You probably know that mercury, lead and other heavy metals are not good for the body and can cause so many problems. But whether fluoride is safe (or effective) is more controversial.

Is fluoride beneficial?

In the early 20th century, it was discovered that small communities with higher levels of natural fluoride in their drinking water had fewer dental cavities. Water naturally fluoridated at about 1mg/L appeared beneficial for health dental.

Unfortunately, the substance that is often added to water supplies in the United States is hydrofluoric acid, not elemental fluoride or calcium fluoride. It is well known that natural substances are generally better tolerated by the body than synthetic ones.

But because early studies showed little dental decay in communities using fluoridated water, fluoridated water has become one of the top 10 public health achievements of the 20th century according to the Center for Disease Control (CDC).

However, dental caries rates have decreased in all Western countries, whether or not they use fluoridation. This suggests that there is no link between fluoridated water and fewer cavities.

Sources of fluoride

Fluoridated water is an obvious source of fluoride, but there are many others. Because there are so many sources of this compound today, it is particularly worrisome that the water supply is "fortified" with fluoride. Here are some of the main sources of this substance:

• Packaged foods and beverages (made with fluoridated water)
• Pesticides
• Tea (the plant naturally absorbs fluoride; herbal teas are good)
• Teflon pans
• Mechanically separated meat (bone fragments may be left behind)
• Industry (aluminum, fertilizers, iron, petroleum refining, semiconductors and steel)
• Fluorinated pharmaceuticals
• Dental products

For someone interested in natural health, avoiding fluoride is not that difficult.

How does fluoride affect the thyroid?

While there is some debate about the safety of this compound, it is fairly clear that it can affect thyroid function, and for anyone at risk to begin with (as many women are), fluoride is potentially dangerous. Considering that thyroid disease affects 20 million Americans (mostly women). This is an important angle to consider.

In the 1930s, a product containing fluoride was used to treat people with hyperthyroidism (overactive thyroid). Fluoride poisoned the enzymes of the thyroid gland and slowed down the production of thyroid hormones. This drug was discontinued because some people's thyroid glands were permanently damaged by its use.

Studies show that it specifically affects the thyroid gland. Studies in India have shown that children in communities with high fluoride intake have significantly decreased thyroid stimulating hormone (TSH). Another study found that people with non-fluoridated water were less likely to develop hypothyroidism.

Fluoride and iodine

Fluoride can cause thyroid inflammation and autoimmune thyroid disease (such as Hashimoto's). It is also an endocrine disruptor.

One study found that iodine levels have a direct impact on the damage that fluoride can cause to the thyroid. On the other hand, many people with thyroid disease such as Hashimoto's disease have low iodine levels, but cannot tolerate iodine supplementation either. In these cases, fluoride is particularly problematic.

How does fluoride affect the skeletal system?

It is also quite clearly involved in bone health problems. Although proponents of fluoride claim that it can help improve bone density, evidence shows that the amount of fluoride plays a very important role in whether it helps or hurts bone health.

This study looked at different populations in China with varying levels of natural fluoride in water ranging from 0.25 mg/L to 7.97 mg/L. The study found that fractures occurred less when fluoride concentrations were about 1 mg/L. But more often when they were located in the lower and upper parts of the interval. Clearly, there is a fine line between what is useful and what is harmful here.

Skeletal fluorosis is a serious bone disease that causes bones to harden and thicken, making movement difficult. It can be confused with a number of other skeletal problems, includingarthritis.

The bright side

Being healthy to begin with, especially normal levels of vitamins and minerals, can help reduce the negative effects of fluoride. One study found that normal calcium levels helped prevent fluoride-induced bone problems in rats. Another found that sufficient levels of vitamin D could be protective. In addition, another study found that magnesium-deficient rats absorbed more fluoride than rats with normal magnesium levels. And that they also had more fluoride in their bones and teeth.

What does this mean? That we can do something about exposure to this substance by doing certain things that are good for our overall health. Optimizing calcium, vitamin D and magnesium levels and following a nutrient-rich diet is an important first step.

Fluoride and the brain

It is a proven neurotoxin and many prestigious journals have reviewed the available research on the subject over the years. A 2012 Harvard review found that of the 27 studies examined, 26 found a link between high fluoride levels and reduced IQ.

New research points to the same neurotoxicity issues as previous studies. A 2017 study found that in utero fluoride exposure was linked to poor cognitive performance later in life.

Fluoride affects other parts of the body

While the effects of fluoride on the thyroid, skeletal system and brain are fairly obvious, the science is less clear on how it affects other parts of the body. Here are some other ways this substance can cause harm:

• Cancer - The link between fluoride and cancer is hotly debated. Probably because the research is inconclusive and sometimes confusing.
• Early sexual development - A researcher has found that fluoride accumulates in large amounts in the pineal gland (which secretes hormones). A 1997 study found that fluoride was associated with faster sexual development in female gerbils in the study.
• Male infertility - there is some evidence to suggest that decreased male fertility may be associated with topical fluoride use. Animal studies are of concern, but more information is needed.

So.... Should I be concerned about fluoride?

There are many conflicting opinions about whether fluoride is safe and whether there is cause for concern. Mark Sisson's opinion on this is that fluoride is not great. But that we should first focus on improving health in other ways (healthy eating, lots of sleep, low stress, etc) before worrying about filtering fluoride from the water. On the other hand, if you filter your water because of a number of other pollutants that may be in it, you may as well filter out the fluoride.

How to protect teeth without fluoride?

Although fluoride can have a protective effect on teeth, there are other ways to keep teeth healthy than coating them with fluoride.

Dental nutrition

What you eat can have an even greater impact on your oral health than brushing or flossing. Teeth are in a constant state of remineralization, as saliva in the mouth provides minerals to the teeth and the cells in the teeth use these minerals to strengthen themselves.

Diet can play a huge role in this process (and the health of your teeth). According to the research of Weston A. Price (and others), a diet rich in healthy fats, vitamins and minerals can help heal and protect oral health.

Balancing hormones

Hormones can have a huge effect on oral health because they can control the acid-alkaline balance in the mouth. They also affect the body's ability to heal or fight disease. Many of us have symptoms of hormonal imbalance. And things like optimizing sleep, stress, diet and fitness can make a big difference in hormonal health (and oral health).

Sources:

Are fluoride levels in drinking water associated with the prevalence of hypothyroidism in England? A large observational study of general practice data and levels in drinking water. https://jech.bmj.com/content/69/7/619

Li, Y., Liang, C., Slemenda, CW, Ji, R., Sun, S., Cao, J.,. . Johnston, JR (2001, May). Effect of long-term exposure in drinking water on bone fracture risk. https://www.ncbi.nlm.nih.gov/pubmed/11341339