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!
This is good to know. I noticed a canker sore on my 1 yr old's tongue a few weeks ago and while she doesn't eat a lot of processed foods (hardly any, I'd say), she has a lot of fruit. I've been trying to cut back on her fruit intake and counter it with more meats, cheeses and vegetables. It takes some effort, that's for sure, but it'll be better for her!
Hi Jane, all sugars including fructose are bad when consumed to excess. Fructose is easier to digest but this doesn't make it better or mean that you can eat a lot of it. Once the gut heals, then double sugars can be consumed again and they must be consumed in moderation as well. Even raw honey, a fantastic sacred food, must not be consumed to excess else is will cause problems.
Found this post intriguing and left with a question. You advocate reducing fructose. What I'm not clear on is whether fructose is worse than other forms of sugar? The GAPS diet recommends honey and fruit as sweeteners because they are easier to digest. So is it that fructose is per se is so bad or is it just sugars overall?
Thanks.
Great point, thanks. In my experience though, HFCS will cause a canker where the same amount of sucrose will not. Perhaps the heavy processing has something to do with it. And, I believe HFCS has more fructose to glucose ratio than sugar (55/45)?
As a point of interest, HFCS and table sugar have about the same chemical balance of glucose and fructose, about 50/50. The "high" in high fructose is in comparison to regular corn syrup, which has no fructose. Scientists figured out a way to chemically alter the HFCS to contain more fructose so it would taste sweeter. My point is that most forms of sugar are high in fructose, not just HFCS. If you want to avoid canker sores, you have to avoid sugar in general, not just HCFS.
Hi Cyn – cold sores are a virus so anything that would keep them at bay would work. Cod liver oil, coconut oil (very antiviral), keeping vitamin D levels optimal all would help considerably. Eating right in general and keeping the refined sugars out of the diet and natural sugars at a minimum helps too. The gut is 80% of immunity so keeping that gut in ship-shape is the best way to go.
Lysine always helps me get rid of one in a day or two.
I used to get canker sores all the time. Since I've been on the GAPS diet, I haven't gotten any. I've also noticed since being on GAPS that I don't have to get up and go pee in the middle of the night.
Great post!
Tina
Sarah,
Something I noticed this past week when I had THE best cinnamon rolls in the world made for us by my dear neighbor, is acid indigestion! I had it two night in a row after eating one (each day) of those! (I hate to say it, but totally worth it!!) I had pretty much cut out all sugar except what occurs naturally in fruit, so I am pretty sure it was the sugar that caused the indigestion.
Any ideas for a true cold sore? They seem to run in our family. Not me, but occasionally my husband, and 2 of my kids.
Thanks,
And I love your little video clips! Very informative!
Cindy
I agree canker sores are so painful. For me checking out all toothpaste shampoo etc for Sodium Lauryl Sulphate,(even from the health food store) and also checking out prescribed medicines for SLS
along with reducing sweets cured mine. It is such a relief not to have those nagging sores, and hope this may help someone.
I was just thinking about this the other day. I used to be plagued with canker sores all the time. I would get especially bad outbreaks after a trip to the dentist and/or before a high stress event. Now, I cannot remember when I last had one. It's been almost 3 years since I've had soda, or sweetened coffee drinks from Starbucks, or any of my old treats and I honestly don't miss them or the canker sores either!