Scientists at the University of Southern California have recommended that fasting be especially important in patients with immune system disorders after cancer or chemotherapy, as well as in the elderly. It has been found that during fasting, stem cells capable of regenerating the human immune system grow. During fasting, the body gets rid of damaged tissues, the immune system is renewed, and during continuous fasting, the body uses up the fat and glucose accumulated in the body, and it also reduces white blood cells. Immunity grows and recovers by giving a signal to develop stem cells in the body of reduced white blood cells. Regular fasting reduces the enzyme PK-A, which is associated with aging and hormone-related cancers. Fasting for 72 hours softens the effects of chemotherapy in cancer patients. Scientists studying the effectiveness of fasting expressed their optimism that the time is near to prove that the positive effects of fasting are not limited to the immune system, but also to other systems of the human body. Not everyone will like this advice. However, it is worth reminding that everyone has the ability to limit some of their favorite things and change their thinking for the sake of their health.