Doctor Zac Turner busts massive mouthwash myth

It’s part of the morning routines of countless Aussies – and now, a doctor explores whether using it does more harm than good.

Welcome to Ask Doctor Zac, a weekly column from news.com.au. This week, Dr Zac Turner explores whether mouthwash is good for you.

QUESTION: Hi Dr Zac, I was scrolling through Instagram and came across a doctor who made some pretty wild claims about mouthwash – he said it can cause cancer, heart disease and gum disease – and that tongue scrapers are a much better option. I use mouthwash every day, morning and night, so I wanted to get a second opinion from a doctor who doesn't make a living from going viral on social media. So what’s the truth – is mouthwash bad for my health? – Chynah, 23 Gold Coast

ANSWER: Thanks Chynah – it’s such a great question – and you know how I love busting social media myths.

We’ve all been told to swish and spit for a minty-fresh mouth, but what if that post-rinse zing comes at a cost? Could mouthwash be doing more harm than good?

There’s been a lot of talk about the old toothbrush-and-tongue-scraper routine edging out our beloved mouthwash.

So, let’s dive into the truth about mouthwash and whether tongue scraping really is the healthier way to go.

Mouthwash is the holy grail for fresh breath, but it’s got a few skeletons in the cupboard.

The good news? Yes, it can kill off the nasty bugs in your mouth that cause bad breath. The bad? It doesn’t discriminate. It kills the good bacteria too – those silent allies that help keep everything balanced.

Too much mouthwash, especially the ones with strong antiseptics, can knock out the bacteria we actually need. This can lead to dry mouth, upset the mouth’s natural microbiome and in extreme cases, contribute to oral thrush. Not exactly what you signed up for with a quick rinse.

Should you use mouthwash? Picture: iStock

The mouth has a delicate ecosystem.

Research published in Frontiers in Cellular and Infection Microbiology found that the regular use of antibacterial mouthwash lowers the diversity of bacteria in your mouth. Less diversity can be an issue, as it could allow more aggressive strains to take over, leading to inflammation or, ironically, bad breath.

So while mouthwash can give you that minty moment, it may actually work against your long-term oral health.

Here’s the twist: some bacteria in your mouth aren’t just there to keep your teeth company. They help produce nitric oxide, a compound crucial for regulating blood pressure, so the Instagram reel was right about that part. Studies in Free Radical Biology and Medicine revealed that mouthwash could interfere with these good bacteria, decreasing nitric oxide production. So if you’re battling high blood pressure, you might want to think twice before making mouthwash a twice-daily habit.

Does alcohol in mouthwash raise cancer risk?

This one’s a bit controversial. Mouthwashes with alcohol have been the subject of debate, with concerns that frequent use could heighten the risk of oral cancer. Alcohol can dry out and irritate the mouth’s lining, which some worry could pave the way for cancerous changes over time.

A recent meta-analysis in the Journal of Oral Medicine and Oral Surgery didn’tconfirm a strong link but hinted that, when in doubt, alcohol-free mouthwashes might be the safer bet.

Alcohol-free mouthwashes might be the safer bet. Picture: iStock

Enter the tongue scraper: The ancient tool making a comeback

When it comes to oral health, sometimes less is more. That’s where tongue scraping comes in. Unlike mouthwash, a simple scrape doesn’t disrupt your oral microbiome; it just removes the gunk that builds up on the surface. Studies back this up: scraping can be even better than brushing the tongue alone for reducing those pesky sulphur compounds that cause bad breath, according to research in the Journal of Periodontology.

Tongue scraping doesn’t mess with the bacteria needed for nitric oxide production, meaning it’s heart-friendly too. It’s super simple and can become part of your morning ritual easier than you’d think.

It doesn’t have to be an either/or situation. Mouthwash and tongue scraping can be great teammates if you use them wisely. If you like that ultra-fresh feeling, try keeping mouthwash as an occasional backup rather than an everyday staple. And if you’re really set on the rinse, opt for an alcohol-free version with natural ingredients like aloe vera or tea tree oil, which are gentler on the mouth.

Tongue scrapers are making a comeback. Picture: iStock

So, is mouthwash bad for you?

The bottom line? Like anything, moderation is key. Swishing occasionally, especially with an alcohol-free formula, won’t hurt.

But if you’re looking for a low-risk, scientifically-backed way to keep your mouth in check, tongue scraping is a solid choice. With none of the potential downsides of mouthwash, a daily scrape can do wonders for your breath without messing up your microbiome or putting your heart health at risk.

In the end, it’s about balance. Embrace the tongue scraper for a fresher, healthier mouth and keep the mouthwash for those days when you need an extra boost.

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Dr Zac Turner is a medical practitioner specialising in preventive health and wellness. He has four health/medical degrees – Bachelor of Medicine/Bachelor of Surgery at the University of Sydney, Bachelor of Nursing at Central Queensland University, and Bachelor of Biomedical Science at the University of the Sunshine Coast. He is a registrar for the Australian College of Rural and Remote Medicine, and is completing a PhD in Biomedical Engineering (UNSW). Dr Zac is the medical director for his own holistic wellness medical clinics throughout Australia, Concierge Doctors.