Radiotherapy is a common means of treating cancer in clinical practice. It works by irradiating cancer cells with radiation to destroy their DNA and cause them to die.

However, radiation can also damage a patient's healthy cells. Because of the environment in which intestinal cells work, they must maintain rapid renewal and are therefore more sensitive to DNA damage caused by radiation.

For example, 60 to 80 percent of patients who undergo radiation therapy for abdominal and pelvic cancer experience early intestinal damage such as abdominal pain, acute diarrhea, and nausea, which are side effects of radiation therapy.

A protein called NRF2 plays a key role in the body's response to the side effects of radiation therapy, regulating how the body fights oxidative stress and helps repair damaged DNA.

However, as people age, the level of NRF2 protein will gradually decline, so it is more difficult for the elderly to cope with the intestinal damage caused by radiation.

However, researchers at Peking Union Medical College have found that oral ingestion of NMN can protect mice with defective NRF2 protein expression from intestinal damage caused by radiotherapy, which means that NMN is expected to help elderly cancer patients resist the side effects of radiotherapy on the stomach and intestines.

The study was published in October 2022 in the journal Free Radical Biology and Medicine.