Contrary to some online claims, at this time there is no data to suggest that toothpaste is impacting the small organ in our brain that's responsible for making melatonin. Topical fluoride treatment is critical for preventing tooth decay and subsequent infections.

The World Health Organization has stated that twice daily brushing with fluoride toothpaste of a concentration between 1000-1500 ppm is a safe and effective measure to prevent cavities in infants, children, adults, and seniors. In the U.S., the Centers for Disease Control and Prevention and the American Dental Association also strongly recommend brushing with fluoride toothpaste and support community water fluoridation. 

The pineal gland is a small organ located at the center of the brain. The main function of the pineal gland is to produce melatonin, a hormone that helps regulate the body’s circadian rhythm, or “internal clock.” One function of circadian rhythm is maintaining a regular sleep cycle. 

Melatonin levels increase from childhood to adolescence and then decline with age. Research has also shown correlations between dysregulated melatonin production and age-related neurodegenerative conditions, like Alzheimer’s disease and Parkinson’s disease. 

One possible factor that may contribute to the age-related decline of melatonin is ‘calcification’ in the pineal gland (the accumulation of calcium deposits). However, the data is not clear. 

Scientists also are not certain why or how calcium accumulates in the pineal gland. One theory is that the more active the pineal gland is, the higher the chance that it will calcify. Another theory suggests that if you have certain chronic medical conditions, you have a higher likelihood of developing pineal gland calcification. 

Another factor that may affect calcification is fluoride. Fluoride is a fundamental ingredient in toothpaste that helps prevent cavities in the teeth. In some countries, it is also added to drinking water. Higher levels of fluoride in the human pineal gland have been positively correlated with pineal calcification. However, correlation does not mean causation. 

More experts have recently been carrying out research to study if any of these sources, especially fluoridated water, could be harmful in excess. Data does not currently suggest this is the case but research is ongoing and influences policy as it emerges. For instance, in 2015, for the first time in 53 years, the U.S. Public Health Service lowered its recommended levels of fluoride in drinking water.

A major limitation to current understanding about fluoride levels, calcification, and brain function is that most research is limited to cell and animal studies. Laboratory cell studies have shown that high levels of fluoride can lead to toxic effects in the brain, including inflammatory reactions, but results from animal studies are mixed. While some have shown that fluoridated water impaired learning and memory in rats, others reported no adverse effects. 

The human studies carried out have failed to identify clear connections between fluoride exposure, levels of fluoride in the human pineal gland, pineal calcification, and neurotoxicity. Importantly, some studies have shown high levels of fluoride in the pineal glands of deceased people who lived in areas with low fluoride exposure, so the source of fluoride accumulation in the pineal gland remains unclear.

Some research has shown that calcium deposits in the pineal gland increase with age. Research has also demonstrated that melatonin production decreases with age. Pineal calcification and melatonin dysregulation have been independently correlated with neurodegenerative diseases. However, more research is needed to better understand the relationships between pineal calcification, melatonin, and neurodegenerative diseases. 

Research has shown that the rate of calcification in the pineal gland goes up with age, but calcification occurs throughout life, even in newborns. Calcification is thought to possibly contribute to the age-related decline of melatonin because some studies have shown correlations between higher levels of pineal calcium and neurodegenerative diseases like Alzheimer’s. While it is possible that pineal calcification may affect melatonin production and neurodegenerative diseases, the relationships are not clear due to a lack of sufficient evidence. 

Some scientists theorize that pineal calcification reduces the brain’s melatonin levels and disrupts circadian rhythm, resulting in insomnia, migraines, and increased levels of reactive oxidative species (ROS, highly reactive chemicals formed from oxygen). Higher levels of ROS may increase the risk of premature aging and developing age-related neurodegenerative diseases. 

These experts speculate that a way to preserve the pineal gland’s function is to delay calcification. One factor that may affect calcification is fluoride. Higher levels of fluoride in the human pineal gland have been correlated with pineal calcification in some studies. However, correlation does not equal causation. 

At this time, we understand that both fluoride and calcium can build up in the pineal gland. It is possible that fluoride is related to pineal gland calcification and dysregulated melatonin production, but this theory remains debatable and more evidence is needed.