Can metformin help you to live longer?
Scientists are always looking for new medications that could help us to live longer lives. One drug that shows promise for longevity is metformin. In this post, we’ll explore what metformin is, how metformin works, and if metformin could help us to live longer.
What is metformin?
Metformin is a drug most commonly used to treat type 2 diabetes. It’s also used off-label to treat polycystic ovary syndrome (PCOS). Metformin works by making your body more sensitive to insulin. That means you have a better response to the natural insulin your body produces. This lowers your blood sugar levels and can help prevent a host of other symptoms. These include kidney damage, blindness, and nerve damage.
Metformin is usually taken as a daily pill or liquid. It has been approved by the FDA since 1995, and between 2000-2015, doctors wrote over 553 million prescriptions for metformin. Common side-effects of metformin include digestive upsets and headaches, which usually go away after a couple of weeks. In extremely rare cases, metformin can cause kidney problems or lactic acidosis. This is a dangerous buildup of lactic acid in the blood.
The rate of lactic acidosis is about 0.03 per 1000 patient-years. That means about 3 in every 100,000 people experience this side-effect in any given year.
How does metformin work?
Scientists are still investigating how metformin increases insulin sensitivity. Metformin comes from a plant called galega or goat's-rue, and it has been used to lower blood sugar since at least the 1950s.
What metformin primarily does is increase mitochondrial stress. Mitochondria are the “powerhouse of the cell,” where energy is made. The energy cells use is called adenosine triphosphate (ATP). Producing ATP is a complicated process that produces lots of unwanted byproducts. That makes mitochondria vulnerable to damage and dysfunction.
Stressing out our mitochondria might sound bad, but at the right level it can be beneficial. When our bodies detect that our mitochondria is stressed, that triggers our inner repair mechanisms. Sending those signals earlier could mean our cells suffer less damage, and that could actually make them healthier.
Why is metformin linked to aging?
Because taking metformin can influence the health of all our cells, it can have a beneficial effect on longevity. One study found that type 2 diabetics who are prescribed metformin live longer than non-diabetics. That’s significant because type 2 diabetes shortens life expectancy by up to 10 years. This study suggests that taking metformin doesn’t only prevent type 2 diabetes from shortening life. It actively increases life expectancy beyond the norm.
To understand why, we can look at the role of mitochondria again. Mitochondria provide the energy our cells need to survive. That means we need healthy mitochondria in order to function at a cellular level. If our mitochondria become damaged or stop working, then our cells die. On a small scale, that might result in a few lines or wrinkles. On a large scale, that can lead to DNA mutations and body-wide symptoms of premature aging.
By protecting our mitochondria and keeping it healthier for longer, metformin can protect all our cells. Studies have shown that metformin can have a positive impact on many of our organs and bodily functions. These include our brains, ovaries, and blood vessels, and fat storage and body weight. This could reduce the chances of developing chronic conditions like fatty liver disease and some cancers.
Metformin as a cancer treatment
Metformin can mimic fasting and calorie restrictions, giving people some of the benefits of dieting without being on a diet. Intermittent fasting has lots of beneficial effects on the body. The root cause of this is forcing our bodies to switch to a different energy source, burning our fat stores instead of sugars in our food.
For cancer patients, this produces an added benefit. Cancer loves sugar. The unchecked growth of cancer cells uses a lot of energy, and these cells consume about 200 times as much glucose as healthy cells. Increasing insulin sensitivity and making your body less reliant on sugar as an energy source could help to fight cancer. One study of breast cancer patients found that adding metformin to their treatment plan produced beneficial results.
The downsides of taking metformin for longevity
While all of this sounds amazing, metformin isn’t a wonder-drug that can help everybody to live longer. For some people, taking metformin might even be harmful.
Exercise places the same stress on mitochondria that metformin does. One study found that taking metformin in later life can trigger metabolism failure. When mitochondria becomes too stressed, it stops working. That leads to the symptoms of premature aging that we need to prevent to extend our longevity.
For healthy people who are middle aged or older, taking metformin could have a negative impact on their health. Metformin can increase their mitochondrial stress beyond acceptable levels. Even for younger people, combining exercise with metformin is counterproductive. Studies show that metformin can undo the health benefits of exercising.
Metformin shows great promise as an anti-aging drug that could help extend our lifespans. However metformin doesn’t have the same effects on everybody. Healthy (non-diabetic) people should be cautious about taking metformin in middle or old age.
The FDA recently approved the first human trials into metformin use for promoting longevity. Lab studies of animals have found that metformin can prevent or delay cancer onset and increase longevity in animals such as mice and roundworms. But human studies to date show both positive and negative effects of metformin.
For individuals with insulin sensitivity, metformin can improve their health, reduce signs of aging, and extend longevity. But for non-diabetic individuals, especially those who are physically fit, the downsides of metformin may outweigh the benefits.