Mouth Sores & Low-Acid Fruits

Mouth sores are more common than you may first think. About 20 percent of people develop canker sores on a regular basis, according to 1. Canker sores are open wounds that develop along the lining of your mouth, primarily on the inside of your lips and tongue and along the gum line 1. Most canker sores go away within one to two weeks 1. The cause of canker sores remains unclear, but eating low-acid fruits may help prevent their formation 1. Talk with your doctor before modifying your diet to treat any medical condition.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.


Canker sores are commonly confused with cold sores, which primarily develop on the outside of the mouth 1. Canker sores are typically round in shape and have a yellow or white center with a red outline 1. Before the blisters are visible, you may notice a tingling or burning sensation in your mouth. Canker sores can range from mild to severe, causing pain and discomfort when you eat 1. The University of Michigan reports that certain foods, especially acid fruits -- such as pineapple, oranges and lemons -- can aggravate the sores. You may feel a stinging sensation from highly acidic foods because of the interaction of the exposed soft tissue.

Low-Acid Fruits

Because highly acidic fruits will cause greater pain with canker sores, you should attempt to eat fruits that are considered low acidic 1. Common fruits that contain low acidic content include:

  • pears
  • sweet apples
  • raspberries
  • papayas
  • strawberries
  • raisins
  • prunes
  • bananas

Eat these fruits along with other low-acid foods, such as

  • bread
  • dairy
  • seeds
  • nuts
  • whole grains

If you notice that any of the listed foods cause increased mouth pain, stop eating that particular food.


Canker sores are typically left alone for the body to heal itself 1. If your canker sores become bothersome or do not go away, call your doctor 1. PubMed Health recommends using a mixture of half hydrogen peroxide and half water that can be applied directly to the sore. Over-the-counter medications are sold to help relieve the pain of canker sores 1. Most pain can be avoided by steering clear of highly acids fruits and spicy foods.


Some mouth sores are a result of an allergic reaction to certain foods. Common fruits that can cause an allergic reaction include tomatoes, pineapple, strawberries, melons and other tropical fruits. Most foods that are highly acidic are also highly allergenic. Avoid all known food allergies to prevent the development of canker sores 1. If you have a canker sore and are not sure where it came from, eliminate acidic foods from your diet to see if the sore goes away.