Hormones don’t just go “south” from stress, poor food choices, or genetic bad luck. They are affected by what you inhale. And how long you sit. Even in your teen-age daughter or your sweet old granny.

I recently did an amazing show with Dave Asprey from BulletProof  on hormones and the environment. Listen to it here.

Air pollution exposures and lack of exercise have historically been linked to heart and lung disease. But now, both air pollution and excessive sitting are being scientifically shown, to adversely affect your estrogens.

Gynecologic science has known that hormones rule reproductive and menstrual health or risk factors, but who knew that sitting for longer hours, or breathing in particulate-polluted air, could actually demonstrate hormonal activity?

It began with a study that not too many have heard about. Approximately thirteen years ago the Women’s Health Initiative (WHI) was a group of studies designed to examine how to better care-take our rapidly growing older female demographic. This group of investigations is famous for it’s ill-fated hormonal trials that first showed that hormone replacement might be dangerous. Re-analysis showed otherwise.

But another study was spun off that didn’t make headlines.

The scientists running the WHI realized that Americans sit more and more. They also appreciated that as we age, most of us sit even more and more and more. Thus, the WHI researchers wanted to see what “prolonged sitting” does to female hormones.

They looked at 1804 postmenopausal women enrolled in the Women’s Health Initiative Observational Study and analyzed 15 estrogens along with their break down products (estrogen metabolites).  They looked at what nestling in for long hours with our derriere, into our favorite chair, did to our estrogens.

The results were gloomy. The more women sat, (over 5 hours a day and especially over 10 hours a day) the “higher” their blood levels of the parent estrogens, estradiol and estrone. These are the key estrogens, when in excess, that are linked to female cancers. Especially estrone. Estrone is the estrogen more linked to obesity, excessive inflammation and higher risks of estrogen-driven cancers like breast cancer.

The amount of time ‘sitting” was more relevant and “independent” on adversely effecting estrogen levels, especially estrone, than even moderate to vigorous exercise or how big your body is (body mass index).

Sitting dings your estrogens in an unhealthy way. In other words, sitting has estrogenic activity!

Many women today are frightened, since the early WHI’s scary headlines, of being prescribed estrogen replacement. They’re concerned about upping their risk of breast cancer. But do they consider how much sitting increases their risk of breast cancer?

There was an ultimate bad recipe that increased the risk of hormonally driven cancers even more. This was prolonged sitting along with lower levels of physical activity. Sitting more along with moving less, was linked to even higher significant levels of the parent estrogens (estrone and estradiol), with lower levels of the protective breakdown metabolites, especially in menopausal women.

More sitting + less moving = higher parents estrogens and lower protective estrogen metabolites.

This scenario creates a hormonal pattern inside your body that increases your risk of breast, uterine, ovarian and perhaps other cancers.

Okay, what if you are sitting more and moving less in a home near a busy highway? Or you sit in traffic for an hour a day? Or you work near a busy freeway? Or close to a city dump? Now you have added polluted air on top of the equation above. Researchers from Boston University School of Medicine wanted to know what polluted air does to our hormones.

These scientists gathered data from the Nurses’ Health Study 2 Study, along with pollution exposure metrics from the EPA air quality monitoring system from the areas where these ladies in this study resided.

The Boston researchers found that exposure to air pollution, in this case, during high school, was correlated with adverse effects on menstruation, such as making the menstrual cycle irregular.

But these effects probably aren’t limited to only teens. Here you are, sitting at home in your home office, 5 blocks from an express way entrance, working away, trying to be a successful entrepreneur, or you’re a grandma knitting a blanket (does anyone do that any more); and you sit more, move less and breathe more pollution.

Your hormones are probably going crazy. I sit way too much. I write blogs, see patients, record radio shows; all activities that require hours of sitting.

Yes, I go to the gym and work out every day. But this WHI study suggests that one hour of motion a day does not healthy estrogens make, if too many other hours of the day are spent sitting, sitting and more sitting.

What to do?

4 Strategies to Protect Your Estrogens While Sitting

I call this strategic sitting hygiene, to “break” the bad physiologic sitting spell.

1. Flex your large thigh muscles every so many minutes, like 10 or 15 minutes. This means contract your quads, you can do this while still in the seated position.

2. Get up and down. When you get up, be in a flexed position that tightens your quads.

3. Get up and move. Every 20 minutes or so get up and walk around or jump and down a bit in place.

4. Have a high quality standing air filter next to where you spend most of your time (I have IQ Air Filters around my home and UV lights in my ducts, and more).

Breaking the sitting spell should keep your estrogens watching your physiologic back rather than taking you down the hormonal rabbit hole of increased risk of cancers and other diseases (let alone obesity). Yes, we need studies to prove all this. But let’s you and me take precautionary action NOW!

We don’t live in a bubble. There’s synergy. The more you sit, the less you exercise, and the more polluted air you inhale, the more your estrogens (and probably other hormones, too) become unhealthy. They develop high-risk patterns between parent hormones and how your body processes these hormones into less risky breakdown hormonal pieces.

The underlying mechanisms are not yet fully known. Perhaps more sitting and pollution modify your genetic expression (epigenetics) or alter your liver health so the liver detox cells can’t process your hormones as optimally.

Whatever the mystery mixes, the choices you make throughout your day, sitting and breathing, is as big a choice as you starting the day with green drinks. If not more.

Food is not your only health insurance. Air and motion are part of the picture. Air is 24/7 and sitting might be close to half a day (not counting sleeping, another gravity-less state) compared to eating, which is usually only 3 to 5 times a day. Look at the bigger picture. Especially at your life’s bigger picture as it relates to keeping your hormones healthy, to keep you healthy.

PS To think that all of this info only applies to females, is short sighted. Males have estrogens, too. So this probaby applies to keeping male estrogens healthy, too. Stay tuned for a lot more ways to analyze and clean your air; it matters, especially to your estrogens!

New Courses! I just launched a new 4 hour course on estrogen, called Everything About the New Estrogen.

Go to Thinktific to take a peek and decide if you want to jump in and learn more.


Perimenarchal air pollution exposure and menstrual disorders. Human Reproduction, 2018; Jan. 25. Air Pollution Exposures During Adulthood and Risk of Endometriosis in the Nurses’ Health Study II. Environ Health Perspect; Vol. 122:2014 DOI:10.1289/ehp.1306627

Sitting, physical activity, and serum oestrogen metabolism in postmenopausal women: the Women’s Health Initiative Observational Study. Br J Cancer. 2017 Sep 26;117(7):1070-1078.

Is endometriosis associated with systemic subclinical inflammation? Gynecol Obstet Invest 62:139–147. 2006. Air pollution and cardiovascular disease: a statement for healthcare professionals from the expert panel on population and prevention science of the American Heart Association. Circulation 109:2655–2671. 2004.

Particulate matter air pollution and cardiovascular disease: an update to the scientific statement from the American Heart Association. Circulation 121:2331–2378. 2010.