Certain words pull attention as surely a teenager will reach for her cellphone. There is an irresistible connection, a whole forest of brain cells that activate when it sees specific words. One of those words is ‘sex’. Sex is literally what keeps the human race going, reproducing through times of peace, economic collapse, war, rising empires, and floods. Even when circumstances are wretched, people still have sex, and by extension, babies. Another word that is charged with meaning is ‘cancer’. Cancer is the opposite dynamic, where cells divide out of control until they sicken their host, or take their life. Cancer slows, or kills member of the human race. So, does the regeneration of humanity that is inherent in sex, push against the deterioration that is cancer?
One study gave a provocative response. Researchers followed Chinese women who had been treated for breast cancer for a decade. The women that had a poor sexual relationship were 570% more likely to either have a recurrence of cancer, or die, than women who had a good sexual relationship with their partners. [i] The implications spin quickly out of this finding. To begin, breast cancer is the most common cancer to afflict women.[ii] Over two million women a year are diagnosed with it. Any finding as to what increases recurrence or death will affect hundreds of thousands of women and their loved ones.
The huge numbers involved are because the researchers did not look at the worst of the worst relationships, the women who were extremely dissatisfied. If they did, then the high risk group would be small. Instead, the scientists defined having a poor sexual relationship as being average or below. That means that half of all women were in the group that was nearly 6 times more likely to have a recurrence of cancer or die.
Second, this is a massive difference. If there was a pill that changed the likelihood of having a recurrence of cancer or early death by roughly 6-fold, it would be all over the news. Every oncologist would be expected to prescribe it. If they did not, they would be sitting in a courtroom, answering some very uncomfortable questions from a malpractice lawyer as to why they did not. It would be the new standard of care, and failure to meet that standard would result in lawsuits and legal battles.
With such an impact, one question that pops up is ‘how’? How does having a connected and satisfying sexual relationship keep cancer from returning? Different groups offer very distinct reasons, and we will first hear from the biologists. They point out that when either men or women orgasm, that the hormone oxytocin is released.[iii] Thus, if women have a sexual relationship that is above average, they will have more oxytocin in their body than their peers with below-average sexual relationships. This raises a very interesting question. Is the superior survival rate of women with good sexual relationships due to oxytocin slowing the recurrence of cancer?
Oxytocin has lots of positive effects. One of the most important is that when people are stressed, oxytocin inhibits cortisol levels.[iv] And this a good thing, because as I wrote in a previous post, high levels of cortisol over the long term eventually damage DNA. It also suppresses the immune system and facilitates weight gain. These three factors increase the risk of cancer. If oxytocin is reducing cortisol levels, then the risk of cancer decreases. Oxytocin does not just dial down the cortisol, it exerts other powerful anti-stress effects. These effects are from nerves that release oxytocin that weave complex paths in the brain to multiple sites that regulate the stress system. [v] These nerves reduce the activity of the fight-flight-freeze system and activate the system that calms and restores the body (parasympathetic system).
The second pathway is what happens right around the cancer cells, in the tumour micro-environment. Women with ovarian cancer who had high levels of oxytocin in the fluid near their tumour lived an average of 1.5 years longer and had a 34% decreased risk of death from disease than patients with lower levels of oxytocin.[vi] The researchers pulled out the test tubes, and found that oxytocin reduced inflammation around the tumour. Other scientists found in the lab that oxytocin inhibited the ability of ovarian cancer cells to proliferate. It decreased the cancer cells’ ability to migrate, and to invade other tissues.[vii] It even induced death in the cancer cells![viii] When oxytocin was present, it partially reversed the effects of cortisol.
Oxytocin slows down other types of cancer cells, such as decreasing the proliferation of breast cancer cells in the lab. Colorectal cancer cells also decrease their ability to invade when exposed to oxytocin. It also decreases the ability of the cancer cells to suppress the immune system. [ix]
At this point, oxytocin is looking like a very powerful weapon in the struggle against cancer. It dials down the cortisol, which has cancer facilitating effects. Oxytocin also activates the system that calms the body. In multiple types of cancer it decreases the ability of the cancer cells to proliferate, migrate, and suppress the immune system. It also facilitates the process leading to dissolution and death in cancer cells.
At this point, it is tempting to fire up the media machine. The headlines can write themselves “Sex stops cancer’s return!” I can almost hear the whine as the hype winds up, the revs spinning faster in the media, shaking and vibrating the printing presses and computer servers. Yes, we do have a study showing a dramatic impact of quality of sexual relationship on cancer recurrence. We also have a biological pathway from orgasm to oxytocin to inhibiting cortisol and inhibiting cancer proliferation. It looks like we have a very thick rope in the net to restrain cancer, a powerful part of the unknown weapon.
But before the tweets get over-hyped, and the FaceBook posts too dramatic, it is important to keep in mind that we have discussed only one study looking at quality of sex and cancer recurrence. And we have only looked at a biological explanation, rather than hearing other perspectives that account for this finding. Be sure to tune in next week to see what other studies have to say on the link between sexual activity and cancer, and what other factors need to be accounted for.
In the meantime, if you want to sit down with your spouse and tell them that there was a study finding that the quality of a woman’s sexual relationship had a dramatic impact on the risk of cancer recurrence, go ahead. If you want to ask how the two of you can improve the quality of your sexual relationship, well, that is a great question. If they raise issues of communication, or timing, or body image, then listen closely and keep the conversation going. You will only gain by having an honest, respectful dialogue about this topic. Once you work through these issues, the passion in the bedroom may increase. If that happens, go ahead, blame me.
Dr. Eric Kuelker
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