Eating bacon, sausages and other processed meats may increase the risk of migraines, research suggests.
Experts suspect that nitrates, which are used to preserve processed meat and are also found naturally in leafy greens, may be linked to migraine attacks.
Around eight million Britons –three quarters of them women – suffer migraine attacks, which cause dizziness, nausea and headaches.
READ: Women’s brains shrink at that time of the month
Painkillers and other drugs can ease the symptoms but they do not work for all sufferers.
Researchers from the University of California San Diego School of Medicine found that those who regularly suffer migraines had raised levels in their mouths and guts of a certain type of bacteria which process nitrates.
The bacteria convert nitrates into nitrites. They then convert nitrites into nitric oxide – a substance which promotes cardiovascular health but is also known to trigger migraines.
Four in five cardiac patients who take nitrate-containing drugs for chest pain or congestive heart failure report severe headaches as a side effect.
Using publicly available data from the American Gut Project, the team identified bacteria found in 172 oral samples and 1,996 stool samples.
Researcher Dr Embriette Hyde, whose work is published in the journal MSystems, said: ‘We know for a fact that nitrate-reducing bacteria are found in the oral cavity.
‘We definitely think this pathway is advantageous to cardiovascular health.
‘We now also have a potential connection to migraines, though it remains to be seen whether these bacteria are a cause or result of migraines, or are indirectly linked in some other way.’
Professor Antonio Gonzalez added: ‘There is this idea out there that certain foods trigger migraines – chocolate, wine and especially foods containing nitrates. We thought that perhaps there are connections between what people are eating, their microbiomes and their experiences with migraines.’
He said more research is needed before he could say that nitrates are directly linked to migraines, but added: ‘If you suspect that nitrates are causing you migraines you should try to avoid them in your diet.’
His team hopes eventually to develop what Professor Gonzalez called ‘a magical probiotic mouthwash for everyone that helps your cardiovascular health without giving you migraines’. Before then, however, the scientists need to understand which microorganisms are related to migraines and establish why nitrates exacerbate migraines.
Four major pharmaceutical firms are racing to be the first to introduce a drug specifically designed to treat migraines – described as one of the few true ‘holy grails’ of medical research.
An injection to tackle migraines is being developed by drugs giants Amgen, Eli Lilly and Teva, who are each competing with Alder to obtain the first licence for the medication.
The first licensing applications are expected next year.
There have been repeated warnings about the risks posed by processed meat. Last month the World Health Organisation said it causes cancer.
Its official report said 50g of processed meat a day increased the chance of developing colorectal cancer by 18 per cent.
Daily Mail