Why Do I Get Headaches After Eating?

Headaches after eating, or, ‘’postprandial headaches’’, can be triggered by what you eat, when you eat, and even how you eat. 

Read on to find out the reasons for your post-meal headache, tips and tricks for headache and migraine relief, when to see a doctor and when to call 999. 

Overview

All of us, at least at one point in our lives, have experienced a headache:¹ a nagging, throbbing, sharp pain in our head, neck or face. According to the Cleveland Clinic,¹ there are over 150 types of headache disorders that are categorised either as primary or secondary headaches. 

Primary headaches are often triggered by lifestyle factors such as certain foods. Unlike secondary headaches, they are not usually a sign or symptom of an underlying medical condition. This article will focus primarily on primary headaches.

Primary headache disorders include migraine headaches,² cluster headaches³ and tension headaches.⁴  Both migraine headaches and cluster headaches occur in one side of the head, however cluster headaches are more severe and frequent. 

Cluster headaches ‘’come in clusters’’, occurring up to eight times a day for weeks to months before going away (remission) for months to years. 

Migraine headaches, on the other hand, can last up to 4 hours to days and cause sensitivity to lights, sounds and smells.

Less severe and more common are tension headaches which are associated with a mild to moderate ‘’tight band’’ pain feeling around the head, face or neck. 

Possible causes of headaches after eating

1. Postprandial hypoglycemia: Hypoglycemia, or low blood sugar,⁵ arises when blood glucose levels drop below 70 mg/dl. It is important to note that, as highlighted by the Migraine Trust,⁶ hypoglycemia does not cause migraines per se, but rather triggers these attacks and makes one more prone to developing migraines  

Hypoglycemia has many culprits including:⁵ 

• Skipping meals, not eating frequently, dieting, fasting or exercising on an empty stomach

• Eating high-sugary foods: This type of hypoglycemia is specifically referred to as ‘’reactive hypoglycemia’’. Blood sugar levels are normally stabilised by one main hormone: insulin. Working similarly to a key (insulin) in a lock (cell), insulin effectively works to lower high blood glucose levels (hyperglycaemia) by ‘’unlocking’’ cells, thus allowing glucose to move from the bloodstream and into the cell, where it functions to release energy. 

When too much sugar is consumed, high concentrations of insulin are released to move the excess glucose into the cell. This in turn causes a sudden and rapid drop in blood sugar levels which can trigger migraine attacks, as reported by a 2019 study.⁷

• Diabetes
• Chronic liver and kidney diseases
• Anorexia nervosa

2. Consumption of a headache or migraine trigger food: According to the American Migraine Foundation,⁸ the following food triggers may exacerbate migraine symptoms and trigger migraine attacks in migraine sufferers: 

• Alcohol: In particular, red wine has been demonstrated to be one of the most common triggers for a migraine attack, triggering headaches and migraines in as many as 33% of susceptible individuals

• Chocolate: A food trigger affecting over 22% of headache and migraine sufferers, chocolate is rich in the amino acid beta-phenylethylamine which is thought to induce migraines by decreasing cerebral blood flow⁹

• Caffeine: Caffeine¹⁰ has a vasoconstrictive effect as it functions to narrow blood vessels, thus decreasing blood flow around the brain. This is also a good thing as it helps relieve pain

However, when coffee consumption is reduced or stopped abruptly, the blood vessels expand in size, causing blood flow to increase around the brain. This action exerts pressure on the head, leading to the development of migraine headaches and tension headaches in 19.9% of susceptible individuals, as reported by one recent study¹¹

• Aged cheeses, yogurt and beans: All three foods (and others) are rich in tyramine, an amino acid derived from another amino acid called tyrosine.¹²

Tyramine is broken down in the body by the enzyme monoamine oxidase.  Interestingly, as demonstrated by the National Headache Foundation,¹³ this enzyme is ineffective in migraine sufferers, causing tyramine levels to be elevated, in turn leading to high blood pressure and eventually, migraine attacks

• Processed meats: Examples include ham, bacon, salami and sausages, all of which may trigger migraines in migraine sufferers due to their high level of nitrates

• Soy sauce, Chinese foods and soups: These foods are rich in the food additive monosodium glutamate (MSG) which can act both as a headache trigger¹⁴ and/or migraine trigger⁸ in susceptible individuals

3. Food intolerances: 

One of the most common food intolerances is gluten, a protein found in a variety of foods that contain wheat, barley or rye including: pasta, bread, cakes and biscuits (amongst others). When gluten is consumed by people with coeliac disease,⁶ it is ‘’mistaken’’ for a harmful pathogen and therefore causes the immune system to attack and damage the small intestine. 

People with gluten sensitivity also react badly to gluten but their small intestine remains intact and the symptoms and complications they experience are not as severe. 

Gluten sensitivity can cause headaches, but the Migraine Trust⁶ concludes that there is no scientific evidence demonstrating a link between either coeliac disease or gluten sensitivity and migraines. However, people with coeliac disease who suffer from migraines may find some relief from both conditions by consuming a gluten-free diet.

4. Temporomandibular joint disorder (TMD): The temporomandibular joint¹⁵ (TMJ) links the lower jawbone to the skull and is found on both sides of the face. It is dysfunctional in people with TMD, resulting in popping and clicking of the jaw, chewing difficulties and jaw pain, all of which may trigger headaches after eating
5. Cold stimulus: Eating or drinking cold foods can give rise to headaches at the front of the head known as ‘’brain freeze’’, ‘’ice cream headache’’¹⁶ or ‘’cold stimulus headache’’. Although painful, these types of headaches are not serious and only last for a few seconds to minutes

Management and treatment for headaches after eating: ¹

• Keep a headache food diary  
• Practice deep breathing and muscle relaxation techniques
• Take over-the-counter (OTC) pain medication
• Exercise
• Apply a cold compress to the head and/or neck
• Rest in a dark, quiet room

How can I prevent headaches after eating?^6,14

• Engage in a healthy eating pattern (eat often and eat well)
• Do not quit coffee cold turkey, but slowly and gradually
• Drink plenty of water

When should I call a doctor?

• Consult your general practitioner (GP) or healthcare provider if:¹ 
  • You suffer from head pain, chronic headaches  or severe headaches that occur once or twice a week and interfere with your daily activities
  • Need to take OTC pain relievers (almost) every day or require two to three doses per week

• Seek immediate medical care if your headaches cause neurological symptoms such as:¹
  • Weakness
  • Dizziness
  • Breathlessness
  • Blurry vision
  • Numbness or tingling
  • Paralysis

Summary

Headaches after eating can occur due to postprandial hypoglycemia, jaw issues (e.g. TMD), brain freeze, food intolerances (e.g. gluten in those with coeliac disease and gluten sensitivity) and the consumption of certain foods with headache-triggering additives such as MSG (e.g. soy sauce) or chemicals including tyramine (e.g., cheeses), beta-phenylethylamine (e.g., chocolate), and nitrates (e.g., processed meats). These common food triggers, in addition to alcohol and caffeine, are thought to trigger migraines and headaches by affecting blood vessels and the nerves surrounding the brain. 

Keep a headache diary to find out which food triggers could cause your postprandial headaches and/or migraines. Seek help from a qualified registered dietitian and consider an elimination diet, if necessary. 

If you get headaches that are painful and do not go away despite avoiding certain food triggers, taking OTC pain relievers, managing mental health and balancing blood sugar, see a doctor. 

If you experience any neurological symptoms from your headaches, call 999 immediately.