Unfortunately for many people, migraine (a neurological condition causing head pain) and IBS (a gastrointestinal disorder affecting the functioning of the bowel) go hand in hand. Fortunately, research has shown that a diet low in short-chain carbohydrates collectively known as FODMAPs, can reduce IBS symptoms. What’s not known, however, is whether FODMAPs can also alleviate migraine symptoms, a topic which will be explored below.

What are Migraines?

Migraine is a neurological condition affecting 14% of the population and characterised by throbbing pain in one particular area of the head. Migraine is frequently experienced alongside gastrointestinal symptoms such as diarrhoea, constipation and nausea, symptoms also common in IBS.

What is IBS?

Irritable bowel syndrome (IBS) is a chronic disorder affecting 1 in 7 people around the world. The gastrointestinal condition is characterised by recurring symptoms including lower abdominal pain, constipation, diarrhoea, bloating and gas, where no abnormal pathology has been observed.

What are FODMAPs?

FODMAPs (Fermentable Oligosaccharides Disaccharisdes Monosaccharides and Polyols), are a group of short-chain carbohydrates (sugars) that gut microbes consume for energy. Passing through the digestive system, FODMAPs aren’t completely absorbed in the gut, instead making their way slowly through the small intestine where they attract water and then onto the large intestine where gut bacteria ferment the undigested carbohydrates, producing gas as a byproduct.

What is the Role of FODMAPs in IBS?

Though most people can consume FODMAPs without a problem, some people respond poorly. How much a person suffers from IBS depends on the degree of malabsorption of FODMAPS experienced by the individual (6). There are two main mechanisms responsible for triggering symptoms in patients with IBS by FODMAPs:

1.) FODMAPs aren’t absorbed well in the intestine. This attracts water, increasing fluid levels, which may distend the small intestine and lead to abdominal symptoms (6). One study has shown that patients with IBS have an abnormal buildup of fluid in the small intestine following consumption of a FODMAP called lactulose. They also exhibited more undesirable symptoms, such as diarrhoea, than the healthy controls (7).

2.) Gut bacteria rapidly ferment FODMAPs. The result is gas production which can lead to pain and bloating due to a distended colon (6).

Given the latter of these two mechanisms, it’s not surprising that one study found both healthy and IBS subjects experienced a reduction in the amount of gas produced by gut microbes when they consume a low FODMAP diet (8). Overall, 52-86% of patients report significant improvement of their IBS symptoms with elimination of dietary FODMAPs (5), highlighting the impact diet can have on health conditions linked to the gut microbiome.

What is the Link Between IBS and Migraine?

As if migraines weren’t bad enough, many patients who present with migraine headaches also suffer from GI conditions such as IBS more frequently than healthy controls and vice versa (1).

Although the exact processes that link IBS with migraine remains unclear, the complex interplay between the brain and the gut may explain their associations (2). Gut microbes have been implicated in the pathophysiology of migraine and IBS (3), through mechanisms that include intestinal permeability, hormones, immune molecules and bacteria metabolites.

Diet plays an important role in the functioning of the gut microbiome, with its implication for health being well documented (7). Given the effectiveness of a low FODMAP diet in alleviating symptoms of IBS, as well the link between the GI condition and migraine, one might speculate whether a low FODMAP diet can also result in alleviating migraine severity.

FODMAP Diet and Migraine

One of the most challenging aspects of migraine, aside from the pain itself, is identifying what triggers it in the first place. While the cause of migraine has long eluded doctors and scientists, various triggers have been identified such as food intolerance and allergy, both of which have also been shown to trigger IBS relapse (1).

For those suffering from migraines, reducing permeability of the intestine, through lifestyle changes such as diet and maintaining a diverse microbial population, may be key to alleviating the prevalence of the condition. One recent study (9) in mice found that a 4-week low FODMAP diet could normalise permeability in rodents subject to high levels of stress – a factor linked to increased gut permeability. Whether these results can be extrapolated to the gut permeability of humans is not known, but it’s an interesting finding that might help understand whether the low FODMAP diet can improve migraine.

One thing to note is that FODMAPs aren’t in and of themselves bad, in fact, they actually encourage growth of good bacteria in the gut. Low FODMAP diets have the potential to cause a reduction in “good” bacteria and increase bacteria associated with dysbiosis. An imbalance in the gut microbiome has the potential to affect the health of the gut lining; the deterioration of which has already been linked to migraine (10).

Many of the high FODMAPs are also high in certain chemicals known to trigger migraines such as salicylates. If you see a reduction in migraines on a FODMAP diet there is a chance it could be to do with a chemical sensitivity rather than a FODMAP issue, hence the importance of consulting with a dietitian to better understand your specific health issue.

Whilst a one size fits all diet approach is appealing, it’s important to note that just like fingerprints, each microbiome is unique. A specific diet that works for one person, may not work for another, hence the need for a tailored approach when it comes to using diets as a treatment for health conditions.

Conclusion

Research into the area of FODMAPs and migraine is limited at present, and while studies have shown the ability for low FODMAP diets to improve IBS, a condition known to be linked to migraine, it still remains unclear as to whether this dietary approach could be useful in migraine status also. That being said, if you are currently trying to determine your own migraine triggers and you also suffer from gut issues, a low FODMAP diet may be something you wish to discuss with your GP or dietician.

Brigid xx

References

(1) Arzani, M., Jahromi, S.R., Ghorbani, Z. et al. Gut-brain Axis and migraine headache: a comprehensive review. J Headache Pain 21, 15 (2020). https://doi.org/10.1186/s10194-020-1078-9

(2) Dai, Yu-Jie. “Potential Beneficial Effects of Probiotics on Human Migraine Headache: A Literature Review.” Pain Physician, vol. 20, no. 2150-1149, 2017, pp. 251-255, https://www.painphysicianjournal.com/current/pdf?article=NDExNA%3D%3D&journal=102.

(3) Doulberis, Michael et al. “Is there an Association between Migraine and Gastrointestinal Disorders?.” Journal of clinical neurology (Seoul, Korea) vol. 13,3 (2017): 215-226. doi:10.3988/jcn.2017.13.3.215

(4) Singh, Rasnik K et al. “Influence of diet on the gut microbiome and implications for human health.” Journal of translational medicine vol. 15,1 73. 8 Apr. 2017, doi:10.1186/s12967-017-1175-y

(5) Liu J, Chey WD, Haller E, Eswaran S. Low-FODMAP Diet for Irritable Bowel Syndrome: What We Know and What We Have Yet to Learn. Annu Rev Med. 2020 Jan 27;71:303-314. doi: 10.1146/annurev-med-050218-013625. PMID: 31986083.

(6) Nanayakkara, Wathsala S et al. “Efficacy of the low FODMAP diet for treating irritable bowel syndrome: the evidence to date.” Clinical and experimental gastroenterology vol. 9 131-42. 17 Jun. 2016, doi:10.2147/CEG.S86798

(7) Abnormal accumulation of intestinal fluid following ingestion of an unabsorbable carbohydrate in patients with irritable bowel syndrome: an MRI study. Undseth R, Berstad A, Kløw NE, Arnljot K, Moi KS, Valeur J Neurogastroenterol Motil. 2014 Dec; 26(12):1686-93.

(8) Manipulation of dietary short chain carbohydrates alters the pattern of gas production and genesis of symptoms in irritable bowel syndrome. Ong DK, Mitchell SB, Barrett JS, Shepherd SJ, Irving PM, Biesiekierski JR, Smith S, Gibson PR, Muir JG J Gastroenterol Hepatol. 2010 Aug; 25(8):1366-73.

(9) Zhou SY, Gillilland M, 3rd, Wu X, Leelasinjaroen P, Zhang G, Zhou H, et al. FODMAP diet modulates visceral nociception by lipopolysaccharide-mediated intestinal inflammation and barrier dysfunction. The Journal of clinical investigation. 2018;128(1):267-80.

(10) Tang Y, Liu S, Shu H, Yanagisawa L, Tao F. Gut Microbiota Dysbiosis Enhances Migraine-Like Pain Via TNFα Upregulation. Mol Neurobiol. 2020 Jan;57(1):461-468. doi: 10.1007/s12035-019-01721-7. Epub 2019 Aug 4. PMID: 31378003; PMCID: PMC6980505.