Dr Caroline Leaf and the genetic fluctuations falsehood

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While idling away on Facebook, as is my usual pass time, I came upon Dr Leaf’s Facebook feed. There were her usual self-indulgent holiday happy-snaps and another couple of Pinterest-style fluffy inspirational posts. Then this: “Our genetic makeup fluctuates by the minute based on what we are thinking and choosing”.

Dr Caroline Leaf is a South African born and trained, US based, communication pathologist. She also claims that she’s a cognitive neuroscientist. Given the quality of the posts on her social media pages recently, no one could ever take such a claim seriously.

To make sure we’re all clear about what she just said, I’m going to say it again: “Our genetic makeup fluctuates by the minute based on what we are thinking and choosing”. It was an astonishing, if not bewildering statement, especially coming from someone with a PhD level education. If Dr Leaf were a medical doctor and publically made a statement like that, her registration would be reconsidered.

The core of the statement, which pushes it so far beyond the boundaries of rational scientific thinking, is the phrase “Our genetic makeup fluctuates by the minute.”

DNA in our cells is like an old audio cassette tape. Audio cassette tape is a long magnetic stripe, storing the code which the tape player decodes as sound. DNA is a chemical string which has a sequence of “bases” off to the side. The full DNA molecule is made of two matching strings joined by chemical bonds between the bases (hence the name, “base pairs”). Depending on what the cell needs, it runs the DNA through a decoder to either copy it, or to ‘play’ it (i.e. using the information stored in the code to build new proteins).

Like the tape in an audio cassette, the code of the DNA is incredibly stable. The rate of DNA mutation is about 1 in 30 million base pairs [1]. DNA doesn’t ‘fluctuate’, (“rise and fall irregularly in number or amount” [2]). It’s not the stock market. The number of genes in each cell of my body does not rise or fall depending on whether I’m having a good hair day.

The other part of Dr Leaf’s statement, that our DNA “fluctuates … based on what we are thinking and choosing” is also scientific nonsense. The only way that your thoughts and choices are capable of inducing genetic mutations is if those thoughts or choices involve cigarette smoking or standing next to industrial sources of ionising radiation.

I think Dr Leaf is trying to say that our thoughts and choices can change our gene expression, which is the construction of new proteins from the instructions in the DNA code. However, gene expression has nothing to do with our thoughts and choices. IVF embryos are expressing genes like crazy as they grow from one cell to an embryo in just a petri dish. It doesn’t think or choose.

More often than not, our thoughts and our choices are the result of gene expression, not the cause of it. We don’t have any specific control over the process either. The process of genetic expression is dependant on a complex series of promoters and tags on the DNA, which are controlled by other proteins and DNA within the cell, not thought or choice.

The truth is that gene expression occurs moment-by-moment, regardless of what we think or don’t think, do or don’t do. Gene expression is simply DNA being read. Our genetic makeup, the DNA code, is stable. It does not fluctuate. There is no part of Dr Leaf’s statement that is scientifically accurate.

Ultimately, Dr Leaf continues on her pursuit of pseudoscience, an affront to the people who trust her to tell them the truth, and the God of all truth that she purportedly represents.

References

  1. 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
  2. Oxford Dictionary of English – 3rd Edition, 2010, Oxford University Press: Oxford, UK.
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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.

References

  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