5 foods that could be causing bad breath

Are certain foods likely to be the culprit of this embarrassing symptom?

Emma Thornton
Qualified Nutritionist (BSc, MSc, RNutr)
Ask Emma

15 February 2019

1. Garlic and onions


Onions and garlic not only smell strong whilst we are preparing or cooking them, but this potent smell can linger as we ingest them too, but why? Onions and garlic are rich in sulphur containing compounds which can kick up a stink. Onions and garlic also fall into a category of foods called FODMAPs. This means they aren’t broken down fully by the time they reach the large intestine. Instead, they’re fermented and broken down by the bacteria that reside there and in doing this; excess gas is produced, which can result in some extra flatulence if you’ve overdone it or are particularly sensitive.

What can be done to help?

Certainly don’t limit eating onions and garlic unnecessarily, both of which are very good for you. If you’re worried about the smell they produce just make sure you combine them with lots of other ingredients which aren’t so potent – variety is key after all!

Why not pair them with some vibrant vegetables rich in vitamin C and soluble fibre including Brussel sprouts, broccoli or bell peppers. Vitamin C is thought to help counteract gum disease which could be a contributing factor when it comes to bad breath. Also, if you opt for crunchy vegetables you can help to clean your teeth and gums in the most natural way possible – so get gnawing!

2. Fish


Fish, especially in the tinned or smoked form, can be particularly smelly initially, but could it also contribute to bad breath some time later? 

Fish is high in protein (and rich in healthy omega-3 fats if you opt for the oily varieties) both of which require a little extra digestive power to breakdown. As a result, they can also delay gastric emptying, which, in turn, could contribute to smelly breath.  As fish is broken down it also releases a compound called trimethylamine, which can give rise to that distinctive ‘fishy smell.’ However, that’s not to say fish should be avoided completely, yet again, just ensure you cook it well and eat it alongside balanced meals. As always, oral hygiene, such as regular flossing, is also important, but that’s a given – right?

What can be done to help? 

Oily fish is a good addition to any diet, so rather than cutting down on vital sources of protein and essential fatty acids, why not pay some special attention to your stomach instead? 

We need sufficient stomach acid to break down protein and fat rich foods (be it your fish dinner or peanut butter snack), so without sufficient gastric secretions we risk increasing our chances of having bad breath at the very least!

To help support your stomach, why not introduce a herbal bitter tincture before meals, such as Yarrow? This helps train your stomach into getting those sufficient juices flowing so your fishy meals will no longer faze you.

3. Dairy


Dairy products are another common culprit that could be contributing to bad breath. Dairy products are thought to be mucus-producing which means they can exacerbate symptoms such as the post-nasal drip, which over time can create the proliferation of bad bacteria at the back of our mouth and the smell that comes with it. 

Then, again, much like garlic and onions, most dairy products also contain amino acids that, when broken down by the bacteria in your mouth, give off hydrogen sulphide which can cause up a bit of a stink. 

Thirdly, people often struggle to break down dairy products sufficiently due to a lack of the necessary digestive enzymes. This can contribute to tummy upset and delayed gastric emptying, which are also thought to be common triggers for bad breath.

What can be done to help? 

If you suspect dairy products are contributing to bad breath or digestive discomfort, it might be worth trying to work some plant-based, dairy alternatives into your diet to see how you get on. 

Interestingly, when it comes to yoghurt, there are some conflicting opinions out there as to whether or not yoghurt can contribute to, or help counter, bad breath. In theory, if yoghurt is probiotic-rich, then this content of good bacteria should help support your digestive system and, in turn, help keep symptoms such as bad breath at bay. However, in reality many yoghurts are packed full of sugar which are only going to make the issue worse. If you fancy trying the probiotic approach, instead go for a good quality supplement such as those in the Optibac range, and support them with a prebiotic such as our Molkosan.

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4. Spicy foods


Pungent spices can leave a strong-smelling layer in your mouth that can be hard to shift – particularly if you’ve consumed them as part of a curry with a base of onions and garlic! It’s also worth considering that capsaicin, the active ingredient in chilli that gives it its fiery kick, can cause havoc with your digestive system – it can act as an irritant. 

Basically, if bad breath is a worry for you, it could signal that your digestive tract is under a little turmoil, for example, altered bowel movements, an upset in the balance of bacteria or delayed gastric emptying could be at play, so considering different aspects of your diet is worth doing until things start to settle.

What can be done to help?

Swap in some herbs instead if you’re worried too many spices aren’t going down so well. Herbs are extremely fragrant and better still, are thought to be neutralising when it comes to bad breath. 

Opt for fresh herbs such as parsley for garnishing dishes and if you can’t quite get away from spices, why not try some gentler options such as fennel and ginger which have been traditionally used to promote digestive calm.

5. Don’t forget about problem drinks 


It’s not just foods that could be contributing to bad breath but drinks too. Alcohol, coffee, sugar or artificially-sweetened drinks are all likely culprits. Alcohol and caffeinated drinks such as coffee risk drying your mouth out. This can give bad bacteria the chance to flourish and, in turn, contribute to bad breath. These options also put pressure on your liver which can contribute to a whole host of digestive symptoms, including bad breath.

If you think soft drinks will let you off lightly then you’re wrong. Excess sugar and sweeteners will quickly disrupt your gut bacteria, which can kick up quite a fuss and contribute to bad breath. 

Also, if you think your ‘diet’ is in tip top condition with all your ‘diet juices’ then unfortunately you may also be quite mistaken. Following very low calorie or ‘low-fat’ fad diets could tip your body into a state of ketosis (using fat for energy rather than carbs) with which, bad breath is a common side effect.  

What can be done to help?

Swap in water for all the alternatives as much as possible to help keep your digestive tract flushing through. If you feel you need an alternative with some taste, try popping some fresh fruit in to add some natural flavour or opt for a herbal, green tea or a coffee alternative such as Bambu instead of some of the more precarious caffeinated varieties.

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