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Could Melatonin Improve Breast Cancer Treatment?

Last updated: March 2022

Melatonin is a hormone produced by the pineal gland, a tiny organ in the brain that serves as a circadian rhythm regulator.

Also known as the “sleep hormone,” melatonin has become known for other applications specific to the treatment of cancer.1

New research suggests it may be an even bigger superhero than previously thought, especially when it comes to breast cancer.

Melatonin as multitasker

The rhythm keeper

Our brains generate this humble substance, but it’s also available as an over-the-counter supplement. It’s inexpensive, effective for circadian regulation, and causes no serious side effects.

We use melatonin to maintain stable circadian rhythms. These rhythms synchronize us to the light-dark cycles of the environment around us.

We’re biologically meant to sleep at night when certain key processes take place as we doze. When we awaken, we’re meant to be physically active for the same reason.

When our sleeping patterns run amok, supplementing with melatonin and practicing good sleep hygiene provide a healthy circadian reset.

If we don’t maintain healthy circadian rhythms, our organs, tissues, and cells become confused. Inflammation and stress make it harder for them to function efficiently.

This lays the groundwork for chronic illnesses to take hold. Getting adequate quality sleep every night is crucial to our overall health and well-being for this reason.

More than a sleep regulator

Melatonin does more than improve sleep. In fact, it plays a key role in preventing cancer, which is a chronic illness that can develop over time in response to disturbed circadian rhythms.

Research shows melatonin, which is found in all of our cells, benefits those with cancer by:1

  • blocking metastasis pathways (how tumor cells spread)
  • improving one’s sensitivity to drugs used to fight both solid and liquid tumors
  • regulating the immune system as a means of protecting healthy cells
  • reducing inflammation throughout the body

Could melatonin be the missing link to the powerhouse breast cancer treatment protocol that scientists seek?

How melatonin might conquer breast cancer

Up until now, it’s been challenging to understand melatonin’s anti-cancer mechanisms.

However, a study published late last year in the Journal of Pineal Research shed important light on melatonin’s anti-cancer role: it supports our genetic material at a level which may effectively kill tumor cells and reduce their spread in cases.2

Breast cancer, in particular, responded well when scientists incorporated melatonin into these investigations of gene expression.

Gene expression 101

Gene expression describes the process by which the information encoded on a single gene builds protein molecules. All cells—including those that make up breast cancer tumors—are composed of protein molecules.

Breast cancer tumors, when given the opportunity, multiply and spread:

  • by taking root and growing in nearby tissue
  • through the lymph, a network of glands that circulates them to other organs
  • by traveling through the bloodstream to areas far removed from the original tumor site

Melatonin can lead the fight

Study author Dr. Luiz Gustavo Chuffa (São Paulo State University’s Botucatu Institute of Biosciences) described how they studied genetic information gathered from the Cancer Genome Atlas.

From this investigation, they identified 46 specific target genes that were altered by the presence—or lack—of melatonin in tumor cells. This discovery gave them a better understanding of melatonin's role in regulating gene activity.

Cancer cells typically run low on melatonin. Chuffa’s research confirmed that when healthy cells carry adequate melatonin, the hormone ultimately signals for cancer-fighting processes to take place. These immune system processes both destroy tumor cells and reduce their ability to spread.

This is what they mean by regulating gene expression. Melatonin basically serves as a commanding officer within the cells, calling up immune system “troops” to contain, neutralize, and even destroy the body’s cancerous enemies.

Melatonin also calls forth other processes at the genetic level which prevent tumor cells from escaping into the nearby tissue, lymph, or bloodstream.

The future of melatonin and breast cancer treatment

Chuffa said that “certain types of tumor appear to correlate directly with the amount of melatonin produced by cells. It’s essential to understand how the hormone influences molecular signaling at the genetic level as a guideline for personalized therapies based on melatonin.”3

In other words, now that they know how melatonin works at the genetic level, they can now develop breast cancer treatments using melatonin in a fashion tailored to the unique needs of individual patients.

Meanwhile, let’s not forget that we also make our own melatonin! Bedtime provides the perfect opportunity for us to bathe our cells in natural melatonin.

To achieve this, it’s imperative to avoid looking at backlit electronic devices within an hour of bedtime. The blue spectrum light they emit blocks the release of melatonin, which is essential to our transition between wakefulness and sleep.4

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This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

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