Nutrition and Colon Cancer

Eating to Fight and Prevent Colorectal Cancer

Diet and proper nutrition are vital tools in the fight against colon cancer. Rapidly accumulating evidence supports eating a healthy diet for both prevention and treatment. In general, dietary recommendations include consuming less saturated fat and salt and eating a variety of colorful fruits, and vegetables rich in vitamins, minerals and antioxidants.

A healthy diet provides a multitude of benefits beyond preventing colon cancer By following the healthy guidelines below for preventing colorectal cancer you may experience a multitude of other positive healthy benefits including feeling more energetic and losing weight.

   1. Eat plenty of brightly colored fruits and vegetables

   2. Eat fresh fish 1-3 times per week

   3. Limit consumption of red meat

   4. Avoid excess salt and saturated fats

   5. Maintain a healthy weight and keep 
       physically active

   6. Limit alcohol consumption

   7. Avoid tobacco in any form


There are several foods well recognized as powerhouses of cancer fighting antioxidants and nutrients. These superfoods may already be part of your daily diet, view each of the foods below for more information: 

Suggestions for lifestyle modifications include: maintaining a healthy body weight and exercising to reduce the risk of obesity. A reduction of dietary fat to less than 30% of caloric consumption and an increased intake of fresh fruit and vegetables, with at least 25 grams of fiber and protective omega-3 fats common in fatty fish, nuts and canola oil can be helpful.

Diet is considered a determinant of increased risk in the development of colorectal cancer. Although it is difficult to ascertain which components of diet are most important in increasing the risk of colorectal cancer, compelling evidence suggests a strong association between red meat and fat intake and colorectal cancer.  While high consumption of animal fat is positively associated with colorectal cancer, consumption of fatty fish and low fat intake may lower risk. Higher cholesterol values (a reflection of total dietary fat intake) correlate significantly with later tumor development. Obesity and lack of physical activity are also associated with an increased risk of colorectal cancer.   Green Pharmacy is a terrific website highlighting the benefits of a healthy diet and is updated regularly by acclaimed ethnobotanist Jim Duke PhD.  Dr. Duke  travelled the world seeking plants with high anticancer activity for the National Cancer Institute and is a wealth of knowledge on food pharmacy, or using food as medicine.   

Weight Loss
For patients with colorectal cancer, maintaining a healthy diet is important in order to withstand the rigors of treatment, and, to reduce the severity of side effects from treatment, whether surgical, chemotherapy, radiation therapy, or a combination of any of these. A healthy diet includes: fluids, to prevent dehydration; protein, to maintain muscle mass and repair body tissue; carbohydrates and fats, to produce the calories that supply fuel to the body for energy; and vitamins and minerals, to maintain normal body functioning.Nutritional status is measured by body weight. Side effects from colorectal cancer treatment that cause weight loss and an unhealthy nutritional status include: constipation, diarrhea, fatigue, gas and bloating, loss of appetite, nausea, sore mouth and throat, taste changes, and vomiting.A diagnosis of colorectal cancer can also cause anxiety, and the treatment can cause pain, both of which can also lead to weight loss.

Omega-3 fatty acids have been found to be beneficial for neuropathy and appetite in cancer patients. A current study at Johns Hopkins has experts looking at fish oils to stimulate appetite. Omega-3 fats have protective properties against cancer and all the other chronic diseases. Omega-3 fats are found in fatty fish (salmon, herring, and mackerel), flax seed and flax seed oil, walnuts, and canola oil. In terms of prevention, patients should take a standard multivitamin with one hundred percent of each vitamin and mineral needed for the day.

Dietary fiber has a protective effect on the pathophysiology of colorectal cancer. Diets rich in vegetables and high fiber grains demonstrated significant protection against fatal colorectal cancer, as revealed in a prospective study of more than 760,000 people.

Fiber appears to have a number of mechanisms responsible for its protective effects: it decreases fecal transit time by increasing stool bulk; it appears to dilute the concentration of other colonic constituents, which tends to minimize contact between carcinogens and colon epithelium; and it is not digested or absorbed in the small intestine but undergoes fermentation in the presence of the colonic flora, which reduces fecal pH and generates short-chain fatty acids. Certain short-chain fatty acids can protect isolated colonic epithelial cells.Diet appears to play a significant role in determining the incidence of colorectal cancers in the general population. Although the international incidence of colorectal cancer varies widely, groups migrating from low-risk to high-risk regions experience an increase in the incidence of the disease. Diets high in fat and low in fiber have consistent associations with increased colorectal cancer risk.

Dietary Modifications and the Side Effects of Treatment

Patients with colorectal cancer can manage many of the side effects of treatment. Knowing that surgery can lead to fluid and electrolyte loss, patients can supplement their diet with as many caffeine- and alcohol-free drinks as possible, and with sports drinks with electrolytes and liquid supplements, such as Ensure, Boost®, Carnation® Instant Breakfast®, etc. Surgery can also cause the mal-absorption of some vitamins; patients can add a regular multivitamin supplement to the diet.Because patients may be at risk for obstructions at the time of surgery, high residue foods, including nuts, popcorn, seeds, raw fruits and vegetables, and anything with a skin, should be avoided.During chemotherapy and radiation therapy, patients can become dehydrated as well as nauseous. Liquids and clear, bland food (baked chicken, buttered noodles, crackers, etc.) can alleviate these side effects.

Eating and drinking slowly and having meals at room temperature or a little colder can alleviate nausea. Patients should not lie down for two hours after a meal. If possible, patients should not eat in a room with cooking smells, and should have someone else prepare the meals.

With all types of colorectal cancer treatment, patients should eat small, frequent meals, usually consisting of foods high in calories and protein. Variations in the amounts of protein and calories may occur when patients address specific side effects. Patients should try not to skip a meal, no matter how bloated or nauseous they feel.Patients should not take any more than one hundred percent of the recommended dose of any vitamin or mineral. A regular Centrum® or One-A-Day® would be within the guidelines. Any amount over one hundred percent may affect the effectiveness of treatment. Patients are encouraged to eat a good variety of foods, including plenty of fruits and vegetables, in order to get all of the necessary nutrients from food rather than from supplements.

Patients should also discuss any side effects they experience with the Johns Hopkins colorectal cancer health care team. Medications may be necessary to lessen the severity of some side effects.

Different side effects require different dietary strategies to manage. The strategies found herein are generalized. Some may work for some patients, others may not. To alleviate constipation, patients should drink plenty of fluids, including prune juice and small amounts of caffeinated beverages, and eat high fiber foods, including bran cereal, oatmeal, and raw fruits and vegetables. If making a change in diet does not work for the patient, medications might be necessary.

To alleviate diarrhea, patients should drink clear liquids, eat low fiber, low fat foods, and avoid heavy, greasy foods, raw fruits and vegetables, strong spices, and caffeine.

To alleviate gas, patients should eat slowly, use a straw and drink out of a glass instead of a bottle, and try Beano®, if necessary. Patients should not eat cruciferous vegetables, including broccoli and cabbage, beans, eggs, garlic, onions, or foods with fructose or sorbitol added. Sometimes dairy products cause gas, so patients should try lactose-free items. Patients should not drink carbonated beverages.To alleviate sore mouth and throat, which patients may experience from treatment with chemotherapy, patients should eat soft, creamy foods; adding gravies, sauces, and dressings to anything to help soften the food. Patients should drink through a straw, and drink liquid supplements, such as meal replacement drinks.

Patients should avoid eating or drinking anything very hot or very cold, and should not eat crispy, crunchy, sour, acidic, or very salty foods or spices, such as pepper, curry, or peppermint. Alcohol and caffeine should also be avoided.

To alleviate taste changes, which patients may experience from treatment with chemotherapy, patients should eat anything that is tart and sour, such as lemonade, limeade, etc. Sourballs tend to help, as does adding spices, herbs, and marinades to food, to give it the strongest flavor possible.If patients experience a metallic taste, they should use plastic silverware and drink with a straw. They should eat and drink things that are cold, cool, or room temperature.

With any and all side effects, patients are encouraged to keep trying a food because taste continually changes. What tastes off today, might taste fine tomorrow. As a patient’s gastrointestinal tract adapts to colorectal cancer treatment, and repairs and replaces lost tissue, symptoms will resolve slowly. Patients are encouraged to add items in slowly, to add one new food or drink at a time to assess tolerance.

After Treatment

All of the nutritional recommendations for patients who have completed colorectal cancer treatment are the opposite of what is recommended for patients during treatment. During treatment, diet is dictated to a great extent by the side effects a patient experiences. After treatment, patients now need to follow eating patterns that will maintain good health and prevent cancer and other chronic diseases, such as heart disease, hypertension, and diabetes.Patients who have completed their treatment regimen and whose side effects have subsided should: eat fruits, vegetables, and whole grains; limit fats, and choose good fats versus bad fats; eat lean meats and poultry; and eat low-fat dairy products. These patients should reduce or restrict alcohol intake.To prevent cancer, the recommended amount of fruits, vegetables, and whole grains is ten servings daily. A piece of fruit, one half cup of fruit juice, a cup of canned fruit, one half cup of chopped vegetables; each is one serving. In terms of fiber, the goal is to aim for 20 grams per day. These foods provide antioxidants and phytochemicals, which protect against cell damage and tumor growth.

Patients should reduce total fat intake. Excess fat causes more bile acids to come into the intestine to digest the fat. Excess bile acids could change the bacteria in the intestine, possibly leading to cell damage and tumor growth. Patients should eat lean meats, low-fat dairy products, and, the good fats, the omega-3 fats.

Both diet and exercise enhance the body's defense system, providing an adverse environment for cancer cells. Patients should engage in 30 minutes a day of moderate, physical intensity.

Diet and nutrition also play a part in complementary and alternative medicine. Besides monitoring diet, palliative care may also be useful to alleviate pain and discomfort comprise.