It is widely accepted that the mood you are in can affect your dietary preferences and may trigger your IBS. But does the food we eat affect our mood? And what foods should you be eating? Monika Bettney, specialist gastroenterology dietitian and medical adviser to The IBS Network, explains.

The human brain operates at a very high metabolic rate, and uses as much as twenty percent of calories and nutrients that are consumed. Nutrients, such as complex carbohydrates, protein, omega three fatty acids, B vitamins, selenium and iron seem to play a key role in regulating our mood.

Any significant shortages of calories or nutrients do not go unnoticed and often lead to irritability, tiredness and depressive symptoms. Observational studies have shown that the rates of depression are lower among people who eat lots of wholegrains, beans and pulses, fruit and vegetables, nuts and seeds, and oily fish.

Here’s how you can incorporate these into your diet without running the risk of worsening your IBS.

Effect on mood if deficient Food sources
B vitamins Feeling irritable, low in mood and tired Fortified breakfast cereals1, animal protein foods, such as meat, fish, eggs and diary
Selenium Increases the risk of depression and negative mood states Meat, fish, seeds and brazil nuts
Iron Feeling weak and tired at all times Meat, fish and fortified breakfast cereals1
Essential amino acids Low mood Nuts2, dairy products, meat, fish and eggs
Omega 3 fatty acids Increases the risk of depression Oily fish, such as mackerel, kippers, trout, sardines, salmon and fresh tuna. Vegetarian sources include chia seeds, ground linseeds, walnuts and hemp seeds
Complex carbohydrates Headaches, poor concentration and irritability Rice, potatoes, oats, breakfast cereals, quinoa, 100% sourdough spelt bread3 and buckwheat

1.     Avoid wheat based cereals, if sensitive to fructans

2.     Avoid cashews and pistachios, if sensitive to fructans and/or galacto-oligosaccharides

3.     If not sensitive to fructans, can have wheat- based complex carbohydrates, such as regular bread and pasta

It is not only about the nutrients that we consume, but also how well we feed our gut bacteria. You have most likely heard the term ‘probiotics’, which are microorganisms that confer a health benefit to the host.

Probiotics that play a vital role in improving mental wellbeing specifically are called psychobiotics. There is growing scientific evidence that gut bacteria have a significant impact on mood and cognition.

Studies have shown that an increase in the amount of good bacteria in the gut can reduce stress hormone (cortisol) levels, reduce symptoms of depression and anxiety, and improve response to stress, as well as having a positive impact on memory.

A diet high in fibre, beans and pulses, and a variety of fruit and vegetables will help nourish your gut microbiome. Some people with IBS struggle to tolerate foods that are high in insoluble fibre. Also, beans and pulses, and fruit and vegetables contain fermentable carbohydrates, which are particularly beneficial for gut bacteria, but can trigger IBS symptoms.

Avoiding fibre and fermentable carbohydrates will help control symptoms short-term, but is likely to have a negative impact on health longer term, therefore, should be avoided. It is a tricky area to navigate and support from a specialist gastroenterology dietitian can be invaluable.

About Monika

Monika Bettney is a specialist gastroenterology dietitian and medical adviser to The IBS Network. She is a member of the British Dietetic Association and is registered with the Health and Care Professions Council (HCPC). With an extensive knowledge of the role of nutrition in disease, she advises clients in dietary modifications, while preventing nutritional deficiencies and ensuring a balanced diet. She has a BSc in Nutrition and a Master’s degree in Dietetics from the University of Nottingham.