Rapid changes in blood glucose levels from eating too much or too little sugar can sometimes cause headaches.
Headaches can range from annoying to debilitating, so understanding what triggers them may enable a person to improve their quality of life.
Blood sugar levels and hormonal changes can both play a role in causing headaches, and sugar can affect both of these.
Can sugar give you a headache?
A person may get a headache from a rapid change in blood glucose levels.
Both too much and too little sugar can cause a headache.
Consuming too much sugar or refined carbohydrates can lead to high blood sugar levels, or hyperglycemia. A carb intake that is too low can cause low blood sugar levels, or hypoglycemia.
When people talk about a “sugar hangover” or a “sugar crash,” blood glucose levels are often the underlying reason.
Low blood sugar can lead to a range of symptoms, including headaches and muscle pain. People who take insulin have a higher risk of having low blood sugar levels.
High blood sugar can affect people who consume too much sugar, have insulin resistance, or have diabetes.
Changes in blood sugar levels can occur if a person consumes a lot of sugar at once, and then does not have any for a while. This can lead to a “sugar crash,” which can cause a headache.
Sugar in moderation should not cause a person to develop a headache, but consuming too much or too little sugar can lead to a sudden shift in blood glucose levels. Some people call this a sugar hangover.
When a person has diabetes, their body is not able to regulate their blood sugar levels naturally. They need to use medication, diet, or other lifestyle strategies to manage their blood sugar levels.
If they are not able to do this, blood glucose levels can rise too high or fall too low, resulting in headaches and other symptoms.
Without effective management, diabetes can damage the blood vessels and nerves. This can change blood circulation to the brain and increase the risk of headaches.
Blood vessel damage can also increase the risk of heart and brain conditions that cause headaches. A sudden, intense headache could be due to a stroke or a ruptured intracranial aneurysm.
Missing meals or eating sugary snacks instead of nutritious foods may trigger a migraine episode, according to The Migraine Trust.
Eating sugary foods can cause the body to produce and release extra insulin. This lead to a sugar crash and a low blood sugar level. Low glucose levels can trigger a migraine in some people.
The exact link between migraine and sugar remains unclear, however.
In 2020, scientists published a study that measured blood glucose levels in 31 people with migraine. They found that levels were higher at the start of an episode, but that they fell over time between episodes. More research is needed to find out why this happens.
Some studies have suggested there may be a link between artificial sweeteners and migraine, but not all the results agree, according to a 2017 analysis.
Migraine triggers vary among individuals, but keeping a record of when and how their migraines occur can help determine whether sugar is a trigger.
Sugar can be habit forming. It may cause brain activity changes similar to those scientists associate with addictive drugs.
Eating less sugar than usual can also trigger a “sugar withdrawal” headache. This could happen on the first day of a new diet, for example, or after cutting down on candy or sugary soda consumption.
A 2016 study noted that, when exposed to high levels of sucrose (a type of sugar), the brain produces more dopamine. The same study noted that in rats with sucrose withdrawal, the dopamine level decreases.
Dopamine is a neurotransmitter that plays an essential role in pleasure, motivation, and mood. Dopamine may also have links to addiction.
When people suddenly stop eating sugar, their brain may go into a state of withdrawal, possibly contributing to a migraine headache. Gradually reducing sugar consumption may lessen these symptoms.
Treatment and prevention
People can treat most mild to moderate headaches with over-the-counter (OTC) painkillers and rest.
However, if a person experiences persistent headaches, they should see a doctor. It could indicate a problem with their blood sugar levels or other issues.
To avoid a sugar headache, people can try:
eating regular and nutritious meals
choosing unprocessed, complex carbs, such as in fruits, vegetables, and whole grains
following the doctor’s instructions for managing diabetes
exercising regularly
limiting sugary sodas, candies, and other foods with added sugar
Other ways of preventing headaches include:
Staying hydrated. Drinking plenty of water prevents dehydration, which can be a cause of headaches.
Getting enough sleep. Too much or too little sleep can lead to headaches.
Managing stress: Yoga, relaxation, and other forms of exercise may help.
Keeping a log. Logging headaches and their possible causes can help a person identify triggers.
There are many reasons why people have headaches. Anyone who has persistent headaches can talk to their doctor for advice.
A doctor can work with the individual to find out what is causing the headaches and to make a plan to manage them.
For most people, moderate sugar consumption is safe. Sugar headaches often stem from sudden changes in blood sugar levels. They are more likely to affect a person with diabetes.
People can often treat headaches with OTC painkillers, but anyone who has concerns about chronic or recurring headaches should speak with a doctor.
