Rapid swings in blood sugar levels caused by eating too much sugar or too little sugar can sometimes cause headaches.

Headaches can range from annoying to debilitating, so understanding what triggers a headache can significantly improve a person's quality of life.

For some people who experience migraines, sugary foods may be a trigger.

Both too much and too little sugar can cause a headache. Consuming too much sugar can cause high blood sugar levels (hyperglycemia). Consuming too little sugar can cause low blood sugar levels (hypoglycemia).

Low blood sugar can cause a range of symptoms, including headaches and muscle pain. People who take insulin have a higher risk of having low blood sugar levels.

People who consume too much sugar, who are insulin resistant, or who have diabetes are more vulnerable to high blood sugar. If a person consumes a lot of sugar at once, then does not have any more in the period that follows, they may experience a sugar crash, which can cause a headache.

Sugar may trigger hormonal changes, particularly in the hormones epinephrine and norepinephrine. These hormonal shifts change the way blood vessels in the brain behave, potentially triggering a headache.

It is not the sugar itself that causes a person to develop a sugar headache. What triggers a headache is a rapid shift in blood sugar, due either to consuming too much sugar or not eating enough. These changes in blood sugar can induce a headache and other symptoms, which some people call a sugar hangover.

Related conditions

Some medical conditions make people more prone to sugar-related headaches, including:

Diabetes: People with diabetes are not able to manage their blood sugar levels naturally. When their blood sugar gets too high or too low, they may experience headaches.

More blood sugar fluctuations typically mean more headaches, so people with diabetes who struggle to manage their condition or do not take medication as prescribed may be more vulnerable to diabetes-related headaches.

Unmanaged diabetes can damage the blood vessels, which may 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, blood clot, or an aneurysm.

Some people with diabetes develop a condition called diabetic ketoacidosis when the body uses fat instead of sugar for energy. People with diabetic ketoacidosis sometimes experience intense headaches, in addition to swelling, confusion, or loss of consciousness.

Migraine: Changes in diet and blood sugar fluctuations may trigger migraines in some people who regularly have them.

Every individual has different triggers, so it is crucial for a person to keep a record of when their migraines occur to determine whether sugar is a trigger.

A 2006 study linked the sweetener sucralose that is found in Splenda to migraines, meaning that even sugar substitutes may play a role in causing sugar headaches.

Sugar withdrawal headache: Sugar can be addictive. In fact, sugar causes brain changes similar to those associated with addictive drugs.

A 2016 study found that when exposed to chronically high levels of sugar, the brain makes less dopamine, which plays an essential role in pleasure, motivation, and mood. Dopamine has also been linked to addiction.

When people suddenly stop eating sugar, their brain may go into a state of withdrawal. Gradually reducing sugar consumptions may reduce these symptoms.

Treatment and prevention

Mild to moderate headaches can usually be treated with over-the-counter painkillers. A person may also want to rest in a dark, cool room for the duration of a headache.

Eating a balanced diet helps to control blood sugar and prevent blood sugar swings. To avoid sugar headaches, a person should eat fiber-rich foods, such as avocados, lentils, dark leafy greens, and beans.

Other ways to prevent sugar headaches include:

• Eating protein. Foods high in protein can help control appetite, which may reduce sugar cravings.
• Staying hydrated. Water prevents dehydration, which can also cause headaches.
• Exercising regularly. Regular physical activity can help the body control blood sugar levels.
• Keeping a log. Keeping a written record of food-induced headaches can help a person identify what triggers their symptoms.

Headaches are complex and can have multiple causes. A doctor will work with a person to determine why they experience chronic headaches. Keeping a log of triggers, including sugar, can help.

Conclusion

For most people, moderate sugar consumption is safe. Sugar is more likely to cause headaches when a person has an underlying medical condition, or when they consume large quantities of sugar that cause blood sugar swings.

Sugar consumption following a period of fasting can also cause symptoms. Giving up sugar suddenly, rather than slowly reducing consumption, may cause withdrawal symptoms, including headaches.

Headaches can be treated with over-the-counter painkillers, but anyone experiencing chronic headaches should speak with a doctor.

—Zawn Villines