TOOTHPASTE AND ORANGE JUICE

When combined together toothpaste and orange juice taste terrible. Everyone knows this and if you don’t, you are probably one out of a million people who has never tried it out. You can experiment for yourself if you want but we don’t recommend it. Just brush your teeth and then take a sip of orange juice. It won’t kill you but it tastes terrible. So, everybody knows this but most people don’t know why. You might be surprised to know that there is actually more than one factor at play. There are multiple reasons for this alteration of your sense of taste.

Sodium Lauryl Sulfate in Toothpaste Bad with OJ

One of the reasons that orange juice and toothpaste don’t go well together is the inclusion of sodium lauryl sulfate. This is a common ingredient in countless products and is included in most types of toothpaste. It actually works in two separate ways to basically make toothpaste taste terrible. First, it suppresses your sweet receptors on your tongue. This masks any sweetness that the OJ once had. Orange juice is supposed to be sweet. Once you take that away everything starts to go down hill in terms of flavor.

The SLS doesn’t stop here though. It also destroys phospholipids. These are fatty compounds that work to inhibit your bitter receptors. They basically control and block you excessive amounts of bitter tastes. Once you stop your phospholipids from doing their job, any bitter tastes in the orange juice will be that much stronger making your toothpaste taste that much worse.

So why is SLS included in toothpaste in the first place? Why do we need / want it? Well, that is actually a controversial topic and many people will tell you that it is actually bad for you and that we shouldn’t be using it in toothpaste in the first place. That may or may not be the case but it is kind of out of the scope of this discussion so we will leave that for another day. It isn’t just about the taste with orange juice though.

The reason we have SLS in most toothpastes is to create bubbles. Yep, it boosts bubble production and that is super important. It is basically a foaming agent and is commonly used in toothpaste. It works because it is a surfactant which means that it decreases the surface tension between two different liquids allowing the creation of bubbles and thus foam. Without this frothy foam brushing your teeth would be an entirely different experience. Much of this is psychological. We feel cleaner when we have a bunch of foam in our mouths. There is also a very practical reason for this too. It helps to spread the toothpaste around and disrupt any dirt or contaminants.

Stannous Fluoride

It doesn’t end with SLS. In the game of orange juice vs toothpaste, there is another player on the field. That is stannous fluoride. This is less accepted as a contributing factor but generally seen as still playing a significant roll in destroying the flavor of OJ. It is believed that fluoride in the paste and the acetic acid in the orange juice combine causing a bad flavor. I’m not 100% clear on the mechanism but it is another source of bad taste when combining the two.

Investigations into Toothpaste and Orange Juice

The success of a toothpaste company hinges on both the effectiveness and the flavor of their brand of toothpaste. Because of this, companies employ flavor scientists to study how flavors are affected. These are people whose full time job is to study and fine tune flavors in different products. They understand the finest nuances of taste to a degree that an average person can only image. R&D teams are acutely aware of these interactions with orange juice and other things that people may combine and put in their mouths. This is not an obscure area that only a few people have ever thought about. People actually study things and it is very well understood. For some brands and product lines it may take an hour for the effect to leave your mouth.

Try It Yourself – Brush and Drink Orange Juice

Does this all hold up? Can you get around this by avoiding these ingredients? You can get toothpaste containing neither fluoride nor SLS. I’ve never tried drinking orange juice after using one of these very specific toothpastes. I would imagine that the taste of the OJ would still be affected at least a little bit, as anything with a conflicting flavor would affect it, but it is probably no where near as horrible as with normal toothpaste.

Other people can tell you how it works too:

more info from howstuffworks.com
an explaination from CNET
see it on youtube too