Posts Tagged ‘homeostasis’

Hormesis and the limbic brain

Posted 02 Jan 2012 — by Todd
Category Health, Hormesis, Psychology

There is a powerful way to re-program your brain that has been largely overlooked.  A way to change your relationship with eating, sleep, sex and basic emotions like fear, love and aggression.  While cognitive therapies can modify behavior, they are of questionable help in altering these basic drives.

Our drives are largely governed by two small primitive brain structures, the hypothalamus and the amygdala – shown in red in the drawing at right.  Remarkably, these two tiny structures are respectively the size of a pea and an almond — representing less than 1% of the brain’s three pounds of neural matter. Together, they constitute the control center of the paleomammalian brain–the “limbic” brain that governs our basic urges and desires as well as our homeostatic “set points” for temperature, sleep, body fat and behavioral urges like sex drive and aggression.

You can attempt to change your behavior by conscious determination and cognitive therapies.  But most attempts at intentional change are temporary and are doomed to fail in the long term because they are strongly resisted by powerful homeostatic processes encoded in our limbic brain.  Modern medicine recognizes the importance of homeostatic drives, and has developed pharmaceuticals to override them with diet pills, sleeping pills and antidepressants.  In fact, these medications do shift the balance of neurotransmitters and neural activity — at least in the short term.  But such chemical interventions are short-sighted “crutches” that promote dependency and come with side effects.  Often they exhibit  a “tolerance” effect: the brain’s control system fights back and weakens the impact of the medication.  To maintain the benefit, doses are increased, but this strategy may not always work.

This article will explain how the hypothalamus and amygdala contribute to the regulation of basic drives like eating, sleeping and sexuality, and how the amygdala can actually override the hypothalamus by enhancing the reward value of foods and other stimuli. (As I will explain, however, my take on “food reward” is different from that of Stephan Guyenet and other advocates of the Food Reward Hypothesis). This dual-control model can help explain anomalies such as obesity, addiction, and disordered sleep.

Finally,  I will provide suggestions on effective and natural ways to re-program the hypothalamus and amygdala and change your homeostatic set points, using the principle of hormesis.

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Obesity starts in the brain

Posted 25 Nov 2011 — by Todd
Category Diet, Health, Psychology

 

Where does obesity begin?  What drives you to eat too much or expend too little energy, and why has there been such a dramatic increase in obesity since 1980? Some recently popular explanations are the carbohydrate / insulin hypothesis (CIH), singling out the prevalence of carbohydrates in the diet, and the food reward hypothesis (FRH), putting the primary blame on the availability of “hyper-palatable” food.

In this post I will present evidence for new paradigm, which I call the  Hypothalamic Hypothesis (HH).  I think it provides a better explanation for the facts of obesity than the CIH and FRH theories, and leads to some different advice about how best to lose weight.

Some recent research suggests that obesity starts with specific physical changes to the brain. Appetite is regulated by the hypothalamus, particularly the arcuate nucleus (ARC), ventromedial hypothalamus (VMH) and lateral hypothalamus (LH). It turns out that two very specific changes to the brain cause us to get get hungry, overeat, burn less fat, and gain weight. And these changes to particular brain structures come about as a result of what you eat, eating frequency, and to some extent your activity level. The problem of obesity or overweight is often portrayed as a single problem, but it is really two problems, and each type of obesity corresponds to one type of brain alteration. Failure to distinguish these two types of obesity has resulted in much confusion. In part, the confusion comes about because these two types of obesity frequently occur together in the same individual, although one type is usually dominant. If you understand this, and you understand the role your brain plays, you can become more successful at losing excess weight.

I’ll spend a little time explaining the theory, provide some specific suggestions for how it can help you fine tune your weight loss program, and try to point out why I think the Hypothalamic Hypothesis overcomes some weaknesses of the other obesity theories.

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Get stronger using stress oscillation

Posted 14 Aug 2011 — by Todd
Category Diet, Fitness, Health, Hormesis

How much weight lifting or other exercise is optimal for fitness?  What is the right amount of carbohydrate restriction or fasting for sustained weight loss and health? What level of exposure to allergens will reduce allergies? How many hours of sun tanning is healthy? How frequently should plus lenses be worn to reduce myopia?  Do I need to take cold showers every day to get their benefit? How much stress is enough — and how much is too much?

Many of the questions I get on this website and the forums are of this type.  People understand the general concept of hormesis, namely that exposure to controlled amounts of stress can be beneficial, because it elicits beneficial adaptive responses in the organism.  They understand that weight lifting builds muscles, and that intermittent fasting and calorie reduction can be healthful. But too much of any stressor — weight lifting, caloric restriction, sunlight, allergens  – can have adverse consequences.  With hormesis, it seems, the Goldilocks principle applies: to get a benefit, the level of stress must be “just right”.  And because it’s so easy to veer into overload, many people seek to avoid even mild stress:  Avoid allergens. Cover up with sunscreen. Eat frequent small meals. Don’t exert yourself. But if you choose this path, you forgo the possible hormetic benefits.

So how do you determine the optimum level and frequency of exposure to a stress?  And how much rest or recovery between exposures is optimal? Read More

Change your receptors, change your set point

Posted 25 Oct 2010 — by Todd
Category Diet, Fitness, Hormesis

Why is it so hard to make permanent changes to your habits, your health, and your happiness?  Some of the most difficult struggles in life involve losing weight (and keeping it off), overcoming addictions, and recovering from depression. Many diets and therapies deliver great short term results, but the most common pattern appears to be relapse.  It often seems that you are destined to fulfill some biological program — that you are stuck with a high body weight set point or an addictive or depressive personality that cannot be escaped in the long run.

This pessimistic message is prevalent among those who have investigated the track records of the “helping” industries: the weight loss companies, the addiction recovery centers, and the various schools of psychology and psychiatry. Unlike the advocates, those who investigate them often find the results are less than what the practitioners might want you to believe.  In the arena of dieting and weight loss, books such as “The Dieter’s Dilemma” (Bennett and Gurin, 1982), and  ”Rethinking Thin”  (Kolata, 2008) echo the original set point theory first propounded by Gordon C. Kennedy in the 1950s; they conclude that your body weight is largely predetermined by a biological set point that is handed to you at birth, plus or minus about ten pounds. I do agree that sustained weight loss cannot be achieved through sheer will power alone, or simply by using diet and exercise in order to create a calorie deficit. Yet, while there is some plausibility to the set point theory, I am convinced that it is wrong because it overlooks some important factors. I’ve already given some of my reasons for my disagreement with set point theory in other posts on this blog (Flavor control diets, How to break through a plateau). But in this post I’ll present some strong evidence for an alternative theory, based on the homeostatic regulation of cellular receptors for hormones and neurotransmitters. This is a variable set point theory which I call the receptor control theory. This theory proposes a mechanism that controls appetite and body weight, as well as regulating the balance of  energy and pleasure in your life. It provides practical tools to lose weight and keep it off, overcome addictions without relapse, and move out of depression into happiness.

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How to break through a plateau

Posted 19 Sep 2010 — by Todd
Category Diet, Fitness, Psychology

You’ve embarked on a new weight loss diet or fitness program. You’ve read a book, become inspired, signed up for a program or health club and what’s more — it’s working.  For the first week, two weeks, a month, the weight is coming off, you’re hitting the gym on a regular schedule. You even drop a size or two and garner some compliments from friends.

And then…progress stalls. You’re still eating the same foods, faithfully completing your workouts, but your weight loss stalls, perhaps the scale even goes up a few pounds. The progress you make at the gym similarly maxes out…you can’t lift any more weight, your running speed or distance maxes out…maybe even some soreness or injury sets you back a bit. You’ve hit the dreaded plateau.  Sometimes it lasts a few weeks and progress resumes. But it can last months. And it saps your morale because you are not getting any more return on your invested effort. In all likelihood, you give up or cut back, your discipline withers. Your weight goes back up, maybe adding a few pounds on top of where you started, and you cut back on or cut out your exercise program. The genie is back in the bottle.

What causes plateaus?  Are they inevitable endpoints in any effort to make progress? Or are they at best temporary way-posts or resting points that you can move beyond with the right approach?  The school of thought that says that plateaus are unavoidable indicators of biological limits is called the Set Point theory. I think that the Set Point theory is wrong, and that there is a reliable way to push past plateaus to bring about substantial weight loss and improved fitness.

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The opponent-process theory of emotion

Posted 04 May 2010 — by Todd
Category Hormesis, Psychology, Stoicism

There is a remarkable psychological theory that explains the paradox of why so often our pleasures turn into problematic addictions and, conversely, why our stressful experiences frequently lead to sustained good feelings and even happiness. This under-appreciated theory was developed in the 1970s by behavioral psychologist Richard Solomon of the University of Pennsylvania. He published his theory and findings in 1980 in the journal American Psychologist, as a seminal paper, “The Opponent-Process Theory of Acquired Motivation: The Costs of Pleasure and the Benefits of Pain”. Solomon’s theory has been verified experimentally with animals and humans, and reflects a sophisticated understanding of the physiology of the nervous system. It provides a framework that has been used to explain behaviors and emotional experiences in areas as diverse as addiction, thrill-seeking, love, job satisfaction, and cravings for food or exercise.  I believe it can also explain the psychological benefits of cold showers that I have described in a separate post here, and why these benefits increase with time and repetition. I would urge followers of this blog to read Solomon’s paper, via the above hyperlink. It provides many important insights regarding how to effectively and reliably use challenge and stress to increase mental and emotional resilience, while maximizing your motivation and enjoyment in doing so. In this post, I will explore Solomon’s theory in some detail, and suggest some practical strategies for how to enhance pleasure and satisfaction in everyday activities, while avoiding the addictive side of pleasure.

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George Leonard’s “Mastery”

Posted 20 Mar 2010 — by Todd
Category Psychology, Stoicism

In any area of self-improvement, a common complaint is that we often reach a plateau and get stuck there, failing to make progress towards our goals. While this is a natural consequence of homeostasis–our organism’s inbuilt resistance to change–the experience of plateaus often leads to frustration and abandoning our resolutions. One person who understood this well and offered sage advice on how to handle the plateau was George Leonard, who recently passed away at age 86.  As an author, fifth degree black belt aikido master, and a giant in the human potential movement of the 1960s and 70s, Leonard’s passing brought to mind his little gem of a book that I first read in 1991:  Mastery: The Keys to Success and Long-Term Fulfillment.  It is a self-help classic that has grown in stature with time, but it is so much more than that. The ideas in this book made a strong impression on me the first time I read it, and it has never been far from my mind.  I picked up the book again this week to take another look and realized how much wisdom it holds, and how pertinent it is to the topic of getting stronger, and persisting through plateaus.  It is a very short book, but powerfully succinct, with profound lessons about the path to mastery in any field. Read More