It may be worth adopting a plant based diet, rich in dark green leafy vegetables, to ease the symptoms of chronic migraine, suggest doctors in the online journal BMJ Case Reports.

The recommendation comes after they treated a man who had endured severe migraine headaches without aura for more than 12 years.

He had tried prescribed meds (Zolmitriptan and Topiramate); cutting out potential 'trigger' foods, including chocolate, cheese, nuts, caffeine, and dried fruit; and yoga and meditation in a bid to blunt the severity and frequency of his headaches. Nothing had worked.

Over 1 billion people worldwide have migraines, characterized as one-sided, pulsating headaches lasting 472 hours, and often accompanied by sensitivity to noise and light and sometimes prodromal auras.

Migraines are either episodic (fewer than 15 days a month) or chronic (15 or more migraine days a month plus migraine features on at least 8 days of the month).

Successful migraine treatment is defined as a halving in the frequency and length of attacks, or as an improvement in symptoms.

While drugs can help prevent and treat the condition, a growing body of evidence suggests that diet may also offer an effective alternative without any of the side effects associated with some meds, say the report authors.

Six months before his clinic referral, the man's migraines had become chronic, occurring on 1824 days of every month.

He described the pain as starting suddenly and intensely in the forehead and temple on the left side of his head. The pain was throbbing in nature, and usually lasted 72 hours.

His headaches were accompanied by sensitivity to light and sound, and nausea and vomiting. On a scale of 010, he scored the pain severity as 1012 out of 10.

Blood tests revealed that he didn't have high levels of systemic inflammation and that he had a normal level of beta-carotene (53 g/dl).

This was likely derived from his daily consumption of sweet potatoes, which, although high in beta-carotene, are relatively low in the nutrients responsible for the anti-inflammatory and antioxidant properties of carotenoids, point out the report authors.

These are instead found in dark green leafy vegetables, such as spinach, kale, and watercress. Systemic inflammation and oxidative stress are implicated in migraine.

The report authors advised the man to adopt the Low Inflammatory Foods Everyday (LIFE) diet, a nutrient dense, whole food, plant-based diet.

The LIFE diet includes eating at least five ounces by weight of raw or cooked dark green leafy vegetables every day, drinking one 32-ounce daily green LIFE smoothie, and limiting intake of whole grains, starchy vegetables, oils, and animal protein, particularly dairy and red meat.

After 2 months on the LIFE diet, the man said that the frequency of his migraine attacks had fallen to just 1 day a month; the length and severity of the attacks had also lessened. Blood tests showed a substantial rise in beta-carotene levels, from 53 g/dl to 92 g/dl.

He stopped taking all his migraine meds. Even when he tried certain 'challenge' foods, such as egg whites, salmon, or iced tea, which triggered headache attacks, these were much less painful and much shorter in duration than before.

After 3 months his migraines stopped completely, and they haven't returned in 7.5 years.

The man was allergic, and previously published research suggests that better control of allergies may lead to fewer migraine headaches. In this case, the man's allergy symptoms improved to the point that he no longer needed to use seasonal medication.

He was also HIV positive, and HIV has been linked to a heightened risk of migraines, so it is certainly possible that the man's HIV status and antiretroviral drugs had contributed to his symptoms, say the report authors.

But it wasn't possible to study this further without stopping the antiretroviral treatment, which is a limitation of the study, they acknowledge.

But they conclude: "This report suggests that a whole food plant-based diet may offer a safe, effective and permanent treatment for reversing chronic migraine.

"While this report describes one very adherent patient who had a remarkable response, the LIFE diet has reduced migraine frequency within 3 months in several additional patients (personal communication)."