Felice Jacka is the director of Deakin University's Food and Mood Centre and founder and president of the International Society for Nutritional Psychiatry Research (ISNPR). She is an expert in the role of nutrition in mental health and has led studies confirming the benefits of dietary improvement on depression.
What I discuss with Felice in this episode:
- What a controlled trial concluded about the efficacy of dietary improvement in treating major depressive episodes.
- How eating too much—or too little—lean red meat can double the chances of experiencing episodes of depression or anxiety.
- How a modern tsunami of chronic physical as well as mental diseases can be correlated with nutritionally poor diet on a global scale.
- The foods Felice's trials have best proven to function as antidepressants.
- The possibilities Felice sees for the future of nutritional psychiatry.
- And much more!
While "you are what you eat" is an adage probably as old as the first mother's attempted introduction of broccoli to her skeptical toddler, nutritional psychiatry is a fairly new field of research that seeks to understand the role diet and nutrition play on mental health.
Joining me for this episode is nutritional psychiatry pioneer Felice Jacka, the director of Deakin University's Food and Mood Centre. Felice and her team conduct research aiming to prove and publicize the correlation between diet and mental health in order to treat and ultimately prevent the occurrence of diet-based mental disorders—a mission very near and dear to my heart.
The Nascence of Nutritional Psychiatry
When Felice pursued her degree in psychology during the early aughts, she was fascinated by research being done at UCLA that focused on modulating nerve cells in the brain using dietary approaches.
The researchers discovered that they could predictably regulate hippocampus production of neurotrophins (proteins responsible for creating, developing, and maintaining neurons) in mice by altering diet.
"So that was saying foods have a direct impact on this really key part of the brain that's important for mental health and brain power," says Felice.
Of particular interest to Felice was a hypothesis that depression was a function of the immune system.
"In the way that a dysregulated immune system—or what they call systemic inflammation—contributes to heart disease and to cancer and to other chronic diseases, there was starting to be pretty good evidence that this was also the case with clinical depression, Felice says. "And of course the things that influence this immune dysfunction—this low-level inflammation—are all the things we know are not great for us: not getting enough sleep, not having enough vitamin D, not exercising, being overweight (because the fat tissue actually releases these proinflammatory molecules). But diet, of course, is a major influence on the immune system.
"I'd always had a really strong interest in diet. I love food! But I've also very much always felt that nutrition was really the foundation. It's like the petrol you put in your engine. If you put rubbish in the engine, you're going to get rubbish out. But I couldn't quite believe when I started hanging out with all these researchers and psychiatrists that no one was looking at diet in relation to mental health and in depression in particular."
A Tsunami of Chronic Disease
"To put it in context, depression is one of the leading contributors to the global burden of disease," says Felice. "Mental disorders and substance disorders in general account for the leading global burden of disability. That means years of life not lives to their fullest because you are not able to fully engage with the community or workplace...it has a major impact.
"We're also now knowing—and this was true 10-12 years ago—that our diets, globally, have changed really for the worse, really profoundly. Obviously we see that reflected in the obesity epidemic, but it's also reflected in the huge tsunami of chronic disease: type two diabetes, obesity, metabolic syndrome, cancer. All of these sorts of diseases related to unhealthy diet."
While she was stunned to find there wasn't much data at this time to support a correlation between nutrition and mental health, it made sense to Felice that mental health disorders could also be identified within this very same tsunami. All that was left was to prove it, and thus began her path to a PhD and a life's calling.
Listen to this complete episode to learn more about what Felice's colleagues initially thought about her hypothesis connecting mental health with nutrition, the details of Felice's research that support this hypothesis, how improving diet in test subjects effectively reversed depression to an extent that even surprised Felice, what Felice sees for the future of her research and what she hopes she can change about the way mental disorders are treated, the relationship between hippocampus size and diet, the foods Felice's trials have best proven to function as antidepressants, and lots more.
Resources from this episode:
A Randomised Controlled Trial of Dietary Improvement for Adults with Major Depression (The 'SMILES' Trial) by Felice Jacka et al., BMC Medicine
World's First Clinical Trial Shows Diet Fights Depression by Max Lugavere
Red Meat Halves Risk of Depression, The Telegraph
Brain Foods: The Effects of Nutrients on Brain Function by Fernando Gómez-Pinilla, Nature
Antidepressants and the Placebo Effect by Irving Kirsch, Z Psychol
Vegetarian Diets and Depressive Symptoms among Men by Joseph R. Hibbeln et al., Journal of Affective Disorders
How to Eat: Diet Secrets from Michael Pollan (and Your Great-Grandma), Houston Chronicle
Nutritional Psychiatry: Where to Next? by Felice N. Jacka, EBioMedicine
Primary Prevention of Cardiovascular Disease with a Mediterranean Diet by Ramón Estruch et al., New England Journal of Medicine
Healthy Eating Pyramid, Nutrition Australia
Ketogenic Diets for Psychiatric Disorders: A New 2017 Review by Georgia Ede, Psychology Today
A1 vs. A2 Milk—Does it Matter? by Atli Arnarson, Healthline
Nutritional Medicine as Mainstream in Psychiatry by Jerome Sarris et al., The Lancet Psychiatry
Genius Foods: Become Smarter, Happier, and More Productive While Protecting Your Brain for Life by Max Lugavere and Paul Grewal M.D.
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