Metformin, a common prescription drug that’s used to treat type 2 diabetes, is making headlines worldwide – but the big news has nothing to do with diabetes. Internet claims and sources boast that metformin may be the key to a longer life – boosting potential life span up to an incredible 120 years.
While that sounds too good to be true, the drug seems to have caught the attention of the Food and Drug Administration (FDA), which just recently approved the first human clinical trials – called Targeting Aging with Metformin, or TAME – to test the use of metformin in people who already have or at who are at risk for cancer, heart disease or cognitive impairment. The goal: to see if the drug can actually help delay the onset of such illnesses and increase longevity.
So what gives? Have scientists really stumbled upon the Fountain of Youth? We talked to internal medicine specialist and chief medical officer of Sharecare, Keith Roach, MD, to separate fact from fiction.
Sharecare: What’s the background on metformin?
Dr. Roach: Metformin’s been around for decades and is one of the most widely used drugs for diabetes. And while it’s very effective for diabetes, for the past 40 or so years, some have also thought that medications in the class of metformin – called biguanides – might have anti-aging properties.
Sharecare: What’s behind the anti-aging claim?
Dr. Roach: Metformin inhibits a protein called IGF1. This protein is associated with a lot of bad things that happen in the body. And now there’s a fairly large amount of evidence that giving animals – from worms to mice – metformin and drugs like it, tends to decrease some of the changes in the cell that we associate with aging. This in turn may lead to a greater degree of longevity.
Sharecare: Metformin working for mice and worms is one thing, but does it have the same effect on humans?
Dr. Roach: It’s unclear. So far, the only thing that’s been proven in humans to reliably decrease disease and slow aging is extreme calorie restriction. One of the things you see in extreme calorie restriction is a decrease in IGF1. So the idea is that maybe we can give this drug, which does the same thing, and get the benefit that’s associated with extreme calorie restriction without the health risks.
Sharecare: But what about people with diabetes who seem to be living longer on metformin? Can you explain that?
Dr. Roach: In long-term studies that have been done in people with diabetes, it’s pretty clear that metformin works better than insulin or other oral drugs. But people who take metformin for their diabetes don’t just magically live forever – it’s just that they may live longer than if they had been put on insulin or not been taking it all.
Sharecare: What’s your take on metformin for longevity?
Dr. Roach: I’m really happy that we’re doing this research, and I can’t wait to see the results. I think this is brilliant. But I’m skeptical. The clinical trial is trying to replicate the longevity benefits that are associated with extreme calorie restriction – but the data in humans that this type of calorie restriction even leads to longer life just isn’t there. Look at it this way: there have been people living in monasteries for thousands of years who practice extreme calorie restriction, and they don’t live to 120 years. Plus, if you look at people who do make it to very old age, extreme calorie restriction isn’t something that we universally see. Also, this isn’t a benign drug – it’s not without its side effects. For example, metformin can lead to serious 24/7 diarrhea symptoms and may even be fatal for those with kidney problems.
Sharecare: So what do you think of all the hype?
Dr. Roach: This should be an exciting time as a clinical trial, but it’s not a license to beg physicians for a metformin prescription in order to live forever. Nobody should take metformin yet, just for the purpose of trying to live longer. And that’s really my take-home point: If you want to boost longevity and reduce your risk of chronic disease, try these top three tips: get regular exercise, eat smart and manage stress.