The human gut (gastrointestinal tract) can be viewed as the petrol tank of the body, supplying the body with fuel (nutrients and energy). Like the rest of the body, your brain is always switched on and needs a constant supply of fuel, which comes from the food we eat. The brain functions best on premium fuel, derived from food that contains lots of healthy fats, high-quality vitamins, minerals and antioxidants. It stands to reason that the quality of the fuel affects the functioning of the brain, including your mood.
Nutritional psychiatry:
Modern healthcare practice has seen a tendency to evolve towards integrative health, with a more holistic, patient centered approach to wellness. This means treating the patient as a whole person, and not just as a constellation of symptoms. Part of this approach is the realization that diet is just as important to psychiatry as it is to cardiology, endocrinology and gastroenterology.
For many years the medical profession did not fully consider the connection between diet and mood. It is only in recent times that the need for a scientifically-based understanding of how nutrients affect mood and behavior has led to the development of a branch of psychiatry called Nutritional Psychiatry. The influence of diet (in the context of nutritional needs and deficiencies) on mood and behavior have an important impact on the diagnosis and treatment of mental health disorders.
How food influence mood:
The gut communicates with the brain along different pathways that include neuronal activation, the release of hormones and immune signals. Scientists refer to this close interaction between the gut and the brain as the gut-brain axis.
Like a high performance car, the brain needs premium fuel to operate at optimum levels. Poor quality fuel has an adverse effect on performance and in the case of the brain, damage can occur when substances from sub-standard fuel are ingested. Diets rich in highly processed and refined foods, such as refined sugars for example, can be harmful to the brain. Refined sugars are not only detrimental to the body’s regulation of insulin, but also promote inflammation and oxidative stress (the free radicals that are produced when the body uses oxygen and which can damage cells). The brain has a limited ability to get rid of free radicals or damaging inflammatory cells. Various studies have found a correlation between a high intake of refined sugars and the worsening of symptoms of mood disorders, such as depression.
The type of diet you eat not only influences how you ultimately feel and behave, but also the kind of bacteria that live in your gut. These bacteria protect the lining of the intestines and provide a strong barrier against toxins and harmful bacteria. Beneficial bacteria limit inflammation and assist with the absorption of nutrients from the diet. These bacteria also play a role in activating the neural pathways that travel between the gut and the brain.
At least 90% of the body’s serotonin is produced in the gastrointestinal tract, which is lined with millions of nerve cells (neurons). Serotonin is a neurotransmitter that assists the body with the regulating of moods, sleep and appetite, as well as inhibiting pain. The processes taking place in the digestive system not only assist with the digestion and absorption of food, but also guides your emotions.
Studies have shown that following a healthy, balanced diet such as the Mediterranean Diet would have a 25% – 35% lower risk of depression. The Mediterranean Diet avoids processed and refined foods, and is high in vegetables, fruits, unprocessed grains, fish and other seafood, with limited consumption of red meat and dairy products. Some of these unprocessed foods are fermented and acts as natural probiotics, such as yogurt, kefir, sauerkraut and pickles.
A better diet can assist with mild mood disorders, but keep in mind that it is only one part of the treatment by psychiatrists and you cannot eat your way out of feeling severely depressed or anxious.
Good mood foods:
- Avoid packaged or processed food. They are high in additives and preservatives that impact on the healthy bacteria in the gut.
- Avoid all foods and drinks with added sugar.
- Eat fresh fruit and vegetables and remember not to add sugar (or too much salt) to improve the taste. Over time your taste buds will get used to eating less sugar and salt.
- Add whole grains and legumes to your diet.
- Fermented foods such as unsweetened kefir or yogurt, sauerkraut, and kimchi are beneficial to a healthy gut.
- Eat less red meat and more lean poultry and seafood.
- The different colours in fresh fruit and vegetables contain different nutrients, vitamins and anti-oxidants, so add variety to your diet.
Sources:
Nutritional psychiatry: Your brain on food. Harvard Health Blog, published online 16 November 2015. Harvard Medical School. (www.health.harvard.edu)
Gut feelings: How food affects your mood. Harvard Health Blog, published 7 December 2018. Harvard Medical School. (www.health.harvard.edu)
Current insights and challenges when studying the human gut microbiome. Published 13 December 2018 in Newsletter # 40. Gut Microbiota Research & Practice. (www.gutmicrobiotaforhealth.com)
Everything you always wanted to know about the gut microbiota. Published online. Gut Microbiota Research & Practice. (www.gutmicrobiotaforhealth.com)
How to get more probiotics. Published online 8 December 2018. Harvard Medical School. (www.health.harvard.edu)
HEALTH INSIGHT
March 2018
