For many migraineurs, the phrase “you are what you eat” rings true when it comes to the onset of the dreaded head throb. It’s generally accepted that migraines can be triggered by dietary ingredients most of which are found in everyday foods. However not all dietary triggers affect everyone and finding out which triggers are unique to you often involves an attentive process of elimination.

The following blog post will discuss what exactly a dietary trigger is, the main chemical culprits that are thought to trigger migraine and how an elimination diet can be used to identify food triggers and thus aid in the reduction of migraine.

What is a dietary trigger?

Not to be confused with a food allergy, dietary triggers do not involve the immune system. Instead, dietary triggers cause reactions by irritating nerve endings in different parts of the body (1). Furthermore, it’s thought that food chemicals can produce reactions via mast cell activation which has been shown to increase intestinal permeability and pain perception (5), factors which may be implicated in migraine.

The degree to which an individual reacts to dietary triggers depends on factors such as the types of symptoms they are prone to, the particular chemicals they are sensitive to and their threshold for reacting. Dietary triggers can affect one or more systems (e.g. skin, airways, gastro intestinal, nervous system) and appear to have a genetic component, usually affecting the same system across generations (1).

How do food triggers impact migraine?

Headache has been a commonly reported symptom of salicylate, amine and glutamate consumption (2,3). When it comes to migraine attacks, it’s helpful to think of their relation to dietary triggers in terms of the “bucket theory”, rather than isolated events.

The bucket theory

Imagine you have a bucket. When it’s empty, you don’t exhibit any migraine symptoms, you are feeling at your very best. Now, add drops of water to the bucket. Think of the water as a dietary trigger. Some drops may be the size of a tablespoon (a small amount of a chemical rich food) whereas other drops could be the size of a cup (larger quantities of chemical rich foods). Drop after drop, the water is raised. The higher the water level, the closer you are to a migraine attack. And when the bucket finally overflows, bam! Migraine!

Food intolerance and food sensitivity reactions are dose dependent, so eating a lot of a food you are intolerant /sensitive to might fill up your bucket straight away, whereas eating smaller amounts of triggering foods over many days may not be enough to produce a migraine, but instead accumulate in your body until your dose threshold is finally exceeded and a migraine ensues.

The bucket analogy helps to explain why certain foods can trigger migraine one week but not the next. It also highlights that migraine prevention is not about cutting foods completely from your diet. Instead it’s about being aware of your threshold and recognising which dietary triggers are more likely to overflow your bucket.

Threshold

It’s also important to understand that everyone’s migraine threshold is different. Some people have a lower threshold and are very vulnerable to migraine attacks. Even small variations in their environment and/or diet can push them over the limit. Other people have high thresholds and can withstand high amounts of stimulation before having a migraine attack. Thresholds are also dynamic, changing day-to-day due to a myriad of factors. Taking care of your health through strategies such as good sleep, exercise and stress management can help raise your threshold, protecting against the onset of migraine.

What are the common food chemicals that trigger migraine attacks?

Common food chemicals listed as migraine triggers include the following (4):

Salicylates: a chemical made by plants. They act as the plant’s immune system, reducing the risk of pathogens invading. Salicylates are found in most fruits and vegetables, as well as herbs, spices, most nuts and seeds, honey, tea and coffee. The amount of salicylate varies according to the type of food and can also be found in non-food items such as mint toothpaste, cleaning products and fragrances (a possible reason why lots of migraneurs are triggered by strong perfumes).

Amines: include histamine, tyramine, dopamine and phenylalanine. Commonly found in chocolates, aged or overcooked meat, fruits and vegetables, yogurt, many aged cheeses, and wines. Because amine formation comes about due to the natural breakdown of protein over time, aged or ripened rather than fresh foods are generally higher in amines.

Glutamates: an amino acid which can be a trigger for some sensitive people when it isn’t bound up in protein but is instead in its free form. This chemical is used to enhance flavour so it is commonly found in foods such as sauces, stocks, cheeses and many savoury snack foods (think flavoured chips and rice crackers).

It’s important to note that due to the lack of well-designed placebo controlled studies, evidence-based advice for removing amines, glutamates and salicylates from the diet to improve migraine symptoms is limited. That being said, efficacy has been observed where certain migraine-triggering foods have been eliminated (6). Thus, until the underlying mechanisms of how dietary triggers influence migraine are further explored, a limited removal of ‘high risk’ foods in adults might be a good first step to determine whether diet plays a role in their migraine onset.

What is the elimination diet?

There are a variety of tests, often with a hefty price tag, that claim to show which foods an individual is intolerant/sensitive to. One such example is the IgG antibody test which isn’t supported by the scientific community due to its inability to identify which foods are causing your symptoms – just what foods you have eaten recently.

The elimination diet, however, is a useful diagnostic tool used by health care professions and is the first step in investigating food chemical sensitivity. The diet, developed by the Royal Prince Alfred Hospital (RPAH) involves cutting down on a range of food chemicals that are known to cause symptoms in some people. Due to its restrictive nature, the elimination diet should only be applied short term so as not to starve the body of essential nutrients.

After being on the elimination diet for at least 3-6 weeks and once migraine symptoms have settled for at least 5 days in a row, the next step is introduced, which involves identifying which particular food chemicals are tolerated by the individual, and which ones are not. This food challenge process involves testing each food chemical one by one, usually done by eating foods that provide a high dose of each particular chemical. If no migraine symptoms are experienced during the period where the food chemical is introduced, it’s assumed that foods containing that chemical are safe to eat. However if migraine symptoms are experienced, then a food trigger is considered to have been successfully identified and it’s now a matter of discovering what an individual’s threshold is for that chemical.

Elimination diet resource

The RPAH Elimination Diet Handbook is an excellent resource for conducting the elimination diet which outlines which foods you can and can’t eat during the elimination phase as well as which foods are low, medium and high in particular chemicals for the reintroduction phase. The resource also includes a handy elimination diet shopping list and recipe guide.

Please note

It’s very important to consult a dietitian or doctor before conducting an elimination diet as cutting out too many food groups may cause not only a nutritional deficiency, but stress and poor quality of life which can lead to negative health outcomes.

Conclusion

For those who suffer from migraine, substances often hailed as superfoods can act like a poison, triggering attacks seemingly out of the blue. Dietary triggers are highly individual and the only way to truly find out what sets off your migraine is through an elimination diet. An antidote to suffering, food can be thought of not solely as fuel, but information as well, leading to a pain-free life one bite at a time.

Brigid xx

References

(1) Swain, A., Soutter, V, & Loblay, R. (2011). RPAH Elimination Diet Handbook with food and shopping guide. Australia: Allergy Unit, Royal Prince Alfred Hospital.

(2) Gray, D. “Food and Drug Administration Memorandum, glutamate in food.” Fed Regist 61.178 (1996): 48102-48110.

(3) Wantke F, Götz M, Jarisch R. Histamine-free diet: treatment of choice for histamine-induced food intolerance and supporting treatment for chronic headaches. Clin Exp Allergy. 1993 Dec;23(12):982-5. doi: 10.1111/j.1365-2222.1993.tb00287.x. PMID: 10779289.

(4) Skypala, Isabel J et al. “Sensitivity to food additives, vaso-active amines and salicylates: a review of the evidence.” Clinical and translational allergy vol. 5 34. 13 Oct. 2015, doi:10.1186/s13601-015-0078-3

(5) Lee, Hyuk et al. “Mucosal mast cell count is associated with intestinal permeability in patients with diarrhea predominant irritable bowel syndrome.” Journal of neurogastroenterology and motility vol. 19,2 (2013): 244-50. doi:10.5056/jnm.2013.19.2.244

(6) Özön, Akçay Övünç et al. “Efficacy of Diet Restriction on Migraines.” Noro psikiyatri arsivi vol. 55,3 233-237. 20 Sep. 2016, doi:10.5152/npa.2016.15961