In defense of biology

The influence and importance of biology is an interesting and controversial topic in the field of eating disorders.  When I was first diagnosed with anorexia ten years ago, the debate centered more on if biology was involved.  Now, it's pretty widely accepted that biology is a factor in eating disorders. The question that remains is how important is biology.

We don't have percentages.  No one can say that biology is 75% important, and environment is 25%.  Every person I have met with an eating disorder has at least one (and often several) tick marks in each category.  For me, in the biology category, I have

  • impaired set-shifting
  • anxiety
  • perfectionism
  • depression
  • loss of appetite under stress
  • temperament traits of harm avoidance, low novelty-seeking, high persistence
In the environment category, I have

  • thin-is-in culture
  • tried to lose weight
  • teased (weight was among those topics, but not always the focus)
  • achievement-oriented culture
  • fat phobic environment
So, yeah.  It's not an either/or question, and it frustrates me to no end that so many people think that it is.  This isn't a game of Red Rover, Red Rover.  You don't need to pick sides.  In fact, you can't pick sides because you can't separate genes and environment.  It doesn't work that way.  Environment affects what your genes do, and your genes affect what environments you seek out.

Even the researchers who specifically study the neurobiology of anorexia don't say that culture is irrelevant.  They say (and I would agree) that culture doesn't cause eating disorders.  But that's far from some sort of robotic, reductionist view that life is just some biochemical soup.  The study of biology in relation to eating disorders has added volumes to our knowledge about the subject.  Biology is a powerful thing.  We shouldn't take it for granted, nor should we scoff at it as an easy way out.  If it's biology, you're either stuck with it, or you just take a pill and All Better!

Which is really funny because none of the researchers I know think anything even close to that.

This is why I was really chagrined to read this article on addiction and eating disorders.  It starts as follows:

These days researchers and writers like to boil all maladies down to the biochemical level. The medicalization of all things sure makes life simple: if it’s just faulty brain chemistry, then there’s eventually going to be a pill for it.

But there is no pill to erase the feelings that grip Katherine’s gut when she walks into her childhood home for Thanksgiving. The Marlboro stench of the old curtains, the worn areas on the carpet, the heaviness on her mother’s hips and in her voice, the back bedroom filled with unopened boxes from QVC shopping binges, her father’s palpable misery about his job, the bathroom where she first learned to throw up…

I will say that when neurobiological studies were first published maybe 20 or 30 years ago, people probably did hope that we could take a pill and cure all of our mental ills.  We've gotten a lot older and a lot wiser since then.  No one remotely believes that you take a pill and bye-bye eating disorder (or depression or anxiety or whatever).  Medications can help, but they're not a cure-all.

Secondly, there's a growing body of research related to PTSD of what happens to the brain during stress and during traumatic events.  Psychologists have long known that environmental cues are a huge factor in relapse in drug addiction.  It's environmental (you see or hear something that reminds you have your drug use) AND it's also biological (this triggers memories and cravings and dopamine and what have you).

Memories are powerful.  One of the times I was most powerfully triggered was when I spoke with the boss I had from when I was most acutely ill.  I was shaking when I hung up the phone.  I wanted to throw up.  I never wanted to eat again.  Her voice immediately took me back to that place.  It's another reason I avoid the gym.  Memories of my exercise addiction trigger cravings for more exercise.

Researchers are looking for ways to help the brain unlearn the traumatic response to an event, and some of these methods may involve pills.  But a pill isn't going to cure PTSD, it's not going to cure anxiety and depression, and it's not going to cure eating disorders.

Walter Kaye is probably the top neurobiologist in the eating disorder field.  And he doesn't give out pills at this San Diego clinic.  He delivers therapy.  Therapy changes the brain.

Biology isn't a dirty word.  It's not the lazy way out, and it's not ignoring or neglecting environmental influences.  And it is important.


Cate said...

It never ceases to amazing me as to the insights you have into the workings of your own mind and this disorder. Everytime I think I'm so stupid, why do I do this, it's such a stupid thing to do, I'm stupid because I can't stop - I come and read what you have written. It is very reassuring to know that at least someone else has the same thoughts, and can articulate why these thoughts exist.

Lindsey said...

* thin-is-in culture
* tried to lose weight
* teased (weight was among those topics, but not always the focus)
* achievement-oriented culture
* fat phobic environment

Every one of us born in America during the 1970s, 1980s, and probably beyond has been raised and lives with that same set of environmental factors. I'm not being sarcastic, but if every female in a demographic is raised with the same set of influential environmental factors, and only... 10%(??) wind up with disordered eating patterns, how much can you even count environment at all? I mean, some people are obviously going to be in a more strenuous environment than others, but still. Seems to me it's much like depression in that way. We all live with the same set of factors to some extent or another, brain chemistry has to have a HUGE, if not exclusive part, in why people follow a path like this.

But you're the scientist. ;)

Carrie Arnold said...


Yes, you're exactly right. If culture were the driving factor behind EDs, then more than 5% of the population would have them (and that's AN, BN, BED, and EDNOS combined).

And yet we don't really know the prevalence of EDs in cultures where thinness isn't the cultural ideal. So it's hard to say how much that contributes. But the best studies show that about 60 to 80% of the risk for AN is genetic. I think the jury is still out on other EDs, but it the preliminary data looks similar.

hm said...

I love this post. Love it, love it, love it. So many people still think it's all environment, what did or did not happen to you, what your mom (or family) did or did not give to you. Of course environment triggers, aids and abets, etc. But it certainly does not hold sole responsibility. And all the understanding of it in the world won't heal what's rooted in the brain. There has to be a balance of addressing both the biological aspects and the environmental triggers.

Carrie, I would be interested in knowing more about the temperament traits you mentioned. Are those from a site, or a specific personality test?

Abby said...

My therapist would often say that 'genetics loads the gun and environment pulls the trigger'. Kind of a violent metaphor but I think it fits well...and might explain a bit of Lindsey's question. Yes, many of us have grown up in similar environments, but some of us are 'loaded' on the genes side. Make sense?

Cathy (UK) said...

I have kept trying to post a response and it won't work :(

HikerRD said...

We're on a slippery slope, as patients, when considering the role of biology and the disease process. On the one hand, acknowledging a biological root to a disorder allows us to let go of some guilty, feeling (appropriately) that something else contributed to this condition or caused it.

On the other hand, it seems we often view biology as simply medical, that someone medical will need to fix for us, taking away our responsibility to also help ourselves.

The more the medical community seems to learn about most diseases, the more it appears they are more complex than we originally believed, combining genetic predisposition, an environmental trigger and then support of the disease process.

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I'm a science writer, a jewelry design artist, a bookworm, a complete geek, and mom to a wonderful kitty. I am also recovering from a decade-plus battle with anorexia nervosa. I believe that complete recovery is possible, and that the first step along that path is full nutrition.

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