Is there evidence of harm from fluoride exposure through toothbrushing or community water fluoridation (Community Water Fluoridation)?

From the Guidelines

There is limited evidence for harm from fluoride in toothpaste or water at recommended levels, but excessive ingestion, especially in young children, can lead to dental fluorosis or other health issues. For toothpaste, the main concern is dental fluorosis (white spots on teeth) if young children swallow excessive amounts, which is why children under 6 should use only a pea-sized amount of fluoridated toothpaste and be supervised while brushing 1.

Key Considerations

• The risk of dental fluorosis is associated with the swallowing of fluoride toothpaste, particularly in children under 6 years old, as they may not have full control over their swallowing reflex 1.
• Water fluoridation, at the levels used in public water systems (0.7 parts per million in the US), is considered safe and effective for preventing tooth decay, with extensive research supporting its benefits 1.
• Some studies have suggested potential concerns about very high fluoride exposure and effects on IQ or thyroid function, but these findings typically involve fluoride levels much higher than those in regulated water systems.

Recommendations

• Children under 6 should use only a pea-sized amount of fluoridated toothpaste and be supervised while brushing to minimize the risk of dental fluorosis.
• Communities should maintain optimal fluoride concentrations in drinking water to reduce the risk of dental caries, while also being vigilant about the potential for fluoride overfeeds and taking immediate corrective action if they occur 1.
• The benefits of fluoride for dental health are well-established, with water fluoridation reducing tooth decay by about 25% in children and adults, and the consensus among major health organizations is that fluoride at recommended levels in toothpaste and water provides significant public health benefits with minimal risk.

From the Research

Evidence of Harm from Fluoride

• There is evidence to suggest that excessive fluoride exposure can cause harm, including dental fluorosis, skeletal fluorosis, and other health problems 2, 3, 4, 5.
• A systematic review of epidemiological and toxicological evidence on health effects of fluoride in drinking water found strong evidence for reduction in IQ scores in children and moderate evidence for thyroid dysfunction 2.
• Another study found that excess amounts of fluoride ions in drinking water can cause dental fluorosis, skeletal fluorosis, arthritis, bone damage, osteoporosis, muscular damage, fatigue, joint-related problems, and chronicle issues 3.
• A review of the literature on water fluoridation's effectiveness and dental fluorosis found that the prevalence and severity of dental fluorosis have increased since 1945, with 40% of fluorosis due to water fluoridation and 60% due to other fluoride sources 4.
• A study on the benefits and risks of fluoride ingestion found that moderate dental fluorosis occurs in 1 to 2% of the population exposed to fluoride at 1 mg/l in drinking water and in about 10% of the population at 2 mg/l 5.

Sources of Fluoride Exposure

• Fluoride can be found in drinking water, dental hygiene products, and food supplements 2, 6, 3.
• The use of fluoride-containing toothpaste is a significant source of fluoride exposure, and the preventive effects of conjoint exposure (e.g., use of fluoride toothpaste in a fluoridated area) are additive 6.
• Other sources of fluoride include infant formula feeds, fluoride tablets, and contaminated soil and water 6, 3.

Health Effects of Fluoride Exposure

• Dental fluorosis is a well-documented health effect of excessive fluoride exposure, with moderate fluorosis occurring in 1 to 2% of the population exposed to fluoride at 1 mg/l in drinking water 2, 4, 5.
• Skeletal fluorosis is another health effect of excessive fluoride exposure, with reports of crippling skeletal fluorosis associated with low concentrations of fluoride in drinking water in tropical countries 3, 5.
• There is also evidence to suggest that fluoride exposure may be associated with reduced IQ scores in children, thyroid dysfunction, and other health problems 2, 3.