Higher caffeine intake linked to greater prevalence of severe headache, migraine

Key takeaways:

• For every 100 mg increase in daily caffeine intake, severe headache or migraine prevalence increased by 5%.
• The prevalence was greater in women, possibly due to hormonal factors.

Higher daily intake of dietary caffeine was associated with an increased prevalence of severe headache or migraine in adults, particularly women, according to researchers.

“Recent studies have shown that genetics, sleep, and diet are contributing factors to headaches,” Lu Zhang, from the Shandong University of Traditional Chinese Medicine’s First Clinical College in China, and colleagues wrote in Scientific Reports. “Headache attacks are related to changes in cerebral blood flow, and caffeine intake or withdrawal can change the speed of cerebral blood flow and aggravate headaches.”

The American Headache Society recommends over-the-counter NSAIDs and combinations of medications, such as acetaminophen and aspirin, plus caffeine as options for reducing migraine symptoms, according to Zhang and colleagues. However, previous research findings vary on the use of caffeine — both alone and with medication — in patients with headache or migraine, with some studies demonstrating improvements in pain relief, whereas others show a negative effect or no significant link.

“Most previous studies are based on surveys of small samples, and studies on adults are insufficient,” the researchers wrote. “Therefore, it is necessary to further investigate the relationship between dietary caffeine and severe headaches or migraines and explore the underlying mechanisms.”

To do this, the researchers analyzed 1999 to 2004 data from the National Health and Nutrition Examination Surveys of America on 8,993 adults aged 20 years or older (mean age, 49 years; 4,759 women). They determined the prevalence of severe headache or migraine through a one-item questionnaire and caffeine intake through two 24-hour dietary recall interviews.

Zhang and colleagues reported that every 100 mg per day increase in dietary caffeine intake was associated with a 5% increase in the prevalence of severe headache or migraine in all adults (OR = 1.05; 95% CI, 1.02-1.07).

When examining the association by gender, the researchers found that every 100 mg increase in daily caffeine intake was linked to a 5% greater prevalence of severe headache or migraine in men (OR = 1.05; 95% CI 1.01-1.08) and a 7% greater prevalence in women (OR = 1.07; 95% CI 1.02-1.11). This could be because hormones — such as menopause, menarche, pregnancy and oral contraceptive use — greatly impact migraine in women, according to Zhang and colleagues.

“Studies also have shown that caffeine intake affects the levels of luteal progesterone levels, luteal total, and free estradiol in premenopausal women,” they wrote.

Meanwhile, the prevalence of severe headache or migraine was 42% (OR = 1.42; 95% CI 1.16-1.75) higher with a caffeine intake of 400 mg or more per day compared with an intake between 0 to less than 40 mg per day.

The researchers explained that chronic caffeine intake “promotes a nociceptive state of cortical hyperexcitability and excitable neurons by antagonizing G protein-coupled purinergic receptors, which induces or exacerbates headaches.”

“In addition, chronic repetitive exposure to caffeine increases the risk of developing analgesic-overuse headaches, chronic daily headaches, and physical dependency,” they wrote.

The researchers concluded that “further prospective studies are needed to clarify whether increased dietary caffeine intake increases the risk of severe headaches or migraine.”