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The foods that we eat don’t just impact our physical health. Just like the body, the brain runs on fuel from our diets – and there’s a strong connection between the quality of that diet and the way that our brains function, particularly when it comes to mood.
Mental illness is incredibly common in the US, with one out of five adults living with a mental, behavioural, or emotional disorder such as depression, anxiety, bipolar disorder, or attention deficit disorder (ADD). And, while there are a variety of causal factors behind these disorders – including genetics and chemical imbalances – researchers have established that there is also a link between the high rate of mental health conditions in the US and a Western diet high in processed and refined foods.
You are what you eat
‘You are what you eat’ may be an overdone phrase, but science tells us that there’s actually quite a bit of validity behind the claim. In a systematic review of 12 epidemiological studies, researchers found plenty of evidence that indicates diet plays a vital role in regulating mental health. Looking at diet quality among children and adolescents, researchers observed ‘consistent trends’ between high-quality diets and better mental health outcomes, as well as evidence for the reverse.
Some of the key findings from the study include children with poor dietary habits had higher rates of depression and anxiety, as well as higher rates of behavioural conditions like ADD and hyperactivity. These results echo similar studies done in adults which found a link between Western diets and depression and anxiety in adult women, and others which suggest the inverse – that a Mediterranean diet high in lean protein, whole grains, and healthy fats decrease the risk of depression, as well as other neurological conditions such as stroke and Parkinson’s disease.
So, why do some foods lead to improved mental health outcomes and others to poor outcomes?
Food as fuel
When we talk about food fueling the brain, we’re not just referring to the basic nutrient requirements needed to keep the brain operating. Instead, it’s about providing the brain with the right type of fuel and avoiding sources that can cause damage.
The fuel that comes from a diet high in processed, sugary, and fried foods can lead to cognitive decline in a number of ways, primarily through increased inflammation and disruptions in cellular pathways. These types of neural impairments can lead to imbalances, including the types that cause mood disorders.
From the opposite perspective, diets high in premium fuel nourish and protect the essential features of the brain, in turn supporting better cognitive function and a reduction in the risk factors that can lead to depression, anxiety, and other mental illnesses.
Instead of looking at diet as the end-all-be-all when examining triggers for mental disorders, it helps to examine the role that food plays in relation to other risks. Diet alone might not be the sole cause of a mental health disorder, but maintaining a healthy diet is a critical part of protecting one’s ability to regulate mood. Likewise, an unhealthy diet sets the stage for the opposite effect and can be a key contributor to poor mental health.
Moods and foods
A well-balanced, mental health-driven diet is one that focuses on both variety and nutrition, with a limited intake of sugar, salt, and saturated fat. To take the guesswork out of achieving this balance, it helps to look at the major food groups and the role that each of them plays in providing the right type of brain fuel.
First up is vegetables and legumes, with a strong recommendation that you try to eat the rainbow whenever possible, meaning colourful veggies and lots of dark, leafy greens. Vegetables and legumes (think black beans, garbanzo beans, and soybean products) are rich in fibre, folate, potassium, and vitamin A, and high daily intakes are related to reduced levels of psychological distress and depressive symptoms.
Next is fruits, which share the benefits of veggies for better mental health. Notably, fruits are high in antioxidants and vitamins A, C, and E, all of which have an important job in regulating neural functions and combatting stress-induced psychiatric disorders like depression and anxiety.
Another key food group for optimal mental health is grains, specifically whole grains, rice, oats, and barley. In addition to providing the body with iron and vitamin B, healthy grains help control blood sugar levels and gut function, both of which can support equilibrium in the body and brain.
And then there’s protein, which is a major food group that encompasses meats, seafood, poultry, eggs, and plant-based items like nuts and seeds. Quality counts here since all protein sources are not created equally. The types of protein that have the most profoundly positive effect on mental health are lean proteins like fish, chicken, whole-fat yoghurt, and high-protein nuts and seeds, which help produce natural chemicals in the brain that improve mood. The benefits of nuts, in particular, are often cited since they offer a quick, healthy, and convenient protein source combined with brain-boosting omega-3s.
The final key food group is dairy, notably whole-fat dairy products like milk and cheese. Dairy has been linked to lower stress levels and is a natural source of feel-good vitamin D.
Eating a healthy diet means finding a balance between the five major food groups, getting in more of the good stuff and less of the stuff outside of these groups, such as sweets, fried foods, and empty calorie beverages like soda and fruit juice. Not only is this type of diet important for maintaining prime physical health, but it’s also instrumental in achieving better mental health.
Again, food alone isn’t necessarily the cause (or the cure) for mental health conditions. But diet is linked to mental health in a myriad of ways, making it all the more essential to make diet part of an action plan for dealing with or preventing a mental disorder. Life happens, and it’s often unpredictable, but eating right can go a long way towards mitigating the risks of mental distress and putting both body and brain in the right space to take on whatever happens.
Dennis Relojo-Howell is the founder of Psychreg.