Thyroid Cancer: Nutritional Considerations

As is the case with many other types of cancer, eating more fruits and vegetables, avoiding animal fat, and replacing animal products with plant-based foods appear to have a protective effect.

Certain dietary patterns may be associated with a reduced risk for thyroid cancer:

• Avoidance of animal products: Persons who consume large amounts of butter and cheese have nearly twice the risk for thyroid cancer compared with those who consume small amounts of these foods. High intakes of processed fish products and chicken were also associated with roughly double the risk for thyroid cancer, while frequent pork consumption raised the risk by about 60 percent. Retinol, a form of vitamin A obtained from animal products, including eggs and milk, increased the risk for thyroid cancer by 50 percent in persons with the highest intakes, compared with those who had the lowest intakes.
• Increased consumption of vegetables and fruits: A diet that includes large amounts of fruits and vegetables appears to reduce thyroid cancer risk by roughly 10 to 30 percent. Individuals with higher intake of beta-carotene appear to have half the risk for thyroid cancer compared with persons with the lowest intake.
  

In addition, it may be that certain components of a traditional Asian diet reduce the risk for thyroid cancer. Studies have found that cancer and other thyroid diseases occur more often among Asian immigrants to the United States than among Asians in their native countries. The explanation may relate not only to the low intake of animal products in an Asian diet compared with a Western diet, but also to the inclusion of soy and tea. When comparing lowest with highest intakes of soy products, women consuming the greatest amount had a 30 to 44 percent lower risk for thyroid cancer. Tea consumption (> 3 cups/day), another characteristic of traditional Asian diets, is associated with a 70 percent lower risk for thyroid cancer in women.