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Recent Research: Brain Tumors are 5x More Likely When Taking Common Contraceptives

Published by Connealy, MD on July 26, 2024

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A French study published in the BMJ earlier this year concludes that prolonged use of specific progestins, synthetic forms of progesterone found in some birth control methods and hormone replacement therapies, is associated with a significantly increased risk of developing brain tumors.

Results showed that long term use of medrogestone, medroxyprogesterone acetate, and promegestone was associated with increased risk of meningiomas. For women taking cyproterone acetate, a progestin often used to treat acne and high androgens, risk of brain tumors was 19 times higher than the control group.

Meningiomas are typically benign tumors that arise from the meninges, the membranes surrounding the brain and spinal cord. Their location within the skull can lead to serious complications by compressing adjacent brain tissue, nerves, and blood vessels, potentially causing loss of neurological function, headaches, vision problems, and seizures. 

The risk factors for developing meningiomas include age, gender, exposure to ionizing radiation, and hormonal influences, particularly the use of certain hormonal therapies and contraceptives.

Data:

The study, which analyzed data from the French National Health Data System, included 18,061 women who underwent surgery for meningioma. The following progestins were linked to increased risk of brain tumors:

  1. Medrogestone: Women using medrogestone for over a year had a 3.5 times higher risk of developing meningiomas compared to non-users.
  2. Medroxyprogesterone Acetate: The risk was particularly high for injectable forms, showing a 5.5 times increased risk.
  3. Promegestone: This progestogen was associated with a 2.4 times higher risk.
  4. Cyproterone Acetate: As a positive control, this progestogen showed the highest risk, with users having a 19 times higher likelihood of developing meningiomas.

There is a lot of confusion surrounding progestins and the bioidentical progesterone. They vary significantly due to structural differences, and as a result, have very different effects. The name ‘progestin’ comes from the substances’ ability to bind to progesterone receptors on cells. So while they can bind to the progesterone receptor, progestins do not have the same anti-proliferative, anti-cancer effects that natural progesterone does. This could be why we see increased tumors. I believe progestins can ‘fool’ the body into thinking that it has enough progesterone, so natural production slows. Progestins have been used since the 1950’s, but we are still learning their effects.

There are a few theories as to why progestins can cause brain tumors, although more research is needed:

  1. Hormonal receptor activation: Meningiomas often express high levels of progesterone receptors. Progestins can bind to these receptors, but because they are synthetic, can stimulate cell proliferation and growth in the meninges, which can lead to tumor formation and growth. This is similar to how hormone-sensitive breast cancers grow in response to estrogen​. (PMID: 34336636)
  2. Immunosuppression: Progestins can modulate inflammatory responses and the immune system. Specifically, progestins can alter the expression of cytokines and other inflammatory mediators, reducing the immune system’s ability to recognize and eliminate abnormal cells. This immunosuppressive effect can decrease the body’s natural tumor surveillance, allowing tumor cells to proliferate unchecked. (PMID: 25697984)

I recognize that the decision to use birth control can be multifaceted. For some, it’s a choice made to delay starting a family, while others may turn to it for managing severe health conditions. However, it’s important to consider that birth control is not without its risks. In many cases, there are alternative treatments that may more directly address the underlying causes of discomfort.

Proponents of birth control often highlight research supporting its safety. Yet, a significant body of evidence and countless personal accounts suggest that it can have adverse effects. 63% of women choose to discontinue birth control use for this very reason. 

I share this information with the hope that women will be able to make a more informed decision regarding their health.I Want women to be aware of all the risks and know that there are other options out there. Although it is not widely popular, there are many natural, safe, and effective alternative solutions to hormone imbalances and pregnancy prevention. Raena has valuable information on this! 

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