The many causes of halitosis (bad breath) and how to avoid having it

DURING the early 20th century, Listerine, the antiseptic solution named after scientist Joseph Lister, was looking for a purpose.

Since the late 19th century it had been used variously as floor cleaner, surgical disinfectant and even a deodorant.

Upon seeing the word halitosis in a medical journal in 1923, Listerine heir Gerard Lambert struck upon a plan that would seal the future of their product. Halitosis, of course, is otherwise known as bad breath (a mixture of the Latin “halitus”, meaning breath, and the Greek suffix “osis”, meaning diseased).

From then on halitosis was the focus of a rebrand that led to campaigns in the Thirties attempting to capitalise on fears of social rejection with tag lines like “often the bridesmaid, never the bride”.

They were clearly on to a winner as, like it or not, bad breath is something we all experience from time to time.

Of course, this is perfectly normal, for example, in the mornings before we brush our teeth, but on occasion bad breath can shift from what is considered normal to what might be classed as pathological and there are all sorts of reasons why this might arise.

According to one survey, two in five adults don’t go to the dentist regularly and two in three people have visible dental plaques. These plaques are essentially biofilms of bacteria which build up if there is an abundance of food debris for them to feed on.

Any malodour that follows is not from the plaques themselves but from the gases produced as all the food is broken down by bacteria.

The more stuff there is to break down, the more bacteria develop and the more gas is expelled.

Our mouths are home to literally billions of bacteria, much of it beneficial, but not all.

That’s why anyone unfortunate enough to have been bitten by another human (think Saturday nights in accident and emergency) earns an almost automatic course of antibiotics.

Generally speaking, having a moist, saliva-rich mouth means that bacteria that build up in the mouth are washed away more easily, so medications or medical conditions that create a dry mouth (xerostomia) might also contribute to a greater risk of distinctly whiffy breath.

Our mouths are generally quite dry in the mornings and even more so for those who mouth breathe while they are asleep, hence the particularly malign morning breath in those individuals. Smoking is another big cause of this.

Bacteria love to feed off sugar. It therefore also follows that people with a sugar-rich diet are more prone to halitosis.

As food is broken down, bacteria that produce hydrogen sulphide cause a smell akin to rotten eggs while others that produce methyl mercaptan cause a smell more like cabbages.

Limiting your intake of sweets and citrusy fruit therefore might be an idea if this sounds like you.

Regular alcohol also increases your risk of bad breath. One study found that heavy drinkers had higher populations of some of the more culprit bacteria within their mouths.

Coffee is perhaps more contentious. On the one hand, it can dry the mouth out like smoking and in combination with things like milk it is thought to ferment into bad breath. On the other hand, on its own it is fairly neutral. It then becomes a question of whether you like coffee breath or not.

Particularly deep or pitted tonsils also encourage bits of food and mucous to stick around — another fuel source for the smell-inducing bacteria. Occasionally these will compact into foul-smelling pale lumps known as tonsil stones. Gargling regularly with water or mouthwash at the back of the mouth can help limit this.

An unfavourable odour produced within the mouth will likely be smelled only via the mouth itself and not from air expelled from the nose.

On the other hand, a bad sinusitis can cause foul-smelling air to come from the nose rather than the mouth.

However, it is possible that if the breath is malodorous from both mouth and nose then the cause is elsewhere. This could include gastroesophageal reflux or an infection within the stomach involving the bacteria Helicobacter pylori or in the lungs in a pneumonia or a more chronic condition such as bronchiectasis.

Those with advanced liver disease might experience bad breath through a build-up of unpleasant chemicals shunted from the blood flow through the liver into the main circulation, something known as foetor hepaticus (foetor being the Latin word for “stench”).

Accumulation of proteins called ketones in the bloodstream can also produce a characteristic sweet smell likened by some to pear drops or by others, in bizarre contrast, to faecal smells.

Such a smell is often a vital sign in diabetic patients when their bodies are not processing their sugar properly, resulting in a rapid and dangerous rise in ketones (diabetic ketoacidosis).

A similar process can lead to alteration of one’s breath when participating in crash diets.

Of course there are more transient forms of bad breath too. Those partial to spicy food or onion, or garlic-rich diets will undoubtedly tend to smell of their chosen food stuff.

The good thing with that is that it’s entirely predictable so one can schedule such a meal for times after which one will have little human contact.

Such odours aren’t classified as halitosis. In other words, they are not pathological.

I often ponder people’s breath when watching grand period dramas or films. While that may seem weird, consider for all their finery what options these historical characters may have had to keep their breath from smelling bad. Today we have toothpaste, only around for 100 years or so. I’ve already mentioned mouthwash.

Is it conceivable that people’s breath was indescribably bad before the advent of these daily rituals? Not necessarily. We must take into account the diets we enjoy in modern times. Sugar in particular has become practically a staple now whereas, a few hundred years ago, it was a delicacy and only available to the rich.

That said, even the ancient Babylonians recognised the need to clean one’s teeth — after all, dental decay and infection could be far more serious back then without the treatments we have available now (apparently they had only twigs to do that job).

The ancient Egyptians used various herbs and spices mixed with honey to create sweets meant to sweeten the breath.

In perhaps a more outlandish suggestion, Pliny the Elder advocated the use of rubbing one’s teeth with a concoction made from the ashes of burnt mouse-dung and honey.

It is safe to say that our ancestors hadn’t fully got to grips with really effective oral hygiene and this is borne out by the extensive presence of dental decay noted in Egyptian mummies.

Whether or not Tutankhamun had halitosis though it is difficult to say. One would hope that, if the famous pharaoh were alive today, he would have a fair chance of maintaining minty fresh breath.

His court physicians would, I’m sure, recommend the following measures:

• Modest intake of alcohol only

• Avoidance of cigarettes

• Balanced and healthy diet low in sugar

• Daily routine of twice daily teeth cleaning using fluoride toothpaste

• Supplementation of that with twice daily flossing and/or interdental brushing and perhaps a mouthwash to top it off.