Diet and mood regulation.

What are the key mechanisms that possibly link diet and mood?

There are a few key mechanisms that link diet and mood, including gut-Brain Axis, inflammation, blood sugar regulation and hormones and nutrient availability.

In the past decade the gut-brain axis has become a central focus of studies and research.These studies found out that, a large proportion of body neurotransmitters (chemical messengers carrying signals across the gaps between nerve cells), such as serotonin, dopamine and norepinephrine are produced in our gastrointestinal tract. These neurotransmitters play a very important role in mood regulation and dietary precursors directly impact their synthesis.

For example a precursor for serotonin, known as happy hormone, is tryptophan, an amino acid that can be found in protein-rich food, so a diet that is deficient in protein and hence tryptophan can have a negative impact on the production of serotonin and contributing on depressive symptoms.

Another example is Omega-3 fatty acids that can be found in oily fish and nuts that can mitigate symptoms of depression and anxiety by modulating dopamine and serotonin pathways via anti-inflammatory and neuroprotective influences, the same as polyphenols particularly flavonoids and resveratrol that can be found in plant-based foods.

A diet pattern based on high consumption of highly processed food, refined carbohydrates and saturated and trans fats, that is usually referred to as the Western diet, can intensify symptoms of depression and anxiety by promoting inflammation and oxidative stress (in simple language cellular rust caused by harmful oxygen molecules). On the contrary, a diet rich in minimally processed food, fruits, nuts, colorful vegetables, healthy fats, whole grains and high-quality lean protein (animal and plant based), known as the Mediterranean diet is the best example for an anti-inflammatory eating pattern. So, following a Mediterranean dietary pattern is strongly linked with better mental health outcomes and western diet and eating habits have been increasingly associated with anxiety, mood irregulating and depression.

The results of the studies on the positive impacts of following an anti-inflammatory diet demonstrates that following a mediterranean diet is associated with a reduced risk of mental health disorders. Having said that, looking at the impact of food and diet on mood and anxiety holistically, demonstrate that a temporary psychological state of mind can affect eating patterns and food choices such as comfort food, emotional eating or the influence of stress on appetite, especially with people with existing mental illnesses or financial and environmental limitations.

Glycemic swings can also have an impact on counter-regulating stress hormones such as cortisol and adrenaline, these are the hormones that can trigger anxiety, irritability and agitation. If a diet contains a high amount of refined carbohydrates and sugar not only can increase risks of obesity and diabetes and other metabolic health risks but this blood sugar ups and downs may be associated with mental health deterioration and mood. Having high blood glucose constantly results in higher insulin demands and this could lower plasma glucose concentration which promotes secretion of hormones such as cortisol, adrenaline, growth hormones and glucagon which can cause anxiety, irritability and appetite irregularities.

Furthermore, it is important to note, there are studies that show hypoglycemia, meaning very low blood sugar, also can have a negative impact on mood and mental disorders as well.

The brain is the organ that uses most energy in the human body relative to its size, about 20% of the body’s total energy, while it accounts for only 2% of the total body mass. This makes brain function very sensitive to the nutritional status and the availability of micronutrients. Macronutrients; fat, carbohydrates and protein provide the energy required for the brain function and micronutrients; vitamins and minerals in small amounts are required to act as important regulators of brain health and internal balance.The most important micronutrients for the brain are Iron, magnesium, and vitamins B, E, D and K. Even though there have been vast improvements globally in terms of food availability throughout the decade, micronutrient deficiencies are still a common issue among low and middle-income countries.

Choosing a diet that contains a variety of whole grains, cereals, fresh fruit and vegetables that is rich in micronutrients can be a great start to address potential micronutrient deficiencies and if there is still a gap in the nutrients due to dietary habits and choices, bio availability and health issues, supplementation can be beneficial. This supplementation must be targeted, individualised and personalised, based on known deficiencies as everyone responds to diet, nutrition and exercise differently.

Every individual has their own genes, gut microbiomes, level of inflammation, body composition and daily habits that shape their responses to nutrition and physical activity.