Why countries add fluoride to public water supplies

[WORLD] Water fluoridation has been a cornerstone of public health policy in many countries for decades. This practice involves adding a minute amount of fluoride to public water supplies to prevent tooth decay and improve overall dental health. Despite ongoing debates and controversies, scientific evidence continues to support the safety and efficacy of this widespread practice. In this article, we'll explore the reasons behind water fluoridation, its benefits, and address some common concerns.

Fluoride is a naturally occurring mineral found in various water sources, soil, and air. Its unique properties make it an essential tool in the fight against dental caries, more commonly known as tooth decay.

Dr. Charlotte Lewis, a professor of pediatrics at the University of Washington School of Medicine, explains, "Fluoride is a natural mineral that can slow or stop tooth decay – also known as cavities. We all have bacteria in our mouth that combines with sugars from food and drinks to make acid. This acid can erode through teeth to cause cavities. Fluoride helps protect teeth from being damaged by the acid and helps rebuild the hard outer layer of our teeth called enamel."

How Fluoride Prevents Tooth Decay

Fluoride works in several ways to protect teeth:

Strengthening enamel: Fluoride helps remineralize tooth enamel, making it more resistant to acid attacks from bacteria.

Inhibiting bacterial growth: It can reduce the ability of bacteria to produce acid, which is the primary cause of tooth decay.

Reversing early decay: In some cases, fluoride can help reverse the early stages of tooth decay before it becomes more serious.

The History of Water Fluoridation

The discovery of fluoride's dental benefits was a serendipitous one. In the early 20th century, scientists noticed that people living in areas with naturally high fluoride levels in their water had significantly fewer cavities than those in low-fluoride areas.

This observation led to the first controlled water fluoridation program in Grand Rapids, Michigan, in 1945. The results were impressive: within ten years, the rate of cavities in children decreased by 60%.

The Effectiveness of Water Fluoridation

Numerous studies over the past 75 years have consistently shown that water fluoridation is an effective public health measure for preventing tooth decay. The Centers for Disease Control and Prevention (CDC) has even named it one of the ten great public health achievements of the 20th century.

Dr. Lewis notes, "In the current era, drinking water with appropriate fluoride reduces cavities by 25% compared to drinking water with too little fluoride."

Benefits Across Age Groups

While children are often the focus of fluoridation efforts, the benefits extend to adults as well. Studies have shown that fluoridated water can prevent at least 25% of tooth decay in both children and adults, even with widespread access to other fluoride sources like toothpaste.

The Process of Water Fluoridation

Water fluoridation involves adjusting the fluoride concentration in public water supplies to an optimal level for preventing tooth decay. In the United States, the recommended level is 0.7 parts per million (ppm).

It's important to note that many water sources already contain some naturally occurring fluoride. Water fluoridation simply adjusts this level to the optimal range for dental health benefits.

Global Adoption of Water Fluoridation

Many countries around the world have implemented water fluoridation programs. However, the extent of coverage varies significantly:

United States: Approximately 75% of the population has access to fluoridated water.

Singapore: The first Asian country to implement a nationwide water fluoridation program in 1956.

Malaysia: As of 2010, 75.5% of the population had access to fluoridated water.

Israel: Fluoridation was required nationwide from 2002 to 2014, but the requirement was later repealed.

Some countries, like Austria and Denmark, have not implemented water fluoridation due to naturally adequate fluoride levels in their water supplies5.

Safety and Regulation of Water Fluoridation

The safety of water fluoridation has been extensively studied and is supported by major health organizations worldwide. The American Academy of Pediatrics, the American Dental Association, and the Centers for Disease Control and Prevention all agree that community water fluoridation is safe and effective in preventing cavities6.

Dr. Lewis emphasizes, "Many studies have been done to understand what is the appropriate and safe amount of fluoride to be in drinking water. Reviews of research conducted by public health, academic, US and international agencies have continued to confirm the safety of community water fluoridation."

Addressing Common Concerns

Despite the overwhelming scientific consensus on the safety and efficacy of water fluoridation, some concerns persist. Let's address a few of these:

Dental Fluorosis

One potential side effect of excessive fluoride intake is dental fluorosis, which causes discoloration of tooth enamel. However, at the levels used in water fluoridation, the risk of noticeable fluorosis is low. The CDC estimates that if water contains 0.7 mg/L of fluoride, about 12% of people may have dental fluorosis that causes them to be bothered about how their teeth look.

Impact on IQ

Some studies have suggested a possible link between high fluoride levels and lower IQ scores in children. However, Dr. Lewis clarifies, "Fluoride in drinking water at the recommended level has not been linked to lower IQ scores. Some studies have noted a possible link between high fluoride levels in drinking water – more than twice the level of fluoride in US drinking water – and lower IQ scores in children."

It's crucial to note that these studies were conducted in areas with naturally occurring fluoride levels much higher than those used in controlled water fluoridation programs.

Alternatives to Water Fluoridation

In areas where water fluoridation is not feasible or implemented, other methods of fluoride delivery are used:

Fluoridated salt: Some countries add fluoride to table salt as an alternative to water fluoridation.

Fluoride supplements: These can be prescribed by dentists in areas without fluoridated water.

Topical fluoride treatments: Professional applications of fluoride varnish or gel can provide additional protection.

The Future of Water Fluoridation

As our understanding of dental health evolves, so too does the practice of water fluoridation. Recent research has led to adjustments in recommended fluoride levels to balance the benefits of cavity prevention with the risk of dental fluorosis.

The Cochrane Collaboration, a respected international organization that reviews healthcare interventions, has noted that while water fluoridation is effective, its benefits may be smaller now than in the past due to the widespread use of fluoride toothpaste and other dental products.

Water fluoridation remains a cornerstone of public health policy in many countries, contributing significantly to improved dental health over the past 75 years. While debates continue, the scientific consensus supports its safety and efficacy when implemented at recommended levels.

As Dr. Lewis concludes, "To protect your child's and your teeth, the American Academy of Pediatrics continues to recommend age-appropriate amounts of fluoride toothpaste and drinking appropriately fluoridated water to protect children's teeth."

As research continues and our understanding deepens, water fluoridation practices may evolve. However, its role in preventing tooth decay and promoting public health is likely to remain significant for years to come.