Friday April 18, 2014 (foodconsumer.org) -- A study published in a 2013 issue of the journal Annals of Oncology suggests that exposure to dental x-ray can increase risk of brain tumors.

The study led by C. H. Kao from China Medical University in Taichung, Taiwan shows that high exposure to dental x-ray was associated with a high risk of developing benign brain tumors in men and women aged an average 44 years.

Researchers analyzed Taiwan National Health Insurance claim data to see how exposure to dental x-ray would affect the risk of both benign brain tumors and brain cancers.

They found men and women who received less than one annual x-ray examination were at 33% increased risk for benign brain tumors and those who received three or more examinations were at 66% increased risk for the disease.

The study did not find an association between the frequency of dental X-ray exposure and the risk of brain cancers.  However, caution needs to be excised to interpret this observation.  The average age for the subjects for the study was 40 years.   There is no guarantee that older people who received frequent exposure to dental X-ray were not at an increased risk for brian cancer.

The researchers concluded "Exposure to dental diagnostic X-rays in oral and maxillofacial care increases the risk of BBTs (benign brain tumors), but not MBTs (malignant brain tumors)."

It has been scientifically proved that any low dose of ionizing radiation like X-ray can increase the risk of cancer.  X-ray is a type of ionizing radiation, which is a carcinogen recognized by the National Toxicology Program.  Ionizing radiation is more harmful than ultraviolet rays or UV because it can cause damage to deep tissue.

In order to reduce the risk, one may try to minimize his exxposure to dental X-ray. When a dental exam is needed, he can be better off using digital X-ray which uses a much lower dose of ionizing radiation, compared with the convental dental X-ray.

Another thing dental patients can do to minimize their risk for brain tumors is orally take high doses of some antioxidants such as vitamin C before and after dental X-ray.  Vitamin C was found in a Japanese study to help prevent radiation induced damage.

Dental X-ray may also drastically increase the risk of thyroid cancer.  

A study released in 1997 in European Journal of Cancer Prevention found female dentists and dental assistants were 13 times as likely as others to develop papillary thyroid cancer.

The study led by G. Wingren and colleagues also found 10 or more exposures to dental X-ray were associated with 250% increased risk for developing female papillary thyroid cancer.

Thyroid gland is very sensitive to radiation and very vulnerable to the damage induced by radiation.  Very unfortunately, few dental patients are offered a shield to prevent the thyroid gland from being exposed to dental X-ray when they receive a dental X-ray exam. (David Liu)