Cutting carbohydrates has been shown to reduce migraines, perhaps by changing the type of fuel that enters the brain.
The ketogenic diet is a very low carb diet that makes the body burn fat for energy instead of carbs. Aside from aiding weight loss, it also seems to ease conditions like epilepsy and schizophrenia in some people.
Di Lorenzo and colleagues (2019) wondered if the diet might also help to prevent migraines. Previous studies have hinted that it does, but have not been able to figure out whether this is due to general weight loss or something specific about reducing carbs.
To find out, the researchers compared the effects of two very low calorie diets – one ketogenic and one not – in 35 overweight or obese men and women who experience migraines. Each person was randomly assigned a diet that they followed for four weeks, before swapping to the other for the same duration. The two diets used prepared meals, such as smoothies and soups, that looked identical. The meals had the same amounts of calories and fat but different ratios of carbohydrates and protein.
Weight loss was similar for the two regimes, but the ketogenic
diet appeared to be far better at reducing migraines. About 74% of people had less than half the number of migraine-affected days as normal while on the low-carb ketogenic diet. This compares with just 9% on the high-carb, non-ketogenic diet.
In comparison, the best migraine prevention drugs, known as CGRP monoclonal antibodies, cut migraine-affected days by half or more for between 30% and 48% of users.
The results are compelling, but larger and longer studies are needed before the ketogenic diet can be recommended for migraine prevention.
Di Lorenzo and colleagues (2019) think that forcing the body to burn fat rather than carbohydrates prevents migraines because the brain adapts by using compounds called ketone bodies. These are produced when fatty acids are broken down for fuel instead of glucose.
In animal studies, ketone bodies dampen brain inflammation and stop the spread of electrical activity associated with migraines. The diet might also work because lower carbohydrate intake reduces the production of insulin, a hormone thought to play a role in migraines.
The diet might sound gruelling for some, but people with migraines are often desperate for relief. Very low calorie diets can usually be tolerated for only about 12 weeks, so there is a risk migraines could come back afterwards.
Lorenzo and colleagues are now planning to test whether the diet cuts migraine incidence in people of ideal weight.
Di Lorenzo, C., Pinto, A., Ienca, R., Coppola, G., Sirianni, G., Di Lorenzo, G., Parisi, V., Serrao, M., Spagnoli, A., Vestri, A., Schoenen, J., Donini, L.M. & Pierelli, F. (2019) A Randomized Double-Blind, Cross-Over Trial of very Low-Calorie Diet in Overweight Migraine Patients: A Possible Role for Ketones? Nutrients. 11(8), pp.1742. https://doi.org/10.3390/nu11081742.
Klein, A. (2019) Ketogenic Diet for Migraines. New Scientist. 24 August 2019, pp.14.