The role of dietary factors in tumorigenesisThe cause of cancer is extremely complex, and scientists are still working hard for it. A large
The role of dietary factors in tumorigenesis
The cause of cancer is extremely complex, and scientists are still working hard for it. A large number of studies show that about 35% of cancer and often smoking, drinking too much alcohol, including lung cancer, oral cancer, esophageal cancer, laryngeal cancer and bladder cancer; about 45% of cancer related to nutritional factors, which refers to the quantity of heat, the dietary intake of saturated fat (and unsaturated fat, cholesterol) too much, lack of certain nutrients in foods (such as vitamin A, dietary fiber etc.) caused by, belongs to this kind of cancer, gastric cancer, colorectal cancer, colon cancer, ovarian cancer, endometrial cancer and breast cancer. Some of these causes of cancer called "way of life of cancer". It is expected that by rationalizing diet, 1/3 can be reduced by reducing the risk of cancer by reducing smoking and alcohol consumption by 1/3. Department of Hepatobiliary Surgery; the third people's Hospital of Yunnan province Wei Xiaogang
For the cause of cancer, human beings have not yet fully understood, but the popular view is that the occurrence of tumors has its own genetic causes, there are environmental reasons. Genetic factors mainly affect the body's sensitivity to environmental factors. According to the study of American scientists suggest that environmental factors and their weights in tumors accounted for as follows: smoking accounted for 30%; the average dietary factors accounted for 35% of the range is 10% to 70%; the fertility and sexual behavior accounted for 7%; the occupation factors accounted for 4%; the alcohol abuse accounted for 3%; the geographical factors accounted for 3%; the environment and water pollution accounted for 2%; the drug and medical factors accounted for 1%.
Many epidemiological studies have also suggested that the occurrence of cancer is related to eating habits. Thus, in the occurrence of human tumors, dietary factors play a very important role. The occurrence and development of cancer are mainly three periods, the starting period, the promotion stage and the malignant progression. During the first two periods for benign tumor growth in this period, the disease can be reversed, and the dietary improper influence on tumor mainly in these two periods, so a good diet can be avoided to the third phase of development. Dietary nutrition not only has good potential for tumor prevention, some of the nutrients and antioxidation, inhibition of tumor cell proliferation, stimulate the body to produce interferon and other functions, so to a certain extent, also played a positive role in the treatment.
Two, nutritional therapy and anti-tumor treatment has an equally important position
At present, the main treatment for tumors is surgery, chemotherapy and radiation therapy. The study found that cancer patients increased diffusion growth, nutrition will contribute to cancer cells, increase the opportunity of transferring the nutritional therapy which makes the tumor in a dilemma, but after repeatedly weighed that an important aspect of nutritional therapy or treatment of cancer, is the basic treatment. At present, our country pays more attention to other treatment methods, and despise the reality of nutritional therapy, we should put the nutritional therapy of tumor patients and anti tumor treatment in the same important position.
The tumor cell is a kind of rapid expansion, the growth of cells, requires a large amount of nutrients, tumor cells and normal tissue will compete for nutrients, and in this battle, the normal cell is always a loser, so there is no nutritional therapy. The first is often damaged normal cells, tissues and organs. Cancer patients, like normal people, if not increased nutrition will cause malnutrition, reduce the body's immune system, seriously affecting the patient's recovery. Therefore, in the treatment of cancer patients, with high nutrition is good. Nutritional therapy benefits the body more than cancer. Nutrition therapy has been an important part of the whole anticancer program.
Nutritional status of appropriate treatment can improve patients, to enhance the patient's immunity, anti-cancer ability, improve the quality of life, but also can improve the tumor patient tolerance to surgical treatment, reduce or avoid the infection after surgery, the postoperative wound can be healed, improve the tumor patient tolerance to radiotherapy or chemotherapy and reduce the side reaction.
Chinese people paid more attention to Chinese medicine and health products, but also no conclusive evidence that nutrients have direct cytotoxic effect on tumor cells, its main function is to enhance the physique and immune function, inhibit tumor growth by the immune system in vivo. In the selection of supplements, should grasp the following points: (1) diet should be put in the first place, the tonic is secondary; (2) not "tonic". The use of several kinds of tonic, or daily use of large doses, not only can not play a good role, but lead to the opposite effect; (3) do not believe that there is a tonic to treat the role of cancer. They are always adjuvant therapy.
Three, changes in nutritional status of cancer patients
All kinds of tumors and their treatment will affect the nutritional status of the patients. Malnutrition is common in cancer patients. The main nutritional problems of cancer patients:
1, anorexia and weight loss: visible in a variety of tumors or surgery, radiotherapy and chemotherapy and other drug treatment of patients. Anorexia is the most common digestive tract cancer, especially esophageal, gastric and colorectal cancers.
2 of cancer patients, abnormal metabolism of energy metabolism increased, generally considered the energy metabolism of tumor patients is higher than 10% under normal circumstances, weight loss is a common phenomenon in cancer patients, may be caused by loss of appetite reducing intake, may also be caused by increased consumption; abnormal carbohydrate metabolism is mainly of many tumors patients with glucose intolerance; protein metabolism abnormalities in protein synthesis, protein conversion rate increased liver protein synthesis increase, reduce muscle and plasma branched chain amino acids decreased; fat metabolism enhanced lipolysis, decreasing lipoprotein lipase activity in serum, hyperlipidemia; vitamin metabolism mainly decrease in vitamin C, vitamin E etc. antioxidant vitamins; reduce blood trace elements in patients with metabolic and blood selenium zinc content visible tumor.
Four, the nutritional treatment of cancer patients
(1) the judgement and classification of malnutrition
Tumor patient malnutrition is a vicious spiral, due to loss of appetite, decreased food intake, caused by reduced physical activity, body weakness, digestion and absorption function decline, further causing anorexia, resulting in weight loss, systemic failure, prognosis.
Malnutrition can be divided into three categories:
Lean dystrophy: mainly due to insufficient calorie intake caused by muscle tissue and subcutaneous fat consumption, characterized by weight and other body measurements decreased, while serum protein remained normal.
Protein malnutrition: mainly due to inadequate or excessive protein intake, and intake of food intake is normal or more caused by visceral protein storage consumption as a feature. The main performance of the serum albumin, transferrin, prealbumin and other concentrations decreased, impaired immune function, and the anthropometric indicators are still normal even higher than normal.
Mixed malnutrition: due to inadequate intake of protein and calories, the performance of hypoproteinemia, the anthropometric indicators were lower than normal. This is the most serious kind of malnutrition, skeletal muscle and visceral protein decreased, endogenous fat and protein reserves empty, multiple organ dysfunction, infection and other complications of high incidence and poor prognosis.
(two) the purpose of tumor nutrition therapy
The nutritional status of 1 to correct or improve the patients, improve the body's immune function and disease resistance and anticancer ability, achieve the purpose of "Fuzheng cowardly evil".
2 by adjusting the nutritional status of patients, improve the quality of life, to avoid anxiety, so patients in the mental and psychological enrichment and pleasure.
3 nutritional therapy is an integral part of the overall treatment plan for cancer patients. Nutritional therapy can improve the patient's tolerance to surgical treatment, reduce postoperative infection, accelerate wound healing, but also improve the patient's ability to tolerate chemotherapy and radiotherapy, reduce the toxic side effects of treatment.
(three) daily nutritional support for cancer patients
The nutritional needs of 1 tumor patients including two parts of daily basic nutritional needs and for the growth of tumor, infection, anemia and treatment to increase the nutritional needs, so the supply of various nutrients was higher than the recommended amount, especially animal protein quality.
2 dairy products, including dairy products in various forms. These foods are the main source of vitamin A, B and D and calcium, but also provide a certain amount of protein.
3 vegetables and fruits: mainly provide vitamins and minerals, especially citrus waxy is the main source of vitamin C, deep yellow green vegetables can provide carotene.
(four) nutritional support in patients undergoing surgery
Surgical treatment is a common method for the treatment of tumors, but at the same time, it must be recognized that surgical treatment in the treatment of disease, but also to the body caused by trauma. If the preoperative nutritional status of the body can be improved, it can increase the body's resistance and tolerance to surgery, reduce postoperative complications and infection, and promote wound healing. Effective nutrition supply has a positive effect on the early recovery of the body. Preoperative nutritional supplementation can improve immunity and promote tumor growth. Shanghai Ruijin Hospital research shows: preoperative nutritional support for patients with gastric cancer, energy and amino acid supplement 1 weeks. The activity of NK cells was increased, CD4 and CD8 were increased, tumor cells were aneuploid, the content of DNA increased, the percentage of S phase increased and the percentage of proliferating cells increased.
For non gastrointestinal surgery patients with low fat, high protein, high vitamin and mineral. Choose fish, chicken, eggs, milk, soy products and fresh fruits and vegetables rich in vitamins and minerals. Gastrointestinal surgery patients before 2~3 days have less residue semi liquid diet. The day before the operation given the liquid diet, or in the 5 days before the operation to give elemental diet. After surgery, when the patient can eat after the diet according to the physical condition gradually increased, the liquid gradually transition to the semi liquid diet, and general food.
(five) nutritional support in patients with chemotherapy
Chemotherapy is an effective means of cancer treatment, but almost all of the chemotherapy drugs can cause patients with different degrees of loss of appetite, nausea and vomiting, thus affecting the nutritional status of patients. Reasonable diet can prevent and reduce weight loss and malnutrition caused by treatment. The study found that some adverse reactions caused by chemotherapy can reduce the antioxidant nutrients, so it should add more antioxidant nutrients, such as vitamin A, vitamin C, vitamin E, beta carotene, ß rich in trace elements of zinc and selenium in food. The study found that 24 hours after supplementation of nutrients can reach the maximum blood concentration of nutrients, so the nutritional supplements after the 24 hour is the most appropriate period of chemotherapy.
The dietary nutrition of patients with chemotherapy should be based on the adverse reactions of chemotherapy. The side effects of chemotherapy were mainly in the aspects of systemic reaction, gastrointestinal reaction, bone marrow suppression and so on. Chemotherapy patients diet should be light, nutritious, easy to digest, eating less semi liquid slag or slag less soft food, avoid greasy and difficult to digest food. To decline to prevent or reduce myelosuppression caused by white blood cells, platelets, and blood should eat meat, cooked to boiling, stewing, steaming method is good, can choose iron rich foods, such as animal offal, egg yolk, meat and so on, in order to correct the tumor patients with iron deficiency anemia. Fungi in letinous edodes, mushrooms, Hericium, fungus like food, has been found which is rich in polysaccharides, has great effect to improve the cellular immune function of human body.
(six) dietary nutrition in patients receiving radiotherapy
Patients often appear dry mouth, sore throat, nausea and anorexia during treatment. Nasopharyngeal dry, urine, urine and other symptoms, especially in the maxillofacial or pharyngeal malignant tumor, radiotherapy response is heavier, can also cause oral cavity, throat, esophagus and other places of radiation inflammation. Therefore, according to the clinical symptoms of different treatment of food related issues. Severe radiation response, poor appetite, swallowing pain, oral ulcers, it is appropriate to use semi - flow diet or tube feeding nutritional support. In order to stimulate the appetite, can be a little more salt in order to ease the mouth of the dull feeling, meat can be fine or braised rotten, vegetables or fruits, if you can not swallow juice. Avoid dog meat, lamb, onions, ginger and other spicy food and spicy food. Head and neck radiotherapy in patients with the soup more, valuables, food list. If the difficulty in swallowing, can eat some cold food to ease. Drinking water. Abdominal radiotherapy, diet should be soft, more easily digested food choices. Drink plenty of water, a small number of meals. Eat less milk, sweets and honey to prevent intestinal discomfort. High protein, high calorie diet should be chosen to supplement the energy loss due to treatment. Choose lean meat, chicken, fish, eggs, tofu and other high-quality protein rich foods.
Five, commonly used nutritional support therapy
If the patient is not able to solve the problem of the patient after the operation or the condition is serious, it is necessary to use the commonly used nutritional support therapy. The aim of nutritional support therapy is to prevent and correct the possible or existing malnutrition in the disease and treatment. Two methods of enteral nutrition and parenteral nutrition. Enteral nutrition (enteralnutrition) includes oral and feeding tubes that provide the nutrients needed for the body's metabolism. Parenteral nutrition (parenteralnutrition, PN) refers to the full and adequate supply of nutrients through the vein, in order to achieve the purpose of maintaining the body's metabolism. When the patient is fasted and all nutrients are supplied via the intravenous route, they are referred to as parenteral nutrition (totalparenteralnutrition, TPN).
The characteristic of tube feeding therapy is that it accords with human physiology, convenient operation and low cost, and maintains the integrity of intestinal mucosa structure and barrier function. Tube preparation for feeding include two kinds, namely blenderized diet and dietary factors. A variety of natural food is often mixed edible homogenate by crushing processed into nutrient liquid. Homogenate indications: gastrointestinal digestion and absorption function of props, but not by diet patients; blenderized diet including contraindications to gastric retention or intestinal obstruction of the digestive tract bleeding intestinal infection, severe diarrhea shock. The physicochemical properties of the homogenized diet: dietary composition close to normal, with natural flavor; their preparation, nutrient content is difficult to accurately calculate the types of food restriction; nutrition is not comprehensive.
Elemental diet is a nutrient comprehensive, chemically defined, no residue diet without digestion can be absorbed by the intestine. Elements of diet is based on human daily dietary requirements and recommended as the basis, with hydrolyzed protein, carbohydrate, fat and micronutrients preparation; characteristics of element diet is a chemically defined, without precise content; digestion; soluble 1kcal/ml; heat; high osmotic pressure, weak acid; not lactose; poor palatability, not oral.
(two) parenteral nutrition provides complete and sufficient nutrients through the vein, which is necessary for the maintenance of body metabolism. When the patient is fasted, all nutrients are supplied via the intravenous route, for parenteral nutrition (TPN). Parenteral nutrition is the indication of protein energy malnutrition, gastrointestinal dysfunction, acute pancreatitis, intestinal obstruction, intestinal fistula, short bowel syndrome, inflammatory bowel disease, high catabolic state, perioperative period, anti tumor treatment, low birth weight, not more than 7 days of eating etc.. Contraindications of parenteral nutrition: serious water electrolyte, acid-base imbalance, shock. Parenteral nutrition preparations are usually made by professional manufacturers, they can not be formulated, can provide the daily nutrient requirements of the human body.
Six, the influence of nutrition treatment of common symptoms and treatment measures
Because of many of the symptoms of cancer and cancer treatment will affect the patient's nutritional intake, through diet and drugs can alleviate the adverse effects of these symptoms.
1 anorexia: one of the most common symptoms of cancer and cancer treatment. In order to reduce anorexia, should be improved from the psychological and food processing methods.
2: amblygeustia Shaoliangduocan, eat more fresh fruits and vegetables, increase food color and flavor, and avoid some protein foods may cause the smell, can partially overcome the adverse effects brought by amblygeustia.
3: dry mouth occurs after radiotherapy of head and neck, due to reduced secretion of the salivary glands. Can increase the diet and juicy fruits, sugar free chewing gum, sour and spicy food should be used with caution.
4: dysphagia is often the head and neck radiotherapy or oral surgery complications, such as serious symptoms, but not available in ruanshi, a liquid food to avoid inhalation of respiratory tract. If symptoms are severe, the need for tube feeding or parenteral nutrition.
5 abdominal distension: it is due to the digestive capacity of the gastrointestinal tract and food through the extension of time, but also with the nature of the food. Shaoliangduocan. Before the meal after meal sit up or walk properly, avoid eating greasy, fried, gas producing foods and carbonated drinks and milk.
6 constipation: may be due to the lack of dietary fiber, reduce activity and use of narcotic drugs. Should increase the fresh vegetables, fruits, whole grain breads and cereals in the diet, should also increase the quantity of liquid can be used when necessary laxative or enema.
7 diarrhea: can be caused by chemotherapy, abdominal radiotherapy or intestinal surgery. Only take the intestinal liquid to rest, gradually increase without slag or less residue of food, and then transition to low residue diet and normal diet. This should avoid eating greasy, spicy, cold stimulation, and more food containing cellulose. Drugs available if necessary.
8 esophagitis: caused by chemotherapy or head and neck radiotherapy. Often cause swallowing pain and difficulty. Gargle or swallow analgesic liquid such as lidocaine can relieve the pain and irritation, help ease of esophageal mucosal irritation, necessary oral antipyretic analgesics to relieve pain.
Six, the prevention of cancer diet
Cancer prevention mainly pay attention to the following aspects: to reduce the intake of carcinogens and carcinogenic precursors in food, such as aflatoxin, fried and fried food; pay attention to balance diet intake, dietary intake of dietary balance refers to the human body in various types of nutrients complete, sufficient quantity, reasonable proportion of dietary nutrients; increase the intake of protective substances of nutrients, such as antioxidant nutrients, dietary fiber, protein and calcium, and anti bacteria food such as garlic, chives and improve the immune function of foods such as fungus of food intake.
Japan's National Cancer Institute to draw 12 pieces of advice, here to introduce to everyone in the daily life for reference: (1) diet should pay attention to taste and nutrition. (2) to overcome the picky eaters, the partial eclipse, not long-term use of the same drug. (3) delicious food is not excessive, so moderate diet. (4) do not drink strong wine, but also avoid drinking too much wine. (5) no smoking, smokers should quit smoking. (6) intake of vitamin A, C, E and dietary fiber. (7) pay attention to eat less salty or too hot food. (8) do not eat burnt food, especially fried fish or meat. (9) don't eat bad food. (10) to avoid excessive exposure to sunlight. (11) control sexual life, avoid overworked. (12) to maintain the room air circulation, pay attention to clean the body.
If you listen to these 12 pieces of advice, the threat of cancer will undoubtedly be greatly reduced.