Can certain dietary choices reduce my risk of cancer?
Ongoing studies are researching whether certain foods and nutrients can reduce the risk of specific cancers. Eating more vegetables and fruits has been linked to a lower risk of lung, oral, esophageal, stomach and colon cancer. But researchers don't know which of the specific nutrients in fruits and vegetables are most helpful.
Studies have shown that following the Mediterranean diet has many health benefits, including protection against cancer. It encourages you to eat foods such as fish, fruits and vegetables, beans and whole grains.
Some findings indicate that calcium and vitamin D may reduce the risk of colorectal cancer. However, these results haven't been consistent. Evidence also suggests that folic acid may reduce cancer risk. More research is needed before specific dietary choices are recommended. In the meantime, you can reduce your risk of health problems by having at least 5 or more servings of a variety of different colors of vegetables and fruits each day. A healthy diet also includes whole grains and is low in fat, cholesterol, salt and sugar.
What specific things can I do to improve my diet?
A healthy diet includes a variety of fruits, vegetables, whole grains, legumes (dried beans and peas), nuts and seeds. For additional protein, consider moderate amounts of fish, poultry, lean meats, and low-fat and fat-free dairy products.Certain fats should be part of a healthy diet. They can lower your risk of disease. Studies have shown that using "good" fats instead of saturated fat can help lower your total cholesterol level. These "good" fats include the following:
- Monounsaturated fats— Found in canola, olive, avocado and peanut oils, and in other nut oils. Also found in legumes, olives, seeds, nuts, nut butters and fresh avocados.
- Polyunsaturated fats— Found in vegetable oils like corn, sunflower and safflower oils, as well as in sesame seeds, sunflower seeds, corn, soybeans, and many other kinds of grains, legumes, nuts and seeds.
- Omega-3 fatty acids— Usually found in "oily" fish, such as salmon, herring, sardines and mackerel. Also found in flaxseeds, flaxseed oil and walnuts.
Omega-3 fatty acids from fish are especially good for your health. For example, studies have shown that they can decrease your risk of inflammation or heart attack if you're at risk for heart disease.
What are phytochemicals?
Phytochemicals are substances found in plant-based foods. Some experts suggest that people can reduce their risk of cancer by eating more fruits, vegetables and other foods that contain phytochemicals. They may also support bone, heart and brain health.Familiar types of phytochemicals include beta carotene, vitamin C, folic acid and vitamin E. Less familiar are isoflavones, flavonoids, phytosterols, and others. Good sources of phytochemicals include broccoli, cauliflower, carrots, tomatoes, garlic, peas and beans (including soy), whole grains, nuts, flaxseed and grapefruit.
Should I take herbs or dietary supplements?
It's easy to get excited about claims that the latest dietary supplement will prevent or cure cancer. However, advertising claims that a supplement will prevent or cure cancer are not likely to have been verified.
Be sure to talk to your family doctor before adding herbs or supplements to your diet. Making extreme changes to your diet may actually put you at risk for new health problems.
While foods that are rich in vitamin E and beta-carotene are very healthy and help reduce cancer risk, the U.S. Preventive Services Task Force (USPSTF) and the American Academy of Family Physicians (AAFP) recommend against taking vitamin E or beta-carotene for the prevention of cancer. People who smoke or have a high risk for lung cancer should not take beta-carotene because it can increase the risk of lung cancer. There is no current evidence that shows that taking multivitamins can help reduce your risk of cancer.
What foods can increase the risk of developing cancer?
Although there isn't clear evidence about whether specific foods prevent cancer, research shows that certain foods can increase your cancer risk. These include the following:
- Heavily processed meats, such as ham, bacon, sausage, salami and bologna, can increase your risk of colorectal cancer if you eat them too often.
- Foods that are high in saturated fats can contribute to weight gain. Being overweight increases your risk of many types of cancer.
- Alcohol increases the risk of cancer of the mouth, throat, esophagus, liver, breast and colorectal area. If you do drink alcohol, do not have more than 2 drinks per day if you are a man or more than 1 drink per day if you are a woman. One drink is a 12-ounce bottle of beer (4.5% alcohol), a 5-ounce glass of wine (12.9% alcohol) or 1.5 ounces of 80-proof distilled spirits.
What other diseases can a healthy diet help prevent?
Research has shown that a healthy diet lowers the risk of developing certain cancers, type 2 diabetes, osteoporosis and heart disease. Another benefit of good nutrition is that it helps you maintain a healthy weight. Carrying too much weight increases your risk of certain cancers, heart disease, high blood pressure and many other health problems. A high-fiber, low-fat diet and regular exercise can help you lose weight and keep it off.
This content was developed with general underwriting support from Nature Made®.
- American Cancer Society. American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention. Accessed August 07, 2011
- American Cancer Society. Common Prostate Cancer Questions Answered. Accessed August 07, 2011
- American Cancer Society. Folic Acid. Accessed August 07, 2011
- American Cancer Society. Phytochemicals. Accessed August 07, 2011
- American Institute for Cancer Research. Nutrition after 50: Tips and Recipes. Accessed August 07, 2011
- Mayo Clinic. Dietary fiber: Essential for a healthy diet. Accessed August 07, 2011
- National Cancer Institute. Obesity and Cancer: Questions and Answers. Accessed August 07, 2011
- National Cancer Institute. Calcium and Cancer Prevention: Strengths and Limits of the Evidence. Accessed August 07, 2011
- National Cancer Institute. Vitamin D and Cancer Prevention: Strengths and Limits of the Evidence. Accessed August 07, 2011
Copyright © American Academy of Family Physicians
This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.