Fight or Flight?

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One of my goals with this weekly column is to make significant human health issues easy to understand and discuss. I was pleased that last week’s piece, the Definitive Guide to Insulin, Blood Sugar & Type 2 Diabetes, garnered some rave reviews. The Case Against Cardio piqued some great conversation and interesting criticisms (one soul out there in the webosphere took issue with the fact that I positioned Cardio exclusively from my personal perspective as a runner rather than authoring a more scholarly article. Well wasn’t that spot on. It’s called my blog.) My opinions can’t please everyone, of course, but — based on my experiences and understanding — I am certain that contributing some insights on health in light of our (all together now) genetic blueprint is a worthwhile and timely endeavor.

Now to the topic at hand. Stress can make you gain weight, and it contributes to premature aging. Understanding how stress is related to your overall health and potentially even longevity is essential to achieving your health goals. But do not, repeat, do not go and buy yourself a bottle of Cortislim — just read this quick summary and you’ll know all you need to know.

walnut Ariel Amanda Flickr Photo (CC) The adrenal glands are not unlike a walnut.

Understanding Stress

Most folks are aware that “fight or flight” is the body’s natural response to stress. When faced with a stressful situation, we either get aggressive or, in the words of a local surf instructor, we bail. This choice depends upon our perception of the circumstances and our corresponding judgment of the odds of success. The “fight or flight” response is, in terms of energy preservation, tremendously efficient. And it is very effective at ensuring greater odds of survival. This makes sense to everyone on a visceral level, but do you know the physiological mechanisms involved?

The fight or flight response begins in the brain. Various regions operate in concert to detect, sense, decode, and respond to a stimulus. Though there are a few different pathways for a given feeling (like fear) to travel, it is ultimately the hypothalamus that is responsible for triggering the fight or flight response. Once the hypothalamus goes to work, what I call your survival systems, i.e. the “gut”, kick into gear. They are the nervous system and the adrenal-cortical system.

Enter physical symptoms: sweating, heart palpitations, muscles tensing, hearing sharpening. You are now extraordinarily alert, but only on the issue at hand: concentration and awareness of anything else fly out the window. The nervous system has flooded your body with adrenaline (scientists often refer to this as epinephrine) and noradrenaline (norepinephrine). Meanwhile, the adrenal-cortical system (which produces these hormones) becomes activated by way of the pituitary gland. The pituitary gland secretes a hormone known as ACTH (adrenocorticotropic hormone…say that three times fast). ACTH journeys — via the bloodstream — to your adrenal cortex, where these small organs will pump out as many as 30 different hormones to address the stressful situation at hand (the adrenals are “fed” by cholesterol). And your immune system temporarily shuts down so your body can utilize all its resources to deal with the perceived threat.

The adrenal cortex produces cortisol, DHEA, estrogen and testosterone, among many other hormones. It’s a beautiful system. Unfortunately, what worked for our old friend Grok does not, I believe, work so well for us. Simply put, our modern lifestyle subjects us to a potentially enormous amount of stress on a daily basis that the body has simply not evolved to handle. To my mind it’s a bit like “deer in the headlights”. We have a big deer overpopulation problem in my area, and you always hear comments along the lines of how dumb the deer are around automobiles. Well, in my opinion they’re not so dumb — in evolutionary terms, after all, cars are very new on the scene. The deer simply haven’t adapted the appropriate stress response. Is it so different for humans?

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