Dr Caroline Leaf and the genetic remodelling myth

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We are all slowly mutating!

Yep, it’s true. Not to the same extent as you might see in shows like X-Files or Dr Who, but still, our DNA is slowly accumulating permanent changes to the pattern of the genes that it contains. Thankfully, it’s only in science fiction that the mutations result in zombie apocalypse scenarios.

Dr Caroline Leaf is a Communication Pathologist and a self-titled cognitive neuroscientist. Still glowing from the unquestioning adulation of her faithful followers at the Switch On Your Brain conference last week, Dr Leaf has hit social media again. Most of her posts have been innocuous quotes that look borrowed from Pinterest, but today, Dr Leaf has ventured into the pseudoscientific again by claiming that, “Our genes are constantly being remodeled by our response to life’s experiences.”

Unless your response to life’s experiences is to stand next to an industrial microwave generator or live in a nuclear waste dump, Dr Leaf’s statement is pure fiction. Dr Leaf confuses the mutation of our genes with the expression of our genes.

The only way our genes actually change is through mutation. A mutation is a permanent change in the sequence of the DNA molecule. A genetic mutation is a permanent change in the DNA sequence that encodes a gene. DNA is constantly mutating, because of environmental damage, chemical degradation, genome instability and errors in DNA copying or repair [1: p97]. Still, the actual rate of DNA mutation is about 1 in 30 million base pairs [2]. So DNA is very stable, and changes for a number of reasons, only some of which are related to our external environment. And as I alluded to just before, slightly tongue-in-cheek, our responses are not the main contributor to these environmental influences, unless we deliberately expose ourselves to ionizing radiation or smoke cigarettes. Our DNA does not change because of our thought processes as Dr Leaf advocates [3].

What does change more readily is the expression of those genes. Gene expression is the cell machinery reading the genes and making the proteins that the genes encode. The genes are expressed to make the proteins needed for the cell to maintain its function. Which genes are expressed is dependant on the cell’s stage of development and the environment it finds itself in. For example, when the body encounters a high level of dietary iron, a series of steps activates a gene to promote the production of ferritin, a protein that helps to carry iron in the blood stream [1: p375-6]. Gene expression isn’t solely dependent on our environment though, because an embryo is expressing genes like crazy in order to make the proteins to build a human being, but the gene expression in an embryo is largely following a pre-determined time course, not the environment [4] (and certainly not because of responses to life’s experiences).

In summary, our genes are controlled by a myriad of different factors, nearly all of which have nothing to do with our responses or choices. Our genes are not changed by our choices or our responses. Our genes may be mutating, but God designed our cells with mechanisms to repair them. Our genes are not being remodelled by our responses. That’s the realm of science fiction.


  1. Strachan, T. and Read, A., Human Molecular Genetics. 4th ed. 2011, Garland Science, New York, USA:
  2. Xue, Y., et al., Human Y chromosome base-substitution mutation rate measured by direct sequencing in a deep-rooting pedigree. Curr Biol, 2009. 19(17): 1453-7 doi: 10.1016/j.cub.2009.07.032
  3. Leaf, C.M., Switch On Your Brain : The Key to Peak Happiness, Thinking, and Health. 2013, Baker Books, Grand Rapids, Michigan:
  4. Ralston, A. and Shaw, K. Gene Expression Regulates Cell Differentiation. Nature Education, 2008. 1(1): 127; http://www.nature.com/scitable/topicpage/gene-expression-regulates-cell-differentiation-931

Like to read more about Dr Leaf’s teaching and how it compares to current science? Download the free eBook HOLD THAT THOUGHT, Reappraising The Work Of Dr Caroline Leaf


Lyme disease in Australia?

Erythema migrans

Bullseye rash of Lyme Disease aka Erythema migrans

Lyme disease is a bacterial infection transmitted by a tick.  Most North Americans will be very familiar with it, but here in Australia, no one believes it exists, or at least, there have been no cases that have originated in Australia.  But things are changing.  More Australians are coming forward with convincing symptoms of Lyme Disease, and although it’s been a while coming, the Chief Medical Officer in Australia has taken the first official steps to recognise an Australian indigenous form of the disease.

The challenge for Australian doctors is to become open-minded to the potential for Lyme Disease and for the clinical pathology labs to start testing locally, because at the moment, formal testing for the disease has to be done off shore.  The Commonwealth Government also needs to reinstate the committee that was working on the problem of Australian Lyme Disease.  The budget is tight, sure.  But Lyme Disease is a debilitating disease if it’s not diagnosed and treated early.  Surely the cost saving of one person prevented from years of sickness would justify the cost of the committee that is working to prevent it.

Lyme disease-like syndrome acknowledged in Australia
Sunalie Silva (Medical Observer 20/8/2014)

A SPECIALLY-established federal government advisory committee has officially acknowledged the possibility of an Australian ‘Lyme disease-like syndrome’ which warrants further investigation.

Just over a year after the federal government established the Clinical Advisory Committee on Lyme Disease in Australia (CACLD), the now-disbanded group handed down its final recommendations about diagnostic testing, treatment and further research requirements in relation to Lyme disease last month following its meeting on July 15.

A progress report released by the Chief Medical Officer Professor Chris Baggoley reveals there is still no conclusive evidence that Borrelia spp – the bacteria thought to cause the disease – exists in Australia, making exploration of a potential infection in Australian patients with no relevant travel history nearly impossible.

It states that an appropriate laboratory testing algorithm has yet to be agreed upon and, while clinical presentation is frequently the basis for diagnosis, there is still no agreed case definition.

However, it has now agreed that there may be an Australian ‘Lyme disease-like syndrome’ that needs investigation.

“The lack of an agreed case definition for Lyme disease hampers the diagnosis of patients in Australia. Clarity around the presenting signs and symptoms of an Australian Lyme disease-like syndrome would aid the investigation into whether an indigenous form of Borrelia exists in Australia,” it said in its report.

Dr Mualla McManus (PhD), pharmacologist, founder of the Karl McManus Foundation for Lyme Disease Research & Awareness and CACLD member said the outcome, though inclusive, is a significant step.

“The role of CACLD was to put to the CMO that a Lyme disease-like syndrome unique to Australia might be what’s happening here and we are pleased that the he has now officially taken this on board.”

She said many in the scientific community know that there is a pathogen or pathogens unique to Australia being transmitted to humans by tick bite. The focus now will be to find out what type of organism that is.

“There is a Lyme disease-like syndrome in Australia – it may be a totally unique bacterium that has its own distinct characteristics or it may be multiple bacteria transmitted together – we don’t know yet but we need to answer these questions before we can start diagnosing the condition,” she told MO.

Dr McManus said the treatment approach at the moment relies on the broad application of antibiotics.

“At the moment a lot of these patients are bombarded with a broad range of antibiotics. Luckily the antibiotics we’re using are killing basically every kind of bacteria you can think of but we don’t really know what we’re treating.”

According to the committee, a short course of antibiotics such as doxycycline would be the initial treatment for Lyme disease acquired overseas. However, treatment of chronic Lyme disease is contentious, it said because the existence of this form of disease is still strongly disputed.

Dr McManus argues that in the US, where Lyme disease is a recognised condition, people are treated at acute stages of the infection and so there are very few people who will present with a chronic form of the disease.

“It’s different in Australia. For the last 20 years no-one has been detecting and treating the acute phase of this disease, so we are in a situation now where a we have a backlog of people who have become chronically ill.

She said most people with chronic infection were ultimately diagnosed with chronic fatigue syndrome, fibromyalgia, Parkinson’s or motor neurone disease.

“These are the box of conditions that clinicians are able to treat without doing any differential diagnosis because there isn’t supposed to be any Borrelia spp. in Australia.”

The committee’s report advised that if a person who has been diagnosed with Lyme disease does not respond to treatment or has relapsed, then the treating medical practitioner should consult with a medical practitioner who has experience in treating Lyme disease.

According to Dr McManus, the way forward now lies within the scientific community. CACLD has identified 12 gaps in knowledge along with scoping study research proposals – though research groups will of course need to apply for NHMRC or ARC funding.

“The solution to the problem now has to be within the scientific community – our group pre-empted this long before and has been funding the research at the Tick Borne Diseases Unit at the University of Sydney.”

Research like this will hold the answer she said.

“We need to know what the causative agent is so we can develop tests and treatment protocols for that specific pathogen so that we know what we are killing.”

Hold That Thought – Reappraising the work of Dr Caroline Leaf

Hold That Thought Cover

It’s been more than a few late nights in the making, but sixteen months and 68,000 words on, the early release of my new book is now available on line through Smashwords: https://www.smashwords.com/books/view/466848.  Apple iBook, Kindle, and a number of other platforms will come online soon.

Dr Caroline Leaf is a South African communication pathologist and self-titled cognitive neuroscientist, now based in the USA.  This book is an in-depth look at the current scientific understanding of thought, stress, free will and choice, as well as a thorough critique of Dr Leaf’s foundational teachings and the evidence she provides as proof of her hypotheses.

In the coming few days, I will make the text of the book available on this blog as well.  If you have any questions, send them in.  I’m happy to put up a FAQ page.  And as always, I’m happy to answer any legitimate criticism of my work, so long as it’s constructive and evidence based, not personal.

And as always, Dr Leaf herself is welcome to comment.  Indeed, I would value her feedback, and I’m sure any comment she wishes to make would be welcome by the Christian community as a whole.

Dr Caroline Leaf, Testimonials, and Levels of Evidence


It’s nice to be appreciated.

Gratitude is a wonderful thing. The Bible encourages it (1 Thessalonians 5:18), and psychology has detailed why. Gratitude increases happiness and life satisfaction, while tending to decrease depressive symptoms [1]. And it’s not just good for the giver, but also the receiver. I always appreciate it when my patients thank me for helping them. Genuine gratitude makes you feel good inside.

Dr Caroline Leaf, Communication Pathologist and self-titled Cognitive Neuroscientist, must be positively glowing right now. She has been getting a lot of positive feedback from her fan base of late, and she has decided to share it with the world via her social media feeds.

I’m sincerely happy for those people who feel they have been helped by Dr Leaf’s work. I remember my darkest days, feeling far from God and unable to find my way out of the emotional black hole of depression. It’s always so good to hear that others are finding their way out too.

While I’m happy for those who are sharing their stories to Dr Leaf, I can’t say I feel the same for Dr Leaf herself. It’s excellent that people are sharing their stories with her privately but publishing them is another matter. At best, it’s ethically delicate.

The testimonies are likely to be from people recovering from a psychological or emotional challenge, which carries an ongoing level of vulnerability. Even if Dr Leaf has their consent to publish their stories, sharing their problems with the world can still cause or contribute to psychological damage. Without knowing their whole story, Dr Leaf has no way of judging whom she may or may not harm.

It’s also a bit disingenuous. By publishing a series of testimonials, Dr Leaf is essentially self-promoting. It’s one thing for a supporter to spontaneously offer her praise in a Facebook or blog comment. But Dr Leaf specifically asked for her followers to send in their testimonies so she could publish them.

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Soliciting testimonials to republish is an old advertising trick. According to the Market Science Institute, “Testimonial solicitations – in which firms solicit consumers’ personal endorsements of a product or service – represent a popular marketing practice. Testimonials are thought to offer several benefits to firms, among them that participating consumers may strengthen their positive attitudes toward a brand, through the act of writing testimonials.” [2]

Testimonials are very good as a marketing tool. Who can argue with a person who says that Dr Leaf helped turn their life around? Saying anything negative just makes you sound like a cynical old boot.

And that’s the real problem, because while publishing a whole bunch of positive stories is good for marketing, it makes it very hard for those who had a genuinely bad experience to say anything. No one wants to listen to those people whom Dr Leaf has confused or mislead – it makes for terrible PR. Those people feel devalued, and sometimes worse, because it seems like everyone else had a good result from Dr Leaf’s teaching, except them.

Testimonials also make for very poor scientific evidence. Indeed, testimonials are considered the lowest form of scientific evidence [3]. It’s all very well and good for a bunch of people to share their positive experiences, but as life changing as the experience may have been, they are not evidence of the effectiveness of Dr Leaf’s teaching. Without specific, well-designed research, no one can say if the testimonials Dr Leaf is publishing are the norm. Recent research demonstrates that self-help literature for depression may not have any benefit over a placebo treatment [4]. So it may be that any improvement attributed to Dr Leaf’s teaching was actually the placebo effect. Dr Leaf can list testimonials until she’s blue in the face, but that doesn’t prove that her work is scientific or therapeutic.

I’m sure would say that she’s asking for testimonies so that she can share the joy of others with her followers, or seek to give glory to God, or something like that. And perhaps she is. I’m not sure how she reconciles that with Jesus words, “Be careful not to practise your righteousness in front of others to be seen by them. If you do, you will have no reward from your Father in heaven.” (Matthew 6:1) But that’s for her own personal consideration.

Whatever her intentions, the soliciting and publishing of personal testimonials from potentially vulnerable people is ethically delicate. I think she’d be better to step away from publishing these testimonials.

And for her readers and followers, the testimonials need to be seen for what they are: just individual stories. Sure, we should rejoice with those who are rejoicing (Romans 12:15), and so good for those who feel Dr Leaf has helped them. But they do not constitute evidence for the therapeutic efficacy or scientific integrity of the work of Dr Leaf.


  1. Toepfer, S., et al., Letters of Gratitude: Further Evidence for Author Benefits. Journal of Happiness Studies, 2012. 13(1): 187-201 doi: 10.1007/s10902-011-9257-7
  2. Marketing Science Institute. Consumer Testimonials as Self-Generated Advertisements: Evaluative Reconstruction Following Product Usage. [cited 2014, Aug 3]; Available from: http://www.msi.org/reports/consumer-testimonials-as-self-generated-advertisements-evaluative-reconstru/.
  3. Fowler, G., Evidence-based practice: Tools and techniques. Systems, settings, people: Workforce development challenges for the alcohol and other drugs field, 2001: 93-107
  4. Moldovan, R., et al., Cognitive bibliotherapy for mild depressive symptomatology: randomized clinical trial of efficacy and mechanisms of change. Clinical psychology & psychotherapy, 2013. 20(6): 482-93