Diet & Mental Health: You Are What You Eat

There is a fascinating relationship between diet and mental health. In this Huel Digest, we look at what recent research says about food and mood. 

For most people, food is a source of pleasure—whether you’re enjoying a crisp apple, a comforting stew, some fresh wholemeal bread or, let’s be honest, a big slice of chocolate cake. But beyond the short term joy of eating, what we consume can also have a longer term effect on how we feel. 

Around the world, researchers have been studying the links between food and mental health. Overall, there’s growing evidence that what we eat may influence how we feel. 

In this article, we’ll explore:

• Links between nutrition and mental health
• Is there a ‘mental health diet’?
• Suggestions for eating when you’re struggling

Different ways food and mental health are linked

In the last few years, there has been a growing number of studies into nutrition and psychological health. Researchers have looked at the relationship between food and mental health from a few different angles. There isn’t a single cause and effect relationship here - it’s a complex field and scientists are still learning a lot. But, we’ve summarised some of the most interesting insights. 

Getting help for mental health

Before we look into diet and mental health, a quick word on getting treatment for mental health conditions. While diet can play a role in mental health, treatment of mental health includes interdisciplinary treatments from health care professionals.

If you’re facing mental health struggles, book an appointment with your GP. Treatments such as talk therapy, medication, and other medical/holistic treatments may be recommended by your health care professionals. Certain psychiatric conditions, such as disordered eating, may require a specific kind of dietary guidance and interventions.

Nutrients and brain function

There have been numerous studies into the relationship between nutritional deficiencies and our brain health. 

This is basically about chemistry. Your brain needs certain ‘ingredients’ to be able to produce the chemicals it needs to function properly.

For example, you might have heard of serotonin. It’s a neurotransmitter (a chemical messenger in your brain) that makes us feel good. To produce serotonin, you need to consume food that contains vitamin B1, riboflavin, copper, calcium and an amino acid called tryptophan (among other things). If you don’t consume enough food with these vitamins and minerals, your brain and body may struggle to produce optimal levels of serotonin. Obviously, we’re simplifying a little here. 

Other vitamins and minerals that help your brain work optimally include:

• Vitamin B6
• Omega-3 fatty acids
• Zinc
• Vitamin D
• Folic acid (vitamin B9)
• Magnesium
• Choline
• Chromium
• Water

Read more: How food can affect your mood

The direct impact of things we eat or drink

Have you ever felt yourself crash a couple of hours after a meal? You might feel sluggish, moody, and generally a bit unpleasant. 

This sort of crash is common and is often related to sudden peaks and troughs in blood sugar levels. 

What’s interesting, is that there’s evidence that this could, over the long term, contribute to mental health problems. Some studies suggest that diets high in refined carbohydrates (like sugar or white bread) may be linked with an increase in depressive symptoms over time. 

One possible explanation is that, to compensate for rapid increases and decreases in blood sugar, your body releases ‘stress’ hormones like cortisol or adrenaline. In turn, these affect mood.

Excessive intake of refined carbohydrates aren’t the only culprits here. There’s also an association between excessive caffeine intake and anxiety attacks for those with anxiety disorders. Excessive alcohol consumption has also been associated with higher rates of depression and anxiety. 

Gut microbiome and mental health

Your ‘gut microbiome’ refers to the trillions of bacteria and other microorganisms living inside your large intestine. 

In recent years, scientists have been doing a lot of fascinating research into how these tiny creatures affect our health, including our mental states (our guts are sometimes referred to as our ‘second brain’). It’s important to note that this relationship isn’t fully understood, and much of the research so far has been done on animals. Nonetheless, there are some very interesting findings. 

One example is this study that found when people were given a daily tablet containing various ‘good bacteria’, their scores for anxiety and depression reduced over a 30 day period.

We’re still not exactly sure what the relationship is between our gut microbiome and our mental health, as there are a lot of factors at play. One possible explanation is that, if you have a very healthy intestinal flora, it prevents toxins from entering your bloodstream, meaning there’s less inflammation in your body and brain. 

Another link is through the vagus nerve, which connects your brain with your intestines. The microbiota in your gut secrete neurotransmitters like dopamine and serotonin and these may send positive signals to your brain, boosting mood.

Healthy diet and mental health

On a more general level, researchers have looked at the effects of certain types of diet on mental health. It doesn’t come as a huge surprise, but diets that are associated with good physical health also seem to be associated with good mental health. 

For example, in a 12-week study of people with major depression in Australia, about half the participants were given social support but continued with their typical Western diet. The rest were asked to follow a Mediterranean diet (that is, one high in whole grains, vegetables, fruit, fish and olive oil). By the end of the experiment, the group that had changed to the Mediterranean diet had significantly lower markers for depression.

The social element 

The link between food and mental health might not just be about what we eat. Research shows that when we eat with others, we are also more likely to feel connected and have lower markers for mental health disorders. Eating together reinforces our social networks, reduces loneliness and can make us feel generally better about ourselves.

Is there a ‘mental health diet’?

Food alone can’t prevent conditions like depression, anxiety, or bipolar disorder. There are a variety of factors, including genetics and traumatic events, that can contribute to the development and severity of mental health conditions. However, the following foods may help support mental health as part of a general strategy to support your mood. 

• Probiotics: These are foods that contain ‘good bacteria’ that can improve overall gut health. They’re available in supplement form as well as found in things like natural yoghurt, kefir, sauerkraut, kimchi, kombucha and beyond. 
• Prebiotics: These are forms of soluble fiber that support the good bacteria in our gut. They can be found in foods like bananas, onions, chicory root, artichoke, garlic and leeks.
• More fruit and veg: These are consistently linked with better health overall — including some evidence of benefits for mental well-being. They will help to ‘feed’ your microbiome, plus they also contain lots of vitamins and minerals.
• Whole grains and pulses: These foods are consistently linked with better overall health, including some evidence of benefits for mental well-being. How? They provide you with lots of vitamins, minerals and fiber to support both your gut and overall health.
• Fish, nuts or seeds: Oily fish (such as salmon or mackerel) contain lots of Omega-3 fatty acids, as do walnuts and things like flaxseed. 

At the same time, you might want to limit these  foods for mental health. 

• Some types of ultra-processed or refined foods like crisps, sweets, cakes, biscuits/cookies, sugary breakfast cereals, processed meats, and sugary drinks.
• Large quantities of red meat
• Alcohol
• Food containing trans fats

In small quantities, these foods are often perfectly fine. But if they make up a large part of your diet, they could have a negative effect on your mood.

Diet and mental health when you’re struggling

Everyone struggles with their mental health from time to time — it’s totally normal. If you’re struggling, you might not have any desire to cook a meal or eat at all. Alternatively, you might find yourself binge eating or reaching for convenience foods that are not very nutrient dense. 

Here are some ways you can navigate nourishing your body when struggling with mental health:

• Prepare healthy meals in advance: It’s not always easy to know when a mental health crisis might happen. But for days when you can’t face leaving the house or cooking a meal, your freezer is your friend. By preparing a few healthy meals and keeping them in the back of the freezer, you know you’ve got something you can blast in the microwave that’s easy and nutritious. 
• Keep eating: You might not always feel like eating, but having some healthy snacks in the store cupboard will help keep your blood levels steady and avoid mood-busting crashes. Nuts, dried fruit, and some cereal bars can all help.
• Simple one pot meals: It’s really handy to have a couple of one-pot meals up your sleeve for days when you’re down. They require less effort, and there’s also less cleaning up at the end. Simple bean chillies, veg soups or red lentil dals are super nutritious but won’t require loads of prep and tidying. 
• Healthy ready meals: You might also find it helpful to have a few healthy instant meals in your cupboard. Choose meals that are nutritious and contain all the minerals and vitamins your body needs. 
• Pre-prepared whole foods: We’d also recommend using pre-prepared whole foods when cooking on bad days. Things like tins of beans, frozen vegetables or jars of ready-chopped garlic/ginger/onions contain all the same nutrients, but cut down prep time. That can make cooking a healthy meal much easier. 

Suggested: What is ‘wellness’?

Take nutrition and mental health seriously

There is a lot of evidence that following a healthy, balanced diet can contribute significantly to improved mental health. While food certainly isn’t the only factor here, it does seem to play a part in people’s psychological state. 

The good news is that, by taking the time to learn about diet and mental health, you’re already taking a positive step toward supporting your overall well-being.