When you’re feeling cranky, irritable, angry, short-tempered or just plain down, is it simply because you woke up on the wrong side of the bed? Have you ever really thought about WHY you feel so lousy?
What causes a bad mood?
Maybe you didn’t sleep very well and you’re tired.
Maybe you got in a fight with a friend or your spouse.
Maybe you received some upsetting news.
Maybe your work or your kids are stressing you out.
Maybe you’re in a particularly irritable part of your menstrual cycle.
Certainly, all of the above can leave you feeling on edge, whittle away your resilience and darken your mood. But I believe something else is at play—something that could be influencing HOW you react to the “causes” listed above.
The gut-brain connection
In a number of studies (see first three resources, below) that have compared traditional diets, such as the Mediterranean or Japanese diets, to a standard western diet, the risk for depression is 25-35% lower among those who eat a traditional diet.
Let’s take a look at why this might be by first exploring the gut-brain connection—one of three food-related systems in your body that can directly impact your mood, emotional well-being and your mental health.
In a very real sense you have two brains: one in your head, of course, and the other in your gut. These two systems are connected via the vagus nerve that runs from your brain stem into your abdomen. The vagus nerve is the primary route your gut bacteria uses to transmit information to your brain. Maintaining optimal gut function is therefore paramount in supporting your mental state.
A healthy gut consists of different types of bacteria; each person’s microbiome (the composition of bacteria in your gut) is unique, and this diversity maintains wellness. There is no one right array of bacteria for everyone. Thanks to the vagus nerve, the quality, quantity and composition of the bacteria in your gut have an enormous influence on your brain. There are even certain bacteria that appear to have a connection with specific mood disorders.
Research is underway to learn more. For instance, studies have shown that when people take probiotics, their anxiety levels, perception of stress and mental outlook often improve.
Another study examined the differences in the bacterial makeup of the microbiome in patients with major depressive disorder compared with healthy individuals. The severity of depressive symptoms was related to the amount of a specific bacterium found in their gut: faecalibacterium. Lower levels of this bacteria were associated with more severe depression.
In another study, people who took a multi-strain probiotic for at least four weeks reported a lessening of rumination and, therefore, anxiety. Yet another study found that the probiotic Lactobacillus rhamnosus had a marked effect on GABA levels in certain brain regions of a mouse model, resulting in reduced anxiety and depression-related behavior.
This is just a very small sampling of the amazing research being done right now on the strong connection between the microbiome and the brain.
How to protect your microbiome Add foods and environmental factors that will increase diversity:
Fermented foods: eat foods with active and live cultures daily (sauerkraut, pickled veggies and fruits, kimchi, miso, tempeh, kefir, kombucha)
Probiotics: if you don't eat fermented foods daily or are already dealing with a mood disorder (like depression or anxiety), you may want to add a supplemental multi-strain probiotic
Fiber: a diet high in plant fiber naturally feeds and supports healthy microbes; aim for 30+ grams of fiber every day
Prebiotics: these are fibers that specifically feed good bacteria and are found in certain plants (Jerusalem artichoke, dandelion greens, garlic, leeks, onions, asparagus, jicama, banana, chicory root)
Get your hands dirty: germ-free living is not in your best interest; build your microbiome diversity with gardening, caring for pets, letting your kids play in the dirt
Open your windows: research shows that opening a window and increasing natural airflow can improve the diversity and health of the microbes in your home and, by consequence, in you
Stress management: chronic stress increases inflammation and disrupts microbial diversity; having solid strategies in place to cope with stress is essential to a healthy gut
Avoid foods and environmental influences that kill the good bacteria and decrease the diversity of the microbiome, such as:
Antibiotics (only take when absolutely necessary) and antibacterial soaps (there is no reason to use antibacterial soap; regular soap is good enough. Keep antibacterial gel use to a minimum; use only when absolutely necessary)
Chlorinated water: in the shower or bath as well as in the water you drink
Pesticides: many agricultural chemicals act like antibiotics in our body and kill beneficial bacteria
Processed foods: added sugars, artificial sweeteners and the plethora of flavorings, colors and preservatives found in processed foods have all been shown to disrupt the microbiome
Conventionally raised meats/animal foods: the antibiotics and other medications given to the animals, as well as the pesticides found in the grain they're eating, can all kill beneficial bacteria
Inflammatory fats: fried and hydrogenated/partially hydrogenated oils
Food sensitivities: foods like gluten, corn, soy or dairy are all known causes of gut irritation and inflammation, ultimately killing bacteria
So, take some time to take a close look at the health of your gut and ask yourself if there's anything you can do to make it healthier. Your brain will benefit. Next week, we’ll look at the other two food-related systems our bodies rely upon for optimal well-being.
Resources
Dietary recommendations for the prevention of depression. www.ncbi.nlm.nih.gov/pubmed/26317148
Mediterranean dietary pattern and depression: the PREDIMED randomized trial. www.ncbi.nlm.nih.gov/pmc/articles/PMC3848350/
Healthy dietary indices and risk of depressive outcomes: a systematic review and meta-analysis of observational studies. www.nature.com/articles/s41380-018-0237-8
Intestinal microbiota, probiotics and mental health: from Metchnikoff to modern advances: part III – convergence toward clinical trials. www.ncbi.nlm.nih.gov/pmc/articles/PMC3605358/
Altered fecal microbiota composition in patients with major depressive disorder. www.ncbi.nlm.nih.gov/pubmed/25882912
Probiotics may keep you from dwelling on the past. www.newhope.com/probiotics/probiotics-may-keep-you-dwelling-past
Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. pubmed.ncbi.nlm.nih.gov/21876150/
Dionne Detraz, RDN
Dionne Detraz, RDN, is a Cancer Nutrition Expert and Registered Dietitian Nutritionist. She specializes in helping people navigate cancer treatment with integrative diet and lifestyle strategies so they can have more energy and fewer side effects from treatment.
Dionne’s experience includes over 15 years of working in health education, wellness and nutrition. Before starting "The Rustic Dietitian, Inc." in 2016 she worked for two years at the University of California San Francisco Osher Center for Integrative Medicine and spent more than 10 years as an outpatient dietitian and health educator at Kaiser Permanente. Her education includes a unique blend of medical nutrition therapy with integrative and functional medicine.
Originally from California, Dionne lives with her husband and their two daughters in France. Last year, she published The Cancer Diet Cookbook: Comforting Recipes for Treatment and Recovery. Website: therusticdietitian.com/ Email: support@therusticdietitian.com Instagram: @therusticdietitian Facebook: @therusticdietitian The Cancer Diet Cookbook: Comforting Recipes for Treatment and Recovery