​A surge in thyroid cancer risk is associated with frequent consumption of animal foods rich in nitrites, such as processed meats.

The purpose of this study was to determine the relationship between the intake of nitrite and nitrate from food sources and the risk of developing thyroid cancer. Using validated food frequency questionnaires, researchers examined the diets of 73,317 women between the ages of 40-70 years who were recruited from the Shangai's Women Health Study. The thyroid cancer hazard ratios of all the participants in this study were also evaluated.

Researchers discovered that high dietary ingestion of nitrite-containing foods, especially animal foods such as processed meats, doubled the risk of developing thyroid cancer. On the other hand, regular consumption of foods high in nitrates was found to have no effect on thyroid cancer risk in this study. The findings of this study reveal that habitual consumption of animal foods rich in nitrites, such as processed meats, may be a contributing factor to the development of thyroid cancer in women.