Food and Mental Health – are they connected?

food and mental health

You are what you eat, let food be thy medicine…we see these quotes circle all the time. And while the connection to our digestive and even immune health is relatively obvious, the link between eating for mental health is a bit more blurred. This blog post aims to shed light on the matter. Mental health and wellbeing is a huge topic, affecting many families and individuals’, especially in today’s society. However, it’s also an area that deserve more attention and focus, often not talked about enough in public. There’s so many facets to the conversation and the content below is by no means here to ‘cure’ or ‘claim importance’. The hope is that it helps you to see that diet can certainly support mental health and wellbeing. So food and mental health – are they connected? Let’s dive in.

Food and Mental Health – are they connected?

In Europe, one in five persons will develop a depressive episode during their lifetime

Your mental health is essential to your overall well being. Throughout our lifetime, we encounter different worries ranging from general everyday to much bigger issues so it’s normal to feel down at times. In addition, our resilience and ability to respond to these issues will vary so no one issue will affect the same person in the same way.

As a basic definition, mental health is the state of someone who is “functioning at a satisfactory level of emotional and behavioural adjustment”. When things go in the wrong direction, mental health problems range from psychological distress to more serious mental health disorders. Again the length and breadth of these is vast and complex. So where does food fit into all of this?

Food and Mental Health

As you can gauge from reading above, the area of mental health is a complex topic. Not only that but each ‘disorder’ or type of mental health issue can vary in severity, type, manifestation etc. For example, anxiety doesn’t manifest equally in each individual. Some might have trouble going to work, others flying etc. What’s fascinating, however, is that we’re seeing research show that the food you eat, your digestive health and your gut microbiome can play a big role in affecting your mental health for the better or worse.

To give you a glimpse of the research to date: our microbiome has been linked to anxiety, magnesium deficiency is linked to anxiety, adaptogens for anxiety, stress, anger, confusion and depression, CBD oil for PTSD, sleep and anxiety, broccoli for schizophrenia,  

How diet affects mental health

In order to begin this conversation, let’s break the effect of diet on mental health down into three categories: the microbiome, the vagus nerve and a leaky gut. Remember that your body comprises ten systems working in unison together 24/7 to keep you alive and functioning. These systems don’t work in isolation and the relationships/dependencies that do exist are highly complex.

The Second Brain

The food we eat has to be broken down, digested and assimilated by our bodies via the digestive process. This process happens at different stages and in different parts of the body, aided by other systems and/or organs. The tube from mouth to anus (oesophagus, stomach, intestines, rectum, colon) is lined by an extensive network of neurons called the enteric nervous system. In fact, there are more neurons there than in the spinal cord or the peripheral nervous system. The role of this system is to regulate aspects of digestion, from breaking down food, to absorbing nutrients, to expelling waste.

When it comes to the final stages of absorbing nutrients back into the diet and sifting out the waste, our gut microbiome deserves a mention. These bacteria outnumber our cells at a ratio of roughly 10:1 so it does become a question of who is living on whom? What we do know is that we have a symbiotic relationship with these guys.

To sum up, this vast network of neurons combined with our gut flora is now being referred to as the the second brain. As for our diet, the food we eat has a direct impact on the health of our gut lining and the health of our microbiome. But if you eat the wrong foods, you can upset the balance of bacteria which then can impact on the relationship and/or cause overgrowth of the bad guys (candida, SIBO etc). It’s worth mentioning antibiotics too can have an impact.

The Vagus Nerve

Your brain sends signals around the body 24 hours a day. A large portion of this job is done via the vagus nerve, a nerve that supplies much of the chest, abdominal cavity and the digestive tract.

When you’re stressed, anxious or going through a low period, your brain activity is decreased which can also decrease activation of the vagus nerve. This in turn can have a detrimental effect on the digestive process, from reducing enzymatic production to causing bacterial overgrowth in the gut. Up to 90% of fibres in the vagus nerve carry information from the gut to the brain and not the other way around and scientific evidence suggests the gut can communicate directly with the brain, perhaps too impacting emotions and mood.

Given its importance to the gut, if the vagus nerve isn’t working properly, it will cause digestive disorders which then affects your ability to effectively digest food and extract nutrients. This then leads to added pressure on the immune system and potentially a leaky gut.

Leaky Gut

To put it succinctly, stress, anxiety and depression cause leaky gut. Based on the above points you can see how this might manifest, especially if you’re already eating a poor diet full of inflammatory and processed foods. This means that leaky gut develops when the space between the cell walls of your gut widen and start to allow substances like undigested food, bacteria and metabolic waste pass the wall into your body. We wrote a blog post to answer the question what should you eat to heal a leaky gut.

When your intestinal permeability is compromised, your immune system starts to attack the foreign bodies that make their way across the compromised cell walls. This  creates inflammation and the inflammatory cytokines that are produced in the gut travel through the blood to the brain. An inflamed brain has decreased activation which then manifests as stress, anxiety, depression and so on. it’s a vicious circle.

Five simple actions

If you could only do five things today to kick start your mental health:

  • Social support: Talking is regarded as one of the most effective ways to look after your mental health. 95% of Irish people agree that talking with a friend or family can be helpful to your health.
  • Get outside: being out in nature, breathing fresh air and getting away from the stresses of the day
  • Exercise to get those endorphins flowing!
  • Eat more vegetables
  • Sleep – cannot stress enough the importance of sleep. Here’s 6 tips to get a better night’s sleep.


This post has taken a brief look at the connection between food and mental health. It’s worth another mention, but this topic is very complex and effects people in different ways. We also know that health is impacted by much more than what you eat; it’s also influenced by how you live. 

Curious how you can support mental health with diet? Stay tuned, our next post will dive in.

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