IBS & Depression: What You Should Know

bloating constipation fodmap ibs mediterrranean diet

Are you someone who suffers from irritable bowel syndrome (IBS) and a mental health condition? You’re certainly not alone. There is a higher prevalence of mental health conditions among people with IBS. In fact, it’s estimated that the risk is 3 times higher, with roughly 50-90% of people who suffer from IBS also suffering from one or more mental health condition, commonly anxiety and depression [1,2].

While research is still emerging on the link between mental health and IBS, it appears to be related to the two-way communication between the gut and the brain, known as the brain-gut axis. While the exact cause of IBS is unknown, a miscommunication between the brain-gut axis is thought to play a role.

This may seem intuitive when you think about it! Symptoms of depression and anxiety can worsen symptoms of IBS and vice versa. Additionally, those who experience higher amounts of psychological distress have been found to experience more severe IBS symptoms [2]. Not to mention, many people with IBS report symptoms negatively impact their quality of life as it affects their ability to eat out, maintain relationships and travel [3].

The low FODMAP diet is one of the more well-known dietary therapies for managing IBS and it is highly effective. However, for those who also suffer from mental illness, it may not be feasible to undertake a restrictive diet and it could further negatively impact quality of life.

In this case, an alternative dietary approach may be a better option! Science is starting to investigate the Mediterranean Diet for IBS. It’s abundance of plant-based foods promote good gut bacteria; it has been shown to reduce IBS symptoms, AND is linked to improved mental health.

The Mediterranean Diet

The Mediterranean diet is a predominately plant-based diet that is inspired by the traditional eating habits of countries that border the Mediterranean Sea. Foods to include every day include vegetables, fruit, whole grains, extra virgin olive oil, legumes, beans, and plenty of herbs and spices. It also includes moderate amounts of fatty fish, poultry, eggs, dairy, and wine while limiting red meats and ultra-processed foods.

Mediterranean Diet and IBS

 There is some evidence to suggest that the Mediterranean Diet can help improve IBS symptoms.

  • May decrease abdominal pain and improve stool quality.

Recent research has found that those who suffer from predominantly diarrhoea experience a decrease in abdominal pain and stool frequency as well as improved stool quality when following the Mediterranean diet [4].

  • May be easier to follow.

Some studies have found that the diet is easier to follow than the low FODMAP diet but may still help avoid an excess of FODMAPs at any given meal. In a recent study, a balanced Mediterranean diet involved dividing intake into five meals. This resulted in smaller quantities of FODMAPS at each meal and helped to ease symptoms [5].

  • May be equally effective.

There is increasing research that suggests the Mediterranean diet may be equally effective as the low FODMAP diet in alleviating IBS symptoms without reducing quality of life [6].

Mediterranean Diet & Mental Health

Not only is there evidence that the Mediterranean diet may improve IBS symptoms, but it may also help to improve mental health!

The SMILES trial was a randomised control trial (in other words, a good one!) that investigated the effects of adopting a modified Mediterranean Diet among participants who suffer from depression. In this trial, it was found that depressive symptoms significantly reduced after only three months of following the diet [7]. Other studies have shown similar results [8].

One reason this may be the case, is that the Mediterranean Diet is rich in omega-3 fatty acids from foods like extra virgin olive oil, fatty fish, nuts, and seeds. Omega-3 fatty acids may have a protective effect against poor mental health [9].

It’s also rich in a type of polyphenol plant compound called flavonoids which are found in foods like extra virgin olive oil, berries, herbs, and red wine. Some studies have found an association between flavonoids and a reduced risk of depression [10].

The Bottom Line

Mental health illnesses are common among those who suffer from IBS. The Mediterranean Diet may be helpful in improving IBS symptoms as well as improving symptoms of mental illness and may be a suitable dietary approach for those suffering from both. If you would like help on your gut health journey, our friendly gut expert dietitians can help you with a personalised nutritional plan!


[1] Lydiard RB, Falsetti SA. Experience with anxiety and depression treatment studies: implications for designing irritable bowel syndrome clinical trials. Am J Med. 1999 Nov 8;107(5A):65S-73S. doi: 10.1016/s0002-9343(99)00082-0. PMID: 10588175.

[2] Zamani M, Alizadeh-Tabari S, Zamani V. Systematic review with meta-analysis: the prevalence of anxiety and depression in patients with irritable bowel syndrome. Aliment Pharmacol Ther. 2019;50(2):132-43.

[3] Hungin AP, Whorwell PJ, Tack J, Mearin F. The prevalence, patterns and impact of irritable bowel syndrome: an international survey of 40,000 subjects. Aliment Pharmacol Ther. 2003;17(5):643-50.

[4] Di Rosa, Claudia. The role of different dietary patterns on irritable bowel syndrome (IBS) symptoms. Università Campus Bio - Medico di Roma. 2023 Mar 20.

[5] Paduano D, Cingolani A, Tanda E, Usai P. Effect of Three Diets (Low-FODMAP, Gluten-free and Balanced) on Irritable Bowel Syndrome Symptoms and Health-Related Quality of Life. Nutrients. 2019 Jul 11;11(7):1566. doi: 10.3390/nu11071566. PMID: 31336747; PMCID: PMC6683324.

[6] Dale HF, Lorentzen SCS, Mellin-Olsen T, Valeur J. Diet-microbiota interaction in irritable bowel syndrome: looking beyond the low-FODMAP approach. Scand J Gastroenterol. 2023 Jun 29:1-12. doi: 10.1080/00365521.2023.2228955. Epub ahead of print. PMID: 37384386.

[7] Jacka FN, O'Neil A, Opie R, Itsiopoulos C, Cotton S, Mohebbi M, Castle D, Dash S, Mihalopoulos C, Chatterton ML, Brazionis L, Dean OM, Hodge AM, Berk M. A randomised controlled trial of dietary improvement for adults with major depression (the 'SMILES' trial). BMC Med. 2017 Jan 30;15(1):23. doi: 10.1186/s12916-017-0791-y. Erratum in: BMC Med. 2018 Dec 28;16(1):236. PMID: 28137247; PMCID: PMC5282719.

[8] Sánchez-Villegas A, Martínez-González MA, Estruch R, Salas-Salvadó J, Corella D, Covas MI, Arós F, Romaguera D, Gómez-Gracia E, Lapetra J, Pintó X, Martínez JA, Lamuela-Raventós RM, Ros E, Gea A, Wärnberg J, Serra-Majem L. Mediterranean dietary pattern and depression: the PREDIMED randomized trial. BMC Med. 2013 Sep 20;11:208. doi: 10.1186/1741-7015-11-208. PMID: 24229349; PMCID: PMC3848350.

[9] Dighriri IM, Alsubaie AM, Hakami FM, Hamithi DM, Alshekh MM, Khobrani FA, Dalak FE, Hakami AA, Alsueaadi EH, Alsaawi LS, Alshammari SF, Alqahtani AS, Alawi IA, Aljuaid AA, Tawhari MQ. Effects of Omega-3 Polyunsaturated Fatty Acids on Brain Functions: A Systematic Review. Cureus. 2022 Oct 9;14(10):e30091. doi: 10.7759/cureus.30091. PMID: 36381743; PMCID: PMC9641984.

[10] Ko YH, Kim SK, Lee SY, Jang CG. Flavonoids as therapeutic candidates for emotional disorders such as anxiety and depression. Arch Pharm Res. 2020 Nov;43(11):1128-1143. doi: 10.1007/s12272-020-01292-5. Epub 2020 Nov 22. PMID: 33225387.

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