Today I’m in Sydney, a vibrant, bustling city which centres on one of the most beautiful harbours in the world.  When I booked my flights in April, I was originally going to spend the day attending Dr Caroline Leaf’s Australian Think and Eat Yourself Smart workshop.  Dr Leaf and her minions revoked my ticket a few weeks later.  She also changed the workshop twitter hashtag from #thinkandeatsmart to just #eatsmart, so perhaps Dr Leaf doesn’t want free thinking at the workshop.

It’s such a shame really, because I was looking forward to being part of the history of Dr Leaf’s first workshop on Australian soil.  But no matter … why waste a perfectly good plane ticket when I can have a day to sightsee, take photos, and catch a few Pokemon here and there as well.

And as a special something for all the people who’re attending the workshop today with Dr Leaf, I thought I’d pen a blog in their honour … something for them to ponder as they listen to Dr Leaf’s presentation, and maybe even provide them with a nidus of a question to pose to her during the day.  So here goes …

As the name would suggest, the Think and Eat Yourself Smart workshop is based on Dr Leaf’s book, Think and Eat Yourself Smart.  Does the book (and the subsequent workshop) deliver what it promises?  That is, can you really think and eat yourself smart?  It’s all well and good for Dr Leaf to espouse her fringe opinions on the food industry and modern farming, and to recycle nutritional information that doctors and dieticians have been promoting for years, but if her book can’t deliver on its titular promise, then it’s just an unoriginal rehash.

To support her thesis that we can think and eat ourselves smart, Dr Leaf declares that what you think affects what you eat, and what you eat affects what you think.  It’s on these intertwined ideas that Dr Leaf’s book stands or falls.  Let’s look at those statements in more detail.

Statement number 1 – “What you think affects what you eat”

Dr Leaf has a broad approach with this premise.  She suggests that the mindset that you have will not only determine what you consume, but also how your body will process it.

For example, she said on page 84 of Think and Eat Yourself Smart, “Research shows that 75 – 98 percent of current mental, physical, emotional and behavioural illnesses and issues come from our thought life; only 2 – 25 percent come from a combination of genetics and what enters our bodies through food, medications, pollution, chemicals, and so on.  These statistics show that the mindset behind the meal – the thinking behind the meal – plays a dominant role in the process of human food related health issues, approximately 80 percent.  Hence the title of this book: you have to think and eat yourself smart, happy and healthy.”

She goes on to say, “If we do not have a healthy mind, then nothing else in our life will be healthy, including our eating habits.”

We can break down these statements to assess their validity.

First of all, this statement is predicated on her 98 percent myth, something which I’ve previously proven to be implausible, but which Dr Leaf continues to use despite the overwhelming evidence against it.  To arrive at this conclusion, Dr Leaf has over-extrapolated, paraphrased, and exaggerated a handful of sources that were either out-of-date, clearly biased, or irrelevant.  She even had the gall to ascribe a made-up figure to an article which, ironically, twice contradicted her.  If you want to know more, see Chapter 10 in my book (http://www.debunkingdrleaf.com/chapter-10/)

This means that Dr Leaf’s statement, and indeed, her entire book, is built on gross misrepresentations of illegitimate resources.  Genetics and our external environment actually play a much greater role than she is willing to give credit for.  The mindset behind the meal is largely irrelevant – nowhere near 80 percent as Dr Leaf suggests.

But for the sake of argument, let’s take a couple of well-known medical conditions that are often associated with lifestyle and compare the research examining the difference that thinking and food make to them.  After all, if your mindset really is responsible for more than 80 percent of our health, then these two very common conditions should improve by more than 80 percent when thought patterns are changed.

Example 1: Hypertension.

Hypertension is also known as high blood pressure.  First, a brief explanation of what the numbers mean when talking about blood pressure so we’re on the same page: Blood pressure is measured in units of millimetres of mercury (or mmHg).  The old sphygmomanometers were hand pumps attached to a rubber bladder and a column of liquid metal mercury.  The blood pressure reading was however high the column of mercury rose at the two ends of the cardiac cycle.  There are always two numbers, expressed as ‘number 1 over number 2’ and written as N1/N2, like 120/80 or ‘one hundred and twenty over eighty’.  The top number is the maximum pressure in the arterial system when the heart pumps the blood into the arteries.  The bottom number is the pressure left over in the arterial system just before the heart beats again.  A blood pressure of 120/80 is the gold-standard physiological reference of normal blood pressure.  A blood pressure consistently above 140/90 is considered high.

Primary hypertension, which accounts for about 95 percent of all cases, has a strong genetic component.  According to eMedicine, “Epidemiological studies using twin data and data from Framingham Heart Study families reveal that BP has a substantial heritable component, ranging from 33-57%.” (http://emedicine.medscape.com/article/241381-overview#a4)  Environmental causes account for nearly all of the rest.  Secondary hypertension is related to a number of different diseases of the arteries, kidneys, hormone system and many others.  Diet is clearly part of those environmental causes.  Psychological stress is in there too, but the question is, how important is it?  If Dr Leaf is right, it should be 80 percent.

According to medical research, reducing alcohol intake to one standard drink per day or less reduces the systolic blood pressure (the top number) by between 2 and 4 mmHg.  Reducing salt to less than 6g a day decreases the systolic blood pressure by between 2 and 8 mmHg.   At best, that’s a 12mmHg reduction.  The DASH diet is as close to Dr Leaf’s macrobiotic tree-hugging anti-MAD diet as one could reasonably get, relying not just on cutting out salt, but also consuming low fat milk and lots of fruit and vegetables.  At best, the DASH diet could shave another 6mmHg from the standard low salt diet.  So that’s a grand total of 18mmHg with even the most optimistic of expectations.

Compared to diet, the best improvement in blood pressure from mind control is 5mmHg at best (and given the size and quality of the studies, that’s being generous) (Anderson et al, 2008; Barnes et al, 2008).

So for hypertension, changing your thinking has, at best, only about a quarter as powerful as changing your diet, not four times more powerful as Dr Leaf would have us believe.  One more nail in in the coffin for Dr Leaf’s theories.

Example 2: Dyslipidaemia.

Dyslipidaemia is medical jargon for cholesterol behaving badly.  Cholesterol is a waxy substance that’s found as a component of the fats in our diet.  To simplify a complex process, we need cholesterol to make our cell membranes, and cholesterol is also an essential building block for most of our hormones.  Cholesterol is usually carried around the body on protein transports called lipoproteins.  If there’s over-production of these lipoprotein particles or they’re not cleared by the liver properly, then the cholesterol they carry can get up to mischief.  The pathways and means of lipid metabolism in the human body reflect complex processes, and genetics, certain medical conditions, medications, and environmental factors can change how the lipoproteins behave.

So how much does thinking affect our cholesterol?  Well, there isn’t a lot of research looking at the subject, but a few studies have looked at cholesterol (specifically triglycerides, one of the lipids in the cholesterol ‘team’) and ‘mind-body practices’ (such as self-prayer, meditation, yoga, breathing exercises, or any other form of mind-body related relaxation technique or practice).  In a cross-sectional analysis of a cohort from the Rotterdam Study, Younge and colleagues examined the association between mind-body practices and the blood levels of triglyceride.  They found that mind-body practices were associated with a triglyceride level 0.00034 mmol/L less than those who did not perform mind-body practices (Younge et al, 2015).  That’s nearly imperceptible, possibly an artefact.  In fact, the average effect of placebos (the fake pills given as a control in therapeutic drug trials) are far greater – 0.1 mmol/L on average (Edwards and Moore, 2003).  Dietary interventions such as low carbohydrate diets decreased triglycerides by 0.26 mmol/L compared to low fat diets (Mansoor et al, 2016), and low fat diets up to 0.27 mmol/L lower than standard diets (Hooper, 2012).  Statins, the lipid-lowering medications, reduce triglycerides by between 0.2-0.4 mmol/L depending on the specific drug studied (Edwards and Moore, 2003).

The point of all this isn’t so much the specific numbers but the obvious difference between the (lack of) power of thought over an important lifestyle condition compared to the effectiveness of diet and medications.  If thinking was four times more important to the process of human food related health issues as Dr Leafs proposes, then thought-related ‘mind-body’ interventions should be at least four times more effective than any other intervention.  But the numbers don’t reflect that – ’Mind-body’ interventions are 1000 times weaker than dietary or drug interventions.

So Dr Leaf’s pronouncement that “the mindset behind the meal – the thinking behind the meal – plays a dominant role in the process of human food related health issues, approximately 80 percent” is complete bunkum.  There is no evidence to support the 98 percent myth which forms her statements underlying premise, and the examples of hypertension and dyslipidaemia, two common lifestyle conditions with proven genetic and dietary links, prove that thought based interventions are much, much weaker than dietary or drug interventions.

Therefore Dr Leaf’s claim that what you think affects what you eat is entirely baseless.

Statement number 2 – “What you eat affects what you think”

Dr Leaf writes, “Although your brain is only 2 percent of the weight of your body, it consumes 20 percent of the total energy (oxygen) and 65 percent of the glucose – what you eat will directly affect the brain’s ability to function on a significant scale.  Your brain has ‘first dibs’ on everything you eat.  I call this the ’20 percent factor’ or the eating behind the thinking, and it underscores the fact that how and what we eat affects our mind, brain and body.” (p84-5)

On face value, the statement seems to hold some weight.  Food does have an impact on how our brain works.  It certainly isn’t the only factor though – demands in the environment, our oxygen levels, our hormones, the function of our major organs, infections or injury, and our levels of sleep, all play a significant role on how our brain functions too.  But strictly speaking, what we eat does have an impact on how we think – if we haven’t eaten, or if we don’t consume enough calories, especially carbohydrates, our body slows some of our bodily functions down to preserve energy, including some of our cerebral functions.  So when you hear people complain that they can’t think because they have low blood sugar, that may in fact be true.  On the other hand, a pure glucose load can shift the balance of the amino acid tryptophan in our body, which enables the brain to produce more of the neurotransmitter serotonin, which can lift our mood.  Or ingesting food or drinks with stimulants like caffeine, such as my morning espresso, also improves how we think by making us more alert.

Unfortunately, Dr Leaf’s application of this premise goes several steps too far.  Later on page 85, Dr Leaf says, “if you eat while emotional, your body does not digest your food correctly.”

Well, that statement may contain an element of truth but only because it’s so hazy and indefinite that it’s applicable in the broadest sense.  Technically, we’re always emotional to one degree or another.  Even if I assume that Dr Leaf’s is meaning ‘angry’ when she says ‘emotional’ then it’s not so much that our body digests food incorrectly, but just differently.   When you’re highly aroused (physiologically, not sexually, just to clarify), your body goes into fight or flight mode.  The body diverts blood away from your intestines and towards your muscles, heart and lungs, so that you have the energy to handle the crisis.  The food in your stomach and guts isn’t going anywhere, and your body leaves it where it is to come back to it later when the crisis has been averted.  This is a normal physiological response.  The body still digests the food and absorbs it correctly, things are just delayed a little (Kiecolt-Glaser, 2010).

The biggest problem with Dr Leaf’s ‘eating behind the thinking’ argument is that it directly undermines her previous teaching.

Dr Leaf has made multiple social media posts claiming that the mind is separate from the brain and controls the brain.  She’s written much the same sentiment in her books.  Take a meme she posted to social media in May 2016.  It said, “As triune beings made in God’s image, we are spirit, mind (soul) and body – and our brain being part of the body does the bidding of the mind …”, and “God has designed the mind as separate from the brain. The brain simply stores the information from the mind and your mind controls your brain.”

So the obvious question is, “If God designed our mind (our thinking) to be separate from the brain and to control the brain, then how can the food we eat make any difference to what we think? My diet affects my brain through the amount and timing of glucose I ingest, but can my diet can’t affect my thinking if the mind is separate to the brain and controls the brain?

Either the mind is separate to the brain, or it’s not.  It can’t be both.  If the mind is separate to the brain, then what you eat can’t affect what you think and the book becomes an emaciated shadow of rhetoric.  If the mind is dependent on the brain then the book and seminar maintain some semblance of validity, but the rest of Dr Leaf’s ministry crumbles like a well-made cheesecake crust, since the entirety of Dr Leaf’s ministry rests on her idea that the mind is separate from the brain and controls the brain, not the other way around (https://cedwardpitt.com/2016/05/30/dr-caroline-leaf-and-the-mind-brain-revisited/).

At the very least, this must be embarrassing for Dr Leaf, and if she keeps shooting herself in the foot, people will eventually notice that she’s limping.

So other than the free-range, fair-trade, grass fed, organic agro-ecologically produced kale and spinach root muffins and the chia and dandelion broth, it appears that the attendees at Dr Leaf’s workshop today may not be getting what they signed up for.  What you think does not radically change your health, or influence what your food does to your body, and the food you eat does not significantly change how you think.  Our diet is important to our health, but we can’t think and eat ourselves smart.

To all the attendees at the workshop, I hope you got something valuable out of the workshop.  While you were all sitting in a small room, listening to Dr Leaf and snacking on lemon and quinoa stuffed free-range quail giblets, Sydney was outdoing itself.  Not that I’m rubbing it in or anything, but see for yourself …

Dr Mary Booth lookout

Milsons Point

Milsons Park, Neutral Bay

Cremorne

Point Piper

Macquarie Lighthouse

Blues Point Reserve

Blues Point Reserve

References

Anderson JW, Liu C, Kryscio RJ. Blood pressure response to transcendental meditation: a meta-analysis. Am J Hypertens 2008 Mar;21(3):310-6

Barnes VA, Pendergrast RA, Harshfield GA, Treiber FA. Impact of breathing awareness meditation on ambulatory blood pressure and sodium handling in prehypertensive African American adolescents. Ethn Dis 2008 Winter;18(1):1-5

Edwards JE, Moore RA. Statins in hypercholesterolaemia: a dose-specific meta-analysis of lipid changes in randomised, double blind trials. BMC Family practice. 2003 Dec 1;4(1):1.

Hooper L, Abdelhamid A, Moore HJ, Douthwaite W, Skeaff CM, Summerbell CD. Effect of reducing total fat intake on body weight: systematic review and meta-analysis of randomised controlled trials and cohort studies. Bmj. 2012 Dec 6;345:e7666.

Kiecolt-Glaser JK. Stress, food, and inflammation: psychoneuroimmunology and nutrition at the cutting edge. Psychosomatic Medicine. 2010 May;72(4):365.

Mansoor N, Vinknes KJ, Veierød MB, Retterstøl K. Effects of low-carbohydrate diets v. low-fat diets on body weight and cardiovascular risk factors: a meta-analysis of randomised controlled trials. British Journal of Nutrition. 2016 Feb 14;115(03):466-79.

Younge JO, Leening MJ, Tiemeier H, Franco OH, Kiefte-de Jong J, Hofman A, Roos-Hesselink JW, Hunink MM. Association between mind-body practice and cardiometabolic risk factors: The Rotterdam Study. Psychosomatic medicine. 2015 Sep 1;77(7):775-83.