Air pollution and extreme heat linked to more migraine attacks, Israeli study finds

Air pollution is a major headache for humankind.

It leads to millions of premature deaths because microscopic pollutants penetrate deep into the lungs and enter the bloodstream, causing widespread inflammation, organ damage, and respiratory and cardiovascular disease, as well as increasing the risk of cancer, dementia, and even affecting the unborn fetus.

Migraines – headaches that can cause intense throbbing pain or a pulsing feeling, usually on one side of the head, often with nausea, vomiting, and extreme sensitivity to light and sound lasting for hours and even days – are a pain for those who suffer from them. If someone also gets an aura – visual changes such as blind spots or flashes of light before or with the headaches – it can be even more agonizing.

Migraine is a leading cause of neurologic disability, yet predicting when episodes occur remains elusive, thus limiting doctors’ ability to provide anticipatory care (including pills) at the first sign of an attack and preventive care (including injectable treatments) to reduce the frequency and severity of attacks.

Assessing the prevalence of migraines is complicated because of the lack of diagnostic biomarkers and the low percentage of migraine sufferers who consult a medical specialist. Estimates, however, suggest that about 14% of the world’s population, or 1.13 billion people, suffer from migraines, making them the sixth most common disease worldwide. According to the Israeli National Health Interview Surveys (INHIS) conducted over the years, 6.8% to 9.9% of Israeli adults, between 400,000 and 500,000 people, suffer from migraines.

Now, a study at Clalit Healthcare Services’ 1,200-bed Soroka University Medical Center and Ben-Gurion University (BGU) in Beersheba has found that pollution and extreme climate conditions are linked to increased migraine attacks.

Published in the prestigious journal Neurology under the title “Acute environmental triggers and intermediate-term modulators of emergency migraine-related health care encounters,” the study discovered that persistent climate conditions and brief exposure to pollution affect the risk of migraine attacks.

The researchers were led by Dr. Ido Peles of Soroka’s Center for Clinical Research in collaboration with Prof. Lena Novak, director of the Negev Institute for Environmental Health Research; Dr. Michal Gordon; BGU Prof. Batya Sarov; and Prof. Gal Ifergan, who has been director of the hospital’s neurology department since 2012, a clinical neurologist and a researcher.

“Prevalence is about three times higher in women than in men, and the median age for a first migraine attack is 23.2 for women and 25.5 for men, Ifergan told The Jerusalem Post in an interview. “The attacks usually start in a person’s 20s, but they can suddenly appear in the elderly. Women with migraines who have passed menopause usually find that they suffer less, thus hinting at the hormonal factors that make it more common in younger women.”

The study population was covered by the Clalit Health Services health fund, which insures about 70% of the city’s residents. Ambient air pollution and meteorological data were obtained from the Environmental Protection Ministry monitoring network.

The climate in the Beersheba area is characterized by hot, dry summers, mild winters, and significant differences between the daily high and low temperatures within a 24-hour period. These extreme daily swings are highly affecting both human physiology and pollutant dynamics.

Most past studies looked only at short-term triggers, ignoring how they interact with long-term factors. Migraines happen due to a mix of long-term biology, medium-term environmental changes, and short-term triggers.

The Soroka/BGU study looked at how both short- and medium-term environmental factors affect migraines, based on data from 7,032 adult migraine patients from the Beersheba area between 2000 and 2023. The researchers studied the relationship between daily exposure to air pollution and weather conditions and urgent treatment requests for migraine, as well as the use of specific medications such as triptans (a first-line class of prescription medications used to abort acute migraine and cluster headaches by stimulating serotonin receptors in the brain and narrowing swollen blood vessels, thus halting the release of pain-causing chemicals).

“In California, for example, wildfires that cause a lot of air pollution. In Israel, it comes from dust particles from deserts in other countries, as well as vehicles, polluting industries, and climate change,” said Ifergan, who said he himself has mild migraines and his “whole family” also suffers from it. “There’s a biological tendency to get migraines, but we showed from our data that air pollution is also a major factor. Paris may in the years to come have the climate of the Negev, and they don’t have air conditioning as Israelis do.”

There are daily air pollution alerts, so people with migraines, as well as lung diseases such as asthma and chronic obstructive pulmonary disease caused by tobacco smoking, secondhand smoke, occupational dusts, and chemical fumes, need to take preventive action. “Pollution affects most bodily organs and contributes to various diseases, including cardiovascular diseases, and even moods. Those at risk should stay indoors, but nobody has researched whether facemasks, humidifiers, electronic filters, trees, and plants reduce the risk,” he added.

The findings showed that exposure to daily air pollution – mainly nitrogen dioxide related to traffic pollution, and tiny particles in the air originating from smoke, industry, and dust – is linked with an increase in headaches. According to the study, in the short term, an increase in air pollution levels and solar radiation was linked with a higher risk of an acute attack leading to an urgent request for treatment. At the same time, cumulative exposure over time to the same pollutants was linked with an increase in the frequency and severity of migraines.

The outcomes relied on routinely collected clinical and pharmacy data instead of diary-based headache information. Migraine episodes were identified only through health care encounters, which likely represent the more severe end of the spectrum, but they constitute the only population-wide, longitudinally stable outcome available for more than two decades of follow-up, the authors wrote. Only 46.7% of patients ever used triptans.

Ifergan and his team plan to expand their research based on their collected data to find factors that could protect against migraines, including certain types of architecture, such as towering buildings or private homes, and living near parks and in specific neighborhoods.

Peles added: “We see that the environment plays a dual role – on the one hand, conditions such as heat and humidity affect sensitivity over time, and on the other hand, sharp increases in air pollution can serve as an immediate trigger for an attack. A better understanding of these connections could in the future allow for the prediction of high-risk days and help patients prepare in advance.”

Environmental risk alerts could be delivered via WhatsApp or integrated into migraine-prediction apps, providing patients and clinicians with practical tools to align treatment strategies with exposure dynamics, they suggested.