It had been a few weeks I’d been pondering this idea – how does the food we eat affect our emotions, how we feel? What does it do to your mood, and are there specific foods that you can eat to change your mood?

As it may be, one of my favorite podcasts at the moment, the Deliciously Ella podcast, just happened to release an episode exactly on that topic earlier this month. I’ve been a fan of Ella and her whole Deliciously Ella brand for a few years now and I’ve been loving her podcast — it explores topics on health and wellness, nutrition, sleep, happiness, and even entrepreneurship. The episodes aren’t too long, which makes them perfect for listening on commutes or walks. So when I saw the exact topic I’d been thinking of writing about, I thought “It was meant to be!”.

In the episode, Ella interviews Dr. Felice Jacka, author of Brain Changer: How Your Diet Can Save Your Mental Health — Cutting Edge Science From the Expert (click to listen to it here). On the episode, Dr. Jacka offers some surprising facts about how the food we eat is interconnected with our brains and she also dismisses some of the myths around the topic. I did some further research after listening and found some further insights into the science that suggests a connection between our diets and our emotional states.

So is there a real connection between food and mood? The bottom line is that there is a proven link between what we eat and our mental health and how we feel, although there is no direct link to any specific foods that are more or less effective at altering our mood states. Patricia Chocano-Bedoya, a visiting scientist in the Department of Nutrition at the Harvard T.H. Chan School of Public Health states “It is not yet possible to identify a single nutritional factor that increases or decreases the risk of depression.” However, there is some a variety of evidence that favor certain food groups for good mood. Not surprisingly, these foods are the cornerstones of a healthy diet; vegetables, fruits, grains, legumes, nuts, seeds, and other plant-based foods. According to Dr. Jacka, too little of a healthy diet and too much an unhealthy diet are independently problematic for mental health.

The Gut Microbiome

The research on the food-mood connection is mostly attributed to the more recent and increasingly popular interest of scientists on the gut microbiome. What is the microbiome you may ask? It’s the staggering community of microorganisms that live in the human digestive tract. Your intestines are  lined with millions of nerve cells and the function of these nerve cells is influenced  by the billions of bacteria in your intestinal microbiome. It has become an increasingly popular topic among researchers in the last few years and is the reason why research into the connection between food and mood is relatively new. The important point is that this interworking of our gastrointestinal trace doesn’t just help digest food, it also helps  guide our emotions. For example, did you know that 95% of the serotonin in your body (that’s the “happy” hormone) is produced in your gastrointestinal tract? 95%! Research into neuroplasticity, oxidative stress, and chronic inflammation is also leading to our learning about all the ways the brain is affected by the food we eat. 

How Diet Affects the Microbiome

Our brains function best when they receive good quality nutrition; that is, foods that contain a lot of vitamins and minerals because they protect the body from oxidative stress (the damage to cells caused by free radicals which are produced when the body uses oxygen). If our brains don’t receive this good quality nutrition, it can be damaged and this damage can be very difficult to repair or get rid of. Dr. Jacka states that changing your diet can have radical effects on your gut  microbiome and thus, your brain. Studies show that even within 5 days of test participants increasing their fiber intake with plant-based foods (vegetables, beans, lentils, legumes, fruits, nuts, and seeds) there was a pronounced difference seen in the microbiome and only within 2 weeks was there a measured drop in cancer risk markers and fatty acids.

Too Much or Too Little of Certain Food Groups Can Be Destructive to Your Health

Since there isn’t a single food that has been found to have a significant effect on mood, it’s important that we be cautious when reading articles on the Internet or watching the segments  on TV telling us that this or that specific will miraculously and instantaneously affect the way you feel, as this false information is mainly driven by journalists who are looking for catchy headlines or clickbait to get more traffic on their sites or news programs. We also must be careful about what we decide to add or eliminate to our diet as a consequence of reading a few  catchy articles or seeing a food trend on YouTube or Instagram. Cutting out whole food groups, for example, can prevent your body from getting all the nutrients it needs and can lead to your mood taking a radical nosedive, as well as decreased energy. In addition, spikes in blood sugar caused by eating too many refined or “simple” carbs can lead to low energy and irritability. You don’t want to not be eating at all either; skipping meals, especially breakfast, can lower your blood sugar and will also leave you feeling weak and tired. In addition, although there is no conclusive research on the effect of dietary factors on depression, a 2014 study in Brain, Behavior, and Immunity found a significant correlation between diets rich in sugar-sweetened soft drinks, refined grains, and red meat. Dr. Eva Selhub, a contributing editor to Harvard Health Publishing adds that diets high in sugar not only worsen the body’s regulation of insulin and promote oxidative stress, but that multiple studies have found a correlation between a diet high in refined sugars and impaired brain function, including the worsening of symptoms of mood disorders.

Fruits, Vegetables, and Other Plant-Based Foods

“There is consistent evidence for a Mediterranean-style dietary pattern and lower risk  of depression” says Dr. Chocano-Bedoya. Studies that compared traditional diets, such as traditional Japanese and Mediterranean diets with Western diets found that that risk of  depression in those participants on traditional diets was 25%-35% lower. What were the significant factors? Traditional diets contain higher amounts of fruits, vegetables and fermented foods, contain small amounts of lean meats and dairy, and don’t contain any processed foods. 

Higher intakes of fruits and vegetables has been associated with lower probability of both  depression and anxiety, even after controlling  for age, gender, income, education, physical activity, chronic illness and smoking. Dr. Jacka says foods high in fiber can have a pronounced difference in the microbiome. A 2013 study on 281 young adults found that their mood was better on days they ate more  fruits and vegetables. Their consumption of  fruits and vegetables also predicted a positive mood for the next day as well. The conclusions of the study lead its  researchers to recommend 7-8 servings of fruits and vegetables a day for a positive mood.

It’s also interesting how fermented foods come into play with mood and emotions. Of course, fermented  foods,  which include yogurt, kimchi, sauerkraut, miso and tempeh, are packed full of probiotics — the gut-friendly bacteria the microbiome craves. Therefore it’s no surprise that frequent consumption of fermented foods has been shown to significantly lower symptoms of social anxiety, especially in people prone to neuroticism. Those who take probiotics have been found to show improvement in their anxiety levels, perception of stress, and mental outlook.    

Water Also Counts

We already know that staying hydrated and drinking plenty of water is one of the keys to good physical health, but it turns out it’s also important for mental health. A study conducted on 120 young women found that those who drank just over  3 liters of water a day had the lowest mood disturbances and also reported the least signs of depression, tension, and confusion. On the other hand, those who drank the least amount of water, about 1.5  liters a day, scored higher on mood disturbances and signs of depression. According to a few other studies even mild dehydration, defined as a loss of 1-2% of body water, causes poor concentration, short-term memory problems, moodiness, and anxiety.

Takeaway: Whole, Plant-Based Foods Are The Way to Go

So how can we use this information to our advantage? Dr. Jacka insists that it’s super easy to change your gut health – it’s all in your diet. Changing the food that you eat will dramatically change the bacteria in your gut and the results of that will not be seen some time far off in the future, but quite literally in a matter of days. “You can make changes and have a benefit very quickly” she says, “The gut is your seat of health…Feed your gut and you’ll be feeding your health.” 

Incorporating more plant-based foods in your diet is something we should  all be striving towards. Even adding some more vegetables and greens (you can read more about the amazing benefits of leafy greens in our Leafy Greens blog series) to every meal is a great place to start. It’s also something you can start doing right now with resources that are already available to you at no extra cost. “It doesn’t need to be difficult, and it doesn’t need to be expensive” she adds. You also don’t need to be beating yourself  up for not eating big portions of  plant-based  foods every day. “People don’t need to have a perfect diet to reap the benefits” she says. It’s all about  balance and consistency; what  you do most of the time will be what reflects on your health, not what you do some of the time. We simply need to bring more attention to what we’re feeding our bodies, and how our bodies react to it. Dr. Eva Selhub suggests “Pay attention to how the food you eat affects you — immediately and in the next few days.” By doing so, we can begin to understand the incredible power of food on all aspects of our health.

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Sources:

• Deliciously Ella Podcast, “How Food Affects Our Mood” Interview with Dr. Felice Jacka, July 1, 2019.

• Mental Health First Aid, “What Is the Relationship Between Food and Mood?” By Amy Magill, March 13, 2018.

• Harvard Health Publishing, “Food and Mood: Is There a Connection?,” Harvard Women’s Health Watch, June 2018.

• Harvard Health Publishing, “Nutritional Psychiatry: Your Brain on Food” by Eva Selhub MD, April 5, 2018.

• Des Moines University, “The Food-Mood Connection” by Catherine Knepper, April 4, 2016.