Normal people with a blood pH value of 7.35 or less are called acidic, while those with a pH value between 7.35 and 7.45 are alkaline, but these people account for only about 10% of the total population. It is generally recognized that an excess of acidic foods in the diet is the root cause of acidic body and related diseases, and that acidic body also affects a child’s intelligence. An acidic body is more susceptible to disease than an alkaline body. Medical evidence shows that if the human body tends to be acidic, the metabolism will be slow, the function of various organs will be weakened, aging will be accelerated, and it will be easy to get sick. What is the relationship between cancer and an acidic body? Literature reports that almost all cancer patients have acidic body, cancer cells like acidic environment, and their surrounding PH value is 6.85-6.95, which is on the acidic side. It is easy to get cancer when the human body is acidic for a long time, and the lower the PH value of body fluids is, the more suitable for the survival and development of cancer cells; the lower the PH value of body fluids of an organ, the easier it is for cancer cells to metastasize to that organ. Whether it is radiotherapy or chemotherapy, it will kill normal cells while killing cancer cells, and it will also produce a large amount of acidic substances – oxygen free radicals, which will lead to a decrease in the body pH value, lowering the body’s immune function, and allowing new cancer cells to reproduce under such an environment. Therefore, one should not just choose anti-cancer drugs with high toxicity, because the more toxic they are, the easier it is to harm the liver and kidney. Liver and kidneys are important organs for excretion of acidic substances and maintenance of acid-base balance. When the liver and kidneys are injured, the human body will be easily acidified and the cancer cells will be active again. Therefore, the relationship between cancer and acidic body is very close. International nutritional and cancer prevention organizations basically recognize that: cancer cannot form in an alkaline body; cancer can only form in an acidic body; cancer can only expand in an acidic body; if your body becomes weakly alkaline, cancer will not be able to form or expand. Food therapy is the prevention and treatment of diseases by controlling your daily diet. Foods containing phosphorus, chlorine, sulfur and other elements are generally acidic foods, such as flour, meat, grains, oil, alcohol, white sugar, etc. Foods containing more potassium, sodium, calcium, magnesium and other elements are generally alkaline foods, such as fruits, vegetables, soy products, dairy products, kelp, alkaline beverages and so on. Diet against cancer should firstly: control the intake of fat; increase the intake of protein; appropriate amount of vitamins; increase crude fiber in food; and supplement trace elements in appropriate amount. It is also necessary to consume more of the following anti-cancer foods. Vegetables: carrots, tomatoes, eggplants, asparagus, cabbage, lilies, potatoes, tofu, cucumber, bitter melon and ginger, etc.; Mushrooms: black fungus, white fungus, shiitake mushrooms, flat mushrooms, etc.; Fruits: apples, apricots, figs, rosella, strawberries, umeboshi, wolfberries, lozenges, olives, jujubes, hawthorn, walnuts, sugarcane and bananas. At the same time, do not drink carbonated beverages, sugary drinks are prohibited, drink more weak alkaline references to water, do not drink acidic water. We believe that by improving our dietary habits, we can not only adjust the acid-base balance in our body, but also minimize the incidence of cancer; it will also play an optimal role in assisting the treatment of cancer patients.