Canker sores, also known as aphthous ulcers, appear as shallow, light-coloured mouth sores of different sizes and affect one in five North Americans. While no one is certain of any single cause, research does point to a few possibilities. Among them, a genetic predisposition might be the biggest cause, says Michael Martin, PhD, of the Department of Oral Medicine at the University of Washington.
Certain foods, such as citrus fruits, can make painful canker sores worse.
"When both parents have a history of canker sores, the likelihood of their children developing them can be as high as 90%," he says. Other research points to food allergies and hormonal changes, such as chronic stress, anxiety and the menstrual cycle.
Recent research provides a few other clues on what may be behind canker sores and what to do about them.
B12 is key
A team of physicians at Ben-Gurion University say that a nightly dose of vitamin B12 is a simple, effective and low-risk therapy to prevent canker sores. They tested 58 randomly selected patients with recurrent canker sores who received either 1,000 mcg of B12 by mouth at bedtime or a placebo, and were tested monthly for six months. Almost three quarters of the patients taking B12 and only a third of the control group achieved remission at the end of the study. The treated patients expressed greater comfort, reported less pain, fewer ulcers, and shorter outbreaks during the six months while among the control group the average pain level decreased during the first half of the period but increased during the second half.
Herbal help
Other researchers examined the effects of licorice extract applied via an adhesive patch for treatment of canker sores versus no treatment. After seven days of treatment, ulcer size in the group who took the licorice was significantly lower, while ulcer size in the no-treatment group had increased 13%.
Licorice, typically in the form of DGL (deglycyrrhizinated licorice) is also widely used as a treatment for gastric ulcers. DGL lozenges are available in health food stores and may be an alternative to adhesive patches. Dr Michael Martin adds that "in addition to speeding healing of the canker sores, the licorice extract helped to reduce pain after just three days of treatment."
Nutrition clues
An earlier study points to other nutrient deficiencies that may contribute to canker sores. Japanese researchers compared food intake among patients with recurrent canker sores and control patients. They found a significantly positive correlation with lower intake of calcium, iron, vitamin B1 and vitamin C among canker sore sufferers. They concluded that "not only iron and vitamin B1 might be deficient in these patients but also calcium and vitamin C."
Sources: General Dentistry, Mar/Apr 2008; Ben-Gurion University of the Negev, Feb 10, 2009; Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2001 Jan;91(1):45-9
