Obesity and Headaches: Are They Related?
Obesity is defined as excessive weight or fat accumulation that has an adverse affect on health, according to the World Health Organization (WHO). (1) Obesity can be measured by using The Body Mass Index (BMI), defined as the ratio of body weight to height. (2)
A headache or cephaligia is defined as pain anywhere in the head or neck. Most headaches originate in the neck either because of muscle contraction, muscle pain and fatigue, or the dilation of the cerebral blood vessels. (3) The most common types are tension type headaches and migraines. Headaches can be acute, occurring less than 15 times in a month, or chronic, more than 15 times a month. Headache prevalence is about 90% in any given year. According to the National Headache Foundation, three out of four Americans had a headache in the past year. (4) There are many contributing factors to the onset of headaches, one of these factors has been identified as obesity. (5)
How obesity and headaches are linked:
Circulatory system problems
With obesity the excess body weight puts a strain on the circulatory system. Peripheral venous stasis, or venous insufficiency occurs when the veins have trouble sending the deoxygenated blood back to the heart, to be oxygenated. The veins are constricted by the extra body weight preventing the flow of blood that is oxygen poor as a result. This deoxygenated blood then accumulates behind the body-brain barrier. The congregated blood clogs and fills up the vascular structures in the brain’s blood vessels, causing a headache, a kind of warning that the brain is not receiving enough oxygen. Thus the cerebral blood vessels dilate, to increase the amount of oxygenated blood which passes through the brain-blood barrier. Excess weight puts a strain on the circulatory system by constricting the blood vessels, allowing less oxygen to pass into the brain. Therefore an argument can be made, that obesity can increase the likelihood of a headache developing. (6)
Being overweight puts a strain on the body’s muscles. A larger body fat to muscle ratio means that fat is weighing down on the fatigued muscles, causing them to contract. Contracting muscles in the neck, cut of the flow of oxygenated blood to the brain, causing a headache. A sedentary lifestyle may also cause headaches, lack of exercise, or general fitness making it harder for the body to transport oxygenated blood to the brain. The heart is under pressure to pump enough blood through the fat-constricted body. Exercise also releases endorphins, (7) allowing pain relief, as well as making the muscles able to take more strain, allowing for healthier blood flow. Poor posture also puts pressure on the body and if it is co-morbidly associated with obesity, straining the neck and back muscles and leading to headaches. (8)
BMI and headaches
One study found a relationship between the BMI and the occurrence of headaches. The BMI defines obesity as a BMI of larger than 30 kg/m2. Data was collected from the National Health and Nutrition Examination Survey of 1999-2002. The statistical sample was made up of 7601 men and women over the age of 20. The study took place over a three-month period, and the number of severe headaches or migraines was counted.
The results showed that those with a BMI of less than 18.5 kg/m2 had an age-adjusted 34% prevalence of headaches. BMI = 18.5 kg/m2 to less than 25 kg/m2 per 18.9% prevalence. BMI = 25 kg/m2 to less than 30 kg/m2 per 20.7% prevalence. BMI = more than 30 kg/m2 per/ 28.9% prevalence. Those with a BMI score of less than 18 kg/m2 or more than 30 kg/m2 had a higher prevalence of headaches than those in the middle range. Suggesting that BMI is associated with headaches, as under or overweight participants in the study both had higher prevalences of headaches than those with a healthy body weight. (9)
It was studied how BMI influences the occurrence and severity of Chronic daily headache (CDH). CDH is defined as a headache that comes at least 15 times a month, with no underlining medical conditions. (10) Telephone interviews were conducted where information was gathered about the 30,215 large statistical sample; severity of the headaches, medical features, height and weight. Of the sample the prevalence of CDH was 4.1%. In the healthy body-weight group this prevalence was lower at 3.9%. While in the overweight group the researchers found that the prevalence was 5.0% , and in the morbidly obese group (BMI 35 or more kg/m2 ) the prevalence was 6.8%. These studies clearly show the trend that higher BMI scores positively correlate with the higher prevelance of headaches. (11)
According to a study conducted on 74 obese patients and 74 healthy BMI index scoring patients it was found that 56 of the 74 obese patients had headache diagnoses and 49 migraine diagnoses, while 36 had incapacitating headaches. They found that primary headaches are more common in obese patients, than in the control group, or than incapacitating headaches. (12)
Migraine headaches and fatty food
Migraine headaches are defined as the most common type of vascular headache. The arteries in the brain spasm (constrict), while other arteries dilate, causing a throbbing pain in the head as the brain is flooded with serotonin, which release the substances into the blood vessels that causes pain. (13) High levels of blood lipids and free fatty acids are important factors in the triggering of migraine headaches. A high fat diet is one factor that seems to directly influence the onset of migraine headaches. Decreased dietary fat over a 28 day period was show to decrease in turn the prevalence of migraine type headaches. Their findings showed a positive correlation between lower dietary fat intake and lower headache frequency. (14)
Obesity and headaches
Obesity can lead to circulatory system irregularities, muscle fatigue, both of which can in turn cause a headache-prevalence increase. Lack of exercise and unhealthy dietary practices also lead to higher headache prevalence.