Are carbs really the key to preventing brain disease?

The Times recent promotion of a new book by neurologist, David Perlmutter, raises some interesting questions t regarding the evidence base behind the books claims.  David’s book is called ‘Grain Brain: The Surprising Truth About Wheat, Carbs and Sugar – Your Brain’s Silent Killer’ and asserts that gluten consumed through wheat and grains are responsible for triggering brain disorders such as depression, dementia, schizophrenia, epilepsy, ADHD and decreased libido.  Let’s take a look at The Times piece and see if there is any merit in the claims.

David is quoted as saying; “The origin of brain disease such as dementia is predominantly dietary, he says, and the result of us consuming too many carbohydrates (particularly wheat-based bread and pasta as well as sugar) and too few healthy fats”

Straight off I think the word dementia has been misused here as (according to Alzheimer’s Society) dementia is an umbrella term used to describe the symptoms that occur when the brain is affected by certain diseases or conditions.  So dementia is not a brain disease but a symptom of a brain disease – the most common one being Alzheimer’s.

Now while there is some evidence for diet as a contributing factor to lifetime risk of Alzheimer’s disease it has in no way ever been concluded as the predominant factor.  Alzheimer’s Research UK and the NHS both state that age, family history, genetics, smoking and other diseases including  diabetes and obesity all increase lifetime risk of Alzheimer’s.  The only mention of ‘carbohydrates’ comes from a recommendation that people with diabetes need to control their blood glucose.

David continues to point out that; “Researchers have known for some time that the cornerstone of brain disorders is inflammation, he says. Gluten — consumed through wheat and other grains — and a high carbohydrate diet are among the most prominent stimulators of inflammatory pathways that reach the brain”

It would be hard to dispute that there is a link between inflammation and brain disorders such as Alzheimer’s, but to state that high carb diets are ‘the cornerstone of brain disorders’ because of potentially eliciting an inflammatory response seems a little far-fetched.  In fact, most people would argue that the greatest risk factor for Alzheimer’s is age.  Whether gluten and a high carbohydrate diet constitute a ‘prominent stimulator of inflammatory pathways that reach the brain’ is something I am not aware of, or know particularly much about, but I have yet to read anything to convince me.

Permultter argues that people should move onto a low-carb, high-fat diet, in order to protect themselves from brain disease.  To suggest nutrition is that simple is irresponsible.  Nutritional demands to sustain a healthy lifestyle are individual and increasing foods such as fats (suggested from cheese, meat, butter and eggs) could put some people at increased risk of other diseases.

It has been pointed out that very low carb diets can be a therapeutic tool for treating some neurological disorders.  However, it has been noted that ‘recommending a low-carb diet as an intervention for sick people is very different from promoting it as a preventative measure for the entire population, which is what Dr. Perlmutter does in Grain Brain’.

The truth is that we don’t know a great deal about the risk factors for brain disease, nor do we understand how they interact with each other or the level of risk each poses.  It has been stated by others more knowledgeable of this field than me that ‘which also suggest an element of blame towards the person with the condition, are unhelpful and do not do justice to the complexity of these diseases’.

Thanks to @_josephinejones for the article info

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