Sunday, July 15, 2018

Cellular Conflicts: Is Extending Life Possible—or Even Worth the Trouble?

Barbara Ehrenreich is probably best known for her book Nickel and Dimed: On (Not) Getting By in America.  She actually has authored a long list of books, all with intriguing titles, that appear sociological in focus.  It is somewhat surprising then to realize that her formal education resulted in a doctorate in cellular immunology from Rockefeller University.  Apparently, her range of interests were too broad to be constrained by a career in such a narrow discipline.  It would be awareness of a growing revolution in knowledge of how the human immune system actually worked that would drive her back to her original field for the production of her most recent effort: Natural Causes: An Epidemic of Wellness, the Certainty of Dying, and Killing Ourselves to Live Longer.  She was motivated by an article she encountered.

“The article….reported that the immune system actually abets the growth and spread of tumors, which is like saying that the fire department is indeed staffed by arsonists.  We all know that the function of the immune system is to protect us, most commonly from bacteria and viruses, so its expected response to cancer should be a concerted and militant defense.”

We tend to think of our bodies as well-tuned, highly-efficient machines with all sorts of mechanisms in place to ensure continued functionality.  But we all know that once the body reaches adulthood (or maximum efficiency), it begins a long downhill journey to dysfunction and ultimate death.  Given this initial view of ourselves we tend to believe people who tell us that this gradual decay is something that we can overcome by exercise, diet, or medication.  Ehrenreich’s devotes a great deal of her book to the attempt to disabuse us of these foolish notions.

“The body….is not a smooth-running machine in which each part obediently performs its tasks for the benefit of the common good.  It is at best a confederation of parts—cells, tissues, even thought patterns—that may seek to advance their own agendas, whether or not they are destructive of the whole.  What, after all, is cancer, other than a cellular rebellion against the entire organism.”

“I know that in an era where both conventional medicine and the wooliest ‘alternatives’ hold out the goal of self-mastery, or at least the promise that we can prolong our lives and improve our health by carefully monitoring our lifestyles, many people will find this perspective disappointing, even defeatist.  What is the point of minutely calibrating one’s diet and time spent on the treadmill when you could be vanquished entirely by a few rogue cells within your own body?”

Ehrenreich reached an age at which death was no longer improbable.  Rather than try to stave off further physical and mental decline by taking heroic measures, she decided that the time she had left was best used by pursuing a lifestyle that provided her pleasure and satisfaction.  Let others forgo pleasure and satisfaction in the vain attempt to prolong a life that is thus rendered much less worth living.

Ehrenreich elaborates on these thoughts throughout the book.  What is of interest here are the details she provides about the surprising roles of the immune system.  

To perform its function of protecting us from things like microbes and parasites that are foreign to our bodies, the immune system consists of an impressive array of structures and processes designed to disable or destroy these things.  However, the power to destroy can be dangerous if malfunctions can occur.  And they do.  There are at least 80 types of autoimmune diseases where the immune system, for whatever reason, turns on specific body parts.  Examples include rheumatoid arthritis, lupus, celiac disease and Graves disease. 

Ehrenreich likes the analogy to powerful military forces that are necessary for defense but, historically, have been difficult to control.

“Any human society within a spear’s throw of potential enemies needs some kind of defensive force—minimally, an armed group who can defend against invaders.  But there are risks to maintaining a garrison, or, beyond that, a standing army: The warriors may get greedy and turn against their own people, demanding ever more food and resources.  Similarly, in the case of the body, without immune cells we would be helpless in the face of invading microbes.  With them, we face the possibility of treasonous attacks on our ‘selves’—the autoimmune diseases….likened to ‘a mutiny in the security forces of a country’.”

Given that there is no explanation for why autoimmune diseases exist, Ehrenreich tends to think of immune system processes as being unreliable, in much the same way that humans are unreliable.  This is the basis for her earlier reference to immune system cells “that may seek to advance their own agendas.”  It is the readers’ choice if they wish to buy into this line of thinking.  One should at least keep an open mind while considering her description of the role a particular type of cell plays in “protecting” us.

Ehrenreich spent her graduate student days studying the cells known as macrophages (translates to “big eaters”).  Her studies convinced her that these were powerful actors working to protect us.

“With the exception of stem cells, there is probably no cell in the body more versatile than the macrophage, which originates, like so many other leucocytes, in the bone marrow.  Immature macrophages, called monocytes, are released into the bloodstream, where they may become attracted to a stationary object, like a dead or injured cell, and settle down to devour it.  As the macrophage eats, it grows and becomes ‘activated’—filled with vacuoles containing digestive enzymes that allow it to eat still more.”

Besides this clean-up function, macrophages are the designated killers of microbes deemed dangerous.

“Antibodies are the ingeniously bespoke protein molecules designed to bind to particular antigens—or patches of a microbe’s surface—either disabling the microbe or marking it for destruction by macrophages.”

As if they had a mind of their own, macrophages also participate in activities that are far from benign.

“Macrophages had been known since the nineteenth century to gather at tumor sites….optimistically, one might imagine that the macrophages were massing for an assault on the tumor.  Instead, it turned out that they spent their time in the neighborhood of tumors encouraging the cancer cells to continue on their reproductive rampage.  They are cheerleaders on the side of death.  Francis Balkwill, one of the cell biologists who contributed to the recognition of treasonous macrophage behavior, described her colleagues in the field as being ‘horrified’.”

“The evidence for macrophage collusion with cancer keeps piling up.  Macrophages provide cancer cells with chemical growth factors and help build the new blood vessels required by a growing tumor.  So intimately are they involved with the deadly progress of cancer that they can account for as much as 50 percent of a tumor’s mass.  Macrophages also appear to be necessary if the cancer is to progress to its deadliest phase, metastasis, and if a cancerous mouse is treated to eliminate all its macrophages, the tumor stops metastasizing.”

This type of behavior was first recognized in the case of breast cancer, but it has since been observed in other cancers.

“Breast cancer is not the only form of cancer that depends on macrophages for access to blood vessels and hence metastasis to new sites in the body.  So far, there is evidence that macrophages assist in the metastasis of lung, bone, gastric, and other cancers.”

Where there is inflammation, macrophages will congregate for the or the bad. Macrophages are now recognized as the cells most involved in the production of plaque which contributes to atherosclerosis.

“Many pathological or at least annoying conditions, from acne to arthritis, arise from inflammation. And inflammation, which involves a variety of leucocytes, is spearheaded by macrophages….At a later stage in the human life cycle, we find macrophages involved in arthritis  and diabetes, as well as chewing away at living bones to produce osteoporosis.”

Ehrenreich does not pretend to provide a complete description of all the immune system features, nor even just the roles played by macrophages.  She does provide enough information to make one wonder about the wisdom of the common advice to do whatever is possible to strengthen one’s immune system as a counter to disease.

Her goal was to convince the reader that his or her body is not a well-tuned machine that only needs to be maintained in order to continue to run healthily.  Health can be something we have no control over.  And as we age the effort to maintain health can be so intrusive in our lives that it detracts from our ability to enjoy the time we have left.  She provides this advice.

“I hope this book will encourage you to rethink the project of personal control over your body and mind.  We would all like to live longer and healthier lives; the question is how much of our lives should be devoted to this project, when we all, or at least most of us, have other, often more consequential things to do.”

“You can think of death bitterly or with resignation, as a tragic interruption of your life, and take every possible measure to postpone it.  Or, more realistically, you can think of life as an interruption of an eternity of personal nonexistence, and seize it as a brief opportunity to observe and interact with the living, ever-surprising world around us.”

The interested reader might find the following articles informative:

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