Our cumulative exposure to estrogen  – women and men – during our lifetime is the single most important risk factor for estrogen-driven cancers.

ome women learn about managing their estrogen levels when the stakes are high — they have been diagnosed with estrogen-dependent cancer like breast cancer, ovarian cancer or endometrial (uterine) cancer that uses our body’s estrogen to develop and grow.

Some women — and I include myself here — prefer to learn how we can take preventative steps to NOT get these cancers in the first place, to the degree it’s in our control.

For the past 30 years, I’ve tweaked my estriol levels (and progesterone levels). And I’ve written extensively about bioidentical hormones.

I tweak my estriol and progesterone levels because I understand that:

• Estriol hormone therapy helps prevent cancer initiation.
• Progesterone hormone therapy helps prevent cancer promotion caused by excessive estrogens (estriol included).

I’m going to explain in this article why topping up our estriol and progesterone levels using bioidentical hormones is protective and can be used long-term, providing we keep levels as low as absolutely possible, and we take regular breaks from dosing.

A Snapshot of Our Body’s Estrogen

The word “estrogen” is, in fact, a word that covers a group of hormones, not a single hormone.

Here are the three main estrogens we need to be aware of:

• Estrone (E1) is produced mainly by fat cells and is the primary form of estrogen after menopause.
• Estradiol (E2) is made in our ovaries during our reproductive years.
• Estriol (E3) is primarily made during pregnancy.

Our Exposure to Estrogen and Risk of Breast Cancer

How much estrogen we are exposed to over the course of our lifetime, and how our cells respond, is where current research is taking place.

This cumulative exposure to estrogen — for women and men — is the single most important risk factor for estrogen-driven cancers.

Our risk of developing breast cancer by age:

• By age 30: 1 in 2,525
• By age 40: 1 in 217
• By age 50: 1 in 50
• By age 60: 1 in 24
• By age 70: 1 in 14
• By age 80: 1 in 10

As we age and hormone levels decline, our risk of breast cancer increases.

The Good News

When compared with our more potent estrogens — estrone and estradiol — estriol was thought to have little significance due to its weak estrogenic activity. But that’s not proving to be the case. Research has found that estriol’s ability to protect the body hinges on this weak estrogenic activity to protect against these more aggressive estrogens.

Estriol plays an essential role in allowing the differentiation of the normal stem cells in the breast that are more vulnerable to carcinogenic (cancer-causing) insults. This is a key to breast cancer prevention.

Estriol is protective of the human genome because its level increases a thousand-fold during pregnancy and is at its highest level just before birth.

Some of the most common and effective treatments that employ estriol include:

• hot flashes
• insomnia
• skin enhancement
• vaginal atrophy
• reduced frequency of urinary tract infections.

Estriol has been used clinically in many countries, including the USA, for at least 70 years.

Estriol may be safer in relation to cardiovascular health and potentially cancer risk and FDA approved for treating menopausal symptoms. But unfortunately mainstream medicine hasn’t adopted its use in terms of prescribing habits.

Many bioidentical hormone replacement regimes use only estradiol — a potentially dangerous estrogen with increased associated risks.

Emerging evidence indicates estriol has potential immunomodulatory benefits for many disease states, including autoimmune, inflammatory, and neurodegenerative conditions.

Applying Hormones Directly to Our Skin

Topping up our estrogen levels with estriol offers considerable benefits for postmenopausal women, and has reduced risks usually associated with more potent estrogen therapy.

When we rub hormones topically into our skin, we bypasses the liver and therefore we can use a much smaller physiological dose to achieve excellent results.

Using our skin (transdermal) to deliver estriol (and progesterone) to the body is not associated with increased cancer risk. In fact, it’s preferred for long-term use of bioidentical hormones.

What Are the Dangers?

Estrogen can be dangerous when metabolized down the wrong pathways.

There are a lot of things that can drive estrogen down the wrong metabolic path, such as having too much of it without adequate progesterone, exposure to excessive levels of petrochemical products (xenoestrogens), eating trans-fats, too little Vitamin D and not having adequate vitamins such as B6 and B12 which help to detoxify the bad estrogens.

The most interesting thing about the differences in the three primary estrogens made in our body — estradiol, estrone, and estriol — is that only the first two, and not estriol, are capable of being converted by enzymes into what we call the bad estrogen metabolites that damage DNA.

Estriol is a one-way street. It never loses its unique identity. Estriol cannot be converted to a bad estrogen by these same enzymes, which may be why Mother Nature makes so much of it during pregnancy — to protect the fetus’ genome.

While estriol is not capable of initiating cancer, it can stimulate the growth of a pre-existing cancer if the estriol concentration is high enough.

Whether or not estriol stimulates breast cancer cell growth depends on the dose, the timing and the delivery system. When studies of oral vs vaginal delivery of estriol were looked at, it’s pretty clear that when you drive the estriol concentration up high enough, you can get stimulation of the endometrial (uterus) lining and breast tissue.

Researchers have found that the estrogen receptors in the lower reproductive tract have a higher affinity for estriol than they do for estradiol. This is why vaginal dosing has been reported to help with vaginal dryness and atrophy without stimulating the growth of the uterine lining or breast cells.

As stated, estriol does not convert to bad estrogens and initiate cancer. It is only those cancers that are already present in women after growing for many years (probably 5 to 7 years), whose growth is stimulated by estrogens, that make them show up clinically a little faster.

What is different about estriol is that it does not continue to increase risk and actually decreased it beyond 5 years. This reduced risk is likely because, beyond 5 years of estriol therapy, no more tumours are forming due to estriol’s protective actions on cancer initiation.

Estriol, like any other estrogen, has the potential to stimulate the growth of pre-existing breast cancers. Estriol, therefore, may be contraindicated for those with estrogen-dependent malignant tumors.

Dr Wulf Utian, the editor of the North American Menopause Society’s journal MENOPAUSE stated, “Estriol has the potential of reduced risk, but similar benefits to alternative estrogen or estrogen-progestin formulations. The potential to minimize risks yet maximize most benefits places estriol in a unique category among estrogens.”

What Level of Estriol is Protective?

Many years ago now, I wrote about the Estrogen Quotient (EQ) — a formula developed by Dr Henry Lemon, an estrogen researcher.

The EQ provides us with a way of comparing the ratio of the strong estrogens — estrone (E1) and estradiol (E2) — to the protective estriol (E3).

The EQ mathematical equation looks like this: EQ= E3/E2+E1.

E2 and E1 are the most potent of these estrogens and therefore have a greater risk of estrogen-dominant cancers, whereas E3 can have a protective anti-cancer effect.

If our EQ is below 1.0 the risk of breast cancer is higher than those whose EQ is above 1.0.

The optimal ratio that is considered most protective is an EQ greater than 1.5.

Doctors can evaluate your EQ from a 24-hour urine hormone panel by looking at this ratio of ‘good’ estrogen to ‘bad’ estrogen.

What is the Correct Dose of Estriol?

The trick to getting estriol to work successfully as a form of Estrogen Replacement Therapy that does not stimulate the breast cells is to use it at the proper dosing.

Lower dosing of estriol is recommended.

The aim is to keep levels in the bloodstream low, so it has fewer growth-promoting effects on the uterine lining and breast cells.

A dose of 0.5mg (cream or gel) applied to the vaginal area every SECOND day is recommended.

Giving our body a break from dosing for a week here and there isn’t a bad idea either, to ensure our estriol levels are kept low and we do not bombard our estrogen receptor sites.

Important: Never apply estriol to the upper part of the body, such as the breasts. Always apply your estriol lotion or cream to the lower body, targeting areas of the skin where veins are close to the surface. Vaginal application is ideal. However, you can also apply estriol cream directly to your feet or the area behind your knees.

Why Progesterone is Essential Too!

Progesterone is our body’s natural “anti-estrogen”. It neutralizes the cancer-promoting properties associated with too much estrogen in the body. While estrogen promotes cell proliferation, or cell growth, progesterone decreases cell growth. Too much cell growth is a precursor for cancer.

The research shows the use of progesterone has been linked to lower rates of uterine and colon cancers and may also be helpful in treating other cancers such as ovarian, melanoma, mesothelioma, and prostate.

Progesterone may also be helpful in preventing cardiovascular disease and preventing and treating neurodegenerative conditions such stroke and traumatic brain injury.

And, more recently, research is evaluating the status of bioidentical progesterone as a credible determinant of immune regulation and dysregulation in relation to, and its clinical use in COVID-19. It proposes a clear answer to the question: “why are males and old patients most likely to have critical illness due to COVID-19?” Possible clinical applications of progesterone to treat critically ill COVID-19 patients will open an avenue for hormonal treatments of infections and other immune-related diseases.

Use Estriol and Progesterone for Best Outcomes

These two hormones — estriol and progesterone — that have the greatest potential to mitigate estrogen-driven cancers have historically been maligned by our medical establishments as “potentially” having the same risks as more potent estrogens and synthetic progestins. Science says this just isn’t true.

While sex hormone deficiencies may be a “normal” part of our aging, low levels clearly present challenges to how we age — and what it might hold in store for us.

Using bioidentical estriol and progesterone to restore hormone balance towards a more youthful range may significantly reduce our risk of cancer and very preventable diseases that creep up on us as we age.

If this information was helpful to you, perhaps you’d consider buying me a cup of coffee.

Love, light & laughter