2. Heavily salted foods
A Japanese study linked salted foods with a 15 percent increase in cancer. In addition, salt allows cancer-causing Helicobacter pyloric bacteria to thrive in the stomach. Researchers at Korea's National Cancer Center followed 2.2 million people and found that, like the Japanese, those who ate a lot of salty foods increased their risk of developing stomach cancer over those who had a lower sodium intake. Gastric cancer, the No. 1 diagnosed cancer in Japan and Korea, is likely due to the love of salty foods.