Dr Caroline Leaf, behaviour and genetic destiny

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Today on her Facebook feed, Caroline Leaf posted a quote which said, “Your behavior can and does dictate your genetic destiny”. Dr Caroline Leaf is a communication pathologist and a self-titled cognitive neuroscientist. In isolation, it sounds like she has found confirmation of her view that our thoughts and behaviour control the physical properties of our DNA (Leaf, 2013, p35).

However, I wanted to look at the quote in a broader context, because in the broader context, the quote still doesn’t confirm Dr Leaf’s teaching.

The quote comes from an American doctor, Sharon Moalem. Dr Moalem is obviously a smart man. According to Wikipedia, “Dr. Moalem is an expert in the fields of rare diseases, neurogenetics, and biotechnology. He is the author of the New York Times bestselling book ‘Survival of the Sickest’ and ‘How Sex Works’. Moalem has cofounded two biotechnology companies and is the recipient of 19 patents for his inventions in biotechnology and human health.” (http://en.wikipedia.org/wiki/Sharon_Moalem)

It’s not that Dr Moalem’s quote is wrong. In the book from which the quote is taken, Dr Moalem discusses the expression of genes (Moalem, 2014). There is no doubt that our behaviour affects the expression of genes. For example, when the body encounters a high level of dietary iron (ie: we eat a big juicy steak), a series of steps activates a gene to promote the production of ferritin, a protein that helps to carry iron in the blood stream (Strachan and Read, 2011, p375-6). These changes in genetic expression are mostly protective (for example, ferritin is used to keep toxic elemental iron from damaging our tissues). There are some behaviours that will override the body’s protection, for example, excessive exposure to UV radiation will eventually lead to skin cancer. But overall, the changes in genetic expression that our behaviour causes are protective, and do not adversely affect our health.

Unlike Dr Leaf, Dr Moalem does not promote the notion that our behaviour changes the genes themselves. Neither does he promote that our behaviour, in isolation, is the only modifier of our genetic expression. The quote that Dr Leaf used came from the second chapter of Dr Moalem’s book, “Inheritance: How Our Genes Change Our Lives, and Our Lives Change Our Genes”. Really, the title says it all. Our behaviour influences our genetic destiny, but our genes influence our behaviour just as much, if not more.

For example, small variations in the genes that code for our smell sensors or the processing of smells can change our preferences for certain foods just as much as cultural exposure. Our appreciation for music is often changed subtly between individuals because of changes in the structure of our ears or the nerves that we use to process the sounds. The genetic structure of the melanin pigment in our skin changes our interaction with our environment because of the amount of exposure to the sun we can handle. Our genetic destiny is also largely influenced by our environment, most of which is also beyond our choice (Lobo and Shaw, 2008).

So your behaviour can and does influence your genetic destiny, but your genetic destiny is more influenced by our genes themselves, and the environment that is beyond our control.

Dr Leaf’s quote doesn’t look quite so supportive after all.


Leaf, C.M., (2013) Switch On Your Brain : The Key to Peak Happiness, Thinking, and Health, Baker Books, Grand Rapids, Michigan

Lobo, I. & Shaw, K. (2008) Phenotypic range of gene expression: Environmental influence. Nature Education 1(1):12

Moalem, S., (2014) Inheritance: How our genes change our lives and our lives change our genes, Grand Central Publishing, New York.

Strachan, T. and Read, A., (2011) Human Molecular Genetics. 4th ed. Garland Science, New York.

The pain and gain of grief

Floral tribute to the Sydney siege victims, at Martin Place, Sydney

Floral tribute to the Sydney siege victims, at Martin Place, Sydney

In many ways, 2014 hasn’t been the best of years, unless you’re a florist.

A dear friend of mine recently went through an unimaginable personal loss, but politely requested that no one send her flowers, because the unintentional metaphor of receiving something beautiful that soon withered and died simply reminded her of what she had lost. Not that I could have given her flowers anyway – it seems like all of Australia’s bouquets have been laid in Martin Place.

The siege in the Lindt Cafe was an assault on Australia’s national psyche as much as it was an attack on a small café in the CBD of Sydney, and marks a highpoint of suffering in the midst of several tragedies back to back. Soon after the tragic events in Martin Place, news came of the murder of eight children from the one family in Cairns. Two weeks before, we were rocked by the sudden death of cricketer, Phil Hughes.

Like many, many others in the last few weeks, I’ve felt that discombobulating mix of sadness, compassion, anxiety, and numbness (and many other feelings) that accompanies loss. I was grieving.

Grief is not fun. There are a wide variety of ways in which people grieve, of course, though grief is rarely described as joyous. Rather than being the five stages of grief that used to be dutifully learned by every medical and psychology student, grief is now considered a mish-mash of nearly every different emotion that a human can experience, for different lengths of time, at different intensities, in different patterns. Like your fingerprint, your emotional pattern of adapting to loss is as individual as you are. I felt helpless at the news from my close friend, shock at the death of Phil Hughes, and anxious when thinking about the Lindt Café. Each tragedy was also accompanied by a deep sadness.

As well as being emotionally draining, the process of grieving can have physical effects as well, associated with high levels of pro-inflammatory cytokine release and the changes that are associated with that (O’Connor, Irwin & Wellisch, 2009). Pro-inflammatory cytokines are also released because of physical stress or infection, so grief would physically feel like you have the flu, which is probably why grieving makes you feel physically awful as well as mentally distraught.

As awful as these feelings are, they are important to our healing and restoration. Grief functions as a way of helping us adjust to life on the other side of our loss. Like our body has to heal and adapt to physical wounds, grief helps us heal and adapt emotionally. Grief is not a disease, but a normal process that everyone experiences at one point or another.

Some authors teach that negative feelings and emotions are toxic, or that the outcome of different stresses in our life is dependent on our personal choices. If there was ever a case-in-point of the benefit of “negative” emotions, and why the outcome of stressful events is not entirely under our control, it’s grief. Grieving is a process which, by definition, is distressing. The storms of painful emotion roll through us, triggered and controlled by our subconscious brain, with our conscious mind along for the ride. As distressing as those emotions can be, they are not ‘negative’ emotions, but the process of healing,

At times of intense sorrow, we can try and ‘help’ those who are grieving by telling them how they should feel, or what they should do, but during times of grief, being too directional is usually not helpful. The blog today is more general in nature because I don’t want to try and push one particular way of grieving over another. There is no right or wrong way to grieve.

My Physical Education teacher often used to say, “No pain, no gain.” Actually, it was more barking through his megaphone, trying to make me run faster in my cross-country race. It may seem an odd match, but the principle applies here too. If you are feeling the sadness and loss over the Lindt Café, Phil Hughes, Robin Williams, or any other personal loss you may have experienced, it’s ok to feel the distress. The pain is hard. The feelings are raw, and they are real. But you will get through them, and they will help you to experience the joy in life again.

I am coming to terms with each of these different tragedies in my own way. Lets pray that 2015 is a much better year.

If you are struggling and don’t know where to go to talk or find assistance, see your GP or psychologist, visit BeyondBlue (http://www.beyondblue.org.au), or the Australian Centre for Grief and Bereavement (http://www.grief.org.au).

If you want to donate to the funds or foundations set up in honour of the Sydney siege victims, please go to http://www.beyondblue.org.au/get-involved/make-a-donation or http://thekatrinadawsonfoundation.org.


O’Connor, M.-F., Irwin, M. R., & Wellisch, D. K. (2009). When grief heats up: Proinflammatory cytokines predict regional brain activation. NeuroImage, 47(3), 891–896. doi:10.1016/j.neuroimage.2009.05.049

Don’t stress about stress – Part 4: Stress breaking bad

This is the last blog post in my brief series on stress. Today, we’re going to look at what happens when we do hit stress overload, and a few simple methods that may be able to help you through a tough situation.

One of my favourite shows of all time was Breaking Bad. Breaking Bad told the story of Walter White, a high school chemistry teacher and average family man, who is diagnosed with terminal lung cancer. To support his wife and disabled son after he’s gone, he uses his knowledge of chemistry to launch himself into an underworld career manufacturing crystal meth.

Allostatic overload is the term modern scientists use for stress breaking bad. Stress moves from an agent of growth and change to an agent of disease and death.

In the last few blogs, we discussed that stress is actually more of a positive than a negative. It’s not that stress can’t be bad, because we know from the stress-productivity curve and from the Yerkes-Dodson Law that too much stress overwhelms our capacity to cope with it. The model used to describe the balance of stress on our body is the theory of Allostasis.


All living things maintain a complex dynamic equilibrium – a balancing act of the many different physiological systems that all rely on the other systems working at an optimal range. Imagine trying to stack ten spinning tops on top of each other while trying to keep them spinning. The body does the chemical equivalent of this very difficult combination of balance and dexterity every day. It’s called homeostasis. This balancing act is constantly challenged by internal or external events, termed stressors. Both the amount of stress and amount of time that the stressor is applied is important. When any stressor exceeds a certain threshold (“too strong, or too long”), the adaptive homeostatic systems of the living thing activate responses that compensate.

The theory of allostasis is related to these homeostatic mechanisms, although not just in terms of stress, but broadly to the concept of any change of the optimal range of these homeostatic balancing processes, in response to a change in the environment or life cycle of an organism [1].

McEwen and Wingfield give an example of some bird species, which change their stress response to facilitate their breeding capacity during mating season. They note that the benefit of the increased chance of breeding is important to the bird, but also comes at a cost of increased susceptibility to some diseases because of the weakening of the stress response at the time [1].

When it comes to stress, we adapt in a similar way. A lack of stress, or an excess of a stressor in some way (either too long or too strong) results in adaptation, which is beneficial, but can come at a cost. This is demonstrated by that broadly applicable U-curve, the stress productivity curve.

Chrousos wrote, “The interaction between homeostasis disturbing stressors and stressor activated adaptive responses of the organism can have three potential outcomes. First, the match may be perfect and the organism returns to its basal homeostasis or eustasis; second, the adaptive response may be inappropriate (for example, inadequate, excessive and/or prolonged) and the organism falls into cacostasis; and, third, the match may be perfect and the organism gains from the experience and a new, improved homeostatic capacity is attained, for which I propose the term ‘hyperstasis’.” [2] And as noted by McEwen, “Every system of the body responds to acute challenge with allostasis leading to adaptation.” [3]

More often than not, we adapt to the stressor, either the same as before, or possibly better. It’s only if the response to the stressor is inadequate, excessive and/or prolonged that stress ends up causing us trouble. This is what people normally think of when they think of stress – called allostatic overload – simply stress breaking bad.

Keeping stress in check

To ensure that we keep our stress levels at the optimum to ensure maximum productivity and growth, here are a few simple techniques. Remember, everyone handles stress differently, and so which of these techniques works best for you will be something you’ll have to learn by trying them.


The simplest tool is breathing. Sounds a little silly really, since you obviously breathe all of the time! But we usually take shallow breaths, so our lungs are not being used to their full capacity. When we focus on our breathing and deliberately take slow, deep breaths we increase the amount of air going in, and therefore allow more oxygen to enter the blood stream. This better fuels our cells and helps them do their job more efficiently. However, it also sets in motion a physiological mechanism that slows our heart rate.

Our heart pumps blood from our body, through the lungs to get oxygenated. As we take a deep breath, more blood is sucked up into our chest cavity from our veins, because breathing in causes a temporary vacuum in our chest cavity. The extra blood then fills our heart more efficiently. A more efficient heart beat reduces the need for the body to stimulate the heart to pump harder. This promotes more of the parasympathetic “rest-and-digest” nervous system activity, and less of the sympathetic “fight-or-flight” nervous system, via the vagal brake mechanism.

So, to slow your breathing down simply sit in a comfortable position. Take slow, deep breaths, right to the bottom of your lungs and expanding your chest forward through the central “heart” area. Count to five as you breathe in (five seconds, not one to five as quickly as possible) and then count to five as you breathe out. Keep doing this, slowly, deeply and rhythmically, in and out. Pretty simple! This will help to improve the efficiency of your heart and lungs, and reduce your stress levels.

Remember, B.R.E.A.T.H.E. = Breathe Rhythmically Evenly And Through the Heart Everyday.


Meditation takes the techniques of breathing one step further, in that meditation involves deliberately switching your brain’s focus to something simple, and in the present. Focussing on nothing – just breathing and turning off your thinking for while – does take some practice. Concentrating on something in the present (not thinking about the past or the future), tends to be easier and requires less practice, although ignoring all the other thoughts that routinely clamour for your attention might be hard when you first try it.

Focusing on the present moment is part of the practice of Mindfulness. Mindfulness meditation has been studied quite extensively over the last few decades, and has been shown to have benefits over a large number of psychological symptoms and disease states [4].

Sometimes it is easier to focus on something visual, that you can see easily in your field of view, or listen to something constant, like the ocean, or a metronome. The easiest thing to do is to again, focus on your breathing. Concentrate on the sound, rhythm and feeling of your breathing, but don’t engage your thoughts, or allow others to creep in. Meditation quietens the mind, which is excellent for reducing stress, and can help to revitalise and refresh your mind.

Guided Imagery

Guided imagery is a step along from meditation. Instead of focussing on something tangible, guided imagery lets you imagine that you are somewhere pleasant, relaxing, or rejuvenating. Some people describe it as a vivid daydream.

Get comfortable, close your eyes and start to breathe slowly and deeply. Once you begin to relax, imagine your favourite scene. It could be at the beach, or in a log cabin in the snow-capped mountains, or swimming in the cool waters in a tropical rain-forest. Whatever you choose, try to imagine the scene in as much detail as possible, and involve all five of your senses if you can, like, for example, the cool water of the waterfall on your bare skin, the sounds of the birds in the trees, the smell of the moss-covered rocks, the canopy of tall trees and vines split by the waterfall and stream allowing the sunlight to spill in to the forest floor. Enjoy the details and the relaxation that this brings. To “come back”, some recommend counting back from ten or twenty, and to tell yourself that when you reach one, you will feel calm and refreshed.

Guided imagery allows you to actively replace the harassing thoughts of your daily routine with pleasant soothing thoughts. There is some early scientific literature suggesting effectiveness, although more research is required [5, 6]. Again, with practice, this can be done anywhere, and can be done quickly if you need a short break to unwind.


Visualisations build on the techniques of guided imagery, but instead of the rain-forest or tropical paradise, you imagine yourself achieving goals, which again could be anything from improving your health, closing that deal, or hitting that perfect drive from the first tee. Again, try and imagine the scene in as much detail as you can, and involve all of your senses.


Progressive Muscle Relaxation, or PMR for short, is similar to meditation, except that you contract, hold, and then relax your muscle groups in turn. You concentrate on the feel of the tightening and relaxing of the muscles instead of, or as well as, your breathing. Like meditation, it can be done anywhere and involves very little training.

The contraction of the muscle groups, beginning in your feet – working your way up the calves and thighs, tummy, chest, arms and neck, sequentially pumps all of the blood back towards your heart, giving you a boost of blood flow to your lungs. The deep breathing oxygenates this extra blood and hence, gives your brain a burst of oxygen.

Using PMR to meditate helps engage the vagal brake, and there is some evidence that it helps to reduce persistent pain [7, 8].


Exercise releases stress and enhances your physical health [9, 10]. It is flexible and easily adaptable – it is usually free and can often be done without any equipment. The downside is that it is not possible everywhere (you can’t go jogging in a plane), but as a daily discipline, it will enhance your physical and emotional wellbeing.

The benefits of exercise are firstly physical. It gets your heart pumping, the blood flowing and your lungs working to their full capacity. It builds physical fitness, which is important to enable the heart and lungs to work efficiently at all times. Exercise has effects on mood, improving depression [11] and anxiety [12].

It can also act as a form of meditation – the solitude of a run or swimming a few laps, concentrating only on the splash of your strokes or the pounding of your feet on the ground – is similar to meditation except that you’re moving (whereas meditation proper involves being still and relaxed). But the outcome is the same, and stress is often reduced by a session of physical exercise.


Music is almost as fundamental to human existance as breathing, and it’s almost as diverse as mankind itself. Listening to ones favourite music can enhance feelings of control and can increase pain tolerance and improve short term anxiety (stress) [13]. The common characteristics of ‘therapeutic’ music was music which had less tonal (pitch) variation, less prominent chord changes, bass lines, or strong melodies [14].

But the key element was personal preference overall, as some of the participants in the study chose music like Metallica. So enjoy music. Make it part of your day. Even Country and Western may be considered therapeutic!


Yoga is an ancient practice that has several components including physical postures (asanas), controlled breathing (pranayama), deep relaxation, and meditation.

It’s not for everyone, but it has clearly defined and scientifically validated benefits to your physical and psychological well-being. “It is hypothesized that yoga combines the effects of physical postures, which have been independently associated with mood changes and meditation which increases the levels of Brain-derived neurotrophic factor (BDNF). Other effects that have been noted include increased vagal tone, increased gamma-amino butyric acid (GABA) levels, increase in serum prolactin, downregulation of the hypothalamic-pituitary-adrenal axis and decrease in serum cortisol, and promotion of frontal electroencephalogram (EEG) alpha wave activity which improves relaxation.” [15] So, translated: Yoga is good for stress relief!

Most gyms and community centres will have yoga instructors, so go ahead and make some enquiries.


I love massage! The first time I had a proper massage was in the small city of Launceston in the tiny Australian state of Tasmania. After just 30 minutes of the therapist kneading my muscles with her fingers of iron, I felt pretty good, but when I sat up, I was actually light-headed for a little while. My heart rate and blood pressure had reduced so much that it took me a while before I could stand up properly!

Deep pressure massage has also been shown to help release the vagal brake enhancing the activity of the parasympathetic (rest-and-digest) part of the autonomic nervous system. There is good evidence of this effect in pre-term infants [16]. The evidence for adults isn’t so strong, although that’s probably because of a lack of quality research [17]. The good studies that have been done show a reduction of cortisol, blood pressure and heart rate after massage, with some studies showing small persistent effects [17].

The data might be thin, but there is enough evidence to make it worth trying at least once.


I add probiotics to this list as a reference for the future. There is good evidence of the anxiolytic effect of having a friendly bacteria garden in your intestines that interacts with your gut and your immune system in positive ways. But there is, at this point, very little in the way of good quality human clinical trials. And we still don’t know exactly which strains of probiotics are the most helpful for different conditions [18, 19]. But given that they are unlikely to be harmful, it may be worth trailing a course of probiotics, and see how you feel in 30 days.

The bottom line – stress is not the enemy. Sure, if it isn’t handled right, stress can overwhelm us and make us sick, but most of the time, stress makes us productive and strong, and helps us to grow. So, don’t stress about stress.


  1. McEwen, B.S. and Wingfield, J.C., What is in a name? Integrating homeostasis, allostasis and stress. Horm Behav, 2010. 57(2): 105-11 doi: 10.1016/j.yhbeh.2009.09.011
  2. Chrousos, G.P., Stress and disorders of the stress system. Nat Rev Endocrinol, 2009. 5(7): 374-81 doi: 10.1038/nrendo.2009.106
  3. McEwen, B.S., Stressed or stressed out: what is the difference? J Psychiatry Neurosci, 2005. 30(5): 315-8 http://www.ncbi.nlm.nih.gov/pubmed/16151535
  4. Keng, S.L., et al., Effects of mindfulness on psychological health: a review of empirical studies. Clin Psychol Rev, 2011. 31(6): 1041-56 doi: 10.1016/j.cpr.2011.04.006
  5. Jallo, N., et al., The biobehavioral effects of relaxation guided imagery on maternal stress. Adv Mind Body Med, 2009. 24(4): 12-22 http://www.ncbi.nlm.nih.gov/pubmed/20671330
  6. Trakhtenberg, E.C., The effects of guided imagery on the immune system: a critical review. Int J Neurosci, 2008. 118(6): 839-55 doi: 10.1080/00207450701792705
  7. Baird, C.L. and Sands, L., A pilot study of the effectiveness of guided imagery with progressive muscle relaxation to reduce chronic pain and mobility difficulties of osteoarthritis. Pain Manag Nurs, 2004. 5(3): 97-104 doi: 10.1016/j.pmn.2004.01.003
  8. Morone, N.E. and Greco, C.M., Mind-body interventions for chronic pain in older adults: a structured review. Pain Med, 2007. 8(4): 359-75 doi: 10.1111/j.1526-4637.2007.00312.x
  9. Fletcher, G.F., et al., Statement on exercise: benefits and recommendations for physical activity programs for all Americans. A statement for health professionals by the Committee on Exercise and Cardiac Rehabilitation of the Council on Clinical Cardiology, American Heart Association. Circulation, 1996. 94(4): 857-62 http://www.ncbi.nlm.nih.gov/pubmed/8772712
  10. Warburton, D.E., et al., Health benefits of physical activity: the evidence. CMAJ, 2006. 174(6): 801-9 doi: 10.1503/cmaj.051351
  11. Rimer, J., et al., Exercise for depression. Cochrane Database Syst Rev, 2012. 7: CD004366 doi: 10.1002/14651858.CD004366.pub5
  12. DeBoer, L.B., et al., Exploring exercise as an avenue for the treatment of anxiety disorders. Expert Rev Neurother, 2012. 12(8): 1011-22 doi: 10.1586/ern.12.73
  13. MacDonald, R.A., Music, health, and well-being: a review. Int J Qual Stud Health Well-being, 2013. 8: 20635 doi: 10.3402/qhw.v8i0.20635
  14. Knox, D., et al., Acoustic analysis and mood classification of pain-relieving music. J Acoust Soc Am, 2011. 130(3): 1673-82 doi: 10.1121/1.3621029
  15. Balasubramaniam, M., et al., Yoga on our minds: a systematic review of yoga for neuropsychiatric disorders. Front Psychiatry, 2012. 3: 117 doi: 10.3389/fpsyt.2012.00117
  16. Field, T., et al., Preterm infant massage therapy research: a review. Infant Behav Dev, 2010. 33(2): 115-24 doi: 10.1016/j.infbeh.2009.12.004
  17. Moraska, A., et al., Physiological adjustments to stress measures following massage therapy: a review of the literature. Evid Based Complement Alternat Med, 2010. 7(4): 409-18 doi: 10.1093/ecam/nen029
  18. Bested, A.C., et al., Intestinal microbiota, probiotics and mental health: from Metchnikoff to modern advances: Part II – contemporary contextual research. Gut Pathog, 2013. 5(1): 3 doi: 10.1186/1757-4749-5-3
  19. Bested, A.C., et al., Intestinal microbiota, probiotics and mental health: from Metchnikoff to modern advances: part III – convergence toward clinical trials. Gut Pathog, 2013. 5(1): 4 doi: 10.1186/1757-4749-5-4

Going green – why envy is an adaptive process

The Bible says, in Job 5:2, “For wrath kills a foolish man, And envy slays a simple one.”

A German proverb goes, “Envy eats nothing, but its own heart.”

Dr Caroline Leaf, communication pathologist and self-titled cognitive neuroscientist, posted today on her social media feeds, “Jealousy and envy creates damage in the brain … but … celebrating others protects the brain!”

Yes, sometimes envy isn’t good for us. Emotions guide our thought process, and like all emotions that are out of balance, too much envy can cloud our better rational judgement and bias our perception of the world. Thankfully, envy doesn’t literally eat out our hearts or literally cause brain damage.

If anything, envy when experienced in a balanced way can actually improve our brain functioning. According to real cognitive neuroscientists, envy and regret are emotions that help us because they both fulfil the role of effectively evaluating our past actions, which improves our choices in the future. As Coricelli and Rustichini noted, “envy and regret, as well as their positive counterparts, share the common nature that is hypothesized in the functional role explanation: they are affective responses to the counterfactual evaluation of what we could have gotten had we made a different choice. Envy has, like regret, a functional explanation in adaptive learning.” [1]

When it comes to the human psyche, there is no black or white, good vs evil distinction between different feelings or emotions. B-grade life coaches and slick pseudoscience salespeople dumb down our emotions into a false dichotomy because it helps sell their message (and their books). Every emotion can be either helpful or unhelpful depending on their context in each individual.

As Skinner and Zimmer-Gembeck wrote, “Emotion is integral to all phases of the coping process, from vigilance, detection, and appraisals of threat to action readiness and coordinating responses during stressful encounters. However, adaptive coping does not rely exclusively on positive emotions nor on constant dampening of emotional reactions. In fact, emotions like anger have important adaptive functions, such as readying a person to sweep away an obstacle, as well communicating these intentions to others. Adaptive coping profits from flexible access to a range of genuine emotions as well as the ongoing cooperation of emotions with other components of the action system.” [2]

If you find your thoughts and feelings tinged by the greenish hue of envy, don’t worry, it’s not necessarily a bad thing. Your heart isn’t going to consume itself and you won’t sustain any brain damage. Use envy or regret as tools of learning, tools to help you evaluate your choices so that you make a better choice next time. Having balanced emotions is the key to learning and growing, coping with whatever obstacles life throws at us.


  1. Coricelli, G. and Rustichini, A., Counterfactual thinking and emotions: regret and envy learning. Philos Trans R Soc Lond B Biol Sci, 2010. 365(1538): 241-7 doi: 10.1098/rstb.2009.0159
  2. Skinner, E.A. and Zimmer-Gembeck, M.J., The development of coping. Annu Rev Psychol, 2007. 58: 119-44 doi: 10.1146/annurev.psych.58.110405.085705

Dr Caroline Leaf and the law of great power

Screen Shot 2014-12-05 at 12.37.55 am

Tonight as I was flicking through Facebook one last time, a post caught my eye. It read,

“The thought you are thinking right now is impacting every single one of the 75-100 trillion cells in your brain and body at quantum speeds”

Dr Leafs social media gem gave me an eerie sense of deja vu. It was only the end of October when she posted the same factoid on social media. Today’s version has been tweaked slightly, although in all fairness, I can’t describe it as an upgrade.

Dr Caroline Leaf is a communication pathologist and self-titled cognitive neuroscientist. On the 23rd of October 2014, she posted this on her social media stream, “Every thought you think impacts every one of the 75-100 trillion cells in your body at quantum speeds!”

On comparing the pair, Dr Leaf has added “brain” into the number of cells under the influence, and then massaged the opening slightly. I already had significant concern about the scientific validity of the previous meme in October. That hasn’t changed. Rather than improving the accuracy of her meme, Dr Leaf’s changes have left it missing the mark.

The fundamental fallacy that thoughts are the main controlling influence on our brain is still there. Thought is simply a conscious projection of one part of the overall function of our brain. Our brains function perfectly well without thought. Thought, on the other hand, doesn’t exist without the brain. Our brain cells influence our thoughts, not the other way around.

The myth of “quantum speeds” is still there. Our neurones interact with each other via electrochemical mechanisms. Like all other macroscopic objects, our brains follow the laws of classical physics. It’s not that quantum physics doesn’t apply to our brains, because quantum mechanics applies to all particles, but if you think you can explain macroscopic behaviour using quantum physics, then you should also try and explain Schrodingers Cat (see also chapter 13 of my book [1] for a longer discussion on quantum physics). Dr Leaf is particularly brave to make such bold statements about quantum physics when even quantum physicists find it mysterious.

What made me slightly embarrassed for Dr Leaf is the new part of her statement. In my blog on Dr Leaf’s previous attempt at this meme, I pointed out that Dr Leaf’s estimate of the number of cells in our body was more than three times that of the estimate of scientists at the Smithsonian (http://www.smithsonianmag.com/smart-news/there-are-372-trillion-cells-in-your-body-4941473/?no-ist). The fact that Dr Leaf so badly estimated, when all she needed to do was a one line Google search, suggested that she just made the number up. Failing to cite her source eroded at her credibility as a scientist.

Today, Dr Leaf still claims that there are 75-100 trillion cells in the brain and the body. The Smithsonian still hasn’t changed its estimate. Dr Leaf still hasn’t cited her source, and has ignored a world-renowned scientific institution. Perhaps Dr Leaf believes she knows more than the scientists at the Smithsonian? Perhaps she has a better reference? We’ll never know unless she cites it.

Taken as a whole, her meme is no closer to the truth than it was six weeks ago. Some may ask if it really matters. “Who cares if we have 37.2 trillion cells or 100 trillion cells or even 100 billion trillion”. “So what if our thoughts influence us or not.” If this was just a matter of a pedantic argument between some scientists over a coffee one morning,then I’d agree, it wouldn’t be so important. But Dr Leaf claims to be an expert, and more than 100,000 people read her memes on Facebook and many more on Twitter, Instagram, and the various other forms of social media she is connected to. Nearly every one of those people take Dr Leaf at her word. Ultimately the issue is trust.

If Dr Leaf can misreport such a simple, easily sourced fact, and not just once but twice now, then what does that mean for her other factoids and memes that she regularly posts on social media? If Dr Leaf incorrectly says that every thought we think impacts every cell in our body, then hundreds of thousands of people are wasting their mental and physical energy on trying to control their thoughts when it makes no real difference, and if anything might make their mental health worse [2, 3].

This is more than just a pedantic discussion over a trivial fact.  These memes matter to people, and can potentially influence the health and wellbeing of many thousands of lives.

Peter Parker, quoting Voltaire, said, “With great power comes great responsibility.”  Just because Spiderman said it doesn’t diminish the profundity of that statement.  This law of great power applies to Dr Leaf as much as it does to Spiderman.  I hope and pray that she gives this law of great power the consideration it deserves.


  1. Pitt, C.E., Hold That Thought: Reappraising the work of Dr Caroline Leaf, 2014 Pitt Medical Trust, Brisbane, Australia, URL http://www.smashwords.com/books/view/466848
  2. Garland, E.L., et al., Thought suppression, impaired regulation of urges, and Addiction-Stroop predict affect-modulated cue-reactivity among alcohol dependent adults. Biol Psychol, 2012. 89(1): 87-93 doi: 10.1016/j.biopsycho.2011.09.010
  3. Kavanagh, D.J., et al., Tests of the elaborated intrusion theory of craving and desire: Features of alcohol craving during treatment for an alcohol disorder. Br J Clin Psychol, 2009. 48(Pt 3): 241-54 doi: 10.1348/014466508X387071

Dr Caroline Leaf and the cart before the horse, take two

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In between her sightseeing in the UK and ballet concerts in the Ukraine, Dr Leaf, communication pathologist and self-titled cognitive neuroscientist, took the time to post some more memorable memes.

Today, Dr Leaf posted, “A chaotic mind filled with thoughts of anxiety, worry, etc. sends out the wrong signal right down to the level of our DNA.”

Hmmm, that one looked familiar … actually, Dr Leaf posted the exact same phrase on the 5th of October this year.  I’m all for recycling, but of renewable resources, not tired ideas.

This meme has been soundly rebuffed before, and the idea that the mind controls our DNA has been thoroughly dismantled.  Reposting it won’t make it any truer.

This meme is better off being put into the trash than the recycling bin.

(For more information on the rebuttal of the mind over matter meme, see also “Hold that thought: Reappraising the work of Dr Caroline Leaf“, “Dr Caroline Leaf: Putting thought in the right place” Part 1 and Part 2, “Dr Caroline Leaf and the matter of mind over genes“, “Dr Caroline Leaf, Dualism, and the Triune Being Hypothesis”, “Dr Caroline Leaf and the Myth of the Blameless Brain” and “Dr Caroline Leaf and the Myth of Mind Domination” just to name a few references).

Dr Caroline Leaf and the organic foods fallacy

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Organic foods. They are amazingly popular. More than a million Australians buy organic foods regularly, and several million more buy it occasionally. The retail value of the organic market is estimated to be more than $1 billion annually. The assumption made by most people is that because it’s so popular, organic foods must be good for you, or at least have something going for them to make them worth all the hype.

Of course, just because something’s immensely popular and has a billion-dollar turnover doesn’t necessarily mean it’s beneficial (One Direction is a case-in-point).

In fact, despite organic foods being touted by their supporters as healthier, safer, and better for the environment than normal foods, actual scientific evidence fails to show any significant difference. I wrote about this earlier in the year (see: Borderline Narcissism and Organic Food). Since then, another large prospective trial deflated organic food’s bubble, with a British study showing no change in the incidence of cancer in women who always ate organic foods versus those who never ate organic foods [1].

The dearth of benefit from organic foods wouldn’t be so bad if they were just another guy in the line-up, something neutral and inert. Unfortunately, not only can organic produce be contaminated if farmed incorrectly [2, 3], but they come at an extraordinary premium, sometimes costing four times more than their conventional counterparts (Borderline Narcissism and Organic Food).

Dr Caroline Leaf is a communication pathologist and a self-titled cognitive neuroscientist. A couple of months ago, she let slip her intention to publish a book in 2015 about food. Who knows what she’ll actually say, but if today’s social media meme is anything to go by, it will likely follow the same pattern of her other teachings.

Today, she wrote, “Research shows that dark organic CHOCOLATE lowers blood pressure, improves circulation, increase HDL (“good”) cholesterol, reduce the risk of heart attack and stroke, and increases insulin … and … recent research has even suggest it may prevent weight gain!”

As I discussed recently, Dr Leaf does herself a disservice by not citing her sources. It’s very brave to write in a public forum that dark chocolate reduces the heart attack and stroke, since this could be interpreted as medical advice, which she is not qualified to give. As for the actual effects of dark chocolate, there is not a lot of quality evidence on dark chocolate on its own. A 2011 meta-analysis of general chocolate consumption on cardiovascular risk did indeed show a relative risk reduction of 37% [4]. But before you prescribe yourself two dark chocolate Lindt balls twice a day, consider that a relative risk reduction of 37% isn’t a big effect. Plus, the recommended 50 grams of 85% organic dark chocolate to attain the small benefit for your cardiovascular health contains just over 300 calories/1280 kJ (the average can of Coke contains 146 calories/ 600 kJ), and is 30% saturated fat (http://caloriecount.about.com/calories-green-blacks-organic-dark-chocolate-i110689). So any health benefit that may be associated with the poly-phenol content is likely nullified by the high saturated fat and calorie count.

What concerns me about Dr Leaf’s future foray into dietetics is that little word sitting quietly in her opening sentence: “organic”. Dr Leaf is an organic convert. But rather than act like a scientist that she claims to be, she preaches from her biases, ignoring the evidence that organic food is all hype and no substance, encouraging Christians everywhere to pay excessive amounts of money for something that’s of absolutely no benefit. Dr Leaf is welcome to eat whatever she chooses, but encouraging organic eating without clear benefit is more hindrance than help for most of her followers.


  1. Bradbury, K.E., et al., Organic food consumption and the incidence of cancer in a large prospective study of women in the United Kingdom. Br J Cancer, 2014. 110(9): 2321-6 doi: 10.1038/bjc.2014.148
  2. Mukherjee, A., et al., Association of farm management practices with risk of Escherichia coli contamination in pre-harvest produce grown in Minnesota and Wisconsin. Int J Food Microbiol, 2007. 120(3): 296-302 doi: 10.1016/j.ijfoodmicro.2007.09.007
  3. Sample, I., E coli outbreak: German organic farm officially identified. The Guardian, London, UK, 11 June 2011 http://www.theguardian.com/world/2011/jun/10/e-coli-bean-sprouts-blamed
  4. Buitrago-Lopez, A., et al., Chocolate consumption and cardiometabolic disorders: systematic review and meta-analysis. BMJ, 2011. 343: d4488 doi: 10.1136/bmj.d4488