Hey Mountaineers!
I hope all of you are reading this as you decompress and enjoy some relaxation with friends and family after what I can imagine was a long and challenging semester. While I’m sure there were fun memories, laughs and great food over these last several months (physically-distanced, of course), I think it’s important to have an honest conversation about a topic that has impacted many of us (myself included). That topic is mental health.
I’m sure this comes as no surprise when I tell you that anxiety impacts a large number of people. When I say large amount, I mean around 40 million adults (Naidoo, 2016). When anxiety is discussed, typically depression is also a part of that conversation. While I believe that it is essential for everyone to speak with a licensed therapist about concerns related to anxiety and depression, I wanted to take this opportunity to also shed light on how nutrition impacts our mental health. The nutrition and mental health connection is complex to say the least. Before we dive into these connections, I wanted to remind you that if you are interested in receiving mental health services, please contact the Carruth Center or reach out to me to receive more information.
Nutrition, Anxiety and Depression
Without further ado, let’s talk about the nutrition and mental health connection! There has been a lot of research in recent years suggesting that specific types of foods, supplements and vitamins/minerals can decrease anxiety and depression (how cool is that!?). I cannot stress this enough: I am NOT implying that adding some healthy foods to your diet is a substitute for therapy, but I am suggesting that considering foods and their influence on our mental health with the support of a therapist can make a positive impact (and these foods are yummy, if I do say so myself).
For example, research has connected probiotic foods to lowered social anxiety and depression. Foods such as pickles, sauerkraut and kefir are linked to decreased symptoms of anxiety (Hilimire, et al., 2015). Other products that have gotten more press recently, like kombucha and various yogurts, can have some pretty cool effects!
So what are probiotics and why do they have some awesome health benefits? Well, probiotics are these live microorganisms that assist your body in maintaining or improving your gut flora. Another phrase for gut flora is gut microbiota; either phase is referring to the microbiome which includes good bacteria, archaea (just another type of bacteria) and fungi that is found in your digestive tract. Good bacteria in your gut is important because immune cells that fight off infection in our bodies are influenced by this bacteria. Gut bacteria also has influence on our hormones, emotions and brain function. Gut health and bacteria has also been connected to general health and various comorbidities like heart disease, cancers, diabetes and more (Zhang, et al., 2015).
While benefits of probiotics in connection to anxiety and depression are mixed, the current thinking is that probiotics can’t hurt and COULD help in managing these conditions (along with various therapy modalities). Not to mention other benefits of probiotics, such as supporting a healthy immune system, preventing infection and enhancing digestion and nutrient absorption (just to name a few).
Other foods and supplements that have been connected to anxiety and depression include various amino acids, complex carbohydrates, omega-3 fatty acids, and vitamin D and B-complex vitamins (Gracious, et al., 2012; Rao, et al., 2008). Let’s start with complex carbohydrates (because I’m team carbs all the way). Interestingly, low or no-carbohydrate diets tend to give rise to depression related symptoms and diagnoses. This can be connected to the fact that the good brain chemicals like serotonin are triggered by carbohydrates. So no carbohydrates equals no feel-good hormone triggers. Various carbohydrates like fruits, veggies and whole grains can give us long-lasting energy, improve our mood and potentially decrease depressive symptoms. (Rao, et al., 2008).
Along these same lines, the amino acid (aka a building block of protein) tryptophan, is a precursor of the feel-good brain chemical, serotonin. Consuming adequate amounts of proteins and foods that contain tryptophan 1 can impact depression symptoms that are connected to deficiencies in serotonin (Rao, et al., 2008). While there are many animal products that contain tryptophan, recent macronutrient recommendations related to gut health have been related to plant proteins. There is growing evidence that supports plant-based proteins and the correlation with gut bacteria diversity. In other words, the more good bacteria in our gut, the better! Now, before you run off and buy all of the supplements containing tryptophan, I want to add that it is important to obtain various amino acids like tryptophan from a diet containing whole foods. This is because there is a synergistic effect of tryptophan and other amino acids paired with healthy fats, carbohydrates and fibers (Tomova, et al., 2019).
If you haven’t already guessed, we now need to talk about the third macronutrient and its impact on mental health. I’m talking about fat. And more specifically, omega-3 fatty acids 2. Interestingly, scientists are still narrowing down exactly how omega-3 fatty acids provide antidepressant effects. Nevertheless, we know that these fatty acids positively impact neurotransmitters and assist with the signaling, synaptic function and building material of the brain (Meeusen, R., 2014). Omega-3 supplementation has been connected to promising benefits related to depression, bipolar disorder and other mood disorders (Bozzatello, et al, 2016). Omega-3 fatty acids come in different forms, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). If you are interested in learning more about supplementation and dosing related to omega-3 fatty acids, I suggest you speak to a dietitian (that's me!) to ensure that the amount, type and brand are supported by evidenced-based research.
Gut-Brain Axis
I don’t know about you, but this stuff can feel complicated when factoring in all of the nutrients, foods and supplements involved with the brain and subsequent mental health effects. Hold tight, because I will wrap all of this information into some recommendations soon. The connection of our brain, its neurotransmitters and the impact on mental health might seem like an easy assumption even though the details are pretty complex, but our gut bacteria and brain neurotransmitters? Really? Trust me, you’re not alone with the head scratching and questioning! I was shocked, too, when I first learned about this Gut-Brain Axis.
The study of gut bacteria and its impact on the rest of the body, including the brain, is ever-evolving because it is a more recent area of research. We know now that many factors, such as what we eat, various types of stress, medications, and the quality/quantity of sleep can change our gut bacteria, and subsequently alter just about every system in our body (Clapp, et al., 2017). For example, acute and chronic stress are both connected to increased gut permeability. This means that stress is tied to our gut lining losing its integrity and allows materials to come in contact with the bloodstream, immune system and central nervous system (Kelly, et al., 2015). This breakdown of our gut lining, combined with decreased good bacteria and increased inflammation in our body are all connected to what we call central nervous system inflammation (Galland, 2014). Individuals diagnosed with depression typically have an increase in stress and inflammation hormones called cytokines that can be connected back to gut bacteria (Appleton, 2018). This inflammation and increased stress response influences brain function and how it reacts (Galland, 2014).
Nutrition Recommendations with Mental Health Considerations
So how do we increase the good bacteria, decrease bacterial overgrowth and decrease the likelihood of gut permeability? Well, that’s exactly what scientists are currently investigating! We know that meeting nutritional adequacy with various types of foods and nutrients can improve our emotional well-being. There is a shift taking place in the research being done on the impact nutrition has on mental health. Factors that impact our physical and mental health are complex due to the interactions between countless variables (like nutrition, sleep, movement, stress level, socioeconomic status, trauma, etc.). Therefore, studies have started focusing on total diets versus single foods or supplements (Lai, et al., 2014). More research is pointing to mental health benefits with diets higher in fruits, vegetables, fish, whole grains, fiber containing foods (prebiotics), probiotics and olive oil (Lai, et al., 2014). Whoah! That is a long list, so let’s break this list down to get a better understanding of why these foods are recommended and how to apply this information to your current lifestyle.
Fruits and Vegetables
When we are considering mental health and nutrition strategies backed by evidence-based science, fruits and vegetables are typically grouped together. Here's why — fiber, prebiotics, antioxidants and phytonutrients are found in these foods (take a look at the whole grain section for more information on fiber and prebiotics). Fruits and vegetables with vibrant colors like greens, reds, blues, purples, oranges and yellows are a great indicator of antioxidants and vitamins and minerals that are connected to improving gut bacteria, mental health and inflammation.
Now, you might be thinking, I already know that I should eat more fruits and veggies — this isn’t anything new! And you're right. Recommending fruits and veggies isn’t new and typically is followed with feelings of guilt if you're not eating enough. I’m with you! I can only eat baked broccoli so many times! I suggest thinking of creative ways you can consume these foods. For example, adding some spinach to a smoothie or some scrambled eggs is a great way to add powerful antioxidants without a lot of prep work. I’d also like to challenge the idea that half your plate has to be fruits and veggies! While I am a huge fan of all things fruits and veggies, I also want to acknowledge that depending on your family, culture, and lifestyle, these foods can be included in sauces, drinks, condiments and flavorings and don't necessarily fit the standard MyPlate visual. So next time you're thinking about how to incorporate some antioxidants and phytonutrients into your diet, consider adding pesto to your pasta, or add a mango pineapple hoisin sauce to your veggies or rice!
Probiotics, Prebiotics and Whole Grains
While evidence for probiotic foods and mental health benefits have been mixed, there is solid evidence that shows a connection to improved gut bacteria diversity. Additionally, some evidence suggests that probiotics reduce inflammation and infection in the intestine, which could have an indirect positive impact on mental health. Similarly, prebiotics are fibers that help your gut grow good bacteria. Our bodies can’t digest prebiotic plant fibers so they act as a food for your digestive tract, which feed the good bacteria. Prebiotic foods include legumes, fruits, garlic, onions and whole grains (just to name a few). Whole grains are various grains and cereals that contain three parts of the grain (which are the endosperm, germ and bran) compared to refined grains which only contain one part. Whole grains contain antioxidants, fiber, proteins, vitamins and minerals that have been connected to boosting one’s energy and mood. Recent research has suggested that whole grains can assist with stabilizing mood due to the connection with serotonin and tryptophan.
It can seem daunting when considering how to include probiotics, prebiotics and whole grains in your diet. We’re talking about kefir, legumes, whole grains and fruits - and then there's vegetables. Well, let’s try and break some of these items down. For example, getting more probiotics in your diet by consuming kefir might seem like new territory, until you realize that this product can be used in a lot of different recipes. Adding kefir (fermented milk drink similar to a thin yogurt) to overnight oats can be a great way to up your probiotic game! Substituting kefir for mayonnaise in recipes or adding it to pancakes and baked goods are also some great ideas!
Consuming foods that contain prebiotics and whole grains can also be fun and simple. Switching out your refined bread (white bread) or wraps to a whole grain version can be a simple way to enjoy a sandwich but also incorporate some great fibers. Adding flax seed to your overnight oats, yogurt snacks or baked goods can not only give you some great fiber and prebiotics, but also protein and omega-3 fatty acids! Last but not least, adding some onion and garlic to your yummy pesto sauce, ground turkey or pasta dish can be a great addition!
Olive Oil and Fish
The benefits of fiber and omega-3 fatty acids are found in olive oil (which I like to call a super oil). We already know that omega-3 fatty acids have an anti-inflammatory effect on our body, and more specifically, our nervous system, which may indirectly impact our mental health. I think it’s safe to say that fiber is a pretty big deal, considering its impact on the diversity of our good gut bacteria. When considering fish consumption, the mechanism for reducing risk of depression is a little less clear. Researchers have proposed that the combined protein, vitamin and mineral consumption found in fish with the added benefit of polyunsaturated fatty acids does the trick in benefiting our mood and brain health (Li, et al, 2016). Give this quick baked tilapia recipe a try!
Final Thoughts
I know that for many, this is a time of relaxation, getting to see family again and time away from your studies, but I believe this topic is relevant no matter what you're doing or where you're at! My hope is that this month’s issue of the Dietitian Dish gave you some new information, practical tips and fun recipes to incorporate this summer. As always, feel free to email me with what you think. Until next time!
1 Tryptophan containing foods include: leafy greens, seeds, soybeans, mushrooms, broccoli, peas, eggs, fish, cheese, animal meats, beans, nuts, etc.
2 Omega-3 containing foods include: Atlantic Salmon, farm-raised Atlantic Salmon, wild Atlantic Herring Rainbow Trout, wild Canned Tuna Oysters Shrimp Scallops, nuts, seeds, plant oils (flaxseed oil, soybean oil, canola oil) and fortified foods such as certain cereals, eggs, yogurt, juices and milk. Omega-3 dietary supplements are also available and come in forms such as fish oil, algal oil, etc.
References:
- Appleton, J. (2018). The Gut-Brain Axis: Influence of Microbiota on Mood and Mental Health. Integrative Medicine, 17(4), 28-32.
- Clapp, M., Aurora, N., … Wakefield, S. (2017). Gut microbiota’s effect on mental health: The gut-brain axis. Clinics and Practice, 15;7(4), 987.
- Galland, L. (2014). The Gut Microbiome and the Brain. Journal of Medicinal Food, 17(12), 1261-1272.
- Gracious, B.L., Finucane, T.L., Friedman-Campbell, M. et al. (2012). Vitamin D deficiency and psychotic features in mentally ill adolescents: A cross-sectional study. BMC Psychiatry, 12, 38.
- Hilimire, M.R., DeVylder, J.E., Forestell, C.A. (2015). Fermented foods, neuroticism, and social anxiety: An interaction model. Psychiatry Res, 15;228(2), 203-8.
- Jun S Lai, Hiles, S., Bisquera, A., Hure, A.J., McEvoy, M., Attia, J. (2014). A systematic review and meta-analysis of dietary patterns and depression in community-dwelling adults. The American Journal of Clinical Nutrition, 99(1), 181–197.
- Kelly, J.R., Kennedy, P.J., Cryan, J.F., Dinan, T.G., Clarke, G., Hyland, N.P. (2015). Breaking down the barriers: The gut microbiome, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci. 9,392.
- Li, F., Liu, X., Zhang, D. (2016). Fish consumption and risk of depression: a meta-analysis. J Epidemiol Community Health, 70, 299-304. Meeusen, R. (2014). Exercise, Nutrition and the Brain. Sports Med, 44, 47–56.
- Rao, T. S., Asha, M. R., Ramesh, B. N., & Rao, K. S. (2008). Understanding nutrition, depression and mental illnesses. Indian Journal of Psychiatry, 50(2), 77–82.
- Tomova, A., Bukovsky, I., Rembert, E., Yonas, W., Alwarith, J., Barnard, N. D., & Kahleova, H. (2019). The Effects of Vegetarian and Vegan Diets on Gut Microbiota. Frontiers in Nutrition, 6, 47.
- Zhang, Y. J., Li, S., Gan, R. Y., Zhou, T., Xu, D. P., & Li, H. B. (2015). Impacts of gut bacteria on human health and diseases. International Journal of Molecular Sciences, 16(4), 7493–7519.