2. Sweet potato also contains a substance similar to estrogen, which has a certain effect on protecting human skin and delaying aging. Eating sweet potatoes regularly helps to maintain the normal folic acid level of the human body, and low folic acid content in the body will increase the risk of cancer. Sweet potato is high in dietary fiber, which can promote gastrointestinal peristalsis and prevent constipation and colorectal cancer, and is very suitable for the elderly.