Fluoride in New Zealand’s Water: Safe, Effective, and Backed by Science

What is the latest research on fluoride?  

If you are concerned about fluoride exposure, the latest research from New Zealand’s health community may put your mind at ease.  

What you need to know about fluoride in New Zealand 

In 2014, the Royal Society Te Apārangi published a review looking into the health effects of fluoridation in New Zealand. The review found that there were no adverse effects arising from fluoride use in our water supply. In 2021, they published an updated version of their review. Here is what they found: 

• New research has found that at very high levels and with chronic exposure fluoride could have negative neurodevelopmental impacts. This is not a concern in New Zealand as the level of fluoride added to our water supply is very low and has been proven to be safe. 
• While it is possible to be exposed to higher levels of fluoride than what’s necessary to keep teeth healthy, researchers haven’t found any adverse effects arising from fluoride exposure in New Zealand. 
• Excessive fluoride intake at levels found in the New Zealand water supply (and combined with fluoride exposure from other sources) does sometimes result in dental fluorosis. This causes opaque white spots on our tooth enamel but isn’t harmful to the health of our teeth. These spots also go away over time. 

You can read more about the updated evidence in the Office of the Prime Minister’s Chief Science Advisor’s summary here. 

Why do we need fluoride in our water supply? 

Fluoride is a naturally occurring substance found in water and helps to prevent dental cavities. In New Zealand, the level of fluoride found in our water supply is too low to protect our teeth health. As a result many towns and cities made the decision to fluoridate their water in the 1960s.  

There’s now over 60 years of data on fluoridated water in New Zealand. One oral health survey from 2009 showed that children with access to fluoridated water experienced around 40% less tooth decay than children that don’t have access to fluoridated water. 

Why can’t I just use fluoridated toothpaste? 

While there are other ways to add fluoride to your diet, adding it to the water supply is important for the health of all kiwis. It’s an important contributor to equal health outcomes for underserved communities. Fluoridated drinking water provides some of the greatest benefits for Māori, Pacific communities and children.  

Fluoridating our drinking water is more cost-effective than spending money on other public health measures that may improve oral health at an individual level. 

Why is fluoride considered controversial? 

Claims that fluoridated water contributes to health conditions or interferes negatively with the body aren’t supported by scientific evidence. Fluoride toxicity that occurs at very high levels should not be confused with any effects that can occur from the levels found in community water supplies. Unfortunately, many studies that make these claims don’t distinguish between very high levels and safe drinking levels.  

Are there any side effects of fluoride at levels found in New Zealand? 

No severe side effects of fluoridation have ever been reported in New Zealand but mild forms of dental fluorosis are possible. Mild cases have been found in children living in fluoridated and non-fluoridated areas. Fluorosis reflects overall fluoride absorption at a young age. Children that regularly swallow toothpaste can develop higher levels of fluoride in their system. 

How can I be sure that fluoride is safe? 

With around 60 years of research into fluoridation rates in New Zealand, dentists and health officials have plenty of evidence that drinking fluoridated water is safe. In 2015, a report into national and international data estimated that fluoride is responsible for: 

• A 40% reduction in tooth decay among children and teenagers 
• A 48% reduction in hospital admissions for the treatment of tooth decay in children aged 0-4 
• A 21% reduction in tooth decay among adults aged 18-44 
• A 30% reduction in tooth decay among adults over 45 years 

In short, research supports that everyone benefits from fluoridated water supply in New Zealand! 

What if I still have concerns about fluoride? 

There are many resources about the safety of fluoridated water in New Zealand. If you’d like to learn more, the Ministry of Health is a great place to start. There you’ll find links to reviews by the Office of the Prime Minister’s Chief Science Advisor, the Royal Society of New Zealand Te Apārangi and the Ministry of Health’s 2024 updated review – all sources we have mentioned in this article. 

You can also talk to your dentist about the best ways to protect your teeth. At Gentle Dental, you’ll receive judgment free advice, and comfortable care. Book your first appointment today.