Canker Sores

This post has been a long time coming, having been a request from my roommate. Canker sores are really painful and seem to appear spontaneously. So what are canker sores and why do we get them?

What are Canker Sores?

Canker sores, also called aphthous ulcers, are shallow, open sores that can be formed on your tongue, on the inside of your cheeks or your lips. These sores are typically white in colour with a red border.

Don’t confuse canker sores with cold sores! Canker sores are inside our mouths while cold sores are usually on the outside of our mouths.

What causes Canker Sores and why do we get them?

To both questions, my answer is the same: I have no clue.

Science is still unsure of what exactly causes canker sores and why they form. There are a lot of different causes being discussed, seeming to work together. I’ve read about stress-induced sores, as well as sores that form as a result of a very citrus-filled diet (oranges, pineapples, tomatoes, strawberries). Some toothpastes and mouthwashes contain sodium lauryl sulfate, which is thought to contribute to the development of aphthous ulcers. Poor nutrition has also been linked to canker sores, specifically deficiencies in vitamin B12, iron, zinc and folic acid. These factors indirectly cause the formation of canker sores. Some doctors believe that hormones play a role too, as twice as many women as men get these mouth ulcers.

There are certain individuals that are more likely to form canker sores. There is a disease called Aphthous Stomatitis, where an individual has a weakened immune system, and can lead to canker sores being formed. There’s a theory that maybe the individual’s white blood cells irritate the lining of the cells, causing the sores.

There are also researchers who believe that there is a genetic component to aphthous ulcers that results in a higher predisposition of the sore in relation to others. If your parents or siblings had/have a lot of canker sores, then it’s highly likely that you’ll have a lot of them in your lifetime too.

Are Canker Sores contagious?

Luckily, canker sores are not contagious!! They just hurt… a lot.

How do we get rid of Canker Sores?

Canker sores usually disappear after a week or so on their own. The best thing to do to ensure that the canker sores do go away as quickly as possible would be to stay away from anything that may irritate the sores, like citric acids, spicy or crunchy foods, or sodium lauryl sulfate-containing toothpastes/mouthwashes. Also, stay healthy – make sure you are not deficient in any particular vitamins or minerals.

There needs to be more research done on canker sores to really understand what’s going on to cause them; but seeing as they usually don’t last long, aren’t contagious and pretty much heal on their own, it’s probably best that we have more people researching  other things.

American Dental Association. 2005. Canker sores and cold sores. The Journal of the American Dental Association 136: 415.

Lucille Packard Children’s Hospital. 2013. Aphthous Stomatitis. <>. June 6, 2013.

Nemours Foundation. 2013. Canker sores. <>. June 6, 2013.

Tonn, E.M.. 2012. Dental health and canker sores. <>. June 6, 2013.

Morning Breath

It’s awful when you’re sleeping over at a friend’s house (or a “friend’s” house) and you wake up only to  find that your breath smells absolutely dreadful. Morning breath is extremely unfortunate, yes, but is it really as bad as we make it out to be? It may surprise you what morning breath really represents!

Why do we get morning breath?

When we sleep, our cells are still active. They allow our hearts to beat, our lungs to intake oxygen, our muscles to move and so many other functions that we don’t even register when we’re asleep or even awake. To keep active, our cells constantly require a particular molecule, referred to as adenosine triphosphate or ATP, that helps drive several different biological reactions. They get this molecule by breaking down glucose, which we find in our diet and which other ingested sugars are usually converted to.

When we eat during the day, our bodies don’t require all of the glucose ingested, so it stores it in the form of glycogen, which is just a chain of glucose molecules.

So when we aren’t eating, our cells access these stores of glucose and break them down to produce ATP. This happens when we’re sleeping too. However, we’ve used so much of this glucose throughout the day that, eventually, our stores of glucose run low. The cells don’t want to use every single molecule of glucose, so they resort to another molecule to breakdown in order to generate ATP: fats.

That’s right, our cells use FAT; they breakdown fat for energy via a process called β-oxidation. This yields a product that, when under ‘fasting conditions’, is converted into ‘ketones’ by the liver. These ketones, which are acetones, are the culprits of the bad smell (think of the smell of nail polish remover and mix that with fruit!). The more ketones that have been produced, the worse your breath will smell but also the more fat your body has degraded… while you were sleeping.

So is morning breath really that bad? I think it’s a good trade-off, especially because the morning breath is an easy fix for most people.


So we keep hearing about these holes that form in our teeth, which are known as cavities.We know that we get cavities when we don’t brush our teeth frequently enough or properly, but what causes cavities?

What is a cavity?

Cavities are also referred to as dental caries or tooth decay. They are structural damage, such as holes, formed on our teeth.

What causes a cavity?

Remember when we talked about how there are bacteria in our mouths, some of which are selfish? Well, two selfish bacterial species, Streptococcus mutans and Streptococcus sobrinus, love to eat the food residues on our teeth. This food allows them to grow quickly and reproduce, which can lead to plaque formation, which is a problem.

But these bacteria, in addition to other bacterial species that feast on the food residues on our teeth, are also responsible for the formation of cavities. When they eat the sugars that we haven’t swallowed or digested, the bacteria oxidize the sugars; they break the sugars down into smaller molecules in their cells in order to obtain energy. The products of this break down of sugars are high acidic. They are so acidic that our teeth are unable to withstand it, and are consequently damaged slowly. This leads to the formation of structural damages and, in the case of cavities, holes!

Brush your teeth at least twice a day!

The recommended frequency of brushing your teeth is twice/day, while its duration is recommended to be approximately two minutes. If you don’t brush your teeth properly by getting every area of your teeth or if you don’t brush your teeth frequently enough, then your chance of forming cavities increases significantly. Sugars, food residues and bacteria will accumulate on the surfaces of your teeth without a good brushing routine. The bacteria will then be able to use those sugars to grow, which will result in the production of more acid, which leads to more structural damages to your teeth.


Remember when we talked about fluoride in toothpaste last week? Well, toothpastes that help to prevent cavities contain fluoride as it helps to promote strength in your teeth. This increase in strength will allow any [hopefully minimal] acid production to have a lesser effectiveness, meaning there will be less damage!

So brush your teeth often, properly with a dash of toothpaste and SMILE.


So, last week, we talked about the importance of brushing your teeth. This week, we’re going to talk about how toothpaste helps in getting rid of those bacterial plaques and even, in situations where you don’t have much else to resort to, treating acne. So how does toothpaste help us in the fight against bacteria?

What’s in toothpaste? 

According to Colgate and The US National Institute of Health, there are two main components to toothpaste:

Sodium fluoride 

Fluoride is the most well-known ingredient of toothpastes. But what does it do and how does it work? Sodium fluoride inhibits the decay of tooth enamel and promotes enamel growth! In fact, it helps make your teeth stronger when it helps remineralize them. However, once you have a cavity, the fluoride cannot help rebuild the enamel.


Triclosan is an antibacterial agent. This component works against all sorts of bacteria and is often used in disinfectants. Even though you brush your teeth, and likely dislodge a majority of the bacteria on your teeth, Triclosan acts as a second line of attack against the microbes. This helps ensure that your teeth are sparkling without you having to worry pesky plaques forming. Thanks Triclosan, you’re the best!

Toothpaste and Acne?

Triclosan is the reason why toothpaste has the potential to work against the acne induced from bacterial growth clogging your pores – it will kill the microbes, preventing further growth! But again, it’s best to use the other treatments in a regular fashion. Toothpaste treatments are a last resort, if even a resort.

Why shouldn’t we eat toothpaste?
Fluoride, while helpful to our teeth in that it prevents cavities by making our teeth stronger, is hazardous to our bodies at high dosages. The reference daily intake of fluoride is 4mg for people over the age of 4, which isn’t that much fluoride.
In fact, we can get that much fluoride from drinking 1 liter of tap water, depending on where you live.
You see, fluoride was introduced into our water to promote dental health (Hurray for you tap-water drinkers!). But the United States Environment Protection Agency has set a maximum goal of 4mg of fluoride/L of drinking water. If a city were to violate that goal, you would be at risk after drinking a liter of water just because you’ve gone beyond your reference daily intake for fluoride.
What happens when you have too much fluoride in your system?
When you’ve ingested a large amount of toothpaste, you may develop stomach pains and intestinal problems for the day. You could also experience some of the following:
  • Weakness
  • Vomiting
  • Tremors
  • Diarrhea

Worst case scenarios:

  • Seizures
  • Heart attacks
  • Difficulty breathing
  • Slow heart rate

But, again, you’d have to ingest a LOT of toothpaste. And if you ingest a lot of toothpaste over your lifetime, or even just a lot of fluoride, you increase your chances of bone fractures.

Ironic, right? What we thought to help us strengthen our teeth also has the potential to weaken our bones. So remember, little in this case is more. And don’t eat your toothpaste, no matter what flavor you bought.

Additional Sources: Seeley, R.R., Stevens, T.D., and Tate, P. 2008. Anatomy and Physiology (8th ed.). pp. 935. New York: McGraw-Hill.

Brushing Your Teeth

It’s at the start of your day and, hopefully, before you shut your eyes for bed when you brush your teeth. But why do we need to brush our teeth? Sure, the ‘scary’ dentist tells us to. Our parents scared us into it too; except when I was smaller, we were given sticker books that we got to fill for every morning and night we brushed our teeth (stickers=fun!!). But what’s the deal with brushing our teeth?

Why do we brush our teeth?

Alright, you smart alecs, I know what you’re going to say: Because it’s hygenic, Meera! Okay, yes, you’re all right, it is hygenic. But how? What are we trying brush off?

Why do we really brush our teeth?

There are several species of bacteria in our bodies, helping us perform various cellular processes but there are also some bacteria who are just selfish. There are two notable species of bacteria in our mouths; Streptococcus mutans and Streptococcus sobrinus. Both of these bacteria are greedy.

After we eat food, the food residue(sugar) on our teeth act as a buffet of sorts for these two bacteria. The by-products of this consumption of sugar are acids, which break down the enamel of our teeth. These bacteria also grow, thanks to the supply of sugars that they’ve received; their growth in a thin layer on our teeth is what we call the formation of plaque. Plaque can lead to gingivitis, which is a disease of the gums which makes them inflamed and sore.

It’s important to remember that it’s the sugars that we eat that provides bacteria with the nutrients to grow and multiply. So the more sugar we eat, the more food we’re giving to the bacteria.

So we really brush our to break down the bacterial plaque that forms on our teeth after we eat. This is why it’s necessary to brush at least twice a day; with all the sugar we consume in one day, it’s necessary that we prevent bacteria from forming plaques.

And that is how brushing your teeth is a form of hygiene. Next week, we’ll talk about how toothpaste works to help us brush our teeth.