The number one food that causes most canker sores and how simple avoidance is all that is needed for most people to banish them for good! 
Chances are, you’ve suffered from a canker sore or two in your life. These painful, open ulcers on the inside of your lips, cheeks, or even your tongue seem to take forever to heal and can really cause some grief!
One young man I know in our community suffers excessively from canker sores. His frequent outbreaks are so bad that ulcers often occur not only in his mouth but also down into his throat. This causes severe pain even when swallowing sips of water.
Canker sores should not be confused with cold sores on your lips or nose that are caused by a virus and are contagious. This cold sore remedy works great for that type of skin issue.
Unlike cold sores, canker sores are not contagious. In most cases, they are the direct result of what you eat.
Even if a canker sore seems to be triggered by something else, like a scrape from a dental appliance like braces or accidentally biting your tongue, the underlying cause is still diet. In other words, the mouth inflammation was already present such that the wound that occurred in the mouth resulted in a canker sore!
That’s right! What you eat GREATLY affects whether or not you suffer from mouth ulcers on a regular or infrequent basis.
The Number One Food That Causes Canker Sores
Guess what frankenfood is the primary cause of canker sores in the Western diet?
That culprit would be high fructose corn syrup or HFCS. Manufacturers sometimes list it as corn sugar on some food labels.
High fructose corn syrup promotes inflammation in the body, which in turn impairs the immune system. An impaired immune system is thought to be the underlying cause of canker sores.
A person on a typical diet of supermarket foods is a prime candidate for frequent mouth ulcers. This is because this stuff is in everything. Plain corn syrup is problematic as well.
This is why eating too much fruit or fruit juice can cause canker sores as well. The sugar in fruit is primarily fructose. Surprisingly, it isn’t the acid in most cases that is causing the problem. Although, acidity may be a contributing factor.
If acid were the primary problem, drinking kombucha tea would also cause canker sores. Most people I know prone to mouth ulcers can drink kombucha regularly without issue.
TOO MUCH FRUCTOSE = CANKER SORES
Even agave nectar, which many consider a health food, contributes to canker sores. The truth is that agave nectar is best avoided. It is highly processed in a manner very similar to HFCS. It is neither healthy nor helpful in any way to the person consuming it. Stay away from it if you want to avoid canker sores!
I used to suffer from canker sores all the time to the point where I had at least one bothering me much of the time.
I haven’t had a canker sore now in over 25 years. Simply cutting out all HFCS from my diet easily accomplished this huge improvement in quality of life! In addition, I watch my intake of regular fructose from other sources like fruit.
If you start checking food labels, you will be shocked. Even commercial peanut butter and ketchup contain it. Simply switching to health food store brands will quickly rid it from your life in most cases.
How Much Fructose is Too Much?
A good idea is to limit your intake of fructose from all sources to no more than 15 grams per day. This is about half the amount of total sugar intake per day that can be tolerated without ill effects.
Dr. Richard Johnson MD in The Sugar Fix describes how important it is to limit your fructose intake for health and weight control.
To give you some idea, in a big, ripe banana, you’d get maybe 10 grams of fructose.
So, if you eliminate HFCS in your diet completely and eat no more than 1-2 pieces of fruit a day, that would be a good way to go.
Be aware also that going over the fructose limit of 15 g per day (25 g at the absolute most) can cause a canker sore very quickly. Sometimes, within a few hours, one or more can appear.
When my kids were younger and attended birthday parties, if they had even ONE Capri Sun juice or a half a can of soda they would invariably have a canker sore within a day or two. I trained them very early to only drink water.
Bottom line is that even if you control your fructose intake 99% of the time, consuming a single food loaded with HFCS can cause one of these baddies very fast.
Imagine what incredible damage a high fructose diet is doing to a person’s insides if it can cause an ulcer in the mouth so quickly!
So here is what has an affect on me. When I drink carbonated drinks and eat citris fruit it’s a guarantee that I will get a canker sore. I can drink non-alcoholic beer and not get one, but if in that same day I will get one. I can eat all the fruit I want and never get a canker sore. I go for a long time without one but this combination surely will give me one. Also I found that mouthwash rinse helps prevent them and for those that do appear they don’t last as long.
The doctor who wrote this article knows what he’s talking about. I never used to have any issues with canker sores. For some reason out 5 years ago, I started getting them – and when I mean getting them I don’t just mean one or two every once in awhile. I would continuously have at least three in my mouth; sometimes up to 6 or 7. It was the most terrible thing to go through. At times I wasn’t even able to talk. Up until about 4 months ago, i had had no relief for 5 years. I had seen my dentist about it, seeing my primary physician about it. No one seemed to know what the cause was or how to fix it. I began my research about one year into my suffering. I tried lysine 1000 milligrams daily, B12 every other day. (which worked fine since it took my levels to double what they should be!), had all of my blood work done, removed Gatorade from my diet- research Gatorade and canker sores – removed chocolate from my diet, bought toothpaste that does not have lauryl sulfate in it (this toothpaste DID help some; can brush your teeth when you have canker sores without too much burning sensation).. but still almost always had 1-3 canker sores. After a few years of research, I discovered website what the Pill That is supposed to prevent canker sores. After reading the testimonies, I decided to give it a try since I had exhausted on my other resources. Amazing, amazing, amazing! Have not had one single canker sore since starting this pill. I feel the need to share it with others since it took me years to find relief. They have their own website or you can Google it. Make sure you add the word “the” in front of it or it will take you to a different website. It’s called the canker spanker. Pretty easy directions. There is a dose to take when you have active outbreaks and it dose to take if you want to prevent outbreaks. It has made my life so much better. Having canker sores in my mouth continuously- on the inside of my lips, on the sides of my mouth and my tongue, down my throat.. I wasn’t able to talk normally, I wasn’t able to play with my child since getting touched on that general area caused tremendous pain, and overall gave me an ill feeling. Because of the issues I was having, I use the green pill which is severe canker sore. They also I’ll have a more standard red pill 4 canker sores. I have not tried that one I think I’ll change anything I’m doing now. I still keep Gatorade out of my diet. Very rarely I can eat chocolate. I continue to use my 18 toothpaste. First I took the severe canker sore pill twice a day for about 3 to 4 weeks. Now at a point where if I feel one coming on, I can take one per day for 3 to 4 days and it will never develop. It is so wonderful. Good luck to you all and I hope this has helped! After all, if you’ve suffered from canker sores you know exactly what I’m talking about and you would do anything for relief.
What is the name of the pill and how much it cost
Did you ever find out what kind of canker sore pill Abby E. was talking about? Thank you!
The pill is called THE Canker spanker as it says in the comment above.
I have gotten canker sores since I was little and it is due to very sensitive skin. For years I tried to avoid acidic food and still got canker sores. I get canker sores from toast, chips, crackers, popsicles, even from brushing my teeth. I get canker sores in my throat if a sharp piece of food scrapes my throat. Clobetisol gel gets rid of them, its a prescription. I have tried everything and this works the best.
I completely avoid HFCS and I still get them. I’ve been getting them since I”m 8 years old! At times during my life when I had high stress, I would get 5 in my mouth at one time, that was including the throat. ;( Very painful indeed.
I have been watching my diet & I find every time I eat red sauce, (tomatoes) pizza, grapefruit, oranges & pineapple…I will get one or two. I’ve noticed when taking B vitamins & eating healthy foods, they will not be as bad, but I can still get one.
I heard L-Lysine is a good. I will try that for a while and see what happens.
I’ve struggled with canker sores regularly since childhood. When I was 16 my Dr recommended that I take 1000mg of lysine daily. I am now 40 and can report that as long as I remained on the supplement I rarely got one. When I did they were painless & disappeared quickly. Lysine also helped with my minimal acne as a teen. I have had seasons of not taking the supplement as long as 6 months at a time. During those times I noticed a pattern of canker sores returning when I was sleeping fewer than 7 hours a night. During the periods that poor sleep was accompanied by high stress the sores plagued me until I got back on lysine. By the way, I am probably one who eats too much HFCS. Vitamin B complex seems to be helpful as well. Now my son has started getting them. The Dr told us they were hereditary & there is plenty of research available on line to substantiate his claim. From what I have researched there can be multiple causes of canker sores.
I am learning that mine are coming from a histamine response. It is not an allergy. Different people can get a histamine reaction from different foods. I make a list of foods i eat, and see a pattern. I get small ones on my tongue. Sometimes it turns into a larger lump. I also have skin problems. Same reasons. For me the canker sores are a telltale that i ate something my body doesn’t like. They show up within an hour of something i ate. Sometimes minutes. The skin is confusing, it can take days.
For me, chocolate is the biggest trigger. I used to have canker sores almost all the time. Years ago I read on wikipedia that a type of chocolate allergy can trigger them for some people, so I tried cutting out chocolate completely. Now I only get a few cankers per year, usually after eating pineapple. Other fruit even eaten in large quantities does not cause them for me. I think the cause for each person is personal, and making generalizations is not so helpful.
When do canker sores end? I’m worried because I have one and I really love eating fruits I just can’t help it and almost every night my dad gives me pears, MY FAVORITE FRUIT and I just can’t help eating it! Also does honey help cure canker sores? Please reply!!
They’re not just caused by sugar they can also be caused by food intolerances and allergies
I agree, Noah. I personally haven’t had a canker sore in years because I don’t eat tomatoes anymore. This allergy has been passed down genetically. My aunts, mother, sister, brother all get them and I’ve told them how I cured mine (they continue to get them because they continue to eat the tomatoes and think they occur for other reasons). I also cut out onions because I was experiencing indegestion. I can drink Orange Juice, eat all the fruits I want anytime I want, and I do. I can also eat all the hot spicy foods I love – especially Jalepenos! I eat very little processed foods – very little and only eat fruits and veggies fresh!
When I would eat a tomatoe – especially the large red ones – I would feel the tingling hours later in my mouth. Because I like the tingle from spices, I ignored this in the past. After reading an article on the Tomatoe allergy causing canker sores – I stopped eating them. Later I ate one to prove a point and within the next two days I woke with a mean cold sore on my lip. I vowed I would never eat them again, and haven’t had a canker sore since.
I think I have a canker sore something in my cheeks hurts!! I have been eating an apple for about 4 years or more not everyday but some days and now… 2015 something hurts in my cheeks! And also what ages have these because I’m only 10! 🙁
Wait how do I know I have a canker sore? (I have these 2 white spots on the bottom of my gums and meat and looks like a baby tooths!) but they couldn’t because I already have a full set of teeth!
If it’s on your gums you might have an abscess tooth. A canker sore will have a sharp sting like pain, usually on cheek or tongue. An abscess tooth will be a more deep pain and as it gets worse will feel like you got shot in the face.