Metformin is a very old drug that is used to treat type 2 diabetes. It was developed from the French lilac plant, Galega officinalis. Healers in the 17th century used extracts from this plant to treat symptoms associated with type 2 diabetes. The diabetes drug metformin was first used as a medication in France in 1957. It is one of the most widely prescribed drugs in the world for this metabolic disorder. Now, however, scientists are discovering that the diabetes drug metformin may also benefit a range of other health problems. The latest discovery: metformin vs. asthma!
Metformin Reduced Asthma Attacks:
The headline in the journal JAMA Internal Medicine (Nov. 18, 2024) caught our attention:
Antidiabetic Medication and Asthma Attacks
Here is the question the researchers were asking:
“Question: In patients with asthma and diabetes, are metformin (the first-line diabetes medication) or any add-on antidiabetic medications associated with a reduced risk of asthma attacks?”
The reason they asked this question is because 1 out of every 3 asthma patients is seriously overweight. Half of these individuals have type 2 diabetes (T2D). We wonder if the liberal use of corticosteroid-type medications to treat asthma might contribute to overweight in susceptible individuals. But that’s a question for another day.
Not surprisingly, these UK researchers wanted to know if the first-line treatment for type 2 diabetes, metformin, might have an impact upon asthma attacks. That’s because this medication has anti-inflammatory activity in the lungs. There are other mechanisms as well, but we won’t overwhelm you with detailed pharmacology.
They also note that prior studies suggested the diabetes drug metformin might provide potential benefits against asthma:
“A Taiwanese study found that metformin was associated with a 60% decrease in asthma attacks, but they did not account for smoking, weight, and glycemic control. A US study found metformin was associated with a 40% reduction in hospitalized asthma attacks but had no association with asthma-related oral corticosteroid use.”
And the envelope, please:
“In this population-based asthma cohort study, we found that metformin, the first-line, affordable, and effective antidiabetic drug, was associated with an approximate 30% reduction in asthma attacks.”
They also discovered that the hot GLP-1RA add on diabetes drugs such as semaglutide (Ozempic, Rybelsus) and tirzepatide (Mounjaro) “…were associated with an additional approximate 40% reduction in asthma attacks.”
The metformin anti-asthma effect was not related to either blood sugar control or weight loss. The exact mechanism remains mysterious.
Nevertheless, the authors conclude:
“These findings suggest potential for repurposing antidiabetic drugs to much-needed alternative treatments for asthma. Further research, including randomized clinical trials and mechanistic studies, are now needed to confirm their effect and the mechanism of action in asthma.”
Could Diabetes Drug Metformin Benefit Pulmonary Fibrosis?
Researchers have also discovered that metformin may have other health benefits. Scientists at the University of Alabama at Birmingham report that the drug appears to be helpful in models of pulmonary fibrosis (Nature Medicine, July 2, 2018).
This condition affects over 150,000 people each year and it can be fatal. The small air sacs called alveoli become scarred and stiff as a result of a repair process that goes awry. Pulmonary fibrosis can be triggered by certain medications, cancer chemotherapy, radiation or infection. Environmental toxins such as silica or coal dust, asbestos fibers and bird droppings may also contribute to fibrosis. Treatment is difficult, and there is no cure available at this time.
A review of the anti-fibrotic effects of metformin was published in the journal Cells (Aug. 19, 2021).
The authors describe the drug’s actions this way:
“Metformin is an effective, safe and inexpensive first-line pharmacotherapy for type 2 diabetes mellitus. Heralded to be an anti-aging drug, it also has emerged a drug of interest in combating the fibrotic changes and mitochondrial dysfunction, seen in glaucomatous eyes. It has been shown to have protective effects on ocular complications in patients with type 2 diabetes (T2DM) through its anti-inflammatory, anti-angiogenic and anti-aging effects.”
If the preliminary research with metformin holds up in clinical trials, this ancient medicine might become a breakthrough for reversing pulmonary fibrosis.
Diabetes Drug Metformin May Also Protect the Thyroid:
Metformin holds promise for certain other conditions in addition to diabetes, asthma and pulmonary fibrosis. It is also being studied for its ability to prevent the development of certain cancers. One reader wrote about a somewhat unexpected benefit of taking the diabetes drug metformin.
Does the Diabetes Drug Metformin Control Thyroid Nodules?
Q. My endocrinologist has prescribed the diabetes drug metformin to control thyroid nodules and prevent thyroid cancer. I am not diabetic, so my other doctors wonder why I would be taking metformin. Is there any evidence that metformin has anticancer benefits?
A. Your endocrinologist is keeping up with medical research. A review in the journal Frontiers in Endocrinology (Nov. 14, 2017) discusses the anticancer activity of metformin, particularly with respect to thyroid cancer.
There is also evidence that this drug can reduce thyroid nodules and may both prevent and help treat thyroid cancer. A systematic review concluded that metformin might be helpful in treating colorectal and prostate cancer as well (Coyle et al, Annals of Oncology, Dec, 2016).
Does Metformin Has Role in Cancer Prevention?
Scientists have been studying exactly how metformin can reduce the risk of various types of cancer. They are also considering how it might be used in conjunction with more conventional therapies to treat certain cancers (Morales & Morris, Annual Review of Medicine, 2015).
In addition to colorectal and prostate cancers, researchers suggest that its ability to keep cancer cells from proliferating could be valuable in treating lung cancer (Gupta et al, Panminerva Medica, online Jan. 25, 2018). They are even evaluating its usefulness in helping to treat glioblastoma multiforme, an aggressive brain cancer (Valtorta et al, Oncotarget, Dec. 2017). This medication suppresses cancer stem cells, including those from pancreatic, breast, colon and prostate cancers (Saini & Yang, Acta Biochimica et Biophysica Sinica, online Oct. 7, 2017).
The Diabetes Drug Metformin Reduces the Risk of Head and Neck Tumors:
Researchers have reported that metformin may also offer benefits against head and neck tumors (Curry et al, The Laryngoscope, Aug. 2017). In this pilot study, the researchers took tissue samples from 39 patients with head or neck tumors. The participants then took metformin at about half the dose used by people with diabetes. The scientists sampled the tumors again and compared the metabolic markers.
How Does Metformin Fight Cancer?
Metformin interferes with cancer cells’ ability to create energy for growth by changing the pathways they use. Cancer cells are fast-growing, so they need a lot of energy generated quickly. The medication also encourages cancer cell death by disrupting the cancer support system. Because metformin is generally well-tolerated and far less toxic than standard cancer drugs, it may become a valuable adjunctive treatment for a variety of tumors.
We have written previously about the diabetes drug metformin being used to fight cancer. You can read about it here and here.
Most oncologists have not embraced metformin either as a preventive or treatment approach. Let’s be honest, this inexpensive drug does not have a big pharmaceutical company licking its chops to explore any anticancer benefits. Modern anti-cancer treatments can cost tens of thousands to hundreds of thousands of dollars a year. A drug like metformin that is incredibly affordable does not stimulate much interest.
There are thousands of articles about metformin and cancer, though. When last I checked, there were 7,808 results of a PubMed response in the National Library of Medicine. Here is a link to that search.
Other Readers’ Experience:
Keep in mind that risk reduction is based on statistics. Nothing that we know of prevents cancer in everybody.
Everett wrote of his disappointment:
“My dermatologist just did a full-body inspection and found a squamous cell cancer on my forehead. I’ve been taking metformin for two years, so in my opinion, its anticancer activity is overrated.”
Lyn cautioned:
“Metformin does have negative side effects for some people. Be sure to check with your physician in light of your own medical history before you jump into taking it.”
Luna offers a different explanation for an anti-cancer benefit:
“Okay, there seems to be evidence that people who use metformin to manage diabetes have a lower risk of certain cancers. So, is it the metformin or is it better management of blood sugars that minimize cancer risk?
“If it’s the latter, how about skipping the pharmaceuticals and use other methods to manage blood sugars – with a side benefit of minimizing cancer?”
Gary adds this perspective:
“I’ve taken metformin for over 20 years. I have not experienced any of the mentioned side effects. It has been doing a good job keeping my blood sugar in check. And if it has some anti-cancer affect and/or increases longevity, just added benefits.”
You can read more about metformin side effects and how to overcome them here. If you have had experience taking the diabetes drug metformin to prevent or treat cancer, please tell us about it in the comment section below.
