1. High-fat diet is one of the most risk factors leading to breast cancer High-fat diet can change the endocrine environment, strengthen or prolong the stimulation of estrogen on epithelial hormones and increase the chance of cancer. Experts suggest that fatty and high-calorie foods should be abstained from adolescence and physical exercise should be enhanced to reduce the accumulation of excessive fat. International surveys show that the incidence of breast cancer is higher in countries with higher lipid intake. In the United States, the amount of lipids in the diet is one times higher than in Japan, and the number of women suffering from breast cancer is also one times higher than in Japan. Recently, in a seminar on diet and women’s health sponsored by the American Dietetic Association, some experts pointed out that high fat in the diet is a moderate risk factor for breast cancer, and it is a factor that must be controlled. Breast cancer can be passed on to offspring The incidence of breast cancer in patients with a family history of breast cancer is two to three times higher than normal, due to mutations in their germ cells that cause cancer. Women with a family history of breast cancer should often perform breast self-examination and have regular health checkups. Weight gain after menopause is the main risk factor for breast cancer. Weight gain after menopause is the main risk factor for breast cancer because 98% of estrogen in the body during this period comes from adipose tissue and liver, so weight gain should be controlled. The correlation between estrogen and the incidence of breast cancer has been confirmed by clinical research results. Those who apply estrogen with a total amount of 1500mg or more have 2.5 times higher risk of cancer than those who do not use it. 5.Radiation can cause breast cancer Among the survivors of the atomic bombings in Hiroshima and Nagasaki, Japan, the incidence of breast cancer is on the rise. Breast tissue is sensitive to radiation, so avoid unnecessary X-rays or other ionizing radiation as much as possible. Age at menarche or age at menopause is related to the incidence of breast cancer. The risk is 2.2 times higher for those who have menarche earlier than 13 years old than those who have menarche > 17 years old, and women who have menopause > 55 years old than those who have menopause.