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What causes bad breath and what can you do about it?

What causes bad breath - featured. Reflection of a woman in the mirror as she holds a toothbrush with one hand and puts the other one over her mouth

Bad breath can be distressing for the person who has it and for those around them, so what causes halitosis and what can you do about it?

Most of us have suffered from halitosis, or bad breath, at some point. Even if you use one of the best electric toothbrushes twice a day, you can still fall foul of funky breath. Since it can impact our confidence and self-esteem, we decided to speak to the experts to find out what causes it and whether it is easy to treat.

What causes bad breath?

Certain foods and drinks are often the most likely culprits behind short-term bad breath; however, for some people, the problem lingers on and, while studies vary, around a quarter of the population will suffer from sustained halitosis, potentially needing professional help.

For most of these persistent cases, the common causes are gum disease or a coating on the tongue but, for a small percentage of sufferers, bad breath might indicate a problem elsewhere in the body.

What food and drinks cause bad breath?

It almost goes without saying that what we eat and drink can cause bad breath. We are also a nation of tea and coffee drinkers but, sadly, both of these beverages have strong scents and dry the mouth, allowing odour-causing bacteria to get a hold. Experts suggest that drinking a glass of water after your cuppa will help rinse your mouth and restore the moisture levels you need for a healthy mouth. Similarly, alcoholic drinks can also dry the mouth and have a pungent smell, so the same advice applies.

Onions and garlic are on the list too. As is canned fish, which can have a smell that lingers long after your meal. Some foods can also act as fuel for the bacteria that cause bad breath, particularly sugary foods as well as some highly acidic foods, including many fruits and vegetables.

Dr Kajal Tutt is a dentist in Bexleyheath who graduated from King’s College London. She says, “Be mindful of your sugar intake and avoid foods and beverages known to contribute to bad breath, such as garlic, onions and strong spices”.

Tutt also suggests drinking plenty of water to stimulate saliva production. Another top tip is to avoid tobacco: “Tobacco products not only stain teeth but also contribute to dry mouth and increase the risk of gum disease, leading to persistent bad breath”, she explains.

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Does mouthwash reduce bad breath?

Many of us will reach for the mouthwash after eating foods we know are strong-smelling. Studies have proven that mouthwashes will reduce bad breath, especially if they contain antibacterial agents. However, their impact is short-term and there is evidence that overuse of alcohol-based mouthwashes can cause dry mouth, which can worsen bad breath. Instead, look for a mouthwash that contains probiotics to help maintain the balance of bacteria in your mouth.

You might also bear in mind that there are foods that can act as a natural mouth cleanser, including apples and melons, as well as greens like spinach, which can balance out the pH level in the mouth.

Why gut health is important

Anna Mapson is a registered nutritional therapist and the owner of Goodness Me Nutrition. She argues that it’s important to also consider gut health when you’re tackling bad breath. As she explains: “Normally we don’t have as many gut microbes in our small intestine as the large intestine. But some people can have an overgrowth of bacteria and archaea in the small bowel which create gas when they ferment the food we eat. This is referred to as Small Intestine Bacterial Overgrowth (SIBO). You might also get bloating, diarrhoea, constipation and abdominal pains. These microbes can create gas, which can cause flatulence or excessive burping. The gas [you breathe out] may have a rotten smell like old cabbages or a sulphurous smell like rotten eggs.”

People who are adhering to a ‘keto’ diet – the ketogenic diet is very low in carbohydrates and typically high in fat – may also suffer from bad breath because of the ketones produced when fat is burnt for energy. When these are in excess, you might suffer from breath that smells like nail polish remover or chemicals, says Mapson. She adds: “Keto breath is worse when adjusting to the diet, so if you’re cycling in and out of any low-carb diet, you might find this more of a problem”.

In this situation, many of us might turn to chewing gum to counter this bad breath, but you should be aware that some gums contain xylitol. While this sweetener is good for oral health – it’s even used in some toothpastes – if you are sensitive to sugar alcohols, it could worsen your symptoms. “This is because it’s a high FODMAP sugar alcohol which is rapidly fermented by the gut microbes, producing more gas”, Mapson says.

Mapson also suggests good hydration and choosing foods that keep your digestion moving. She says: “Avoid constipation and slow digestion by increasing your fibre through wholegrains, as well as a good variety of fruits and vegetables”.

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Can good oral hygiene combat bad breath?

For most people, good oral hygiene is enough to get rid of bad breath. Dr Tutt suggests brushing your teeth twice daily with an effective toothbrush and toothpaste, and flossing regularly to remove food particles and prevent plaque.

What causes bad breath. Close up of a woman smiling as she uses dental floss

She adds: “The majority of bad breath bacteria live on the tongue, so my top tip is to purchase a separate tongue scraper, like the stainless steel ones.” She also suggests regular dental check-ups for professional cleaning and “examinations to detect any underlying oral health issues early on.”

Seeking professional help for bad breath

If the problem is persistent, despite practising good oral health, professional treatment may be necessary. It’s a good idea to visit a dentist for regular checkups anyway, but Dr Tutt suggests visiting a dental professional if you notice any signs of gum disease – gingivitis or periodontitis. Tooth decay, cavities and abscesses can also result in odour-producing bacteria and a dentist will be able to spot these early on, the same applies to fillings that are going bad.

Bad breath can also be a side effect of medication or the symptom of a medical condition – including sinus infections, liver and kidney disease and diabetes – so you may need to consult a doctor or medical professional to investigate.

Good oral hygiene, awareness of gut health and making some changes to your diet will solve the problem of bad breath for the majority of sufferers. If it has turned into a longer-term issue – even if it’s only just been for more than a couple of days – our experts suggest seeking help, if not just for your own peace of mind.

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