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Most people have canker sores at some time in their lives, and it may happen more regularly for some than others. It is often painful to have canker sores and they make it hard to eat. This blog provides you some food and nutrition tips on how to prevent and manage canker sores.


What is a canker sore?

Most canker sores are round or oval with a white or yellow center and a red border. They develop on the soft tissues in your mouth or at the base of your gums. Unlike cold sores, canker sores aren’t contagious.


Potential causes:

The precise cause of canker sores remains unclear, though researchers suspect they may be caused by a combination of factors, even in the same person. 

Possible triggers:

  • A minor injury to your mouth that may be caused by an accidental cheek bite or dental work
  • Food sensitivities, particularly to chocolate, coffee, eggs, nuts, cheese, and spicy or acidic foods
  • A diet lacking in vitamin B-12, zinc, folate (folic acid), or iron
  • An allergic response to certain bacteria in your mouth
  • Hormonal shifts during menstruation
  • Emotional stress 


 Certain conditions and diseases may also be the cause:

  • Celiac disease, a serious intestinal disorder caused by a sensitivity to gluten, a protein found in most grains
  • Inflammatory bowel diseases, such as ulcerative colitis and Crohn’s disease
  • HIV/AIDS, which suppresses the immune system


Help prevent canker sores through food:

  • If you have gotten canker sores in the past by eating acidic food (e.g., citrus fruits, tomatoes, pineapple) and sharp or harsh foods (e.g., chips, certain spices, salty foods), it might help to avoid these. 
  • Limit the use of alcohol and tobacco 
  • Get enough vitamins and minerals in your diet, like folic acid, vitamin B12, zinc, and iron, by eating a variety and plenty of fruits, vegetables, and whole grains


Relieve the pain caused by your canker sores through food:

  • Eat soft, bland foods that are easy to swallow, such as yogurt or cream soup
  • Cut your food into small pieces or mash or puree it
  • Avoid coffee, chocolate, spicy or salty foods, citrus fruits or juices, nuts, seeds, and tomatoes
  • Drink cold fluids, such as water or iced tea
  • Use a straw so the fluid doesn’t touch the canker sore to avoid the stinging pain that might be caused by fluid touching the canker sore
  • Hold ice on the canker sore until it is numb
  • Rinse your mouth with saltwater. To make a saltwater rinse, dissolve 5 g (1 tsp) of salt in 250 mL (1 cup) of warm water