Posts Tagged ‘hypothalamus’

What cold showers and exercise have in common

Posted 17 Feb 2014 — by Todd
Category Diet, Fitness, Hormesis, Uncategorized

lewisgordonpugh2PA1307_468xCan cold showers, winter plunges, and brisk walks in the chilly outdoors provide some of the same benefits as intense exercise—including weight loss and increased energy levels?  Such a link has been suspected, because cold exposure is known to convert metabolically docile white adipose tissue (WAT) into metabolically active brown adipose tissue (BAT). This “brown fat” helps you stay warmer and burn more energy.  But now there is some evidence that cold exposure doesn’t merely help you turn up your inner furnace, and burn off a little fat in the short term.  It may actually lower your body’s weight set point by activating a hormone that is also released during intense exercise.

That hormone is irisin (pronounced “EYE-rissin”), a cytokine produced in skeletal muscle.  From the initial evidence, irisin and its partner hormone FGF21 may provide lasting benefits by boosting your metabolism and inducing you to shed excess pounds. Read More

The Iceman

Posted 29 Jan 2012 — by Todd
Category Fitness, Hormesis, Psychology

Wim Hof can raise or lower his body temperature at will, overriding his autonomic nervous system. He is able to sit in a box of ice for almost two hours. He can swim 50 meters under arctic ice. Wearing only shorts and going barefoot, he has run a marathon in Lapland and climbed through snow to the summits of Mt. Everest and Mt. Kilamanjaro. In carrying out these feats, he is able to avoid hypothermia, the normal human response to extreme cold. Monitoring by physiologists show that he keeps his core temperature constant and normal during these challenges.

Yet Wim is not a genetic freak or Tibetan monk. He is a 52 year old Dutch man without much body fat. He believes that anyone can adapt to the cold and learn to control body temperature.

In this article, I will try to answer two questions:

  • How does he do it, and can anyone really do the same?
  • Is this basically an impressive stunt, or is there any benefit to learning Wim’s methods?
I will end by reporting on a preliminary experiment of my own with cold exposure.

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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