Can sugar cause headaches? Headache disorders affect approximately 90% of people during their lifetime, yet medical researchers are still struggling to conclusively identify what really causes them. Thus, even in severe types (e.g., migraines), treatments typically focus on symptom relief in the absence of an understanding of the headache cause and how it may have been prevented in the first place. Most recent research does seem to conclude that stress and sleep are most associated with headache onset, rather than dietary factors. However, meal timing and overall dietary patterns do seem to play a role. Most notably, evidence points to skipping meals as a likely cause of headache development. But people also complain of headaches after eating too much.

As it turns out, the two experiences may be related, as both correlate with fluctuating blood glucose levels. So can sugar cause headaches? The answer is complicated, but prevailing wisdom suggests that modifying your diet (including better balancing of your carbohydrate intake), while also consistently exercising and getting higher quality sleep, can help stabilize your blood sugar levels — possibly aiding you in the prevention or mitigation of headache onset and/or severity. 

The type of headache matters

Although there are many different types of headaches, this article will focus on two of the most common kinds of “primary headache disorders” (unrelated to an underlying medical condition): 

• Tension headaches: Affecting 38% of the population, these headaches often result from muscle tension, poor posture, and mental exertion. Even though tension headaches are the most prevalent type of headache, research remains inconclusive regarding root causes.

• Migraines: Affecting 12% of the population, these headaches are the second leading cause of disability worldwide, often causing severe throbbing pain that may be accompanied by nausea and visual impairments.

Clearly, the most important first step in treating headaches is to determine what type you have; so, if you suffer repeatedly from headaches, ask your medical provider for a comprehensive analysis to determine whether you suffer from migraines (for which an extensive array of medical and non-pharmacological treatments are available), tension headaches, or one of the less common types.

Headache causes: What we know and don’t know

As a 2021 meta-analysis summed up, extreme heterogeneity describes the large and complex conglomeration of possible headache triggers and causes, which scientists have yet to fully understand:

“The study of headache triggers is fraught with complications, foremost of which is the considerable variability of individual trigger effects that often precludes establishment of clear cause-effect relationships. No single stimulus serves as a trigger for all patients, and within a single individual rarely does exposure to an identified precipitant always provoke headache . . . establishing causality of headache triggers is both rare and often unfeasible . . . .”

As we’ll discuss below, some of the so-called “triggers” of headaches, medically defined as “environmental and physiological stimuli that may precipitate individual headache attacks,” may actually not be triggers at all. Rather, early stages of a headache (pre-pain) may bring about behaviors (e.g., cravings for chocolate or sweets or even alcohol) that are a response to the headache’s initial stage, not a cause of it. 

To be frank, the science regarding headache causation is still in its infancy — an important caveat to note, as it also affects prevention/treatment decisions. To date, the most accepted triggers or causes of headaches, particularly migraines, are these:

• Genetics and hormonal changes
• Stress
• Poor sleep
• Light, noise, and weather changes
• Strong odors
• Medication and substance overuse
• Diet and hydration

While the first factor (genetics and hormonal changes) is significant, and not always amenable to control or change by an individual, clearly the other factors listed are predominantly environmental — and so relate to lifestyle habits and decisions that can be modified. In our report, How To Prevent Migraines From Stress, we explore most of these factors and discuss strategies for modifying lifestyle habits. 

The role of diet in causing headaches

While diet may not be the major factor responsible for the onset of a headache, particularly a migraine, it does play a role. In this report, we’ll delve deeper into the role of dietary patterns, and focus on the association between blood glucose levels and headaches, and whether sugar consumption is a significant driver of headache disorders generally.

The dietary patterns or behaviors that a consensus of scientists and medical providers associate with headaches include:

• Extreme fasting: Perhaps not surprisingly, people often end up with headaches while fasting during religious holidays. For instance, one study reported that 39% of people had a headache after 25 hours of fasting for Yom Kippur. These headaches tended to be more common in people with a history of tension headaches or migraines.

• Skipping meals: Less extreme forms of fasting are also associated with headaches. One study looked at food diaries in the 24 hours leading to migraines. They found that the majority of headaches could be traced to the absence of food for relatively short periods of time (5 hours during the day or 13 hours overnight). Interestingly, only 2% of people with migraines were aware of this pattern.

• Hypoglycemia: Headaches have long been associated with low blood sugar, or hypoglycemia — and clearly the previously mentioned dietary behaviors (extreme fasting or skipping meals) are two of the most common causes of hypoglycemia leading to headache. Sleep deprivation can also lead to hypoglycemia, so clearly low blood sugar is not just caused by dietary choices; in all likelihood, it’s a combination of internal (genetic) and external (environmental/lifestyle) factors that contribute to changes in blood glucose levels, and thus to headache frequency and severity.

• Dehydration: Since water is part of any dietary regimen, we’re mentioning this here, as dehydration can cause low blood sugar and then lead to headaches.

• Alcohol consumption: Another dietary choice, alcohol can also bring about low blood sugar in many individuals, which in turn can lead to headaches.

Can certain foods cause headaches?

As mentioned earlier, it has long been assumed that certain foods can trigger, or cause, headaches. Current medical guidance, in fact, such as contained in a Cleveland Clinic post, continues to list foods suspected of triggering headaches:

• Aged cheeses, like feta, Parmesan and Swiss.
• Foods that contain the additive monosodium glutamate (MSG).
• Dried meats and fruits.
• High-sugar and processed foods, such as packaged cookies and crackers.
• Meat products like hot dogs and pepperoni that contain additives (nitrates and nitrites).

While certain foods may indeed be a part of the problem, as we mentioned earlier, in recent clinical research scientists have been unable to establish causation for many of the supposed common culprits, including chocolate — a 2020 research review concludes that there is “insufficient evidence” of its role as a migraine trigger; and coffee — which a 2019 meta-analysis determined actually improves glucose metabolism when consistently consumed over long periods (2 to 16 weeks), despite its tendency to impair your glucose response acutely, i.e., over the short term (hours). Caffeine, in fact, has actually been shown to alleviate migraine symptoms for certain individuals. 

Furthermore, as portrayed in a recent article in The New York Times (Can Eating Carbs and Sugar Cause Headaches?), some scientists are now theorizing that “it’s most likely not the foods that cause migraines, but rather it’s the migraines that cause people to eat certain foods.” In other words, in the hours preceding a migraine (known as the “prodrome stage,” which can include photophobia, phonophobia, nausea, vomiting, stiff neck, difficulty concentrating, and irritability), the brain may produce food cravings. When acted upon, the consumption of those certain foods may occur prior to the onset of headache pain, which understandably has led many patients and clinicians over the years to assume that those very foods triggered the headache — when in reality the headache may have already begun, fueling the food cravings. This new research angle, exploring “the bidirectional interaction between migraine and appetite,” is in early research stages, but the preliminary work (utilizing brain imaging and other neuroscience study modalities) holds promise, as summarized in this 2021 review paper.

Can sugar cause headaches?

Since many of the aforementioned “established causes” of headaches seem to relate to blood glucose levels (skipping meals, dehydration, sleep problems), and specifically to low blood glucose, what about the opposite — high blood glucose, or hyperglycemia — which may or may not be exacerbated by too high an intake of dietary sugar (carbohydrates)? Can too much sugar cause headaches? An important hint: Low and high blood glucose levels may be more related than you might think. In fact, scientists are increasingly concerned not just with absolute high or low blood glucose levels, but with the frequency and severity of glucose fluctuations.

Simplifying the science as it relates to headaches, your body converts carbohydrates and sugars into glucose, the simple form of sugar that circulates in your blood and provides energy for your cells. And while some organs in your body use fat and other fuel sources, your brain powers itself almost exclusively on glucose. So, it is not surprising that changes in blood sugar might alter your brain function and trigger a headache. Indeed, it seems that in many people, glucose fluctuations can contribute to both tension headaches and migraines.

We’ve already covered one of the more common causes of headaches, low blood sugar. But you might also develop a headache after overeating, which at first may drive up your blood glucose (hyperglycemia), but then cause your blood glucose level to fall — resulting in low blood sugar. What happens is that the big meal, particularly if it contains a high amount of carbohydrates (especially those that are processed and low in fiber), raises your blood sugar, which then brings on an overproduction of insulin, which paradoxically leads to hypoglycemia (low blood sugar), a condition called reactive hypoglycemia. One of the key symptoms of this condition is headache, along with fatigue, weakness, light-headedness and shakiness. These headaches tend to occur three to six hours after overeating when blood sugars hit their lowest levels.

Whether it’s the added sugars in the Western diet, or perhaps a larger array of “inflammatory foods” that are responsible for blood glucose irregularities (that could lead to headache), remains under debate. A 2022 review paper published in Nature presented evidence suggesting that higher adherence to “a diet with anti-inflammatory properties” was significantly and inversely related to headache frequency, but the study was retrospective and small. Foods classified as anti-inflammatory included beans, fruits, vegetables, seafood, ginger, pepper, garlic, and onions. Conversely, foods all too common in a Western diet (added sugars, saturated fats, high sodium) were avoided.

Thus, the answer to the question, “Can sugar cause headaches?” is a tentative yes — for some individuals under some circumstances.

Is there a connection between sugar, metabolic disorders and headaches?

As a recent clinical perspective paper summarized, many studies have found strong associations between the comorbidity of migraine and glucose-related disorders (impaired glucose homeostasis, insulin resistance, reduced cerebrovascular reactivity, abnormal brain metabolism, among others). 

• A 2022 review concluded that migraines may result from impaired brain glucose metabolism. The authors suggest this can happen when insulin resistance in the rest of the body starts extending to the brain. However, more research is necessary to understand this connection between migraines and glucose metabolism.

Furthermore, several studies have found a bi-directional link between migraine with insulin resistance and type 2 diabetes (T2D). However, diabetes (both types) has been reported to be a protective factor against migraine in some studies, whereas in other studies diabetes seemed to put subjects at greater risk for migraine.

There also appear to be clear associations between migraine headaches and obesity: obesity has been shown to be a risk factor for migraine attacks, and migraine (or its pharmacological treatment) appears to be a risk factor for the development of obesity, the latter considered a risk factor for T2D. 

• A 2014 study noted that chronic migraines and insulin resistance often occur together in obese women. Furthermore, migraines and insulin resistance are both associated with comorbidities including depression, anxiety, cognitive impairment and cerebrovascular diseases. 

In short, the relationships are complex, but promising research is underway to connect the dots, which could result in common treatments and even parallel dietary and lifestyle strategies to reduce disease risks or lessen symptoms of both migraines and metabolic disorders.

Preventing and treating headaches

Medical interventions 

Pharmaceutical treatments are recommended for many migraine sufferers that have persistent and severe disorders. While such treatments are not the focus of our report, readers may note that a 2021 JAMA publication analyzed the efficacy of most current medication therapies, reporting that migraines can be treated acutely with analgesics, nonsteroidal anti-inflammatory drugs, triptans, gepants, and lasmiditan. Consult with your medical provider for further information.

Lifestyle tips for stabilizing your blood sugar 

Scientific evidence suggests that several lifestyle interventions, such as diet, exercise, and sleep, can play a role in headache prevention as well as symptom relief. 

Diet

As previously discussed, the extent to which dietary factors are triggers for headaches is still debated. Nevertheless, most leading medical establishments recommend various dietary strategies. 

• Minimize blood sugar fluctuations. Several foods have been suggested for stabilizing blood sugar, including whole wheat pasta, salmon, quinoa, almonds, avocadoes, broccoli, spinach, cauliflower, sweet potatoes, and lentils. Another review suggested that people with headaches choose carbohydrates that minimize blood glucose spikes, such as yogurt, fresh fruit and oatmeal. High-fiber foods are also a good choice. Although fiber is a carbohydrate, it tends to slow down digestion, preventing massive glucose fluctuations. Several reviews have also suggested that people with chronic morning headaches eat a bedtime snack of carbohydrates (20 to 40 grams) to help avoid hypoglycemia at night. Finally, it is suggested that carbohydrates be consumed every 4 to 5 hours daily to prevent blood sugar lows.

• Food order. An intriguing study suggests that the order in which you eat your food matters. More specifically, the authors investigated the effects of eating protein and vegetables before carbohydrates. Interestingly, this strategy resulted in lower glucose and insulin levels.

• Foods to avoid. Putting aside our aforementioned disclaimer about how new research is questioning the veracity of claims that certain foods cause headaches, most major medical organizations, including the American Migraine Foundation, continue to suggest that the following foods may be associated with migraines: alcohol (especially red wine and beer), chocolate, aged cheese, cured meats, smoked fish, yeast extract, food preservatives that contain nitrates and nitrites, artificial sweeteners and monosodium glutamate (MSG).

• Diets and supplements. Reviews have suggested the benefits of low glycemic diets and ketogenic, high-folate, low-fat, modified Atkins and high omega-3/low omega-6 diets. Among dietary supplements, the American Migraine Foundation suggests riboflavin (vitamin B2), coenzyme Q10 (CoQ10), magnesium, Petasites (butterbur) and feverfew — but please consult with your medical provider before starting any new supplements or diets.

• Stay hydrated. Finally, there is good evidence that staying hydrated is an excellent way to prevent spikes in your blood sugar levels. Studies from 2005 and 2020 observed that drinking more water was associated with fewer migraines.

Exercise

Another great way to improve your insulin sensitivity — and potentially avoid headaches — is through regular exercise. Even moderate exercise can reap benefits. 

• Regular exercise. While some studies suggest that intense exercise can trigger migraines, a 2018 review advises that regular exercise is still the best option to help prevent migraines. Despite potential issues with hypoglycemia, a 2017 review also recommends regular exercise for people with diabetes.

• Exercise after you eat. Exercising after a meal may stabilize glucose levels after ingesting food. A 2021 systematic review concluded that exercise after a meal decreases glucose and insulin concentrations in healthy adults. A 2016 review concluded that 30-45 minutes of light to moderate exercise after eating could reduce blood sugar spikes with minimal risk of hypoglycemia.

• Benefits of moderate exercise. A 2016 review noted that moderate-intensity activity for as little as 30 minutes 3–4 days a week is associated with improved insulin sensitivity and glycemic control. The authors suggest that both aerobic and resistance exercise improve glycemic control and that the best option may be a combination of both. Furthermore, a 2013 study demonstrated that a single session of moderate exercise in obese people improved insulin sensitivity the next day.

Sleep

Even though headaches and sleep disorders often occur together, medical providers rarely consider the two together during treatment. A 2009 review concluded that headache treatment could not be optimized without proper attention to sleep hygiene and sleep disorders. What are some sleeping tips that might help you avoid headaches?

• Improve your sleep hygiene. The CDC recommends the following sleep hygiene tips: 1) be consistent and go to bed/wake up at the same time every day; 2) make sure that your bedroom is dark, quie,t and relaxing; 3) remove electronic devices from your room; 4) avoid large meals, caffeine, and alcohol before bed; and 5) stay physically active.

• Get more sleep. It is well-documented that not getting enough sleep increases your hunger and appetite and causes you to eat more. Insufficient sleep is also a risk factor for obesity, insulin resistance, and type 2 diabetes. A 2018 review suggested sleep extension as a strategy to better regulate glucose in people who tend to sleep less than 6.5 hours a night.

• Getting the right amount of sleep. A 2015 meta-analysis suggested that people who sleep 7–8 hours a night have the lowest risk of type 2 diabetes. However, diabetes risk increases for people who sleep more or less than this.

Key takeaways

So, can sugar headaches? While stress, sleep, and low blood sugar may be three of the most significant causes of headaches, research does point to the likelihood that a diet very high in added sugars and other ultra-processed and inflammatory foods could play a role in headache onset and severity. Modifying your diet (including better balancing of your carbohydrate intake) — while also consistently exercising, hydrating, and getting higher quality sleep — could all work together to better stabilize your blood sugar levels, aiding you in the avoidance or mitigation of headache onset and/or severity. See your medical provider to determine which type(s) of headaches you are experiencing before considering treatment options and dietary and lifestyle changes.