Sunday, April 15, 2012

Are You Cool Enough to have a Healthy Immune System?

What is blogging for, anyway?  Posturing on the internets, vying for position, trying to prove to others that we have optimal genetic material in order to further the chances of our offspring.  I'm not a member of a boy band, so I duke it out in my own niche of esoteric intellectuals…

Adagio from Concerto Grosso Op 6. No. 8 in G minor (I could listen to this piece over and over forever, really…)

Why do we build cities, compose music, or make necklaces from the teeth of conquered foes?  Status.

Status means something even besides being able to purchase that Hermes scarf or diamond pendant.  It could mean everything with respect to how our immune system and health functions.  In agricultural times past, aristocrats were often head and shoulders taller than the peasants due to better nutrition.  And it is no accident that a human-species friendly diet will bring about improvement in appearance, and therefore in confidence and status.

Let's get down to the nitty gritty with some primate studies from PNAS.  A high-powered journal self-assured enough to be free access.  Or lowbrow enough for the masses.  You decide.  Social environment is associated with gene regulatory variation in the rhesus macaque immune system.

These guys don't pull punches.  Right at the top of the intro is the following: "In settings in which hierarchies are strongly enforced or subordinates have little social support, low dominance rank can lead to chronic stress, immune compromise, and reproductive dysregulation."

Don't forget that we are the children of all the winners, generation after generation, for millennia.  The joke is on us that evolution is a Red Queen, and we are not compared to the forebears, but to the winners' descendants, decade after decade.   Hierarchy can determine levels of glucocorticoids, serotonergic and dopamine responses, and sex steroid hormone regulation.  These changes exist in the absence of differences in resources available to primates of different ranks, suggesting that rank alone can lead to the physiologic response.

It's not just primates, of course, whose genes and immune system are affected by hierarchy.  Bees and ants and whatnot are heavily affected by gene-expression profiles dependent upon the role the bee is expected to play, workers, reproductive workers, or queens.  While we are not insects, strong ties between diseases and social status probably indicate that status plays a role in our human immune function.

In the study I linked, researchers checked immune function and gene expression of a set of monkeys.  Just by looking at the expression of immune cells (CD4 T cells, CD8 T cells, B cells, and monocytes), they could correctly rank-order the monkeys with 80% accuracy.  Low ranking females have a low proportion of CD8 cells, if you must know.)  Low-ranking monkeys also have a hyperactive hypothalamic-pituitary-adrenal axis (seen in humans under stress as well), and have reduced response to chemical signals to shut down the cortisol response.  The researchers were able to link DNA methylation to monkey dominance as well.  Methylation is how DNA signals are hushed up or not in the process of epigenetics (or changes in gene expression due to environment).

So dominance in monkeys is highly associated with changes in the genome in certain areas, in the endocrine system with stress hormone responses, and in the immune system with inflammatory changes.  Apparently the researchers were able to track shifts in dominance with shifts in these immune and genetic findings, suggesting that the rank comes first, followed by the epigenetic changes.

If the findings can be extrapolated so far as humans, that means there is always a chance to beef up your immune system by becoming more cool.  There's always room for another blog, and more niches of hierarchy to climb every day. Welcome to the 21st century.  

19 comments:

  1. Unfortunately PNAS is not open access. Only a few articles are.

    ReplyDelete
  2. Awesome post. Ironically 'The Red Queen' is my current (leisure) read. At this rate I'll have it done in about 2 years.

    Wonder what the respective CD8 counts of med students, residents, and attendings looks like? :-)

    ReplyDelete
  3. It looks like it is very healthy to be a really dense narcissistic ass with inflated sense of self-importance.

    ReplyDelete
    Replies
    1. Well, a bad narcissist will tend to have somewhat erratic behavior and the high-handedness will anger most. Therefore he/she will eventually be toppled and marginalized, or driven from the group. Some devoted followers might go with the original, densely narcissistic leader, leading to a "split" in the community.

      Delete
    2. I agree that we, loosely, are the children of the winners, but the post World War 2 developed world generations are increasingly not so. Access to medical science and technology is a two edged sword.

      Delete
  4. Richard Mackarness made this point, I think it is in "not all in the mind", 1976, that hereditary aristocrats do not fatten easily because their ancestors always had enough food. Thus predicting epigenetics.
    He also wrote this wonderful little book in 1958
    http://www.ourcivilisation.com/fat/index.htm

    ReplyDelete
  5. What if the causality worked the other way? The selection pressure are for the monkeys with better immune responses to move up the social ladder. That is, good immune system leads to better chance of higher social status. Rather than higher social status leads to better immune system. Just a guess.

    ReplyDelete
    Replies
    1. The researchers tracked immune response through variations in the hierarchy of the group, finding that immune changes followed rise or change in status, not the other way around. But it could work both ways - a sick individual would likely fall in status also.

      Delete
  6. Given that, unlike other primates, each modern human usually possesses multiple identities from which they might derive a sense of high or low status, it would be interesting to know whether humans' sense of status is constantly fluctuating depending on the scenario.

    Another thought: Do you think that the status-obsessed nature of our brains means that equality is basically impossible? That, unconsciously or not, we put everyone either above or below us? This would mean that if we were to accept status-improvement as an important part of any health-improvement programme, we would need to make "belittle others" another health imperative (I'd like to see that on Chris Kresser's 9 steps!), since status is always relative.

    ReplyDelete
  7. Someone once asked me if my health problems seemed to track with unhappiness, so I started tracking that a year ago and never found a correlation. But the thing was, I was living in NYC. I was living in crowded conditions, often with roommates who weren't so nice. My career was at a dead end and I felt excluded from the "real" culture of NYC, which seemed only for rich people. I wasn't near family and I hardly ever saw my friends. Since I moved to Chicago, my status shot up because it's cheaper here and I guess it's no surprise that my health seems a lot more resilient.

    ReplyDelete
  8. Thanks for turning me on to that adagio. One of my current favorites is Samuel Barber's Adagio for Strings. It's used in lots of movies, most notably, for me, Oliver Stone's "Platoon." Most folks haven't heard the full 11-minute version.

    -Steve

    ReplyDelete
    Replies
    1. I do love the Adagio for Strings, so much, in fact, that I find it hard to find a sublime version worthy of the music! There's nothing quite like a good Adagio...

      Delete
  9. @Nicolas--exactly, we possess multiple identities, and project multiple identities onto others; so perhaps we can project something like equality and value onto everyone, reducing our stress, Zenlike. Overcoming our unconscious tendencies to belittle and rank--could this be enlightenment?

    ReplyDelete
  10. It would be interesting if this was able to be reproduced in a human population, say in a prison or jail (observable hierarchy). I'm guessing more than a few prisoners would be willing to trade a blood draw for a couple extra hours in the yard (except that would then turn into a confounder ;)

    ReplyDelete
  11. The study which Emily cites includes the following reference when it mentions how the findings might relate to humans: Sapolsky RM (2004) Social status and health in humans and other animals. Annu Rev Anthropol 33:393–418

    I had a read through the relevant parts of this and it suggests that everyone would be a lot happier if we lived in less socio-economically unequal societies, citing the correlation between inequality and poor health (which remains even when taking into account a variety confounding factors). Sapolsky mentions hunter-gatherer societies as fairly egalitarian.

    To me, this seems somewhat unintuitive since, in my experience, social environments can be oppressively hierarchical without any distinctions of wealth or social background, and fairly egalitarian even with these distinctions. It seems unlikely that people would be strongly affected by something as abstract as overall socio-economic status. But if that's what the evidence shows, I guess I'm probably wrong.

    I would be really interested in knowing whether Sapolsky's optimism about the status-effect being much weaker in hunter-gatherer societies, due to greater equality, is warranted or not.

    ReplyDelete
    Replies
    1. If I go to prom in that Limo, will it help my immune system? The plot of every movie ever seems to argue yes...

      Delete
  12. "Don't forget that we are the children of all the winners, generation after generation, for millennia."

    That depends on how you define "winner".

    ReplyDelete
  13. There is a completely non-scientific book called "Class" by Paul Fussell that is a must-read on the subject of status.

    And my own favorite quote on the topic summarizes the outlook of the book, although I cannot recall where the quote comes from. It might even be PJ O'Rourke:

    "At either end of the social spectrum lies a leisure class.."

    Sapolsky himself described how much easier life is for the non-alpha males in the troop.

    ReplyDelete
  14. your site is very nice and neat, I'm happy to visit here

    ReplyDelete