White or yellow, with a red halo around them, canker sores or oral aphtae are small painful ulcers that develop in the mouth, mostly on the soft palate, gums and tongue. They appear suddenly, and depending on size, location and quantity they are divided into three distinct types:
- Simple or minor sores, which appear two or three times a year, mostly in people between 10 and 20 years of age. They are round, less than one centimeter in size and clear up within a week or two.
- Complex or major sores are less common than the simple ones and often occur in people who already had them. They are deep ulcers with size greater than one centimeter, they have asymmetrical edges and can last anywhere from two to six weeks.
- Herpetiform sores give the impression of a herpes infection and are made of numerous shallow, small ulcers less than three millimeters in size. They can merge to form big asymmetrical ulcers and last between seven and ten days.
The exact cause of the ulcers is unknown, but some factors have been associated with their appearance: injury to the lining of the mouth, ranging from improper tooth brushing techniques, biting and caused by an accident, hot, spicy or hard food, stress, allergies, fluctuations in hormones, vitamin and mineral deficiencies, problems with the immune system or infections. The risk for developing the sores increases for women and those who have a family history of canker sores. Lysine is one of many amino acids which are needed by the body for tissue repair and growth. Like all biologically important organic compounds, it has a key role in production of proteins, hormones, enzymes and antibodies, which help the body fight off diseases. Various foods supply lysine, but the best sources are red meat and fish.
Even though eggs and dairy products such as milk and cheese are rich with lysine, they are also very acidic, and acidic foods are identified as a key in development of cold sores and prolonging the time necessary for the sores to heal.
Fruits and vegetables, except legumes such as peas, beans and lentils are in general a poor source of lysine.
Lack of lysine in the diet can be one of the factors responsible for the outbreaks, so remember not to exclude lysine rich foods from your everyday diet. Not only does it help speed up the healing process of canker sores, it is also responsible for prevention and treatment of cold sores and herpes infections in general, improving athletic performance and recovery after surgery, in lowering the levels of cholesterol, it increases intestinal absorption of calcium and elimination of its excretions by the kidneys.
The recommended daily dose for treating the sores is from one to three grams, with higher doses being reserved for breakouts. Doses in this range are safe not only for adults but for prepubescent children as well.
It should not be used in patients with high levels of lysine in their blood and urine, and those who suffer from liver and kidney problems.