What is the thyroid?

The thyroid gland is a small butterfly-shaped gland found in the neck just below the Adam’s apple. The hormones that it produces regulate our metabolism, energy levels, heart rate, temperature, blood pressure, bone and muscle health, and brain development. To function properly, it needs a steady supply of iodine.

Unfortunately, many of us are deficient in iodine. Its main sources are:

• seafood, which many people don’t eat regularly

• seaweed, which is commonly eaten in Japan but not often elsewhere, and

• iodised salt, which many people are cutting down on or moving to sea salt or pink salt that doesn’t contain iodine.

The connection between fluoride and the thyroid

Fluorine is structurally very similar to iodine and when there isn’t enough iodine in the body, it can take its place in the thyroid. But the body can’t use it to make thyroid hormones, so you end up with hypothyroidism, low thyroid function. There have been a couple of systematic reviews, covering a large number of studies, that show exposure to fluoride has resulted in higher rates of hypothyroidism (1), (2).

The incidence of hypothyroidism is increasing around the world. I can’t help feeling that the use of fluoride in drinking water in some parts of the world, in toothpaste almost everywhere and even painted on teeth by well-meaning dentists are playing a part in this.

The symptoms of hypothyroidism are:

• weight gain

• fatigue

• feeling sensitive to cold

• dry skin

• puffy face

• hoarse voice

• weak muscles

• poor memory

• joint pain or stiffness

• hair loss.

It isn’t unusual for people to go undiagnosed if they have it mildly, as these symptoms are quite common. And the ‘normal’ range goes below what is optimal anyway, so your doctor may class you as normal when your thyroid is really underperforming.

Links between hypothyroidism and cancer

You may be wondering why I’m talking about the thyroid when my usual subject is cancer. Well, research shows that hypothyroidism is associated with some types of cancer.

A review of 14 research papers found that there was an increased risk of liver cancer and colorectal cancer but a reduced risk of prostate cancer. The research on breast cancer was mixed. Two large and one medium-sized studies found that there was a reduced risk with hypothyroidism, but another medium-sized study discovered that women with the lowest levels of thyroid hormone T4 had an increased risk. One large study found that there was no association between low thyroid function and breast cancer. They found no association with ovarian or endometrial cancers and a possible one with oesophageal and parathyroid cancers (3).

Even when tests show that thyroid function is on the low side of normal, known as subclinical hypothyroidism, another review using 9 studies found that there’s an association with an increased risk of colorectal and thyroid cancers (4).

Reducing the use of fluoride

With the use of fluoride increasing the risk of hypothyroidism, and that increasing your risk of some cancers, I recommend that you think carefully about using fluoride in any way. So how can you reduce your risk?

You can remove fluoride from your water by using a water filter. I recommend using one from Waters Co, which is the one that I use. It has up to 15 filtration stages depending on the model you buy. It doesn’t just remove fluoride, but all the other toxins, heavy metals, chlorine, bacteria, parasites and any rust, sediment or other rubbish in your water. It also remineralises the water, adding back useful minerals like magnesium and calcium, and alkalises it. You can buy it here. This is an affiliate link, so I get paid a small commission if you buy from them, which helps to maintain my website.

There are many fluoride-free brands of toothpaste on the market these days. Make sure that you find one that doesn’t use lauryl sulphates or propylene glycol, which can irritate your mouth, triclosan, or aspartame. And look for one that’s sweetened with xylitol, as it helps to kill the bacteria that cause decay. My personal favourite is Moogoo’s Moothpaste, which uses calcium hydroxyapatite as a substitute for fluoride remineralisation, and it has a whitening effect. It also tastes good. :)

At the dentist, politely decline if they offer to paint your teeth with fluoride. The use of fluoride in drinking water was introduced in some areas because in small doses it slightly improves strength of enamel in children (but not adults). But it can cause tooth discolouration and bone malformations, and can also produce brittle teeth (5). There is also evidence that it causes children’s IQs to be reduced (5). So it’s unlikely to do you much good and could do you harm.

Fluoride is just one of the toxins that I talk about in my book. Sadly, we live in a very toxic world these days. In the book, I discuss the most relevant ones for cancer patients and give advice on how you can avoid them in the most cost-effective ways. You can find out more about the book here and you can buy it by clicking the button below.

References

1.         Chaitanya NCS, Karunakar P, Allam NSJ, Priya MH, Alekhya B, Nauseen S. A systematic analysis on possibility of water fluoridation causing hypothyroidism. Indian Journal of Dental Research. 2018;29(3):358-363. doi:10.4103/ijdr.ijdr_505_16

2.         Malin AJ, Riddell J, McCague H, Till C. Fluoride exposure and thyroid function among adults living in Canada: Effect modification by iodine status. Environment International. 2018;121(1):667-674. doi:10.1016/j.envint.2018.09.026

3.         Trodello C, Higgins S, Ahadiat O, Wysong A. Hypothyroidism as a Risk Factor for Cancer: A Systematic Review and Implications for Future Studies. 4(2):1-7. doi:10.15226/csroa.2017.00136

4.       Gómez-Izquierdo J, Filion KB, Boivin J-F, Azoulay L, Pollak M, Yu OHY. Subclinical hypothyroidism and the risk of cancer incidence and cancer mortality: A systematic review. BMC Endocrine Disorders. 2020;20(1):83. doi:10.1186/s12902-020-00566-9

5.             Peckham S, Awofeso N. Water fluoridation: A critical review of the physiological effects of ingested fluoride as a public health intervention. The Scientific World Journal. 2014;2014:1-10. doi:10.1155/2014/293019