Hormones and Immunity, Part 3: Dirt, Love, and Oxytocin
This is the third of a three-part post on hormones and immunity, and is part of our Superpower Series on defending ourselves in the COVID-19 era.
“Six feet has never felt further away.”
In today’s media marketplace there is no shortage of doomsday scenarios, exaggerated casualty predictions, and needlessly alarming comparisons. For example, the Imperial College London initially estimated U.S. COVID-19 deaths at 2.2 million, a far cry from the actual deaths of 62,406 reported by the CDC as of May 1st.
All of this implies that if we even hesitate to don a face mask the second another human is within six feet, we each might singlehandedly be responsible for the collapse of society and eradication of our species. As if any species with that kind of fragility would ever have been able to survive and spread to all seven continents. And as if the magic distance six feet provides an invisible force field around someone. It’s an absurd assertion, at best.
Here are some indisputable facts:
Most people are not going to be infected with SARS-Cov2.
Most people who do get infected with SARS-Cov2 are not going to die.
That’s most people in the world, most people in the United States, and most people that each of us knows.
All of this is to say that the practice of distancing ourselves six feet away only guarantees a feeling of distance from others and a need to remain constantly aware of — if not obsessed with — the risk of contagion with a virus which has yet to cause a significant rise in the national mortality rate.
Another thing that the six-foot stance might guarantee is a negative effect on our immune system.
Digging in the Dirt
There are numerous health benefits to touching other living things — especially humans (and pets!). For one thing, exposing the immune system to a variety of microbes actually keeps the system in working order.
At one point in human culture, we managed to achieve an unprecedented level of population density without an accompanying improvement in sanitation. Consider The Great Stink of medieval Europe when the average adult could boast of bathing twice a year — whether he needed it or not! Gradually we humans acquired standards of hygiene necessary for good health. In recent decades, however, we have shot past that benchmark to the opposite extreme.
It turns out that it’s possible to be too clean.
Widespread antibiotics in food, rain water and as medicines have wreaked havoc with our intestinal microbiomes, causing an epidemic of gastrointestinal dysfunction. Autoimmune conditions and allergies — both signs of immune system imbalance — are extremely common. Western medical science has only recently recognized the importance of healthy bacteria (the microbiome) and is now only starting to realize that a highly vaccinated, antimicrobial, indoor lifestyle (sound familiar?) leaves the immune system untrained and vulnerable.
So, yes, it seems our lives have become too clean.
If we ramp up our use of antibacterial detergents, wear gloves in public, and stop shaking hands, are we really protecting ourselves or rather just painting ourselves further back into a corner from which we may not escape? Most research that examines the pros and cons of microbial exposure is focused on long-term lifestyle choices, of course, so we can’t say what effects a few weeks of our recent COVID-19 precautions may have on our immune systems. These practices may actually turn out to be helpful. But the idea that we should enter an era of a “new normal” of social distancing is neither historically nor evolutionarily substantiated.
Love Shack
“The [Oxytocin Secreting System]… can integrate neural, endocrine, metabolic, and immune information and plays a pivotal role in the development and functions of the immune system.”
Aside from contact with other microbes, however, another powerful benefit to touching others involves oxytocin, better known as the “love hormone.” Oxytocin is released in response to positive, social touch: hugging a friend, petting an animal, holding hands; a massive release is triggered by sexual contact and orgasm. Oxytocin gives us a warm, safe sense of well-being: calm, cozy, content. Interestingly, however, it is also a major regulator of the immune system.
In fact, circulating immune cells (white blood cells), the bone marrow where they were born, and the thymus gland (source of those Th1 and Th2 cells we discussed in Part 2 of the series), all have specific receptors for oxytocin. Not only that, but large numbers of oxytocin receptors exist in areas where our bodies contact the outside world, such as the gastrointestinal tract, where immune surveillance is highest. Some other recent discoveries regarding the role of oxytocin are:
produces nitric oxide, which affects the vascular system (blood vessels)
produces prostaglandins which control local inflammation
modulates brain structures and development
exerts an “antibiotic-like” effect
improves immune surveillance, and
Synthesized by the endocrine system, modulating the nervous system, and directing the immune system — oxytocin is the ultimate NeuroEndoImmune System (NEI) super hero. It affects both the Th1 and Th2 branches of the immune system, and may be one of the keys to achieving balance between them.
It’s ironic that the Immune System “killing machine” should be controlled by the “love hormone”, isn’t it? Yet oxytocin is one of the factors that keeps our immune system in check, making sure it stays a defensive and protective force instead of an overly offensive one.
Even so, our defensive instincts can turn self-destructive, when deprived of purpose and appropriate stimulation. We do this emotionally, but we also do it in very literal, physiologic ways, eg, developing allergies and autoimmune conditions. Interestingly, even in the case of COVID-19, it isn’t infection with the SARS-CoV2 virus that is potentially lethal; it’s the over-exuberant immune response in the lungs that causes respiratory distress and ultimately kills the individual.
If that's true — and it is — then why are we so focused on COVID-19 and social distancing?
It's a poor immune system causing the deaths and that system benefits from being in close contact with others. If anything, the current pandemic only underlines the importance of having a properly balanced immune system, regardless of what infectious agents we may encounter.
Herd Immunity
But digging in the dirt and needing a regular trip to the love shack consider mostly the individual. When we consider the effect on society — or “the herd” — there are even more negative consequences: the economic and political consequences that we are experiencing, but also negative biological consequences.
In a recent interview, Professor Knut Wittkowski, — a 35 year veteran of epidemiology and former head of the Department of Biostatistics, Epidemiology, and Research Design at The Rockefeller University, New York — made the following statements about “herd immunity":
With all respiratory diseases, the only thing that stops the disease is herd immunity. About 80% of the people need to have had contact with the virus, and the majority of them won’t even have recognized that they were infected, or they had very, very mild symptoms, especially if they are children. So, it’s very important to keep the schools open and kids mingling to spread the virus to get herd immunity as fast as possible. …We are experiencing all sorts of counterproductive consequences of not well-thought-through policy.
Dr. Pietro Vernazza, Professor of Health Policy and Infectious Disease Physician at the Cantonal Hospital St. Gallen in Switzerland, echoes this sentiment:
If we close the schools, we will prevent the children from quickly becoming immune.… We should better integrate the scientific facts into the political decisions.
We discussed in Part 1 of this series that humans we are hard-wired to respond to immediate, life-threatening stressors. Our minds and bodies are much less attentive to the multiple chronic, non-urgent, non-lethal (but still uncomfortable) threats that attend our modern lives. This is why optimal health in the modern era depends on using our intellect (ie, our “Executive Branch” neurological system) to make important life decisions, based on the actual circumstances instead of impulsive, adrenaline-driven reactions.
We need to force ourselves to recognize that neither SARS-CoV2 nor public speaking nor getting a blemish on our wedding day is a lion.
As a society, we also need to use our collective “herd mind” to recognize that COVID-19 is not an invisible 400-pound lion. We need to actively remember to recognize the distant future consequences, see the big picture, play the long game. If those of us who are not vulnerable (the young and middle-aged, healthy, immunocompetent) stay home and avoid infection to save ourselves in the short term, we subject everyone to greater risk in the long-term.
Maybe we could examine the data for ourselves, consider our personal experiences, and hear out the “experts” — all of them, not just the extremist ones who get a lot of media coverage, but the softer spoken, moderate ones, too. As Professor of Theoretical Epidemiology at the University of Oxford Dr. Sunetra Gupta stated,
I’m surprised that there has been such unqualified acceptance of the Imperial model.
Maybe we could decide for ourselves?
By all means, let's keep washing our hands before eating and covering our mouths when we cough; current rules of etiquette already provide guidance to protect us from undue contagious illness. And given that life is lively and definitely messy, let's do our best to engage with lots of lively, messy things. Far from a risk to our lives, it’s what gives us — and our immune systems — strength.
