ANSWER: Mouth ulcers are not well understood. They affect up to a quarter of young adults and a higher proportion of children. It’s believed that the immune system is disturbed by some external factor and reacts abnormally against a protein in mucosal tissue.
Genetic factors have long been thought to influence a person’s risk of developing the sores, given that there is often a family history. Stress, lack of sleep and being run-down have also been blamed, along with trauma such as accidentally biting your tongue or inner cheek, bumping the inside of your mouth with your toothbrush or burning it with a hot drink, ill-fitting dentures, or a rough edge on a tooth. Viral illnesses such as herpes simplex (which causes cold sores) or varicella zoster (which causes chickenpox and shingles) are also a factor. There are few drugs with which to treat mouth ulcers.
In groundbreaking research published in March, a team of international scientists led by the University of Bristol confirmed a genetic link to mouth ulcers. They analysed the DNA of more than 800,000 people in the UK, US and Australia and found 97 common genes related to the painful sores. The findings potentially pave the way for more effective treatments.
“Several of the genes are in pathways that are already targeted by drugs used to treat other diseases such as rheumatoid arthritis and psoriasis,” says University of Bristol researcher Tom Dudding. “There is the potential that such drugs could be used to treat mouth ulcers, although further work is required to demonstrate this.”
Other factors that appear to cause mouth ulcers include food allergies, intestinal conditions such as coeliac and Crohn’s disease, hormonal changes in the menstrual cycle and pregnancy. Certain medications and deficiencies in iron, vitamin B12 and folate are also thought to play a role.
You’ve said that you don’t get mouth ulcers when you’ve been eating red meat. This may well be the case, because red meat is an excellent source of iron, along with vitamin B12.
Iron is an essential part of haemoglobin, the component of red blood cells that transport oxygen around the body. It is also incorporated into a number of proteins and enzymes with important physical and neurophysiological functions. Despite iron’s importance, being deficient in the mineral is one of the most common nutritional imbalances.
As we can only absorb limited amounts of iron, the solution is to regularly eat foods that are rich in it. To do this:
- Eat red meat, chicken and fish, as these contain easily absorbed haem iron.
- Vegetarians must include plenty of non-haem iron sources such as vegetables, legumes, cereals and iron-fortified breakfast cereals.
- Eat vitamin C-rich fruits and vegetables, such as kiwifruit, citrus fruits and leafy greens, as vitamin C enhances iron absorption.
- Avoid drinking tea and coffee with main meals as these decrease iron absorption.
This article was first published in the June 15, 2019 issue of the New Zealand Listener.