It is normal for menstrual flow to start decreasing at the age of 42. This is because after women reach the age of 40, ovarian function slowly decreases and the amount of estrogen in the body slowly decreases. At this time, menstruation will appear different from the past, such as the decrease in menstrual flow, which is a normal physiological phenomenon. It is recommended to pay attention to the diet, such as drinking more fresh soy milk and eating more royal jelly. And there are some foods you can eat more often, such as black beans, peanut butter, and onions, a small amount of red wine, these foods contain plant or animal estrogen, which will be beneficial to the continuation of ovarian function, so you can usually eat more in the diet. In addition, if your menstrual flow decreases, you can go to the hospital to check if your ovarian function has declined, and if it does, you can supplement it with diet and medication. In addition, menopause is normal after the age of 40.