Book Club Corner

Curated reading for functional medicine practitioners — evidence-based, clinically relevant, and worth your time.

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Book of the Month
May 2026
Why Isn't My Brain Working?
Dr Datis Kharrazian
Book of the Month

Why Isn't My Brain Working?

Dr Datis Kharrazian PhD DHSc DC MS MMSc FACN — Harvard Medical School
Neurology Brain Health Gut-Brain Axis Autoimmunity Functional Medicine

In this landmark work, Dr Datis Kharrazian — a member of our Honorary Scientific Board — presents a comprehensive functional medicine framework for understanding and addressing neurological and cognitive dysfunction. Drawing on his extensive clinical and research experience, Kharrazian challenges practitioners to look beyond symptom suppression and investigate the root physiological drivers of brain-based complaints: blood-brain barrier integrity, neuroinflammation, brain autoimmunity, neurotransmitter dysfunction and the gut-brain axis.

The book is particularly relevant to practitioners managing patients with brain fog, depression, anxiety, memory loss and neurological conditions that have not responded to conventional treatment. Kharrazian presents a systems-based clinical approach grounded in published research and supported by practical assessment and intervention strategies.

As a member of the FMI Honorary Scientific Board, Dr Kharrazian's work is directly aligned with the evidence-based functional medicine approach we champion. This is essential reading for any practitioner working with patients presenting with neurological or cognitive complaints.

Discussion Questions for this Month

01 Kharrazian argues that blood-brain barrier permeability is a critical and often overlooked driver of neuroinflammation. How does this concept change your approach to patients presenting with brain fog or cognitive decline?
02 The book presents a detailed case for brain autoimmunity as a distinct clinical entity. What markers or clinical presentations would prompt you to investigate this in your own patients?
03 Kharrazian emphasises the gut-brain axis throughout. How does this align with your clinical experience, and what gut-based interventions have you found most effective in patients with neurological symptoms?
04 The book challenges the neurotransmitter model of depression and anxiety. How do you currently approach these presentations, and has this reading changed your thinking?
05 Which single concept or clinical tool from this book will you implement most immediately in your practice — and why?
Recommended Reading by Category
Functional Medicine Fundamentals
The Ultramind Solution
Dr Mark Hyman MD

A foundational functional medicine text examining the connection between physical health and mental/cognitive function. Hyman presents a systematic approach to identifying and correcting the nutritional, hormonal, inflammatory and toxic drivers of mood and cognitive disorders.

Why Read It
Essential for practitioners treating patients with mood, cognition or psychiatric presentations from a root-cause perspective.
The Disease Delusion
Dr Jeffrey Bland PhD

Often described as the definitive introduction to functional medicine, Bland — widely regarded as the father of functional medicine — makes the case for a systems biology approach to chronic disease, explaining the paradigm shift from symptom management to root cause resolution.

Why Read It
The intellectual foundation of functional medicine in accessible form. Recommended for all practitioners new to the field.
The Toxin Solution
Dr Joseph Pizzorno ND

Dr Pizzorno — founding president of Bastyr University and a member of our Honorary Scientific Board — presents compelling evidence that environmental toxin exposure is a primary and underappreciated driver of chronic disease, including metabolic dysfunction, neurological conditions and autoimmunity.

Why Read It
Authoritative, evidence-based and essential for understanding environmental medicine in functional practice.
Hormone Health
The Menopause Brain
Dr Lisa Mosconi PhD

Neuroscientist and Alzheimer's prevention researcher Dr Mosconi presents the first book to address the neurological dimension of menopause — the effect of oestrogen decline on brain structure, function and dementia risk — with a focus on evidence-based lifestyle and nutritional neuroprotection strategies.

Why Read It
Groundbreaking and rigorously researched. Essential for any practitioner working with perimenopausal or postmenopausal women.
Hormone Intelligence
Dr Aviva Romm MD

An integrative physician and herbalist presents a comprehensive guide to female hormone health across the lifespan — covering PCOS, endometriosis, thyroid dysfunction, perimenopause and HRT — from a functional and botanical medicine perspective, with particular attention to the HPA-HPG axis connection.

Why Read It
Clinically practical and well-referenced. Particularly strong on the stress-hormone interface and botanical adjuncts.
Estrogen Matters
Dr Avrum Bluming MD & Carol Tavris PhD

A forensic re-examination of the Women's Health Initiative study and subsequent HRT research, arguing that the long-standing fear of oestrogen has been based on a systematic misreading of the evidence — with significant consequences for women's health outcomes globally.

Why Read It
Critical reading for practitioners involved in HRT prescribing or counselling. Challenges assumptions with published evidence.
Gut Health & Microbiome
Brain Maker
Dr David Perlmutter MD FACN

A neurologist presents the evidence for the gut microbiome's role in brain health, examining how microbial diversity — and its disruption — influences neurological and psychiatric conditions through the gut-brain axis, neuroinflammation and neurotransmitter production.

Why Read It
Accessible and well-referenced. Strong clinical application for practitioners treating gut-brain presentations.
The Gut Health Protocol
John Herron

A detailed, protocol-based guide to addressing H. pylori, SIBO, dysbiosis and intestinal permeability using evidence-based nutritional and botanical interventions. Particularly relevant for practitioners supporting the 5R framework in clinical practice.

Why Read It
Highly practical and protocol-driven. Excellent clinical reference for gastrointestinal functional medicine.
The Good Gut
Dr Justin Sonnenburg & Dr Erica Sonnenburg PhD

Stanford microbiome researchers present the current science of gut microbial health — how dietary fibre and fermented foods shape microbiome diversity, the consequences of microbial depletion, and evidence-based dietary strategies for microbiome restoration.

Why Read It
Scientifically rigorous and highly readable. Important grounding for dietary microbiome interventions.
Nutrition Science
Food: What the Heck Should I Eat?
Dr Mark Hyman MD

A rigorous evidence-based examination of the nutritional science behind common foods — separating the evidence from industry-influenced guidance on fats, carbohydrates, protein sources, dairy, grains and ultra-processed food — with practical clinical and patient-facing application.

Why Read It
Excellent for addressing patient dietary confusion. Well-referenced and directly applicable to clinical nutrition counselling.
Metabolical
Dr Robert Lustig MD

A paediatric endocrinologist and leading researcher in metabolic disease presents the biochemical evidence for the role of processed food — and specifically added sugar and refined carbohydrate — in driving the global chronic disease epidemic through metabolic, hepatic and neurological pathways.

Why Read It
Authoritative and evidence-dense. Essential for practitioners working in metabolic and cardiometabolic health.
The Pegan Diet
Dr Mark Hyman MD

Hyman synthesises the best of paleo and plant-based dietary approaches into a flexible, evidence-based framework centred on food quality, phytonutrient density, glycaemic stability and anti-inflammatory eating — with practical clinical application for diverse patient presentations.

Why Read It
A practical dietary framework that bridges multiple evidence bases. Useful for patient dietary recommendations.
Longevity & Ageing
Lifespan: Why We Age — and Why We Don't Have To
Dr David Sinclair PhD AO

Harvard geneticist David Sinclair presents his information theory of ageing — arguing that ageing is a disease driven by epigenetic disruption rather than genetic inevitability — and reviews the evidence for interventions including caloric restriction, NAD+ precursors, metformin and lifestyle factors in modulating the ageing process.

Why Read It
Paradigm-shifting and rigorously sourced. Essential for practitioners working in longevity or preventive medicine.
Outlive: The Science and Art of Longevity
Dr Peter Attia MD

A physician specialising in longevity medicine presents a comprehensive evidence-based framework for extending healthspan — covering cardiovascular risk, cancer prevention, metabolic health, neurodegenerative disease and the critical roles of exercise, sleep, nutrition and emotional health — with practical clinical and personal application.

Why Read It
The most comprehensive and clinically relevant longevity medicine text currently available. Highly recommended.
The Telomere Effect
Dr Elizabeth Blackburn PhD & Dr Elissa Epel PhD

Nobel Laureate Elizabeth Blackburn and health psychologist Elissa Epel present the science of telomere biology and its role in cellular ageing, chronic disease and longevity — and the evidence for lifestyle, nutritional and psychological factors that influence telomere length and telomerase activity.

Why Read It
Nobel Prize-backed science made accessible. Excellent for explaining the biological basis of lifestyle medicine to patients.
Mindset & Lifestyle Medicine
Why Zebras Don't Get Ulcers
Dr Robert Sapolsky PhD

Stanford neurobiologist Robert Sapolsky presents the definitive account of the physiology of stress — how chronic psychological stress disrupts every major body system through cortisol, the HPA axis and autonomic nervous system — with profound implications for functional medicine's approach to stress as a root cause of disease.

Why Read It
The essential stress physiology text. Required reading for understanding the biological mechanisms of stress-driven disease.
When the Body Says No
Dr Gabor Maté MD

Canadian physician Gabor Maté explores the evidence for the role of emotional repression, adverse childhood experiences and chronic stress in the development of autoimmune disease, cancer and chronic illness — presenting a compelling case for the inseparability of psychological and physiological health.

Why Read It
Profoundly important for practitioners working with chronic disease. Deepens understanding of the psychological dimension of functional illness.
Why We Sleep
Dr Matthew Walker PhD

The leading sleep neuroscientist presents the comprehensive evidence for sleep as the single most important health behaviour — covering its role in immune function, metabolic health, hormonal regulation, memory consolidation and cardiovascular risk — and the consequences of chronic sleep insufficiency for every body system.

Why Read It
The most important book on sleep ever written. Every functional medicine practitioner should read this and use it in clinical practice.

Nominate the Next Book of the Month

Have a book that has shaped your functional medicine practice? We invite all members to nominate titles for upcoming Book of the Month selections. Nominations are reviewed by the FMI editorial team monthly.

Nominate a Book →
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