We recently published the 10th episode of our Mental Horizons Podcast and that conversation was with Chris Palmer, MD, Harvard Medical School assistant professor of psychiatry, director of continuing education at McLean Hospital, and pioneering researcher in the area of using medical dietary interventions, namely the ketogenic diet, as a treatment for schizophrenia and bipolar disorder.
Our conversation was fascinating and yet it only skimmed the surface of this deeply relevant topic. Dr. Palmer is a uniquely generous individual with a passion for alleviating the suffering of people dealing daily with thought and mood disorders.
Dr. Palmer has been a guest on numerous other podcasts where he goes deeper into this topic. You can find links to those podcasts and many other articles on his resource-rich website, www.ChrisPalmerMD.com. Dr. Palmer is one among a growing field of academics, practitioners, and researchers recognizing the powerful relationship between food, the mind, and the body.
Some of the other research going on in the field of nutritional psychiatry includes the work of Felice Jacka at the Food and Mood Centre in Australia where they conducted the SMILES trial and saw a reduction in depression symptoms when using a Mediterranean diet, a clinical trial currently underway at Stanford University and overseen by Shebani Sethi Dalai, MD, where they are studying the Impact of a Ketogenic Diet on Metabolic and Psychiatric Health in Patients With Schizophrenia or Bipolar Illness, and numerous researchers who are looking closely at the link between our gut microbiome and our mental health (for a sampling of research in this area, see this Google Scholar search result page).
In our interview with Dr. Palmer, he explained the landscape of "nutritional psychiatry" as being broken down into 5 main areas:
1. When something is added to the diet
2. When something is eliminated from the diet
3. Using supplements (vitamin and mineral therapy)
4. Using the ketogenic diet and fasting
5. The gut microbiome
To learn more about each of these 5 areas of nutritional psychiatry, read Diets and Disorders: Can Foods or Fasting Be Considered Psychopharmacological Therapies? written in 2019 by Dr. Palmer.
Food as Therapeutic Intervention
Food is much more than simply 'calories- in-calories-out'. Dr. Mark Hyman, a functional medicine doctor and director of the Cleveland Clinic Center for Functional Medicine defines food this way:
Connectedness: Food is personal and tied into our social and cultural spheres. It is a vital component of our rituals, traditions, and life ceremonies. Food is ever present: you make multiple choices every day around the type of food you are going to eat, when, how, and with whom. In America, where we have a multitude of cultures, food is a gateway to communication and cultural appreciation. Food is what ties us to other species and to the land, creating relationships where we have the choice to be stewards of the environment or contribute to its destruction.
Energy, information, and medicine: once we ingest food, we kick off a cascade of chemical reactions within our bodies. When food is energy, it supports our mitochondria in our individual cells - tiny powerhouses where our bodily energy generation begins. Food is information: when digested and broken down, the molecules of food travel all over our bodies prompting different body systems to speed up or slow down. And food is medicine as the largest therapeutic toolbox available to help sustain and heal our bodily systems and support them in functioning at optimal levels.
The field of psychiatry is the study of mental illness, emotional disturbances, and abnormal human behaviors. It is a field of study and practice that has been in existence as it is defined today a little over 200 years. The field of nutrition deals with food, nutrients, nourishment, health, and growth. Hippocrates, who is often considered the father of medicine, and lived and died in Greece over 2,000 years ago, is quoted to have said, "Let food be thy medicine and medicine be thy food". The concept of food being a critical component of health and healing is not a new concept, but its popularity has certainly waxed and waned over the centuries.
The term "nutritional psychiatry" was coined recently and represents a blending of two once-separate areas of study. The first studies to establish a link between diet quality and common mental health conditions, such as depression and anxiety, were not published until the last few decades. Felice Jacka, director of the Food and Mood Centre in Australia, wrote in 2017,
"We coined the term ‘Nutritional Psychiatry’ in order to promote a new field of research focused on developing a comprehensive, cohesive and scientifically rigorous evidence base to support a shift in thinking around the role of diet and nutrition in mental health" (Nutritional Psychiatry: Where to Next?, 2017).
She and other fellow researchers, in another article, put forth this reasoning:
"Mental illness, including depression, anxiety and bipolar disorder, accounts for a significant proportion of global disability and poses a substantial social, economic and heath burden. Treatment is presently dominated by pharmacotherapy, such as antidepressants, and psychotherapy, such as cognitive behavioural therapy; however, such treatments avert less than half of the disease burden, suggesting that additional strategies are needed to prevent and treat mental disorders. There are now consistent mechanistic, observational and interventional data to suggest diet quality may be a modifiable risk factor for mental illness" (Nutritional psychiatry: the present state of the evidence, 2017).
"...additional strategies are needed to prevent and treat mental disorders"
And so the nascent field of 'nutritional psychiatry' is defined. There is tremendous promise in this emerging field and it is an area to keep a close eye on. As written by Eva Selhub. MD in 2015 for Harvard Health Publishing in an article titled, Nutritional Psychiatry: Your brain on food:
The field of Nutritional Psychiatry is relatively new, however there are observational data regarding the association between diet quality and mental health across countries, cultures and age groups – depression in particular. Here are links to some systematic reviews and meta-analyses:
There are also now two interventions suggesting that dietary improvement can prevent depression:
Diet during early life is also linked to mental health outcomes in children (very important from public health perspective):
Extensive animal data show that dietary manipulation affects brain plasticity and there are now data from humans to suggest the same:
Interested in keeping an eye on those working to bring forth more integrative approaches to alleviating mental health issues? Below is a list of just a tiny handful of the influential players in this space.