Nutrition and Cancer Prevention
A healthy diet is an important component to cancer prevention and promoting a healthy lifestyle. Leslie Judge, MS, RD, CSO, LDN, Dietitian in the Vernon Cancer Center answers your questions about nutrition and cancer prevention.
Are there specific cancer-fighting foods I should be eating?
Research has indicated that people who eat the most fruits, vegetables and other plant-based foods, including whole grains, nuts, seeds and beans, have the lowest rates of cancer. It is harder to determine if certain plant-based foods may be more protective than others. We do know that different colored fruits and vegetables contain different beneficial compounds so eating a wide variety of plant-based foods will allow you to maximize intake of various antioxidants and phytochemicals. In general, I tell my patients to aim for a minimum of five servings of fruits/vegetables daily and to eat a rainbow of colors in order to increase their intake of many different phytochemicals. Lean animal proteins should be chosen in moderation (such as fish, lean meat and lean poultry). Dairy products should be low fat or fat.
Does being overweight increase my risk for cancer?
Yes, being overweight may increase your risk for certain types of cancer, particularly breast (in post-menopausal women), endometrial, esophageal, colorectal, kidney, pancreatic, gall bladder and prostate cancers. Being overweight or obese also likely raises your risk for a number of other cancers.
How does alcohol affect my cancer risk?
Alcohol may increase risk of certain types of cancers, particularly cancers of the breast, colon, rectum, liver, head and neck. The safest thing is to avoid alcohol altogether, particularly if you are at risk for the types of cancers mentioned above. If you do consume alcohol, consuming no more than two drinks per day for men, and one drink per day for women, is consistent with current recommendations from the American Cancer Society. One drink is defined as 12 ounces of beer, five ounces of wine, or one and a half ounces of hard liquor.
Should I choose organic foods over non-organic?
The answer is not a simple yes or no. The research we have available to us now does not suggest that eating organic foods over nonorganic foods decreases an individual’s risk of cancer or any other disease. When making a personal decision to choose organic foods over non-organic foods, it is helpful to weigh the pros and cons. The pros for choosing organic foods include less exposure to chemicals and pesticides and supporting environmentally friendly farming practices. The cons of choosing organic foods can be faster rates of spoilage and higher cost.
In addition to weighing the pros and cons, you must consider your current eating habits. Eating a diet that is high in plant-based foods is the most important thing you can do to lower your risk of cancer. Research tells us that the people who eat the most of these foods have the lowest rates of cancer, regardless of whether they were organic or not. So, if you are someone who does not currently eat at least five servings of fruits and vegetables daily, that should be your first priority.
If you are eating lots of fruits, veggies and other plant-based foods and are interested in adding some organic choices, then consider purchasing organic varieties of fruits and vegetables with the highest levels of pesticides and chemicals, even after washing, known as the “Dirty Dozen.” The “Dirty Dozen” includes celery, peaches, strawberries, apples, domestic blueberries, nectarines, sweet bell peppers, spinach, kale and collard greens, cherries, potatoes, imported grapes and lettuce. Focusing on these options for organic produce allows you to spend your money wisely. When it comes to choosing organic meat, poultry, eggs, dairy and fish, weigh the pros and cons mentioned above.
What are antioxidants and do they help with cancer prevention?
Antioxidants are compounds found in a variety of foods that protect the body from the molecular process in our bodies called oxidation. Oxidation can cause damage to our cells and can be a contributing factor to cancer. By eating foods rich in antioxidants, we can help protect our cells from oxidative damage, and potentially the occurrence of cancer. Antioxidants are found in a number of different foods, particularly those that are plant based. Fruits and vegetables are a particularly good source. Some antioxidants that you may have heard of include vitamin C, vitamin E, vitamin A, lycopene and beta-carotene. Although we know that antioxidants can potentially protect our bodies from cancer, it is important that we get these antioxidants from food sources rather than in pill form. Research involving antioxidant supplements has not shown a lower risk of cancer, and in some cases, taking antioxidant supplements even increased risk of cancer. For now, the best recommendation is to eat a variety of plant-based foods, including fruits and vegetables, to maximize your intake of antioxidants.
How can fat and fiber in my diet reduce my risk for cancer?
Dietary fat may not play much role in cancer risk; however; researchers are still working to determine if there is a connection. Some studies that look at rates of cancer in countries where the usual diet tends to be higher in fat seem to indicate that there may be a higher incidence of certain types of cancers, particularly breast, colon and prostate. Other studies have not supported these findings so results are somewhat hard to interpret. Depending on how you currently eat, lowering your intake of dietary fat may be helpful to your general health.
Fiber intake is particularly important to the health of the GI tract and may prevent cancers of this region, especially colorectal cancer. In general, high-fiber diets are associated with overall better nutrition because high-fiber foods tend to be plant-based. Research shows that people who eat diets highest in plant-based foods tend to have lower rates of cancer. It is recommended to get fiber from food sources, rather than taking fiber supplements, to reduce your risk of cancer.
Can soy-based foods reduce my risk of cancer?
Whole soy foods (such as tofu, tempeh, soy milk and edamame) are an important part of a plant-based diet and are a great source of lowfat protein. Soy does contain beneficial phytochemicals, including isoflavones, which may offer some protection against hormonedependent cancers like breast, endometrial and prostate cancers. Some research does support the idea that eating a diet high in whole soy foods may reduce risk of other cancers as well. Food sources of whole soy are always best. There is currently no research to support the use of soy-based supplements to reduce risk of cancer.
Patients with certain cancers, particularly breast cancer, are often concerned that eating soy foods may negatively impact their treatment or increase their risk of cancer recurrence. These fears are unfounded. Eating moderate amounts (defined as two or three servings per day) of whole soy foods is safe for women with breast cancer or a history of breast cancer. It is also safe for women who are taking certain medications called aromatase inhibitors, to eat moderate amounts of whole soy foods.
If you have questions about your current diet, meeting with a dietitian for personalized suggestions on improving your overall nutrition is recommended.
Leslie Judge, MS, RD, LDN
Dietitian, Vernon Cancer Center
Leslie received her master’s of science in nutrition from Boston University and completed her dietetic internship at Newton-Wellesley Hospital. She also completed an internship in bionutrition at the Mallinckrodt General Clinical Research Center at Massachusetts General Hospital.
For more information about the Vernon Cancer Center at Newton-Wellesley Hospital, call CareFinder at 1-866-NWH-DOCS (694-3627) or visit www.nwh.org/cancer.