Cancer, a potentially fatal disease, is the second most common known cause of death after cardiovascular diseases. In addition to inherited factors, cancer is also known to be affected by environmental factors such as air pollution, incorrect nutrition, and smoking. Epidemiological and experimental studies have revealed an association with nutrition. In addition to cancer-preventing substances, foodstuffs also contain substances capable of causing cancer. Additionally, hazardous substances can also form due to storage and cooking methods. However, a number of foods, healthy eating habits, and appropriate cooking methods are capable of preventing the carcinogenic effects of harmful chemical substances in the body. We hope that this book will be useful in protecting against cancer.