What Does Diet Have To Do With Depression?

This is a guest post by Iris Thieme

Food affects mood. Mood affects food.  What kind of food do you eat when you feel depressed?  Most people tend to eat what they call “comfort foods”.  They are typically highly processed, high sugar, high fat, high salt foods, which give off a temporary dopamine, or feel-good affect.  However, the effect is like a drug, giving you a temporary “high”, followed by a “crash” and feelings of guilt, shame, lack of desire and lack of energy – more depression.  

Did you know that eating more whole plants and less meat and dairy can help alleviate the symptoms of depression and improve overall mood? We all know that eating more fruits and vegetables is good for our body, but we are learning more and more how it is also good for the mind and emotional well-being. When you eat “real” foods, particularly plants, the way nature intended (whole grains, fruits and vegetables, legumes, nuts, and seeds), your dopamine levels stay on an even keel, without the ups and downs and crashes. Here is what we are learning about how diet impacts depression and overall health and what the research is showing:

1. The gut microbiome affects brain and mental health.  Have you ever heard of the gut brain connection?  What is happening in our gut affects what is happening in our brain.  Our gut is full of bacteria, both good and bad (microbiome).  When we eat wholesome plant foods, it feeds the good bacteria in our gut.  When we eat processed foods, meat, dairy and eggs, it feeds the bad bacteria.  The good bacteria produce dopamine and serotonin, influencing mood and behavior.  Studies have shown that depressed subjects tend to be lacking in certain species of gut bacteria.
2. Inflammation is linked to depression.  One study tested the levels of inflammation (CRP or C-reactive protein) in more than 70,000 Danish adults.  They found the higher the blood levels of CRP, the higher the likelihood they were to use antidepressants or be hospitalized for depression (Archives of General Psychiatry).  
3. Saturated fat and trans-fat increase inflammation. The most pro-inflammatory foods are foods high in saturated fat and trans-fat.  The top 5 sources of saturated fat in the US are cheese, cake and ice cream, chicken, pork, and burgers.  Fortunately, there is a ban on artificial trans fats, but they are still found naturally in meat and dairy and they are created in vegetable oils.
4. Fatty foods reduce blood flow.  Have you ever experienced a food coma – felt tired and sluggish after a big meal, particularly a fatty meal?  It is because saturated fat makes your blood thicker, which means less blood flow and less oxygenation of your tissues, making you feel tired and sluggish.  If you repeat this pattern 3 or more times a day, you will have a constant state of low blood flow and you feel rotten all the time.
5. Omega-6 fatty acids may play a role in depression.  One component in certain foods that may increase the risk of depression is arachidonic acid, a metabolite (formed in metabolism) of the omega-6 fatty acids.  Arachidonic acid can impair mood by inflaming the brain. It is found mainly in vegetable oils, chicken, and eggs, and some in beef, pork, and fish.
6. Eating more plants may help alleviate the chemical imbalance in the brain.  Serotonin and dopamine are from an important class of neurotransmitters (chemical messengers that transmit a message from a nerve cell to a target cell) called monoamines.  They are controlled by an enzyme called monoamine oxidase (known as MAO) that breaks down any excess monoamines. “People who are depressed appear to have elevated levels of this enzyme [MAO] in their brains. Many plant foods, including apples, berries, grapes, onions, and green tea, contain phytonutrients that appear to naturally inhibit MAO, as do such spices as cloves, oregano, cinnamon, and nutmeg. This may help explain why those eating plant-rich diets have lower rates of depression. Even on a day-to-day basis, studies have shown that the more fruits and vegetables you eat, the happier, calmer, and more energetic you may feel that day—and this positivity can spill over into the next day.”

So, what can you do to help alleviate depression and anxiety?  You may have issues in your life that you cannot control – we all do, but you can control what you put on your plate and in your mouth!  You can help break the cycle by eating more fruits and veggies, whole grains, beans, nuts and seeds and less processed foods, and animal products. Try it for 3 weeks and take note of what happens!