Can Diet Affect Cancer Risk?
Colorectal cancer is the third most commonly diagnosed cancer in men and women in the U.S. Diet and adequate nutrition may play a role in cancer risk, especially for colorectal cancer. Healthy lifestyle choices, such as eating a diet high in fruits and vegetables and limiting your intake of red and processed meats may help lower your risk of cancer. Getting enough exercise, limiting alcohol, avoiding tobacco use, and maintaining a healthy weight also may help protect you against cancer. Learn how to live a cancer prevention lifestyle that includes adding anti-cancer foods to your diet and eliminating foods and beverages that promote the growth of cancer cells.
Eat More Dairy Products
Calcium is a mineral that is critical for maintaining healthy bones and regulating blood pressure. Results from some cancer research studies suggest that low levels of calcium and low calcium intake increase the risk of colorectal cancer. Vitamin D works to help your body absorb calcium, but one study found that vitamin D is associated with a nonsignificant reduction in colon cancer risk. More research is needed to determine whether the two nutrients together may help lower the risk of colon cancer. .. Ask your doctor if calcium-rich foods and calcium supplements are appropriate for you. Calcium-rich foods to add to your diet include milk, yogurt, cheese, butter, and ice cream.
Eat More Whole Grains
Examples of whole grains include quinoa, oats, millet, brown rice, amaranth, and whole wheat. Whole grains contain all three parts of the seed — the bran, the germ, and the endosperm. They are a type of whole food because it is not processed or refined. Whole grains provide nutrition such as fiber, magnesium, and other vitamins and nutrients that reduce the risk of many chronic diseases. Whole grains mop up cancer-causing compounds in your colon and also help keep you regular. Most Americans do not get enough fiber in their daily diets. The average person in the U.S. gets approximately 16 grams of fiber in their daily diet. The recommended amount you should be getting is 25 to 30 grams of fiber per day. More is even better. Getting adequate fiber in your daily diet also aids in weight loss.
Have Some Beans
Eating more beans, including black beans, soybeans, fava beans, garbanzo beans, lima beans, adzuki beans, soybeans, and kidney beans, may help protect you against colon cancer. Peas and lentils count, too. Beans are plant foods that are rich in nutrients like fiber, B vitamins, vitamin E, and protein, all of which promote health. They also contain flavonoids and antioxidants that may help inhibit the growth of cancer cells and tumors. Looking for more ways to add beans to your diet? Try whipping up a tasty bean dip or lentil soup.
Eat Brightly Colored Fruits and Veggies
Colorful fruits and vegetables have compounds called phytochemicals that inhibit inflammation. Inflammation may fuel cancer growth and other disease processes. Phytochemicals in plant foods may also inhibit the growth of cancer cells. A diet high in colorful, antioxidant-rich fruits and vegetables helps protect the body from a variety of chronic diseases including heart disease, diabetes, cancer, and more. Include a mix of green, yellow, orange, red, and purple foods in your diet every day. Reach for leafy greens, butternut squash, oranges, cruciferous vegetables (broccoli, cabbage, and kale) and other colorful types of produce daily to get vitamin C, beta-carotene, and other nutrients. Eating a diet that includes cruciferous vegetables may also lower your risk of breast cancer.
Colorful produce is a cornerstone of a cancer prevention nutrition plan. Eating this way also reduces the risk of heart disease and boosts the immune system. A plant-based diet is one that is centered on colorful produce, tubers, legumes, and whole grains that limits or excludes meat, eggs, refined flour, refined sugar, oil, and dairy products.
Fill Up on Fish
Fatty fish like salmon have abundant amounts of omega-3 fatty acids, fats that boost heart health and may help inhibit the growth of cancer cells. In some cancer research studies, those who ate fish instead of red meat had lower rates of rectal cancer, making fish the healthier source of animal protein. Taking fish oil capsules is another way to increase your intake of omega-3 fatty acids. Some kinds of fish oil are fortified with vitamin D, which is critical for bone health and a healthy immune system. Getting adequate omega-3s should be part of everyone’s nutrition plan.
Although fatty acids in fish are healthy, other substances in some species of fish may contribute to disease. If you do eat fish, limit your intake of large fish varieties that accumulate mercury, heavy metals, and other pollutants that harm your health. Tuna, tilefish, swordfish, king mackerel, and shark are large species of fish that accumulate more of these dangerous compounds.
Rethink Red Meat
Although protein is an important part of your daily diet, red meat may not be the best choice to get your fill. Diets high in red meat like beef, lamb, and pork make it much more likely that you will get colorectal cancer. Why is that? No one knows for sure, but it may be that harmful, cancer-causing substances form when meat is cooked at a high temperatures. Alternatively, there may be something in the meat itself that is cancer-promoting. Limit your dietary intake of red meat to no more than 18 ounces per week. Red meat is also high in unhealthy saturated fat that increases the risk of breast cancer and aggressive prostate cancer. Eating a high-fat diet increases the risk of many cancers while eating a low-fat diet may decrease the risk of cancer.
Reduce Consumption of Processed Meat
Processed meats are animal-based protein that has been smoked, salted, preserved, or cured with added chemicals. Examples of processed meats include hot dogs, ham, bologna, bacon, and lunch meats. Studies have shown that people who eat these products have higher rates of colon and stomach cancer compared to those who do not eat these meats. Avoid processed meats as part of your anti-cancer diet plan.
Cut Back on Alcohol
You have probably heard that a little alcohol is good for your heart. An occasional drink probably does not affect your risk of colon cancer. However, moderate to heavy drinking — defined as 2 to 3 glasses of an alcoholic beverage per day — may make you 20 percent more likely to get colon cancer. If you are a heavy drinker, your odds of colon cancer increase by approximately 40 percent. Heavy or regular alcohol consumption is associated with a higher risk of breast cancer and other health issues, too. Excessive drinking suppresses the immune system. If you are a drinker and indulge in more than 3 drinks per day, discuss colorectal cancer screening with your doctor.
Eat More Olive Oil
Olive oil is a staple of the Mediterranean diet, which focuses on plant-based staples like fruits, vegetables, legumes, whole grains, and nuts. The diet also includes poultry, fish, herbs, and spices. Red meat is limited. Red wine may be consumed in moderation. In studies, people who consumed higher amounts of olive oil were less likely to suffer from colorectal cancer, breast cancer, and cancers of the digestive and respiratory tract compared to those who consumed less olive oil.
Reach for Herbs
You should add more herbs to foods to enhance flavor and give yourself an antioxidant and anti-tumor kick. In lab studies, extracts from several herbs were shown to inhibit the growth of colon cancer cells. The herbs studied include thyme, sage, rosemary, peppermint, and spearmint. More research is needed to determine if these herbs have a similar effect when consumed. In the meantime, prepare more meals with herbs. It can’t hurt, and it might actually help reduce your risk of colon cancer.
Drink Ginseng Tea
Ginseng is a plant that has been used medicinally in Asia for thousands of years. The results of several studies suggest that consuming ginseng reduces the risk of colorectal cancer. Beneficial compounds in ginseng called ginsenosides may be responsible for the effect. Ginseng both inhibits the growth of colon cancer cells and increases cell death, or apoptosis, of colon cancer cells. Drink ginseng tea to reap the anti-cancer benefits.
Eat More Selenium-Rich Foods
Some studies have shown that diets high in the mineral selenium and the B vitamin folate result in a greatly reduced risk of colon cancer. Where do you find selenium? Selenium-rich foods include sunflower seeds, mushrooms, garlic, onions, Brazil nuts, whole grains, and fish like salmon, tuna, sardines, and halibut. Foods rich in folate include beef liver, leafy greens, and fortified breakfast cereal.
Drink Some Coffee
Coffee may help protect against both liver cancer and colorectal cancer. Researchers think beneficial compounds in coffee may be responsible for the effects. It may be that these compounds act as antioxidants and protect against damage to cells and DNA. The compounds may help regulate DNA repair, boost detoxification in the liver, encourage the death of faulty cells, and/or act as anti-inflammatory agents. Beneficial compounds in coffee inhibit the growth of cancer cells, block the development of new blood vessels that feed tumors, and inhibit cancer spreading to other sites in the body (metastasis).
Researchers are investigating other foods and beverages about their potential role in causing or preventing colorectal cancer. Coffee, caffeinated beverages, tea, garlic, potatoes, and sugary foods are among the foods and beverages being studied. Results of ongoing studies will provide more insight about the role these foods and beverages may play in colorectal cancer risk.
Reviewed by Melissa Conrad Stöppler, MD on 1/16/2018
Colon Cancer: Symptoms, Signs, Screening, Stages
What Is Colorectal Cancer?
Colorectal cancer is the third most common non-skin cancer diagnosed in men and women in the U.S. It is also the second highest cause of cancer deaths. Still, colorectal cancer is highly curable when it is detected early enough. Colorectal cancer is a result of cancer cells that form in the lining of the colon (large intestine) or rectum.
How Colorectal Cancer Starts
Colorectal cancer often begins as a benign growth known as a polyp. Adenomas are a type of polyp and are benign tumors of the tissue lining the colon or rectum. Most polyps will stay benign, but some adenomas have the potential to turn into cancer over the long term. If they are removed early, this prevents them from turning in to cancer.
Risk Factors You Can’t Control
Some risk factors for getting colorectal cancer are beyond your control. The following all increase the risk of getting colorectal cancer:
- Inflammatory bowel disease
- Colon polyps
- Age over 50
- Family history of colorectal cancer
- History of breast or ovarian cancer
Risk Factors You Can Control
However, there are other risk factors for colorectal cancer that you can control. The following risk factors can be modified:
- Eating a diet high in red or processed meat, or eating meat cooked at high temperatures
- Overweight or obesity
- Inadequate exercise
- Cigarette smoking
- Drinking alcohol
Warning Signs of Colorectal Cancer
Screening is important because colorectal cancer in its early stages usually doesn’t produce any symptoms. Screening can detect the cancer before it produces symptoms, when it is most curable. After the disease begins to spread, it can produce blood in the stool, changes in bowel patterns (like diarrhea or constipation), abdominal pain, weight loss, or fatigue. Tumors that cause symptoms are typically larger and harder to treat.
Screening for Colorectal Cancer
It is recommended that most people have a screening colonoscopy every 10 years starting at age 50. A colonoscopy allows examination of the entire colon and rectum using a tiny camera. This test can find cancers in the early, most treatable stage and actually prevent cancers from developing by removing polyps, as shown here.
What Is a Virtual Colonoscopy?
An alternative to colonoscopy uses CT scan images to visualize the colon. This is known as a virtual colonoscopy. As with a conventional colonoscopy, the colon must be emptied as thoroughly as possible prior to the examination. In virtual colonoscopy, polyps or tumors are visualized without inserting the camera into the intestine. One disadvantage is that a virtual colonoscopy can only identify and not remove any polyps that are found. A real colonoscopy is needed to remove polyps that may be identified.
Colon X-Rays (Lower GI)
An X-ray of the colon, known as a lower GI series, can provide another way to image the colon and rectum. A chalky liquid known as barium is used as a contrast agent. This photo shows an example of an “apple core” tumor that narrows the colon. As with a virtual colonoscopy, a real colonoscopy or other surgical procedure would be needed to remove any tumors or polyps that may be found.
Colorectal Cancer Diagnosis
If there are abnormalities seen in your colon or rectum, a biopsy is done to determine whether cancer is present. This can be done during a colonoscopy. The tissue is examined microscopically to look for cancer cells. This picture shows a highly magnified view of colon cancer cells.
Colorectal Cancer Staging
Staging is the process of determining how far a tumor has spread beyond its original location. Staging may not be related to the size of the tumor. Treatment decisions also depend upon the stage of a tumor. Staging for colorectal cancer is as follows:
- Stage 0 – The cancer is found only in the innermost lining of the rectum or colon.
- Stage I – The cancer has not spread beyond the inner wall of the rectum or colon.
- Stage II – The cancer has spread into the muscle layer of the rectum or colon.
- Stage III – The cancer has spread to at least one lymph node in the area.
- Stage IV – The cancer has spread to distant sites in the body, such as the bones, liver, or lungs. This stage is NOT dependent on how far the tumor has penetrated or if the cancer has spread to lymph nodes near the tumor.
Survival Rates for Colorectal Cancer
Higher stages mean that a cancer is more serious and has a worse prognosis. Patients with stage I colorectal cancer have a 5-year survival rate of 74%, while that rate drops to 6% for Stage IV tumors.
Colorectal Cancer Surgery
Except for very advanced cases, colorectal cancer is usually treated by surgically removing the tumor and surrounding tissues. Surgery has a very high cure rate for early stage tumors. For advanced tumors that have spread outside the colon, surgery does not typically cure the condition, but removing larger tumors may reduce symptoms.
Advanced Colorectal Cancer Treatment
Colorectal cancer that has spread to the lymph nodes (stage III) can sometimes still be cured. In this case treatment usually consists of surgery and chemotherapy for colon cancer. In cases of rectal cancer, radiation therapy is added both prior to and following surgery in more advanced cases. Cancers that return after treatment or spread to other organs are harder to treat and more difficult to cure, but treatments may relieve symptoms and prolong life.
Coping With Chemotherapy
Modern chemotherapy drugs are less likely to cause nausea and other troubling side effects than older drugs, and medications are also available to help control these side effects. Clinical trials are always underway to develop better and more tolerable chemotherapy drugs.
Radiofrequency ablation (RFA) is a kind of cancer treatment that uses heat to destroy tumor tissue. CT scanning is used to guide insertion of a needle-like device into the tumor, through which intense heat is applied. RFA can be an option for destroying tumors that cannot be removed by surgery. In patients who have a few metastatic tumors in the liver that cannot be removed by surgery, chemotherapy is sometimes combined with RFA to destroy the tumors.
Colorectal Cancer Prevention: Diet
Eating a nutritious diet, getting enough exercise, and controlling body fat could prevent 45% of colorectal cancers, according to researchers. This means that adopting a healthy lifestyle can dramatically lower your risk of getting colorectal cancer. The National Cancer Institute recommends a diet low in fat with plenty of fiber and at least five servings of fruits and vegetables each day.
Preventing Cancer With Exercise
One study showed that people who got the most physical exercise were 24% less likely to get colorectal cancer than their least active counterparts. There was no difference if this activity was related to work or recreation. The American Cancer Society recommends at least 30 minutes of exercise a day for 5 or more days a week.