The Link Between Food and Mood
The Ancient Greek physician Hippocrates, widely considered to be the father of modern medicine, famously said, “let thy food be thy medicine and thy medicine be thy food.”
This statement is as true when it comes to mental health as physical health, and modern research has confirmed that there is a significant connection between what we put in our mouths and our state of mind.
This article explores the link between food and mood and the best diet for mental health.
The Link Between Food and Mood
The link between mood and food is multidirectional. Our diets affect our mental health directly, as well as indirectly, by affecting our physical health. Our mental and physical health can also affect our diets, creating something of a vicious cycle if we are not feeling great or eating well.
The good news is that we can alter our state of mind by improving our diets, and some of the changes we can make are really simple.
For example, the Mediterranean diet, which promotes a high intake of plant foods, lean protein, and healthy fats while reducing processed foods and red meat, is associated with a decreased risk of depression. Meanwhile, the typical Western diet, which is rich in refined grains and sugars, can increase the risk significantly.
Let’s take a look at some of the key dietary factors that influence mental health and why they are crucial in understanding the relationship between mood and food.
Gut Health and Mental Health
It may come as no surprise to hear that gut health plays a crucial role in mental health. After all, as much as 95% of our serotonin is produced in our guts!
The gut communicates with the brain via what is known as the gut-brain axis. This system relies on hormonal, humoral, nervous, immune, and metabolic signals to transmit information from body to mind. It impacts mood, cognition, and mental health and has been linked to depression, anxiety, and autism, as well as digestive disorders like IBS and IBD.
The gut is also home to trillions of microorganisms, collectively known as the gut microbiome. They play a role in immunity, digestion, and producing a range of neurochemicals, including serotonin, dopamine, and GABA.
The gut microbiome is also involved in regulating inflammation, a key factor in the development of depression (see below). Therefore, keeping our guts happy may help to keep us happy, too.
The best foods for gut health are whole foods, particularly fruit, vegetables, mushrooms, and whole grains. These foods are high in fibre, which acts as a prebiotic, i.e., fuel for the microbiome. It may also be beneficial to consume more probiotic foods, which contain live microorganisms, to help top up your resident community. These include fermented foods like:
Yoghurt
Kefir
Kombucha
Sauerkraut
Kimchi
Tempeh
Eating a wide variety of whole foods each week is key, as this will help increase the microbiome's diversity and benefit overall health. Meanwhile, avoid highly processed foods, refined sugar, and excessive amounts of alcohol.
Diet and Mental Health: Immunity and Inflammation
One of the key differences between the Mediterranean diet and the Western diet is that the former is anti-inflammatory, while the latter is pro-inflammatory. This is highly significant when it comes to mental health, as inflammation has been linked with depression as well as an increased risk of many other chronic health conditions.
Inflammation can occur due to an imbalance in the gut microbiome (dysbiosis) or eating a diet rich in refined carbohydrates, saturated fat, and processed foods. These foods stimulate an immune response and have been linked with mood disorders and overall cognitive decline.
To combat inflammation, we can increase our intake of plant foods, which are rich in anti-inflammatory phytonutrients, such as flavonoids and polyphenols. Healthy fats, such as those found in olive oil, nuts and seeds, and oily fish, are also highly beneficial. Meanwhile, we should reduce our consumption of red meat and other pro-inflammatory foods, as listed above.
Nutrition and Mental Health
There are also some specific nutrients to take into account when eating to improve mental health. Here are some of the most important groups to consider:
Carbohydrates
As mentioned above, refined carbohydrates contribute to inflammation, which can have a negative impact on mental and overall health. This includes foods like sugar, white flour, white bread, pasta, and so on.
Another downside of refined carbohydrates is that they cause blood sugar to rapidly increase and then drop again. These fluctuations can increase anxiety and irritability, as well as hunger. These effects are particularly pronounced with sweets, cakes, crisps, and cookies, which are full of carbs but have little to no nutritional value. Sugary drinks are another major culprit, and diet versions are no better, as artificial sweeteners have a similar effect on blood sugar to the real thing.
Unfortunately, when we feel down, we may have a tendency to reach for carbohydrate-rich comfort foods, and there is good reason for this. Carbohydrate consumption increases serotonin release and can give us a temporary mood boost. However, these effects are often short-lived and followed by a crash.
Rather than cutting out carbs completely, switch the refined foods listed above to complex carbohydrates that release their energy more slowly. Swapping white bread and pasta for wholemeal versions is a simple and affordable way to do this. Eating more whole grains and legumes will also help, as will consuming enough protein and fibre with meals to increase satisfaction and reduce the desire for unhealthy snacks.
Protein
Protein is a crucial component of any healthy diet. Not only does it help to keep the blood sugar stable, but it also forms the basis of our essential hormones, enzymes, and neurotransmitters.
Protein is made up of smaller molecules called amino acids, and there are two of these that are especially relevant to mental health.
Tryptophan is an amino acid that the body uses to produce serotonin. It is also the precursor to melatonin, a hormone that helps us sleep, which directly contributes to our overall mood. Some of the best sources of tryptophan are:
Oats
Bananas
Dried prunes
Peanuts
Chocolate
Dairy products
Tuna
Poultry
Tyrosine is another important amino acid for mental health. The body converts it to dopamine, which is involved in the reward system as well as memory and learning. It also acts as a precursor to norepinephrine and epinephrine, which are part of the sympathetic nervous system and increase alertness and attention. Tyrosine can be found in:
Soybeans
Legumes
Whole grains
Nuts
Dairy products
Eggs
Red meat
Pork
Chicken
Fish
Eating a variety of these foods on a regular basis can help to ensure an adequate intake of tryptophan and tyrosine, as well as the other amino acids. However, it is best to focus on plant-based sources and eat animal sources in moderation, as these will be more likely to increase inflammation.
Healthy Fats
Healthy fats are also essential as they play a vital role in neuronal cell membranes, regulating neurotransmission, and supporting the formation of new nerve cells. Diets like the Mediterranean diet tend to be very rich in these beneficial nutrients.
Omega-3 fatty acids are one of the best-known examples of healthy fats, and the balance between these and omega-6 fatty acids is thought to be particularly key for regulating inflammation and maintaining mental health.
The average Western diet tends to be very high in omega-6 fatty acids but somewhat lacking in omega-3. Some of the best sources of omega-3 fatty acids include:
Flax seeds
Hemp seeds
Walnuts
Oily fish (salmon, sardines, mackerel, etc.)
Consuming more of these foods, along with other healthy fats like olive oil and avocado, could help to improve mood and cognitive function. Meanwhile, we should reduce our consumption of saturated fat (mainly found in animal products) and trans fats (found in processed foods and commercial baked goods), which contribute to inflammation and increase the risk of disease.
Vitamins and Minerals
Several different vitamins and minerals are key for mental function and mood, as well as overall health. Some of the most important include:
B vitamins
These play an essential role in energy metabolism, nervous system function, and the production of neurotransmitters. They can be found in a range of foods, including:
Leafy greens
Legumes
Yoghurt
Eggs
Poultry
Seafood
Beef
Vitamin B12 is especially important as it is required for serotonin production. It is primarily found in animal-derived foods, so those following a plant-based diet may need to consider eating fortified foods or taking a supplement.
Vitamin C
This vitamin has antioxidant properties and plays a role in maintaining neuronal health and supporting cognitive functioning. It is found in most fruits and vegetables, but some of the best sources include:
Citrus fruit
Bell peppers
Strawberries
Broccoli
Eating a wide variety of fruits and vegetables every day can help to ensure adequate intake of vitamin C as well as other vitamins, minerals, and phytonutrients.
Vitamin D
This vitamin plays a role in neuronal growth and serotonin production. Low levels of vitamin D have been linked with memory loss and depression. The best source of vitamin D is sunlight on the skin. However, it can also be found in some foods, including:
Oily fish
Fortified dairy products
Egg yolks
Some mushrooms
Mushrooms produce vitamin D when exposed to sunlight, just like humans do. Therefore, it can be beneficial to slice up mushrooms and place them outdoors for 20 minutes or so before cooking.
Vitamin E
Another antioxidant vitamin that helps to keep brain cells healthy and protects them from oxidative damage. Some of the best sources include:
Plant oils
Nuts and seeds
Spinach
Red bell peppers
Pumpkin
Snacking on nuts and seeds is a great way to increase vitamin E intake while also boosting healthy fat consumption and keeping the blood sugar stable.
Magnesium
Magnesium affects the function of cell receptors in the brain, known as NMDA receptors. These receptors bind with the neurotransmitter glutamate and are involved in healthy brain development. It can be found in:
Nuts and seeds
Spinach
Due to their high magnesium content, these foods are great additions to a brain-healthy diet.
Zinc
Zinc is essential for cellular activities in the brain and plays a crucial role in immunity. Some of the best sources include:
Chickpeas
Cashews
Mushrooms
Spinach
Yoghurt
Lamb
Beef
We only need tiny amounts of zinc each day, but it is important to eat a variety of these foods regularly to maintain brain health.
Potassium
Potassium helps to slow down an overactive nervous system, and low levels of this mineral have been linked with anxiety and restlessness. Some of the best potassium-containing foods include:
Avocado
Pineapple
Tomatoes
Potatoes
Spinach
Melon
Ensuring an adequate potassium intake is another reason why eating a wide variety of fruits and vegetables is key to maintaining mental health.
Phytonutrients
Phytonutrients are beneficial plant nutrients, such as polyphenols, flavonoids, carotenoids, phytosterols, and so on. These plant-derived chemicals have a range of effects on the body, but generally speaking, they have antioxidant and anti-inflammatory properties.
One group of phytonutrients that might be particularly helpful when it comes to mood are the terpenes and terpenoids. These are aromatic compounds that are found in high quantities in herbs and spices.
Many of these chemicals help to regulate neurotransmission, and some also have neuroprotective properties. Therefore, it may be beneficial to switch out regular tea and coffee for herbal tea, particularly since caffeine is known to increase our levels of the stress hormone cortisol.
The Best and Worst Foods for Mental Health
After reading this article, it should be clear that the best foods for mood are whole foods, particularly fruit, vegetables, whole grains, lean protein, and healthy fats. Meanwhile, the worst foods for mental health are refined carbohydrates, unhealthy fats, and processed foods.
Following something close to the Mediterranean diet is a great way to improve overall health as well as mood. However, that is not to say that we should not allow ourselves occasional treats or become obsessive over our food.
And, of course, a good mood diet will be most effective when combined with effective stress management techniques and professional support when appropriate.