The drug finasteride, also known as Propecia or Proscar, treats male pattern baldness and an enlarged prostate in millions of men around the world. But a new study from the University of Illinois at Urbana-Champaign suggests that the drug may also provide a surprising, life-saving benefit: lowering cholesterol and reducing the overall risk of cardiovascular disease.
The study, published in the Lipid Research Journalfound significant correlations between finasteride use and lower cholesterol levels in men who participated in the National Health and Nutrition Examination Survey between 2009 and 2016. In mice taking high doses of finasteride, the researchers found reductions in plasma cholesterol total, delay in the progression of atherosclerosis and less inflammation. in the liver and related benefits.
“When we looked at men taking finasteride in the survey, their cholesterol levels averaged 30 points lower than men who weren't taking the drug. I thought we'd see the opposite pattern, so it was very interesting,” the author said. principal of the study, Jaume Amengual. , assistant professor in the Department of Food Sciences and Human Nutrition and the Division of Nutritional Sciences, both part of the U. of I College of Agricultural, Consumer and Environmental Sciences (ACES).
As exciting as the survey results were, they had their limitations. Of nearly 4,800 respondents who met general health criteria for inclusion in the analysis, only 155, all men over age 50, reported using finasteride. And the researchers couldn't determine how much or for how long the men in the survey had taken the drug.
“This was not a clinical study where you can control everything perfectly,” Amengual said. “It was more of an observation that led us to say, 'Okay, now we've seen this in people. Let's see what happens in mice.'”
But first, why would a hair loss and prostate medication affect cholesterol? Amengual studies atherosclerosis, the condition in which cholesterol plaques clog the arteries and cause strokes, heart attacks and other forms of cardiovascular disease. Because the disease is much more common in men than in premenopausal women, scientists have long suspected that the sex hormone testosterone is important in atherosclerosis, although its role is not entirely clear.
Finasteride works by blocking a protein found in hair follicles and the prostate gland that activates testosterone. The common thread, testosterone, was enough to pique Amengual's interest.
“One day I was reading about this drug and started to notice that there weren't many long-term studies on the implications of the drug. At first, it was just my own curiosity, based on the fact that increased hormone levels are known to have. an effect on atherosclerosis, hair loss and prostate problems,” he said. “So we decided to delve into it.”
After documenting the first, albeit observational, link between finasteride and lower cholesterol levels in men, Amengual asked doctoral student Donald Molina Chaves to see if the pattern held in mice.
Molina Chaves tested four levels of finasteride (0, 10, 100 and 1000 milligrams per kilogram of food) in male mice genetically predisposed to atherosclerosis. The mice consumed the drug, along with a “Western” diet rich in fat and cholesterol, for 12 weeks. After the experiment, Molina Chaves analyzed the levels of cholesterol and other lipids in the mice, along with evidence of atherosclerotic plaques. She also tested gene expression in the liver, looked at bile acid metabolism, and analyzed steroids, triglycerides, immune activity, and more.
“Mice that received a high dose of finasteride showed lower cholesterol levels in both plasma and arteries,” said Molina Chaves. “There were also fewer lipids and inflammatory markers in the liver.”
Although the effects were only significant at the highest dose, a level that Amengual considers scandalous for humans, he explains that mice metabolize finasteride differently than people.
“It's an incredibly high level of the drug. But we used mice as a model, and they are extremely resistant to things that would kill any of us,” he said. “So it's not so crazy when you think about it that way.”
Humans take doses of 1 milligram or 5 milligrams of finasteride per day for hair loss and prostate enlargement, respectively. The fact that a clear pattern emerged in a survey of men likely taking one of these doses suggests that the drug may be lowering cholesterol without the megadoses tested in mice.
The next step is for doctors to start tracking cholesterol in patients on finasteride or conduct a clinical trial to verify the effect. Amengual says it may be especially important to understand how finasteride affects trans people.
“Over the last decade, doctors began prescribing this medication to people transitioning from male to female or female to male. In both cases, hormonal changes can trigger hair loss,” he said. “What's interesting is that transgender people also have a higher risk of cardiovascular disease. Therefore, this drug could have a potential beneficial effect in preventing cardiovascular disease not only in cis men, but also in transgender people.”
Finally, Amengual points out that, like any medication, finasteride is not without risks. People should consult their doctors for more information.