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Retraining the limbic brain to overcome obesity and addiction

Posted 19 Oct 2019 — by Todd
Category Uncategorized

I presented this talk at the Ancestral Health Symposium in San Diego on August 10, 2019. It’s all about the brain processes that drive addiction and obesity — and how can we rewire those processes to regain control.

Click image to view on YouTube:

Here is a slide-by-slide synopsis of the talk.

Retraining the limbic brain to overcome obesity and addiction

  1. I have spoken at AHS in prior years on the principles of hormesis (beneficial low dose stress), the limitations of nutritional supplements, myopia reduction, and the benefits of living of high altitude.
  2. Are the epidemics of obesity and addition an inevitable results of tastier food, strong drugs and other supernormal stimuli?
  3. More than a third of Americans are clinically obese. Drug addiction, particularly to opioids, has reached epidemic proportions.
  4. Addictions are directed towards not just substances, like food and chemicals, but also activities and technologies like gambling, shopping, pornography, the internet, smartphones, and social media.
  5. Obesity and addition are multifactorial, including genetics and many environmental variables. I’ll focus in this talk on one causal factor common to both: cravings, which can defeat even the best-planned diets or recovery treatments.
  6. One prevalent idea is that addiction and obesity result from supernormal stimuli — intense cues for food, sex and sociality that hijack our brains.
  7. But can foods and drugs literally hijack our brains? Stimuli are not inherently addictive, but only become so through learning processes.
  8. One approach to overcoming addiction is abstinence and 12-step programs. But even data from Alcoholics Anonymous indicates that less than 1/3 of its members remain sober for more than 10 years; independent studies show a lower success rate.
  9. Can we just eat less palatable food, as Stephan Guyenet suggests? That might help, but it’s an unappealing approach with its own limitations.
  10. Addiction expert and Bryn Mawr psychology professor expert Maya Szalavitz, herelf a former addict, provides support for conceptualizing addiction as a learning disorder.
  11. The brain processes for addiction are coded in the paleomammailian brain — the limbic system and reward circuits of the basal ganglia.
  12. Addiction is the result of two separate processes: a general process of hedonic reversal, resulting from receptor down-regulation in the hypothalamus; and reinforcement of highly specific addictive responses rooted in classical conditioning. These are coded in the amygdala and reward circuits of the limbic system.
  13. The best account of the general propensity for addiction is the Opponent-Process theory of Solomon and Corbit, which explains how addiction results from the pursuit of pleasure, and at the same time how stressful or thrilling experiences lead to sustained euphoria.
  14. The Opponent-Process theory originated in observations of the euphoria produced by skydiving, which becomes progressively more sustained with repeated jumps.
  15. The model can be generalized to explain the opposite situation: the progressive despair and addiction resulting from adaptation to repeated pursuits of intense pleasures like drugs, gambling or sex.
  16. These opponent processes are the brain’s way to maintain homeostasis of bodily functions and drives like body temperature, appetite and mood — all governed by the hypothalamus.
  17. Judith Grisel, another addiction expert and former addict herself, describes how different drug classes activate different opponent processes associated with specific neurotransmitters. Stimulants activate “wanting” and dopamine receptors, where the opponent processes produce “craving”; Opioids and depressants activate “liking” and opioid receptors, where the opponent processes produce irritability. and even physical pain.
  18. The Incentive Salience model of Berridge and Robinson shows how these opponent processes lead to progressively dysfunctional cycles of anticipation, bingeing, and withdrawal.
  19. Koob and Volkow argue that when multiple cycles of these opponent processes exceed homeostatic tolerance thresholds, the pleasure set points are reset to progressively lower hedonic states. This process is called “allostasis”. As this allostatic process deepens, addicts pursue their addiction not even to feel good, but merely for relief from despair.
  20. I’ve put forward a physiological hypothesis to explain the psychological Opponent Process theory, which I call the Receptor Control Theory. In essence, our pleasure set point or baseline “happiness” is determined by the density and sensitivity of dopamine receptors in the brain (and elsewhere). In this view, obesity and addiction result from a process of “dopamine resistance”, whereby receptor down-regulation impairs satisfaction and drives cravings. Conversely, high receptor density and sensitivity promote satisfaction and dampen cravings.
  21. This theory finds support in PET scans from Nora Volkow showing reduced dopamine receptor density in the brains of addicted and obese human subjects.
  22. And Whitten has shown that dopamine receptor density declines progressively with continued use of cocaine.
  23. Dopamine reward cycles are associated not just with substance use, but also with reinforced activities like extensive smart phone usage.
  24. Here’s the good news: PET brain scans in rats and humans demonstrate how receptor down-regulation caused by obesity and addiction can be reversed by hormesis — exposure to psychologically demanding activities like calorie restriction and exercise.
  25. Now to the specific processes involved in addition: these are shaped by classical or Pavlovian conditioning, stimulus-response behavior coded by the amygdala and reward circuitry.
  26. Skinner described operant conditioning of voluntary behaviors.
  27. Pavlov described classical conditioning of involuntary physiological responses. His famous studies showed how dogs can learn to salivate as a “conditioned” response to an unfamiliar cue like a bell, that becomes associated with repetitive feeding of a natural or “unconditioned” cue like meat. Our hunger craving response to the aroma and sight of a pastry is a familiar example of classical conditioning.
  28. Just as our general drives for food, sex and sleep are governed by the hypothalamus, our conditioned response to specific foods, sexual partners and sleep cues are coded in the amygdala.
  29. The amygdala and hippocampus govern our “gut reactions”.
  30. The dopamine and opioid reward circuitry that reinforce the cycles of wanting and liking described by Berridge and Robinson are coded in the basal ganglia.
  31. There are also specific timing cues. The hormone ghrelin that governs appetite cues associated with meal timing and frequency can be conditioned, e.g. via yabo亚洲 .
  32. We can usefully apply this understanding of classical conditioning to stop unwanted responses to cues by using 4 strategies: (1) stimulus avoidance; (2) cue exposure & extinction; (3) counter-conditioning; and (4) putting on cue.
  33. Most people don’t realize that in his 1927 study of dogs, Pavlov showed how even their supposedly unconditioned “innate” salivation response to the presentation of meat could be extinguished or by repeatedly presenting the meat without allowing the dog to eat it.
  34. Cue exposure therapy retrains responses to addictive cues by systematic exposure to cues without allowing the response.
  35. Conklin and Tiffany reviewed 18 trials of cue exposure therapy to treat addictions, finding that the successful studies incorporated four factors: (1) varied context; (2) repeated presentation spaced in time; (3) presentation of the stimulus without normal cues; (4) extinguishing of behavioral cues, not just sensory cues.
  36. A specific example of reconditioning is separating flavor cues from food reward. The Shangri-La 亚搏体育客户端下载 , devised by Seth Roberts, is an effective example of this, using flavorless calories or calorie-less flavors to deconditioning food cues.
  37. Extinction and counterconditioning are very effective ways to decondition cravings, for example, for food, alcohol or smartphones.
  38. I’ve developed the Deconditioning 亚搏体育客户端下载 as a specific protocol for overcoming food cravings. It has three phases: (1) a low-insulinogenic diet, cutting out snacks; (2) deconditioning using extinction and counterconditioning. Don’t eat when you’re hungry! Expose yourself to food aromas without eating!; and (3) yabo亚洲 to support long term dietary goals.
  39. We can frame this in a more general 3-phase approach to fight cravings and addictions: (1) First increase your resilience and general hedonic state using psychological hormesis — engaging in strenuous or challenging physical activities; (2) Decondition specific cravings using extinction, cue exposure and counter-conditioning; and (3) Rebalance pleasure in your life, based on a goal of either reducing or eliminating an “addictive” pleasure. Reinforce problematic cues with alternative pleasures.
  40. At the end of the video, I’ve provided references and blog posts on this site for on further reading.
  41. In summary, addiction is complex, but a central challenge is overcoming cravings. Supernormal stimuli aren’t inherently addictive but become that way through conditioning. We can work our way out of addictions through a combination of hormesis (to improve resilience and baseline pleasure) and deconditioning of specific cravings using cue exposure and counterconditioning.

In the Q&A session, I fielded questions on several topics, including motivational barriers, complementary methods such as mindfulness, cognitive-behavioral therapy (CBT), “positive” addictions to exercise, hedonic challenges with ketogenic diets, positive reinforcement vs. punishment in banishing cravings, intermittent reinforcement and clicker training.

If this talk interested you, here are links to related posts on this blog:

I’ll be talking at AHS19 in San Diego on August 10

Posted 28 Jul 2019 — by Todd
Category Uncategorized

I realize this blog has been pretty quiet, but that’s about to change. I’ll be presenting at the Ancestral Health Symposium at UC San Diego on August 10, 1:30-2:10 pm.

It’s not too late to register. The conference runs from Thursday, August 8 to Saturday, August 10.

It’s not too late to register – here’s the link to the AHS website:

AHS19 Conference in San Diego – Program Details

Here is the title and abstract of my talk:

“Retraining the Limbic Brain to Overcome Obesity and Addictions”

This talk considers whether food and other stimuli are inherently addictive, or only become that way through conditioning. Insufficient attention has been paid to the role of the amygdala and learning processes in mediating the sensory, emotional and social inputs that can modulate hypothalamic drives for better or worse. I will outline ways that appetite and other drives can be usefully retrained, often with surprising effectiveness for losing weight and overcoming addictions.

Modern maladies such as obesity and addiction have neural correlates in two ancients parts of the brain: the hypothalamus and the amygdala. Research has elucidated the particular neuronal structures and pathways that underlie the development of these conditions. Some have argued that the epidemics of obesity and addiction have their roots in the contemporary environment of hyperpalatable food and other supernormal addictive stimuli that hijack and dysregulate homeostatic control by the hypothalamus. 

Hope to see you there!

AHS 2018 videos: “yabo亚洲 ” and other talks

Posted 15 Oct 2018 — by Todd
Category Uncategorized

Montana State University has now completed producing and editing the talks from this year’s Ancestral Health Symposium in Bozeman, Montana.  My previous post from July 19 is a static upload of the slides and summary point but if you are like me, you will probably find watching the video more understandable and enjoyable.

Here is my talk on “How yabo亚洲 Works”:



And here is a link to the YouTube site with all the other talks from this summer’s conference.  There are some excellent ones here!











I’d welcome comments and feedback on any of these talks.


How yabo亚洲 Works

Posted 19 Jul 2018 — by Todd
Category Uncategorized

I had the pleasure of delivering a presentation on this topic today at the Ancestral Health Symposium, in beautiful Bozeman, Montana.  This is my fourth such talk at AHS, a non-profit educational organization which brings together a collection of academics, practitioners, bloggers and others interested in evolutionary mismatch and its implications for health and well-being.

I’m posting the slides from my talk here – click on the image to see a pdf.  I’ll upload the full video once it becomes available in a few weeks.




This talk is about the biological mechanisms that explain hormesis – the beneficial  adaptation  to  intermittent, low dose stress.  Here is a synopsis of the talk, slide by slide:

  1. Title: How yabo亚洲 Works: The Biology of Beneficial Adaptation to Stress
  2. The yabo亚洲 blog has many specific examples of hormesis.  I have spoken at AHS on 3 prior occasions on different topics, but this will be a deeper dive into the mechanisms that underlie all types of hormesis.
  3. We are faced with pandemics of metabolic disease and psychological disorders.  Do these result from too much stress, or perhaps too little beneficial stress?
  4. yabo亚洲 is defined as the beneficial response  of an organism to a low dose stressor that is otherwise detrimental or lethal at higher doses.
  5. A survey of 9000 toxicology dose response curves in microbes, plants and animals show that 19.5% of them display evidence of a positive or stimulatory effect at lower doses.  The hormetic concentrations vary considerably for different chemicals, stressors and organisms.
  6. Why does hormesis exist?  Organisms must be able to adapt to changing, stressful environments or face extinction.
  7. Ancient man was a hunter gatherer, often facing food shortages, lack of shelter and infection.  Our modern evolutionary mismatch may be the fact that we are too comfortable and protected from the hormetic stimuli in our natural environment.
  8. But how does hormesis actually work?  What are the underlying biological mechanisms?
  9. I propose a “Hormetic Hierachy” of four main types of hormesis.  Starting at the foundation and moving higher, these types are: structural, defense, metabolic and psychological.
  10. STRUCTURAL HORMESIS is the strengthening or adaptation of structural tissues in response to mechanical stimuli such as pressure, friction or stretching.
  11. Resistance  exercise for muscle growth is the classic example of structural hormesis.  Straining causes micro-trauma, release of growth factors that cause satellite cells to fuse into existing muscle and increase size and strength.
  12. This results in supercompensation.  Immediately after training, there is a decrease in strength or fitness.  After rest and recocvery, the resulting strength or fitness exceeds baseline.
  13. Bone is also strengthened by exercise  that  involves loading. This stimulates integrin proteins in the osteocyles to release FAK, leading osteoblasts to migrate, secrete collagen, and mineralize.
  14. Callus forms on skin in response to friction that stimulates the crosslinking of protein and keratinocytes by transglutaminase.
  15. Myopia is also a result of structural changes in the eye.
  16. Excessive reading or screen time induces pseudomyopia (spasm in the lens) resulting in blurry distance vision .  Getting minus lenses for distance correction temporarily solves the problem, but the eye is induced to elongate, cause, spurring a repeated need for stronger lenses.
  17. The lengthening of the eye axis results when repeated cycles of retinal defocus slow the release of neuromodulators that control proteoglycan synthesis in the sclera.  This weakens the scleral tissue integrity, increasing the eye’s axial length. Hyperopia is the opposite process.
  18. This explanation is supported by research in animals and humans showing how minus lenses begin lengthening the eye, while plus lenses shorten. This process starts in less than an  hour after wearing these lenses.  Repeating cycles consolidates the change.
  19. Myopia can thus be reversed by wearing plus lenses and print pushing while reading or at computers, and using progressively weaker minus lenses for distance viewing.
  20. DEFENSE HORMESIS is the strengthening of immune  and xenobiotic defenses against foreign substances  and organisms, by appropriate exposures.
  21. The dramatic rise of allergy and autoimmune disease may be associated with the loss of our “ancestral microbiome” — a set of commensal organisms that co-evolved with us to stimulate regulatory T-cells which  moderate our B and T immunes cells not to over-react.
  22. The book “An Epidemic of Absence” by Velasquez-Manoff details numerous examples of allergies and  autoimmune  diseases controlled by exposure to microbes at specific life stages, including asthma, celiac, multiple sclerosis and autism.
  23. Xenobiotic metabolism is our defense against chemical toxins, including the natural plant toxins that we call “phytonutrients”.  The Nrf2 transcription factor mediates the production of endogenous Phase II antioxidant enzymes that neutralize oxidative stress from toxins as well as exercise.  Ironically, taking oral antioxidants suppresses Nrf2 and counteracts exercise benefits.
  24. METABOLIC HORMESIS is the improved capacity and flexibility to utilize dietary or stored energy.
  25. yabo亚洲 activates a powerful “stress sensor” called PGC-1α, that triggers wide-ranging metabolic changes, starting with mitochondrial biogenesis.  PGC-1α is triggered by stressors such as cold exposure, exercise,, calorie restriction and hypoxia.  A train of hormonal and enzymatic changes bring about appetite suppression, exercise urge, insulin sensitivity and autophagy.
  26. PGC-1α inhibits mTOR activity, the master regulator of protein synthesis and growth processes.  While important in childhood and adolescent development, mTOR is associated with metabolic diseases of aging.  PGC-1α induces the protein REDD-1 that inhibits mTOR.
  27. PGC-1α also spurs autophagy, a cellular housecleaning process that digests damaged intracellular proteins and other byproducts.
  28. Autophagy promotes longevity by reducing inflammation, apoptosis, senescence and oncogenesis.  It stimulates the innate immune response  and removes intracellular pathogens.
  29. A popular theory of why we age is that we accrue progressive oxidative damage, impairing cellular function.
  30. The long-lived naked mole rat is a counterexample to the accumulated damage theory.  It is wracked with extensive oxidative damage in the skin and organs, yet lives 30 years compared to 3 years for laboratory mice.  It protects against the results of this damage via endogenous antioxidant enzymes.
  31. PGC-1α upregulates BDNF, which induces neurogenesis in the brain and improves insulin sensitivity in the muscles.
  32. The PGC-1α cascade also induces exercise salience — the urge to exercise.
  33. In the virtuous circle of hormesis, PGC-1α turns on mitochondrial biogenesis, improving energy flow, increasing the urge to exercise and suppressing appetite and inflammation.  This leads us to be more resilience and willing to expose ourselves to further hormetic stressors.
  34. In  the viscious cycle of inflammation, a sedentary lifestyle, caloric excess and inflammatory foods suppress mitochondrial biogenesis, lowering energy level and increasing the urge to eat while suppressing the desire to exercise.
  35. Keto-adaptation is another example of metabolic hormesis.  While it takes only a few days of fasting to induce ketosis, true keto-adaptation takes several weeks.  A great reference for these metabolic changes is  Phinny and Volek’s “The Art and Science of Low Carbohydrate Performance”, and their website
  36. PSYCHOLOGICAL HORMESIS is increased resilience in the face of discomfort, by voluntary exposure to challenges.
  37. The opponent-process theory of emotion was developed to explain hedonic reversal: how, with time, pleasures become increasingly addictive, while certain uncomfortable challenges become tolerated and even lead to sustained pleasure after the event.
  38. The classic example studied by Solomon and Corbit was skydivers.  While the first jump provokes terror and some satisfaction after the jump is complete, after many jumps the initial fear experience is diminished, while the post-jump experience becomes euphoric and sustained.
  39. This phenomenon is explained by an inhibitory or opponent “B” process that counteracts the intensity of either the pleasure or pain of the intense “A” process. The B process becomes stronger with repetition, dampening the initial intensity of A and sustaining and deepening the intensity of B.
  40. These compensating opponent processes are not “mere psychology”, they are matched by underlying neurological changes. One example is the down-regulation of D2 dopamine receptors, imaged in PET brain scans, as seen in a study of smokers, alcoholics, cocaine users and the obese.
  41. Dopamine receptors are significantly down-regulated in cocaine over 6-12 months, deepening addictive cravings.
  42. Conversely, dopamine receptors can be upregulated hormetically.  Lean rats start with higher receptor density than obese rats, but both show dramatic D2 receptor activity increase after 4 months of caloric restriction.  Similar trends are seen in methamphetamine users who exercise while abstaining.
  43. SSRI anti-depressants exhibit tolerance associated with down-regulation of serotonin receptors.  But exercise has been show to have a lasting anti-depressant effect.
  44. I propose a “receptor control theory”, in which individuals have “pleasure set points” determined by the  number and sensitivity of different types of receptors.  Hormetic activities can increase receptor density, and thereby improve well-being and resilience to stress.
  45. GENERAL PRINCIPLES of hormesis at all 4 levels include: plasticity, specificity,  supercompensation, secondary adaptation, and intermittency.
  46. Secondary adaptation involving lasting changes typically takes weeks or months to consolidate.
  47. Stress oscillation is important.  Hormetic stress exposure should alternate with periods of rest to enable consolidation and avoid chronic stress and burnout.
  48. In summary, hormetic challenge at all levels can bring about increased performance, health and resilience. Try out some hormetic activities like yabo亚洲 , cold showers, rock climbing or sky diving!

Slide 49-52 provide supporting references.

I’d also recommend scanning through past articles posted on this blog for more detail on specific examples of hormesis.



A quick overview of Hormetism

Posted 23 Dec 2016 — by Todd
Category Uncategorized

A recently did a podcast interview with Christopher Kelley, author of the website Nourish Balance Thrive.   Chris is a competitive cyclist who got interested in health and biohacking.  His site provides information and interviews to help athletes (and non-athletes) optimize their health and performance.  His generally Paleo approach combines testing, supplementation and lifestyle changes.  NBT also has a team that provides personal consultation.

I got to know Chris from discussions at several Ancestral Health Symposium meetings, and this led to the podcast interview.

I’m putting up the interview here on my main page because Chris somehow managed to get me to weave together a broad range of topics in a conversational way,  succinctly and concretely illustrating the essence of hormesis and its application to improving health and well-being — what I call “Hormetism”.

I’m also including here his minute-by-minute outline of the topics covered so you can jump in or out on at points that might interest you, and you can also follow up by clicking some of the links.  Enjoy!

Chris Kelley Interviews Todd

Outline of the podcast:

[00:00:24] Myopia: A Modern Yet Reversible Disease.

[00:00:53] AHS16 – Todd Becker – Living High and Healthy.

[00:01:48] yabo亚洲 .

[00:02:35] Low-carb and yabo亚洲 .

[00:03:58] Going on holiday and forgetting glasses.

[00:04:40] Print pushing.

[00:05:02] Exercise.

[00:05:29] Immune system.

[00:06:07] UV.

[00:06:13] Overcompensation.

[00:07:28] Lactose tolerance.

[00:08:35] Unnecessarily avoiding the sun.

[00:10:05] Finding the perfect amount of stress.

[00:12:15] Learning to fast blog post.

[00:13:00] Heart rate variability or even just resting HR.

[00:14:02] Cold showers.

[00:14:43] Alcohol.

[00:15:53] Metabolic flexibility.

[00:16:08] Allostasis.

[00:17:07] Wood smoke.

[00:17:25] Evolutionary mismatches.

[00:17:41] Is charred meat bad for you?

[00:18:29] Catching Fire: How Cooking Made Us Human.

[00:19:02] Phases of detoxification.

[00:19:17] CYP3A4.

[00:19:42] Superoxide dismutase.

[00:20:01] Sulforaphane and Its Effects on Cancer, Mortality, Aging, Brain and Behavior, Heart Disease & More.

[00:21:28] Low-dose dioxins.

[00:21:53] Hormone analogues.

[00:22:14] Gluten.

[00:22:40] IgE emergency response.

[00:22:50] An Epidemic of Absence: A New Way of Understanding Allergies and Autoimmune Diseases.

[00:23:36] Peanut allergies

[00:23:56] Karelia (historical province of Finland).

[00:25:00] Reversing peanut allergies.

[00:25:22] Poison ivy and oak.

[00:26:49] Peanut oil in diaper cream.

[00:27:06] Oral vs topical exposure.

[00:27:23] Epstein–Barr virus infection at certain ages.

[00:28:09] Altitude.

[00:28:24] Boulder has the lowest obesity rate in the US.

[00:29:28] PGC1-a via hypoxia.

[00:30:16] Barry Murray on my podcast.

[00:31:36] Altitude masks.

[00:32:02] Train high race low.

[00:32:24] Jeremy Powers on this podcast.


Happy listening.


Posted 21 Aug 2016 — by Todd
Category Uncategorized

I had the pleasure of attending and presenting at the Ancestral Health Symposium, in Boulder Colorado, August 11-13. My podium presentation was entitled “Living High and Healthy: Why Coloradans and Others Who Live at High Altitude Live Longer, and What Flatlanders Can Learn From Them”.   On several visits to Boulder and the Rocky Mountains, I was surprised that I had lost about 5-10 pounds after returning home to California. Subsequently, I was intrigued to learn that Boulder has the lowest obesity rate in the U.S., and that alpine regions around the world are distinguished by statistically lower prevalence of  obesity and diabetes, and also increased longevity.

My curiosity about this issue spurred a deeper investigation, resulting in this  talk at AHS16. From the scientific literature, I learned that there is a specific hormetic mechanism involving hypoxia (reduced oxygen levels) that probably accounts for the health-promoting effects of living at high altitude.  However, it was particularly exciting to discover that hypoxia is not the only means of activating this hormetic mechanism, which can still be accessed even if you live at sea level!

The Ancestry Foundation is kind enough to produce excellent videos of the talks and release them for free viewing on YouTube.  Enjoy watching!


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FAQ for vision improvement by Hormetism

Posted 01 Mar 2016 — by Todd
Category Uncategorized

Three of my most popular articles are about how to restore your eyesight naturally and liberate yourself from glasses or contact lenses:

I call my general method “Hormetism” — the application of incremental stress to improve health.  While this approach has some similarities to other natural vision improvement methods, what is unique here is how the method is organized around the central principle of applying graduated, incremental defocus stress to induce progressive improvement over time.

Hormetism is the precise opposite of the current standard of care for correcting vision.  Minus lenses are prescribed to provide immediate relief and “correct” a refractive error in the eye — usually a combination of axial lengthening and thickening or spasm of the crystalline lens.  But despite the immediate relief, this approach provides a “crutch” that induces a compensation in the eye that makes the myopia grow worse over time.  The method of Hormetism essentially reverses the process by using focusing techniques or plus lenses to restore the original shape of the eye and accommodative ability of the lens. The above linked blog posts delve into theory and experimental evidence for my method.

Vision improvement by Hormetism is also the single most popular topic on my Discussion Forum, and I’m so pleased to hear from many that these articles have helped them to reduce or even eliminate their dependence on glasses — without resorting to laser eye surgery.

But I get a constant stream of questions asking for clarifications about how to proceed.  I often find myself answering the same questions again and again.

So I’m writing this post to provide an “FAQ”:   Answers to frequently asked “practical ” questions about how to apply this method to get results and improve your vision.  I have tried to boil it down to a simple, step-by-step method.  The information and ideas summarized here are based upon my personal experience, what has worked for others, and my understanding of the science of vision.  I am not providing medical advice, so take responsibility for your own health.

Q1.  How do I start if I am myopic (nearsighted) and can focus close up, but the distance is blurry? 

A1.  Follow this five step process if you are myopic:

  1. Note your Snellen score. First go to the ISEE Website and print out a Snellen chart.  (That’s one of those eye charts you use in the doctor’s office or DMV to test your vision, like the one in the image below).  Hang it on the wall in a well lit area and mark off a line 20 feet back from the wall.  Cover each eye separately and note the lowest line for which you can correctly read all the letters.For example if it is Line 3 for your left eye and Line 4 for your right eye, your Snellen score is 20/70 (L) and 20/50 (R).  The second number after the slash represents the distance that a normal person would have to stand at to see in focus the line that you can see at 20 feet back.  Note that score, because it is your baseline against which to track improvement.Snellen chart
  2. Note your diopter correction.  This is the first number on your prescription, also called the spherical aberration.  Ignore for now all the other numbers after the first — these relate to astigmatism or cylindrical aberration.  (More about that later).  OD is the right eye and OS is the left eye.  So for example, if your prescription is
    OD -3.00 -0,.50 x 95
    OS -2.50 -1.00 x 93
    Then your myopia can be summarized as:
    What are diopters?  Well, 100 divided by the minus diopter number is the approximate distance (in centimeters) that you can see clearly in focus with each eye.  Since there are 39.4 inches per meter, then in inches that would be 39.4 divided by the diopters.  So a person with the above prescription can see
    39.4/3 = about 13 inches with the right eye
    39.4/2.5 = about 16 inches with the left eye
    Your Snellen score and diopter correction have different meanings, so you can’t translate from one to the other.  However, if you don’t have your diopter correction, you may find this chart useful in making an approximate translation between Snellen and diopters.
    ..Screen Shot 2016-02-27 at 1.43.24 PM..
  3. Use print pushing to reduce myopia.  Print pushing is a method that involves “active focusing”.  It is not a matter of passively wearing special lenses.  It requires conscientious awareness of the reach of your focus and an intentional effort to increase that reach by “nudging” it. If your myopia is stronger than -2 diopters or 20/150 in both eyes, then you cannot see normal print in focus beyond about 20 inches.  So you can proceed to do “print pushing” without any glasses or contacts — just your naked eyes.  The idea behind print pushing is to read right at the limit of your focal distance, and to systematically push that distance to become farther and farther away. Print pushing is something you integrate into your normal routine of reading printed matter or computer screens.  About 5 years ago, I defined three distances to keep in mind while print pushing:

    D1. The ‘edge of focus’ – the furthest distance for myope (or closest for a hyperope) where a printed letter is completely in focus
    D2. The ‘edge of blur’ – the distance just beyond the edge of focus, where the slightest blur in the letter can just be detected
    D3. The ‘edge of readability’ – the furthest distance where you can intelligibly recognize each letter.

    Now D1 and D2 are going to be VERY close, almost exactly the same distance. If you are reading at D1, and you push the print slightly away less than an inch, you are immediately at D2. And if you are at D2 and get the tiniest distance closer, you are back at D1 again.You should spend the vast majority of your time reading at D1, in perfect focus, but continually (every few minutes), testing yourself by “pushing” into to D2. That’s because D1 is a dynamic distance, constantly changing.  It depends on lighting conditions, how alter or tired you feel, and other factors.  And you never want to be reading at D3 — that is needless stress on your eyes.The whole idea of print pushing is to keep increasing D1 and D2 so that your range of focus increases.  Once your myopia weakens sufficiently, go to Step 4.

  4. If your myopia is mild (less than about -2 diopters), you should print push with plus plus lens racklenses.
    Once your myopia is -2 or less, you can easily read a book or computer at arms’ length — at up to about 19-20 inches (half a meter) — without glasses.  So you aren’t effectively increasing D1 and D2 any more. That’s when you need to start using “anti-corrective” lenses to make your eyes work harder, by bring D1 and D2 closer.  This is analogous to wearing ankle weights to increase leg strength when you go for a run.  This technique is sometimes known as “plus lens therapy”.Unlike minus lenses, which have concave curvature to “correct” myopia, plus lenses have a convex shape like a magnifying glass, making it easier to see objects up close.  But this also brings D2 closer, making it harder to focus in the distance.  And this is precisely what makes them useful for increasing D2 beyond 20 inches.
    Plus lenses are sometimes called reading glasses or “readers”, mainly to help people with hyperopia or presbyopia read with greater ease.  But you are going to use them for the opposite purpose — for making it harder to focus in the distance.To choose the right strength of plus lens, I recommend making a trip to your local pharmacy or department store, where these “readers” are sold on rotating racks, like those pictured to the right.Try on various pairs to find one that allows you to read comfortably at about 15-20 inches, but begins to blur beyond that.  As a rule of thumb,  your “effective” diopters will be that of your current diopters minus that of of the plus lens you wear.   So if you have worked your way to a -0.75 prescription, you’ll need to wear a +1.25 pair of reading glasses to make it seem like you have -2.00 diopter myopia. So try on the +1.25 pair to see how that works.
    Wear these reading glasses for at least part of the time you read each day.  How much time?  To be effective, I would say about 1-2 hours per day while reading.  You can use them more if you are comfortable.  But rest is important, so it is very important to follow these guidelines:
    – Take frequent breaks every 15-30 minutes or so, removing the glasses to look at objects near and far
    – Stop if you get tired, or if your eyes get sore or red
    – Use plus lenses only for reading and close work.
    Plus lenses will create too much blur for distance activities. (See point 5 below).As your myopia reduces, you will want to replace these plus lenses with stronger plus lenses.  Once you get higher than about +2.5, there is no need to go any higher.
  5. Use under-correction for distance activities. When not reading or doing close work, you can provide further stimulus to myopia reversal by wearing slightly under-corrected glasses or contacts when at work, watching TV, sitting in lectures, or other distance viewing.  This means ordering a pair of lenses that are about 0.25 to 0.5 diopters weaker than your original lenses. So to use the earlier example, for a starting of a prescription that reads:
    OD -3.00 -0,.50 x 9
    OS -2.50 -1.00 x 93
    You would replace these with the following under-corrected prescription, changing only the first numbers and leaving the others alone:
    OD -2.75 -0,.50 x 9
    OS -2.25 -1.00 x 93
    You wear these under-corrected lenses for a while (probably a few months) until your myopia is sufficiently reduced (by the combination of print pushing and wearing weaker distance lenses).  Then you order additional lenses with further reductions in the diopter correction.  When you are looking at distance objects, trace common objects with your eyes and observe fine features, especially lines and edges.  Vary your gaze near and far, and make this into a game.  Play with it!
    Fusing of double images. As your myopia reduces, you may have the experience that many have of “double vision” or ghosting.  This might seem alarming at first, but it is actually a sign of your ability to see objects more sharply!  I suggest watching the video on my post “Myopia: a modern yet reversible disease” for a good description of how to use a technique I call “fusing” to take advantage of double images:

    1. Find distant objects with sharp contrasting edges: telephone wires, tree branches, edges of buildings or signs
    2. Focus on the darker of the double image and away from the fainter image.  With time, the darker image will become darker, and the fainter image will fade away
    3. Eventually the double image with fuse into a single crisp image — very exciting!

    As your myopia reduces, you will start being able to see objects in perfect focus at increasing distances, even with your naked eye!  This is where the technique really pays off and it is exciting and even emotional to experience this.

Q2.  This all sounds great, but I have hyperopia (far sightedness) or presbyopia (reduced accommodation of the crystalline lens) that make it hard for me to read fine print or read up close?  What can I do about that?

A2. Well, if you understand the principle of how Hormetism works to reduce myopia, you should be able to answer that question if you think about it for a moment?  What do you think the answer is?  That’s right — it’s the same method applied in the opposite direction!

When you read, instead of print pushing do “print pulling”.  Define D1, D2 and D3 by moving inward from perfect focus starting at D1.  Generally you can print pull with your naked eye.  Get as close as you can to read at D1, and test yourself frequently by getting closer to the text.  And try to test yourself on finer and finer print.  You can also print out a near vision test card from the I-SEE website  It’s basically a Snellen chart for people with hyoperopia or presbyopia. (It is on the final page of that link, after the standard Snellen chart for distance vision).

Another cool way to improve near vision is to use the “convergence” method of Ray Gottieb.  You can print out his chart and directions from the I-SEE Website.  This is a bit tricky and involves learning to allow your eyes to relax enough that they “cross” slightly.  Not everyone can do this.  It took me a while to make it work for me, but once I got it it was like magic!  Try it, it may or may not work for you.

Q3. My myopia correction is much stronger in one eye than the other. How do I apply your method?

A3.  If  the prescriptions for your right and left eyes are within 0.5 diopters of each other (as in the above example), then you should not have any difficulty doing print pushing. But if they differ by more than 0.5 diopters, then your D2 can be more than a few inches different for the right and left eyes.  So you can’t find a single distance for print pushing that will work for both eyes.

As we age, it is common to develop a condition called “mono vision” where the eyes tend to specialize — one is better at distance, one for close work.  This is the case with me, where my right eye has perfect distance vision but some presbyopia close up, whereas the the left eye is much sharper close up but 20/40 for distance.  The two eyes work very well together, but I keep pushing each eye to improve where it is weak.  I do print pushing with my left eye and print “pulling” with my right eye, as explained in the answer to Question 2 above.

WinkIn such a case, I would advise to work on the eye with a higher degree of myopia first.  But to do that you have to prevent your better “stronger” eye from doing the work, so that your “weaker” eye is forced to improve.  There are several alternative ways to selectively work on just your weaker eye, depicted in the diagram to the right::

  1. Patch. One way to do that is to tape some paper over the lens of the stronger eye.  I recommend using wax paper or tracing paper that diffuses the image and prevent focusing, but lets in enough light to keep your pupil from constricting, so you don’t have to readjust to the light when removing the glasses. Patching is convenient, but you may feel it looks too awkward or “nerdy” in public.
  2. Shield.  I personally like this method when reading for a long time.. Hold one hand with thumb against nose, and tilt at a 45 degree angle to block the stronger eye’s direct view of text, but still allow light in.  Your strong eye will be “looking” at the backside of your tilted hand, but your brain will fill in the gap and “see” what your weak eye sees on the page you are reading.
  3. Wink.  This is similar to shielding, but is leaves both hands free and is the least “conspicuous”.  At first, you may find it tiresome to hold one eye blinked shut, but it is amazing how much easier and almost effortless this becomes with practice.  I can blink one eye shut for 5 minutes without any problem.  And I periodically “flash” it open every minute or so to keep the pupil from shutting down.  This is something you can even do while driving because there is no issue of reaction time to open both eyes.

Q4.  Glasses are expensive. Do I have to keep buying new pairs of glasses as my vision improves? 

A4.  I agree that it would be costly to have to buy a new pair of glasses every time your vision improves.  There are two alternatives I can recommend if you want to save money and are willing to compromise a bit on style:

  1. Buy some inexpensive glasses online.  There are many vendors, but a reliable one is:  They have a wide range of choices of frames, including some under $20, and you can just input your prescription.  It is then relatively painless to order additional pairs with successively weaker corrections.
  2. Buy adjustable lenses.  You can buy these from or Adjustable lenses have the advantage that you can continuously alter the prescription so that it is fine tuned to what you need.  Some adjustable lenses can be adjusted both as plus lenses for print pushing, and under-corrected minus lenses for distance activities, and even minus lenses for print pulling.  I have been experimenting with using them to work on reducing the extent of my own mono vision (slight myopia in the left eye and slight presbyopia/hyperopia in the right eye).  This is a nice all-purpose solution.  The main downside is that these glasses have a somewhat reduced field of vision and tend to have a little bit of distortion that can be annoying.  But very practical.

For the record, I have absolutely no connection or financial interest in any of these sites, or any product whatsoever. I have myself purchased glasses from both Aennioptical and Adlens and have been satisfied, but I make no promises or claims as to how well these products will work for you.  But they are cheap enough that you can afford to experiment and to work through several stages of improvement without spending a bundle of money.

Q5. I have very strong myopia (usually between -6 to -12 diopters).  Will this method work for me or is it hopeless? How long will it take me to get to 20/20?

A5.  The Hormetism method can work no matter how strong your myopia or how old you are.  But you need to be realistic.  It took you many years to become myopic, and it will require patience, consistency and time to undo the damage.  The rate of improvement varies  a lot and depends on many factors, including age, genetics, and diet — and very much on your own consistency and persistence.  Some people can reduce 2 diopters in a year.  Others, only 0.5 diopters per year.

My experience– and that of many who have shared their experience on the Discussion Forum — is that improvements do not occur at a steady rate.  Rather, you will improve in sudden, unpredictable spurts.  You may see absolutely no improvement for weeks – and then one day you find yourself more easily reading books, or you can clearly see flowers in full focus on the other side of the room.  So be patient if you don’t make any progress in the first few weeks, or if you stall after a few months.

And let’s be clear also that some people make a concerted effort and never improve.  But there is really not much downside to trying, right? And you are not exposing yourself to the risks of other more invasive and “irreversible”  methods like laser eye surgery.

At the very least, you may stabilize your vision and stop the further progression of myopia.  Otis Brown champions this as “myopia prevention” and works with young people and their parents to help them stall myopia before it becomes serious.

Don’t minimize the potential impact of diet.  Cordain’s research indicates that the standard American diet, high in sugar and industrial oils, low in fiber, omega-3 oils, and phytonutrients is likely a strong contributor to the myopia epidemic.  I found that when I went on a mostly Paleo diet, my visual acuity sharpened, and I notice that consuming cod liver oil and more brightly pigmented vegetables induced a dramatic brightening in colors at the red and purple end of the spectrum, and better night vision.  If you practice hormetic eye exercises, but eat a lousy diet, you may be working at cross-purposes to your goal of improved vision.

Q6. I have astigmatism.  Will this method help me?

A6. Astigmatism often reduces spontaneously as myopia is corrected.  That is what I found in my own case.  But you may also wish to experiment with specific astigmatism reduction exercises such advocated by Leo Angart, such as tracing with your eyes the spokes of the Tibetan wheel, or the the similar Astigmatism Wheel used by followers of the Bates Method.  I don’t follow the general approach of either Angart or Bates, but happily borrow specific techniques where they prove useful.

I think that the above six questions account for about 90% of the questions I receive via individual correspondence or see posted as comments to previous posts or on the Discussion Forum.  For those who wish to take a deeper dive, I encourage you to head over to the discussion forum and peruse the many insightful discussions on vision improvement, mostly on the this popular board:

Discussion Forum: 亚搏体育客户端下载

If your questions still are not answered by this blog post or what you find on the Discussion Forum, go ahead and start a new three to ask the question or describe your  experience.  I see a lot of good ideas over there and am constantly learning and tweaking my own approach.

Happy seeing!





Is charred meat bad for you?

Posted 06 Sep 2015 — by Todd
Category Uncategorized

imagesAs the end of summer approaches, you love to grill your food on the open flame.  You savor that char-grilled flavor on your meat or fish.  Perhaps you fashion yourself as a modern-day caveman, inspired by the Paleo 亚搏体育客户端下载 and getting back to Nature.

At the same time, you’ve probably heard that eating grilled meat is a bad idea, because compounds in the meat char can cause cancer.

According to the National Cancer Institute, grilling meat to the point of charring causes the formation of heterocyclic amines (HCAs), polycyclic aromatic hydrocarbons (PAHs), and Maillard reaction products such as acrylamide (AA) or advanced glycation end-products (AGEs).  HCAs and AGEs are formed when the amino acids, sugars and creatine in meat react at high temperatures. PAHs are formed when meat fats burn.  Maillard reaction products are those tasty brown “caramelized” substances produced by the reaction of sugars and amino acids when meats and other foods are cooked by grilling, baking, frying or toasting.

The National Cancer Institute reports that HCAs, PAHs and acrylamide have been shown to cause cancer in laboratory animals.  Added to this are a number of epidemiological studies purporting to show an association between consumption of cooked meats and cancer.

So you reluctantly curtail your inner caveman and carefully scrape the blackened parts off your meats, or grill them at a lower temperature.  Or perhaps you avoid grilling altogether, retreating indoors and lightly sautéing or boiling your meat dishes.

Relax. I’m here to make the case that charred meat is not to be feared.  It may actually be good for you, hormetically boosting your general ability to neutralize and dispose of dietary toxins. In this blog post, we will take a closer look at the animal and human studies, combined with a deeper look at the evolutionary record, aided by the perspective of modern toxicology.  I think it may change your mind.

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Live longer!

Posted 31 Mar 2015 — by Todd
Category Uncategorized

Spring Chicken

So you want to live a long life, or at least age gracefully?

Bill Gifford has provided a well-researched and engrossing account of the quest for longevity. In his new book, Spring Chicken, Gifford critically examines the claims of scientists, enthusiasts and hucksters in their attempts to extend life using hormone replacement therapy, telomerase, supplements, drugs, exercise, caloric restriction, yabo亚洲 and other practices. Along the way, he visits with a 108-year old investment advisor and a 76-year old female sprinter who can run a 6:58 mile, and he  takes a close look at mice, monkeys and microbes that live much longer than species norms.

I found the book hard to put down. That’s not merely because Bill’s hilarious account of my wintry swim with him in the Pacific Ocean appears in Chapter 12–as a bracing illustration of how hormesis builds stress tolerance.  I was captivated by reading of his up-close encounters with a diverse set of gerontologists, centenarians and odd, long-lived creatures such as the naked mole rat. Most interesting of all was his meticulous detective work in probing the major competing theories of aging, leading to some unconventional conclusions about what may or may not actually help prolong life and healthspan.

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Myopia: a modern yet reversible disease

Posted 09 Aug 2014 — by Todd
Category Uncategorized

Here is the video and slide set from my presentation at the Ancestral Health Symposium, August 9, 2014, in Berkeley, California. I enjoyed meeting many of you who were at the conference.  I’d recommend watching the video first, and perhaps follow along with the uploaded slide set in a separate window, since it is  more convenient for viewing references and other details.

(Note: You’ll notice some minor differences in the video and slide versions, as the AV team inadvertently projected an earlier draft rather then the final slides I had provided).




(Click on image below and allow 30-60 seconds for slideshow to upload)


Overview of the talk.  For ease of reference, here is slide-by-slide “table-of-contents” summary of the presentation. People are always asking to provide a detailed explanation of exactly what steps to take to improve their vision.  You’ll find this bottom line “practical advice” in Slides 23-36

  1. Title: Myopia: a modern yet reversible disease
  2. My story:   I wore glasses from Grade 10 until 15 years ago. I don’t wear glasses any more!
  3. To reverse myopia, we need to first understand the causes.
  4. Myopia defined.   Myopia can lead to serious problems like cataracts and macular degeneration
  5. The prevalence of myopia has increased by 50-100% since 1970, across all age groups in the U.S.
  6. There is evidence for both genetic and environmental causes.
  7. An 1883 study of military recruits found myopia was much higher in students and merchants than farmers
  8. A 1969 study of Eskimos found that myopia had increased dramatically since Western schooling was introduced
  9. A 2012 study of German students found more than 50% of university graduates had myopia vs. 25% for dropouts
  10. In countries like Singapore and Taiwan, myopia is common among even young school children
  11. There is evidence that certain genes predispose to severe myopia. Copper deficiency induces myopia due to increased scleral wall elasticity.
  12. Cordain found that a high carbohydrate diet and deficiency of EFAs and minerals promote myopia
  13. It appears that a myopiagenic environment (near work) is needed to activate  genetic predisposition to myopia
  14. What is the biological mechanism?
  15. The normal lens changes shape to focus
  16. Myopia progresses in two stages: (1) near work induces lens spasm, causing pseudo-myopia; (2) use of minus lenses temporarily improves distance vision, but leads to eye elongation and axial myopia.  The result of elongation is a need to prescribe stronger minus lenses, in a vicious cycle of ever stronger lenses.
  17. Eye elongation is explained by the incremental retinal defocus theory.  Retinal defocus causes release of neuromodulators that lead to decreased scleral tissue integrity, and axial growth
  18. The IRD theory has been proven empirically in chicks, monkeys and humans using optical reflectometry
  19. How can myopia be reversed?
  20. First, it is useful to understand the framework of hormesis — the beneficial response to low dose stress
  21. Weight lifting is a good example of hormesis and the principle of Specific Adaptation to Imposed Demand
  22. What if gyms had the same business model as optometrists?  They would prescribe exoskeletons to help us walk, but these “crutches” would make us weaker, not stronger.  Lenses are crutches
  23. To reverse myopia with hormesis, we need to use active focus.  That means print pushing and plus lenses while reading, and progressively weaker minus lenses and image fusing for distance activities
  24. To embark on this journey, you must first determine how myopic you are, using a Snellen chart
  25. For print pushing, you need plus lenses only if your myopia is less than -2D. Otherwise use your naked eye
  26. Find the distance (D1) where print is at the edge of focus and (D2) where it starts to blur.  Read between D1 and D2
  27. Move back from your computer or book to stay between D1 and D2. Do this for 2-4 hours a day, taking frequent breaks.  Graduate to stronger plus lenses when you drop below 2D, and continue until you achieve 20/20 vision!
  28. For distance (walking, TV, movies, meetings) buy glasses with a 0.5D reduced prescription
  29. Once your vision gets better, you may notice “double vision” or ghosting.  This is a good sign and something you can use to improve your vision!
  30. Find distant objects with sharp contrasting edges: telephone wires, tree branches, edges of buildings or signs
  31. Focus on the darker of the double image and away from the fainter image.  With time, the darker image will become darker, and the fainter image will fade away
  32. Eventually the double image with fuse into a single crisp image — very exciting!
  33. Most people have a weak eye and a stronger eye with less myopia.  The stronger eye will dominate, so strengthen the weaker eye by patching, shielding or winking shut the stronger eye…until the two eyes are roughly even.
  34. Frequently asked questions
  35. How much time should I spend on print pushing?  Spend 2-4 hours a day while doing routine computer work or reading. This is not a separate exercise, but something you build into daily activity
  36. How long before my vision improves?  Be patient — it’s like exercise or diet and won’t work overnight.  Expect some improvement within a few weeks, but it may take a year or more to clear your vision
  37. Is this the same as the Bates method?  Bates had some incorrect ideas about focusing, but his relaxation techniques can help reduce ciliary strain on the lens (pseduomyopia).  However, his method does not help if you have axial myopia and spend a lot of time at the computer or reading.  Print pushing specifically helps with that.
  38. Does active focus really work?  Check out my blog and forum for success stories
  39. And for the skeptical, here is a page of references on the epidemiology and causation of myopia
  40. And more references on methods and websites that provide a similar approach to mine
  41. Your eyes are adaptive organs which allowed them to become myopic, but you can use that same adaptability to reverse the process using active focus for both near and far activities
  42. Rediscover your natural vision — make it fun, make it a habit, make it a game.  You only have your glasses to lose!

Also be sure to check out these related posts and discussions: