers and were free of the usual signs of ageing and frailty, but we also saw a reduction in muscle wasting and an improvement in muscle strength.
“In other words, the older mice that received anti-IL11 were healthier.”
These results raise the tantalizing possibility that IL-11 treatment could be used as a “cure for aging” in humans.
In their paper, published in Nature, the researchers write: “Our data suggest that anti-IL-11 therapy… is a potentially translatable approach to extending health and life span in humans.”
Professor Cook added: “Our aim is to one day see anti-IL-11 therapy used as widely as possible, so that people around the world can live healthier lives for longer.”
Mice were injected with antibodies designed to inhibit the production of a protein called IL-11. Those that received the treatment (on the right of both images) showed a lower risk of cancer, less gray hair, and better vision compared to those that did not receive it (on the left).
However, experts caution that it is still unclear whether long-term use of IL-11 inhibition would have any negative impact on human health.
There are other potential treatments currently under investigation for their anti-aging properties, but very few can prolong health and lifespan as long as possible.
The drug Rapamycin, for example, works by blocking the actions of a protein that regulates cell growth and breakdown.
Studies have suggested that it has a potential anti-aging effect, but it also produces a number of side effects that could reduce a person’s overall health.
Dr Slack adds: ‘The effects of IL-11 inhibition on mouse lifespan reported in the study are similar to those seen with rapamycin.
“But there are concerns that drugs like rapamycin could have long-term health effects because they do not target specific cells or tissues in the body.”
Renowned eccentric biohacker Bryan Johnson (pictured) takes an anti-aging drug called rapamycin, but there are concerns that the compound could have serious effects on human health.
Researchers believe their IL-11 inhibition treatment will have less severe side effects than rapamycin (pictured)
However, researchers say disabling LI-11 is unlikely to lead to further complications because the protein has no beneficial function.
In a video, lead researcher Professor Stuart Cook explains: ‘This is something we have inherited from fish through evolution and it has beneficial effects on them.
“Unfortunately for us, it’s an evolutionary hangover that causes harm and causes disease.”
The study claims that IL-11 inhibition has a “reassuring safety profile and is currently in early-stage clinical trials for fibroinflammatory diseases.”
Dr. Slack further notes that antibody treatment could be refined to make it more specific and therefore even safer.
However, as is often the case in medical research, it may still be too early to tell whether this treatment could actually work in humans.
“It’s too early to tell from this study, but the initial results reported in human cells are promising,” says Dr. Slacks.
He adds: ‘Clinical trials on human life expectancy are almost impossible: they would take too long and be too expensive.
‘Instead, trials to determine the effects of IL-11 inhibition on age-related health would be much more likely.’