- Estrogen plays an important role in preventing chronic obstructive pulmonary disease and emphysema
- Post-menopausal lung deterioration is reversible with estrogen
Yes, that title may seem sexist (men want to keep their lung function too!), but Nature and Creation have put women at a disadvantage. Women’s lung function is very dependent on estrogen, and as everyone knows, a woman’s estrogen level virtually disappears after menopause.
There are seventy-three research reports (no kidding, check PubMed!) jointly authored by Drs. Donald Massaro and Gloria DeCarlo Massaro—and sometimes other co-authors—from the Lung Biology Laboratory at Georgetown University School of Medicine. Some of these studies have established that estrogen is extremely important to women’s lung health.
Unfortunately, many of us have no idea about estrogen’s role in lung health, since reporting about these studies has been minimal-to-nonexistent in newspapers, television, radio, and major Internet websites, all of which appear to prefer to reprint financially driven news releases from patent medicine companies instead of doing their own investigative research and reporting.
Although chronic obstructive pulmonary disease (COPD) and emphysema are obvious and well-known results of smoking, non-smokers sometimes develop COPD and emphysema, too. And instances of both conditions are much higher in non-smoking women than they are in non-smoking men; women die earlier of them than men.
These facts alone should be a clue, but scientific proof is best, and that’s what the Doctors Massaro have provided. What follows will be limited to four of their reports (can’t come anywhere close to reviewing all seventy-three!). These four studies help explain why women tend to have such lung problems more than men—and show just how simple it can be not only to protect your lungs, but also to repair any damage that’s already been done.
Women “Breathe for Two” with Estrogen
The first research report of these four was published by the doctors Massaro (along with Dr. J.P. Mortola) in 1995.[1] Working with female rats, the researchers discovered that oxygen uptake almost doubled during pregnancy and nursing, even though the structure and surface area of the lungs remained the same as before (total surface area of the lungs directly correlates with the degree of oxygen-carbon dioxide exchange). They suspected that the hormonal increases of pregnancy were responsible for the increased oxygen uptake.
But even though the female rats’ lung surface area didn’t change during pregnancy, the research team also found that mature female rats naturally have a higher total lung surface area for oxygen-carbon dioxide exchange than male rats of the same age. The females also had significantly smaller alveoli (the billions of tiny oxygen-carbon dioxide exchanging “sacs” that comprise the lungs’ spongy tissue) than the males. And the smaller the alveoli in the lungs, the more there are, which accounts for the greater gas exchange surface area.
A year after they reported these initial discoveries, the same doctors proved that estrogen is directly responsible for the difference between the lungs of female and male rats in two ways.[2] First, they removed the ovaries from immature female rats, and found that when they had fully matured, these females had larger alveoli and a smaller gas-exchange surface area than female rats of the same age that hadn’t had their ovaries removed. In the second phase of the study, the researchers gave a group of immature female rats extra estrogen and found that these females developed smaller, more numerous alveoli (resulting in greater gas-exchange surface area) than immature rats not given estrogen.
To rule out the possibility that hormones in general are responsible for lung development, the researchers gave androgens (testosterone and testosterone-related hormones) to a group of newborn female rats. But the extra androgens made no difference to the ultimate size or total oxygen-exchange surface area of their lungs. They also discovered that male newborn rats that had been genetically engineered to be deficient in androgen receptors (so that their own testosterone would be less effective) had the same lung development as newborn male rats with normal androgen receptors.
We’ve all heard about “eating for two” during pregnancy. We know that developing infants obtain all their nutrients from what Mom eats, but we don’t usually think about the fact that developing babies need oxygen, too, just like any other human, even if they can’t use their own lungs yet. A developing baby’s oxygen comes from Mom, just like all the baby’s nutrients! During pregnancy, Mom is “breathing for two”—and this fits perfectly with estrogen’s effect of improving Mom’s oxygen-absorbing capability, an effect not shared—since men don’t get pregnant—with testosterone.
With all of the information they’d compiled, these researchers concluded that estrogen has a major responsibility for lung function in females. From there, they moved on to test the effects of estrogen loss—and replacement—on lung health.
Reversing Lung Damage with Estrogen
First they found that removing the ovaries (a procedure technically known as “ovariectomy”) of adult female mice resulted in both loss of alveoli and of lung surface area. Loss of surface area reduces oxygen-carbon dioxide exchange (in other words, it negatively impacts the ability to breathe easily). But when they gave the rats that had had their ovaries removed estrogen replacement, not only did they regain some of the alveoli they’d lost, but the ones that were damaged actually got better.
They concluded in part that “estrogen is required for maintenance of already formed alveoli and induces alveolar regeneration after their loss in adult ovariectomized mice, and [this research] offers the possibility that estrogen can slow alveolar loss and induce alveolar regeneration in women with COPD.”[3]
In 2006, the Doctors Massaro added to their series of studies with a review article of their own work as well as the research of others.[4] The review pointed out that normal aging already results in loss of lung alveoli, and that menopause further accelerates the loss of lung surface area—which, in turn, reduces oxygen-carbon dioxide exchange and makes breathing more difficult. In other words, since estrogen is critical to long-term protection of women’s lungs, after menopause there’s just not enough estrogen for some women, and their lungs suffer.
They also pointed out that their work and work in other laboratories “has disproved the notion that pulmonary alveoli are incapable of regeneration,” and that research indicates that the factors regulating both alveolar loss and regeneration are “conserved” (scientese for “the same”) for rats, mice, and humans.
Other researchers have since shown that female lungs can definitely be regenerated with estrogens. Here’s what they wrote:[5] “Lungs isolated from old mice (24 months old, estrogen-deficient) demonstrated decreased lung volume and decreased alveolar surface area.. .. ..Estrogen replacement restored lung volume, alveolar surface area, and alveolar wall thickness to that of a young mouse.”
Summarized: In female mice, old lungs can be regenerated into young lungs! And remember that lung loss and regeneration had already been shown (by the Doctors Massaro) to be the same in rats, mice, and humans
Breathe Better—for Much Longer—with BHRT
So what do all of these study results mean for you (or at least the women in the audience)? There are several implications of this research work. First, even if you’re healthy, you should seriously consider bioidentical hormone replacement therapy (BHRT) if you want to maximize your lungs’ ability to absorb oxygen and get rid of carbon dioxide as you get older. This is especially important if you’re an athlete, and want to continue your athletic activities for as long as you can—but maintaining healthy lungs also helps make simple daily tasks like walking up and down the stairs much easier.
BHRT may be especially important for women (non-smokers) who have emphysema and/or COPD. If your estrogen levels are low enough to have caused (or at least contributed to) these problems, chances are that you’re also at a significantly higher risk for the other problems associated with low estrogen levels, such as Alzheimer’s disease, heart attack and other cardiovascular disease, and osteoporosis. But BHRT can help protect you from all of these conditions while it’s helping to repair the damage that has been done to your lungs.
Even if your emphysema and/or COPD can be linked to smoking, BHRT is still worth trying. It may not help as much as if you’d never smoked, but if you’re past menopause, your estrogens are already low, so replacing what your body is missing certainly won’t hurt.
Women’s Vocal Quality, and Singing
Although there appear to be no formal studies on this aspect of BHRT for women, since the early days of BHRT some thirty years ago many, many, many (yes that’s three “manys”!) women—as well as choirmasters and voice instructors—have told me about how BHRT restores vocal quality.
One vocal instructor phoned me from southern California in the late 1980s to thank me for himself and his students for introducing comprehensive BHRT a few years before. He’d noticed that after menopause, almost none of the women he worked with sounded the same.
But when one of his students (a post-menopausal woman) started BHRT, her voice made such a dramatic comeback within just a few months that he recommended it to all the post-menopausal women he worked with, and they all improved.
Think about it: when does a girl’s voice start sounding like a woman’s voice? We all know the answer—when she goes through puberty and her estrogen and other sex hormones “come on.” We all can tell that a woman is “getting older” just by listening to her; her voice “sounds like a grandma.” It just makes sense that as her estrogen goes down, her voice changes.
This article is adapted and updated from the book Stay Young and Sexy with Bio-identical Hormone Replacement: The Science Explained, written by Lane Lenard, PhD, and me, published in 2010. Dr. Lenard and I also wrote and published the very first book about BHRT (with a different title) in 1997.
[1] Massaro GD, Mortola JP, Massaro D. “Sexual dimorphism in the architecture of the lung’s gas-exchange region,” Proc Natl Acad Sci U S A. 1995; 92(4): 1,105-1,107
[2] Massaro GD, Mortola JP, Massaro D. “Estrogen modulates the dimensions of the lung’s gas-exchange surface area and alveoli in female rats,” Am J Physiol 1996; 270(1 Pt 1): L110-L114
[3] Massaro D, Massaro GD. “Estrogen regulates pulmonary alveolar formation, loss, and regeneration in mice,” Am J Physiol Lung Cell Mol Physiol 2004; 287(6): L1,154-L1,159
[4] Massaro D, Massaro GD. “Toward therapeutic pulmonary alveolar regeneration in humans,” Proc Am Thorac Soc 2006; 3(8): 709-712
[5] Glassberg MK, Choi R, et al. 17β-estradiol replacement reverses age-related lung disease in estrogen-deficient C57BL/6J mice. Endocrinology. 2014 Feb;155(2):441-8
