Introduction: Every five years, the American Cancer Society (ACS) publishes a report on the relationship between diet, nutrition, and physical activity and cancer prevention, which serves as a guideline for scientific knowledge dissemination to the general public, communication among health organizations and community groups, and the development of relevant policy guidelines. With research findings showing that China accounts for more than 20% of the world’s new cancer patients each year, the guide will increase awareness of cancer among patients and physicians. The American Cancer Society (ACS) publishes a report every five years on the relationship between diet, nutrition, and physical activity and cancer prevention, which serves as a guideline for scientific knowledge dissemination to the general public, communication among health organizations and community groups, and policy development. The guideline recommendation can be more objective to explain and answer the questions that patients and their families have doubts about, and we hope that we can look at the problem in a scientific attitude and not believe the rumors that can harm others and ourselves. 1.Breast Cancer The most common tumor in American women, the second most common cause of death for women’s cancer, second only to lung cancer. Postmenopausal women who are overweight have a significantly increased risk of developing breast cancer. This is related to excess fat leading to high estrogen levels in the blood. Excessive alcohol consumption and inadequate folic acid intake also increase the risk of breast cancer. Physical activity can reduce this risk. Colorectal cancer is the second leading cause of cancer deaths in the United States. Obesity is directly related to it, and it is especially significant in men. Massive intake of vegetables and fruits and grains with crude fiber, reducing the intake of red meat and processed meat, proper intake of vitamin D and calcium, as well as strengthening daily physical activity can reduce the risk of its occurrence. In addition, regular screening, timely detection and removal of intestinal adenomas (precancerous lesions) are also crucial. 3.Lung Cancer The number one cause of death from cancer in the United States. More than 85% of the patients’ morbidity is related to tobacco. Smoking cessation and high intake of vegetables and fruits can help reduce its occurrence. But be careful: excessive consumption of health food containing carotene and vitamin A, on the contrary, will make smokers of lung cancer risk factor increases. Endometrial cancer is the 4th most common cancer among women in the United States. Endometrial cancer is related to estrogen level. Through a lot of exercise, increase the intake of vegetables, fruits, crude fiber food and beans, and maintain a healthy weight can reduce the possibility of its occurrence. Kidney cancer accounts for 3% of cancer incidence and death in men and 2% in women. Directly related factors are obesity and smoking. Therefore, it is especially important to quit smoking and maintain healthy weight. Pancreatic cancer is the 4th leading cause of cancer death in the United States. Smoking, type 2 diabetes, excessive consumption of red meat and insufficient physical activity are extremely related to it. Cancer of the upper respiratory and digestive tracts Alcoholism and smoking significantly increase the likelihood of cancers of the oral cavity, pharynx and esophagus. Diet overheating leads to esophageal burns, which can trigger chronic inflammation of the esophagus and eventually deteriorate into esophageal cancer. Changing bad dietary habits, quitting smoking and drinking, losing weight and eating more fresh vegetables and fruits are conducive to reducing the risk of its occurrence. Prostate cancer is the most common cancer among American men. Eating more tomatoes, cauliflower, beans and fish can help reduce the risk of its occurrence. The protective effects of vitamin E and selenium and the corresponding supplemental health foods are not yet conclusive. Excessive calcium intake, on the other hand, has been associated with highly malignant prostate cancer, so excessive calcium intake or supplementation with excessive calcium tablets is not recommended. In addition, statistics found that overweight and obese prostate cancer patients have poor treatment effect. Gastric cancer is the fourth most common cancer and the second most common cancer in the world in terms of mortality rate. The occurrence of stomach cancer is mainly due to excessive intake of pickled food and gastric Helicobacter pylori infection, which leads to chronic gastritis and gastric ulcer. Bladder cancer is related to smoking and certain chemical substances. Data show that consuming a lot of fruits and vegetables and drinking a lot of water can help reduce the risk of its occurrence. Meanwhile, ovarian cancer as well as other malignant tumors such as brain tumor, lymphoma and leukemia have not been found to have significant correlation with nutrition, diet and weight. Relationship between food, supplementary nutrients and cancer Q1.Does alcohol increase the risk of cancer? The answer is yes. Alcohol consumption significantly increases the risk of cancers of the oral cavity, pharynx, esophagus, liver, colorectum and breast, especially when combined with tobacco. Women who do not consume enough folic acid have a higher risk of breast cancer. Q2. What are the specific effects of various vitamin supplements on fighting cancer? There is no conclusive evidence to show that they have a significant effect on cancer prevention. It is still recommended to take these essential substances from natural foods such as vegetables and fruits rather than so-called nutritional supplements. Q3. Do sweeteners cause cancer? There is no evidence linking them to the development of cancer. Q4. Is genetically modified bioengineered food safe? There is no evidence to suggest that it is associated with the development or reduction of cancer. Q5. What is the relationship between calcium supplements and cancer? Foods high in calcium can help reduce the incidence of colon and rectal cancer, but there is also evidence of an association with the development of highly aggressive prostate cancer. Therefore, a supplemental calcium dose of 1 gram per day is recommended for people aged 19 to 50 years, and 1.2 grams per day for those over 50 years. Calcium intake from green leafy vegetables and low-fat dairy products is recommended. Q6. Is coffee carcinogenic? There is no evidence that coffee is carcinogenic, nor is there any evidence to support the conclusion that coffee may increase breast and pancreatic cancers, which was previously believed by the public. Q7. What is the relationship between fat and cancer? Excessive intake of fat can lead to obesity and increase the risk of cancer. Certain saturated fats may have a negative effect, but there is no conclusive evidence to suggest that olive oil and rapeseed oil have any special cancer-preventive benefits. Q8. What is the role of edible fiber supplements? Both soluble and insoluble fibers have the effect of lowering blood lipids, but the effect of cancer prevention is weak. Q9. Do fish products prevent cancer? Fish products are rich in omega-3 fatty acids, which have been shown to prevent cancer and inhibit cancer growth in animal studies, but it has not been determined whether they have similar effects in humans. Fish can help prevent cardiovascular diseases. However, since some fish have been found to be deep underwater and contain relatively high levels of heavy metals and other environmental pollutants, pregnant and lactating women as well as infants and young children should minimize the consumption of these fish. Q10. Can fluoride cause cancer? The answer is no. A large number of rigorous experiments have been conducted on fluoride toothpaste, caries treatment medicines, and fluoridated water, etc., and the results do not show any carcinogenic risk. Q11. Can folic acid prevent cancer? Folic acid is a B vitamin found in many vegetables, beans, fruits and grains. Deficiencies in folic acid can lead to an increased incidence of colorectal and breast cancer, especially in alcoholics. Folic acid supplementation is recommended to be obtained from natural foods. Q12. Do food preservative additives cause cancer? No. These substances, which are currently approved by the U.S. Food and Drug Administration for use in the food industry, are not carcinogenic. Q13. Does garlic prevent cancer? There is no conclusive evidence. Q14. Does radiation-exposed food cause cancer? No. The purpose of radiation exposure is to kill harmful microorganisms in food. Q15. Can processed and preserved foods cause cancer? Excessive consumption of processed and preserved foods increases the incidence of stomach cancer and colorectal cancer. These foods contain a variety of cancer-causing chemicals, especially high-temperature fried, pan-fried and grilled meats, which should be eaten as little as possible. Q16. Can olive oil prevent cancer? Olive oil is a healthy alternative to cream and can reduce the incidence of cardiovascular disease. There is no significant correlation with cancer. Q17. What is the relationship between organic food and cancer? Organic food refers to plant foods that are free of pesticides and artificial genetic modification, and there is no significant correlation with cancer. Q18. Do pesticides and herbicides cause cancer? Although these substances have a certain degree of toxicity, the results of a large number of studies have not been able to prove that they have an increased risk of cancer. Q19. Does saccharin cause cancer? The answer is no. Animal studies do show that high doses of saccharin can cause bladder stone formation leading to bladder cancer in rats, but it does not cause similar lesions in humans. It has been removed from the list of human carcinogenic chemicals by the National Institute of Toxicology. Q20. Does a diet high in salt cause cancer? In certain countries and regions that are accustomed to consuming large quantities of salt-preserved foods, the incidence of stomach, nasopharyngeal and laryngeal cancers is higher, but there is no risk of cancer from moderate use of salt in the daily diet. Q21. Can selenium reduce the occurrence of cancer? Selenium is a mineral with antioxidant effect. Animal experiments have shown that it can reduce the incidence of lung, colon and prostate cancers. However, there is no rigorous research result yet. Consumption of its additives in large quantities is not recommended. If consumed, do not exceed 200 micrograms per day. Q22. Can soy products reduce the incidence of cancer? Soy products are an excellent source of protein and a meat substitute, but there is no definite causal relationship between soy products and a lower risk of cancer. Since beans contain estrogen-like substances, breast cancer patients should avoid excessive consumption or consume foods such as artificially made pills and powders as substitutes. Q23. What are the harmful effects of excessive sugar consumption? Excessive consumption of sugar can lead to obesity, diabetes, etc., and indirectly cause an increase in the incidence of cancer. Therefore, it is recommended to minimize the consumption of sugar and candies, pastries and beverages with very high sugar content. Q24. Do multivitamin and mineral supplement pills reduce the incidence of cancer? No. These substances do not have anti-cancer effects and natural foods are the best source of these substances. Even if you take these pills, you should follow your doctor’s advice and not exceed the daily prescribed dose. Q25. Can tea prevent cancer? Animal studies have shown that tea (e.g. green tea) may reduce the incidence of certain cancers, but there is no research data to confirm this. Q26. Is there any nutritional difference between fresh, frozen and canned vegetables and fruits? Fresh vegetables and fruits are the most nutritious. Consumption of large amount of vegetables and fruits can reduce the incidence of oral, esophageal, stomach, lung and colorectal cancers. Microwaving and steaming are the best ways to preserve the nutrients. Consumption of large quantities and variety of vegetables and fruits is recommended. However, there is no conclusion that a vegan diet significantly reduces the risk of cancer. Vegetarians should take care to include vitamin B, zinc and iron, which are especially important for children and premenopausal women. Q27. Does vitamin A reduce cancer? There is no definitive conclusion. And in fact, high doses of vitamin A increase the risk of lung cancer in smokers. Q28. Does vitamin C reduce cancer? Consumption of vegetables and fruits containing high levels of vitamin C is effective in preventing cancer, but taking vitamin C tablets alone is not effective. Q29. Does vitamin D reduce the incidence of cancer? Epidemiological data show that vitamin D has a reducing effect on the risk of colon, prostate and breast cancers (no randomized controlled study is available). It is recommended to obtain vitamin D through a balanced diet and to avoid excessive sun exposure. The daily dose of vitamin D consumption is in the range of 200 to 2000 mg. Q30. Does vitamin E reduce cancer? Vitamin E is an effective and powerful antioxidant, and has been shown to reduce the incidence of prostate cancer in smokers. However, there are no conclusive findings on its other effects. Q31. Can water and fruit juices reduce the incidence of cancer? Drinking large amounts of water can flush out the concentration of urine and toxic substances in the bladder, thus reducing the incidence of bladder cancer, and there are even data suggesting that it is also beneficial in the prevention of colon cancer. It is recommended to drink at least 8 glasses of water daily. Note: Fruit juices provide a lot of water and nutrients, but they contain very little fiber, so they should not be used as a substitute for eating vegetables and fruits.