Physical health and mental health are so closely connected. When we think of physical health, we often think of physical fitness, but food and nutrition are just as important. Eating certain foods will have long-term effects on our health, which is why it is essential to eat foods that are good for us. Food fuels our body and it is necessary that we eat foods with nutrients that our bodies need. But what does food do to our mental health? 

Eating foods low in nutrients can be harmful for our physical health, and it also impacts our mental health. When we eat foods that are lacking in nutrients, we are damaging our brains and bodies because we are not supplying it with the fuel that it needs to run properly. Like any machine, providing it with the best and proper fuel will allow it to run smoothly and at its best. Eating foods rich in fruits, vegetables, and whole grains can help us reduce risks of heart-related illnesses and cancer, strengthen bones and teeth, manage weight, diabetes, improve sleep, and so much more. 

On the other hand, a diet consisting of too much sugar has been linked to mood disorders, like depression [1]. Sugar appears in all sorts of foods like fruits and vegetables, but also in simple, refined foods like soda, baked goods, and more. Sugar can be highly addictive, and it has been found that sugar is more addictive than cocaine. An excess of simple sugars and refined carbs in our diets is commonly associated with obesity and chronic health issues, and these health problems can also be linked to depression. 

Consuming a diet that is high in refined carbs can lead to inflammation and symptoms of inflammation can include loss of appetite and changes in sleep patterns, which are also common with depression [1]. Furthermore, having a diet high in processed foods can also lead to depression and mood disorders. In a study published by Cambridge University press, it was found that participants that had higher consumptions of processed foods like sweetened desserts, fried foods, and high-fat dairy products had an association with higher odds of depression than those with higher consumption of whole foods like vegetable, fruits, and fish [2]. This can explain why when we eat processed, sugary foods, we feel a momentary happiness, but later on we feel sluggish and gross. 

Why does this happen? 

Our body is composed of so many different connected parts, and food ultimately influences all of it. The human gut, often referred to as our “second brain”, has millions of neurons inside the gut wall and gut bacteria extracts vitamins and nutrients from food [3]. The brain uses neurochemicals produced by the gut bacteria to regulate our basic psychological processes like memory and mood [3]. An important neurochemical produced is serotonin. Serotonin is mostly found in our digestive system and it helps with our mood and regulates anxiety and depression. Lower levels of serotonin have been linked to anxiety, depression, poor sleep, and more. For example, clinical depression is often linked with abnormally low levels of serotonin. Because the gut bacteria produces 95% of our body’s serotonin [3], it is important to eat right because our food will impact the amount of “good” bacteria in our gut, which influences serotonin production. 

So how do we naturally increase our serotonin levels? We can increase our serotonin levels by exercising, taking supplements, gut bacteria, getting sunshine, and eating foods with tryptophan. Tryptophan is an amino acid and serotonin is synthesized from it [4]. Certain diets, like the Mediternian diet have been correlated with lower risk of depression, because these diets consist of foods high in whole foods, lean meats, and fish, as compared to the Western dietary pattern where processed and refined foods are common [5/6]. 

Omega-3 fatty acids also influence our mental health as it impacts brain functioning and has effects on dopamine and serotonin transmission and anti-inflammatory processes [7]. In a study on depressed children, it was found that those that received omega-3 with psychotherapy were more like to achieve remission. Omega-3 is found naturally in some whole foods, which further emphasizes the value of eating nutritious foods that are good for us. 

So what are some foods that can help us boost our mood? Here are some examples of foods that have tryptophan and/or omega-3: 

Eggs

Cheese

Pineapple

Kiwi

Banana

Salmon

Nuts and seeds

Beans and lentils

Because food can impact our emotional well-being, it’s important to listen to our bodies and provide it with proper nutrients, and it’s never too late to start adjusting our eating habits. Research shows that small dietary changes can improve mental health. In a study done on adults with depression, after making adjustments to their diets by replacing junk food with nutrient rich foods, they found that those who changed their diets were more likely to improve [7]. We need to start paying more attention to the foods we eat so we can better our long-term health. Switch out some of your processed or sugary foods for some whole foods and see how you feel! 

~ Lucy Li

[1] https://www.healthline.com/health/depression/sugar-and-depression 

[2]https://www.cambridge.org/core/journals/the-british-journal-of-psychiatry/article/dietary-pattern-and-depressive-symptoms-in-middle-age/96D634CD33BD7B11F0C731BF73BA9CD3 

[3] https://www.apa.org/monitor/2012/09/gut-feeling#:~:text=Gut%20bacteria%20also%20produce%20hundreds,both%20mood%20and%20GI%20activity

[4] https://www.healthline.com/health/healthy-sleep/foods-that-could-boost-your-serotonin 

[5] https://www.health.harvard.edu/blog/nutritional-psychiatry-your-brain-on-food-201511168626 

[6] https://www.nature.com/articles/ejcn201086 

[7] https://www.apa.org/monitor/2017/09/food-mental-health