Nutrition Services
Research Updates
- Food, Nutrition and the Prevention of Cancer
- Fortification of Foods: Cause for Concern?
- Healthy eating and exercise promotes greater breast cancer survival rates
- How you cook may be as important as what you cook
Food, Nutrition and the Prevention of Cancer: a global perspective
A report produced by the World Cancer Research Fund together with the American Institute for Cancer Research, published in 2007.
The goal of this report was to review all relevant research in order to generate a comprehensive series of recommendations on food, nutrition, and physical activity, designed to reduce the risk of cancer in all societies of the world. This report is the result of a five-year examination of research by a panel of the world's leading scientists.
As part of their special recommendations, cancer survivors should follow these guidelines for reducing cancer risk, unless otherwise advised by your medical team. With increasing success of cancer treatments, survivors are living long enough to develop new cancers and other chronic diseases; these recommendations are expected to reduce the risk of those conditions. All cancer survivors were also recommended to receive nutrition care from appropriately trained professionals. If you have any questions or concerns about any of these recommendations and how they may apply to your personal life, please request a consultation with one of our Registered Dietitians.
Recommendation 1: Body Fatness
Be as lean as possible within the normal range of body weight
Maintaining a lean, healthy weight is one of the most important things you can do for your health. Sustaining a Body Mass Index within the healthy range of 18.5-25 can protect against cancer. The experts advise adults to avoid weight gain and increases in waist circumference throughout their lifetime.
Tip: Pay attention to small weight changes and increase your physical activity if you notice your clothes fitting tighter.
To calculate your BMI, go to www.nhlbisupport.com/bmi/.
Recommendation 2: Physical Activity
Be physically active as part of everyday life
Physical activity protects against some cancers and helps avoid weight gain and body fatness. A good goal is moderate physical activity for at least 30 minutes per day to start and aiming for 60 minutes or more per day.
Tip: Take two 15-minute walks each day. If the weather is bad, walk around a shopping center or grocery store. The goal is to increase overall activity levels; structured "exercise" may not be necessary. Become more active in small spurts during your day to accumulate the goal of 60 minutes.
Recommendation 3: Foods and Drinks that Promote Weight Gain
Limit consumption of energy-dense foods; Avoid sugary drinks
Consuming less energy-dense, sugary and fast foods can help avoid weight gain and body fatness. Energy dense foods and fast foods often tend to be highly processed and contain less fresh, healthy foods. Sugary drinks contain empty calories that do not promote satisfaction and can lead to weight gain. A good goal is to consume energy dense foods sparingly and avoid sugary drinks and fast food.
Tip: Add lemon, lime, or a splash of juice to water if you are looking for more flavor. Try chilling ginger-lemon tea for a great-tasting, refreshing drink packed with cancer-fighting nutrients.
Recommendation 4: Plant Foods
Eat mostly foods of plant origin
Eating mostly plant foods does not mean becoming a vegetarian, but the dietary habits that seem to be most protective against cancer are those which are high in plant foods, include less-refined grains, and provide natural sources of dietary fiber. Research shows that it's important to eat at least 5 servings of fruits and vegetables combined per day. Incorporating a variety of colors of plant foods has also been found to be beneficial because they provide high concentrations of immune-supportive, health-promoting nutrients. Most vegetables are also low in energy density and can help with weight maintenance. Plant foods also include whole grains, beans, nuts, seeds, soy foods, spices like basil, tumeric, ginger, garlic and cilantro. Plant foods should comprise the majority of every meal.
Tip: At every meal, try to make 50 percent of your plate plant foods, 25 percent a lean protein (like fish or chicken), and 25 percent a whole grain (such as brown rice, oats, quinoa).
View Optimal Diet Plan
Recommendation 5: Animal Foods
Limit intake of red meat and avoid processed meat
Foods of animal origin are a great source of protein and can be healthy if consumed in moderation. The focus should be on lean meats, as diets with high levels of animal fats are often high in energy and can contribute to weight gain. They may also contain other growth factors that can contribute to cancer risk. A good goal is to limit red meat consumption to 11-18 ounces per week, with very little, if any, coming from processed meats. Processed meats include those made with sodium nitrate, such as ham, bologna, pepperoni, and sausage. Lean meats include at least 93 percent lean red meat, fish, white meat chicken, and turkey.
Tip: Try including at least one dinner and lunch each week made from plant proteins (such as nuts, beans, tofu, edamame and other soy foods). Eat fish, such as wild salmon (fresh, frozen or canned) or sardines, at least twice a week.
Recommendation 6: Alcoholic Drinks
Limit alcoholic drinks
Alcohol consumption has been linked with some cancers, although the evidence does not show a clear level of "safe" consumption. Moderate amounts of alcohol can protect against coronary artery disease, therefore alcohol consumption should be limited to no more than 2 drinks per day for men and 1 for women.
Tip: Choose alcohol at special occasions rather than everyday. Take a multivitamin with 400 mcg of Folic Acid to help offset some of the detrimental effects of alcohol and cancer risk.
Recommendation 7: Preservation, Processing and Preparation
Limit consumption of salt; Avoid mouldy cereals (grains) or pulses (legumes)
This recommendation comes mostly from studies of developing countries where foods are preserved with salt when refrigeration and other preservation techniques are not available. The research shows that salt and salt-preserved foods are a probable cause of stomach cancer. Limiting consumption of sodium to less than 2.4 grams per day is ideal.
Aflatoxin, the mould found in grains and legumes, is a cause of liver cancer. Once again, this is mainly a problem in developing countries where storage of these foods is inadequate.
Tip: Choose plant-based seasonings instead of salt to flavor your foods. Try garlic, basil, oregano, sage, chives, cilantro, tumeric, curry, mint, ginger, cinnamon, etc.
Recommendation 8: Dietary Supplements
Aim to meet nutritional needs through diet alone
Dietary supplements are not recommended for cancer prevention. The most potent form of cancer prevention comes from achieving nutritional adequacy through diet. High doses of supplements can be linked to cancer development and can pose risk during cancer treatment. Certain supplements may be indicated to address a vitamin deficiency or other individual need. All supplements should be cross-checked with medications and evaluated for safety and benefit. Be sure to tell your doctor all of the dietary supplements you are taking and ask to speak with a Registered Dietitian for more guidance.
Tip: Take very few vitamins and eat lots of healthful foods for vitamins.
The bottom Line:
Maintaining a lean, healthy weight is very important for cancer prevention. Incorporating physical activity every day will increase lean mass and help with weight maintenance. Limiting energy-dense, empty calorie (including alcohol) and highly processed foods will leave more room in your diet for healthy foods and also help with weight maintenance. Increasing fruits and vegetables as well as whole grains/legumes and limiting red and processed meats are all parts of a healthy, cancer preventing diet. Aim to meet nutritional needs by diet alone.
| Type of Cancer | Convincing Increased Risk | Convincing Decreased Risk |
|---|---|---|
| Kidney | body fatness | |
| Endometrial | body fatness | |
| Breast (postmenopause) | alcohol, body fatness, adult attained height | Lactation/breastfeeding |
| Breast (premenopause) | alcohol | Lactation/breastfeeding |
| Colorectum | processed and red meat, body fatness, adult attained height | physical activity |
| Liver | Aflatoxins* | |
| Pancreas | body fatness | |
| Lung | Beta carotene (supplement), arsenic in water | |
| Esophagus | body fatness, alcohol | |
| Mouth/Pharynx/Larynx | body fatness |
*mostly a problem in developing countries
If you would like to find out more, please visit www.dietandcancerreport.org.
Reference:
World Cancer Research Fund / American Institute for Cancer Research.
Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective.
Washington DC: AICR, 2007
Fortification of Foods: Cause for Concern?
A recent study noting an observation between the addition of folic acid to our food supply and an increase in rates of colorectal cancer in the U.S. and Canada has raised some alarm in the media and brings up a very important public health question. Does fortification of our food supply help or hurt Americans?
Folate comes from the Latin word for leaf and both folic acid and folate are a B vitamin (B9). Neural tube birth defects rates have declined since 1998 when it became mandatory to add folic acid to foods, which is good news for women of child-bearing age. Many food companies add 150-300% more folate than is actually required by government standards. We may now be seeing some of the negative aspects of taking too many vitamins. There's a misconception that all vitamins are harmless. "We just pee out what we don't need," is something nutrition counselors hear often from patients taking multiple, self-prescribed vitamin pills. This study demonstrates that it's not that simple. Science is still discovering how nutrients affect the body on a cellular level and how various doses, forms and concentrations may impact health.
The research results pose a hypothesis based on an observation between folic acid supplementation in foods and increased risk of colon cancer in those with pre-cancerous polyps. Folic acid is used by the body for cell replication and some cancer cells, like colon cancer cells, rapidly divide. Because of this, folic acid could be a potential growth factor for precancerous or cancerous cells. It is important to remember that this data does not definitively show cause and effect, however it does warrant attention and highlights the need for obtaining most of our nutrients from foods in a personalized supplement plan.
Eating a diet rich in naturally occurring folate found in fruits, vegetables, whole grains and beans carries no risk of promoting cancer or B12 deficiency and offers the benefit of helping to reduce the risk of both neural tube defects as well as certain forms of cancer. Cancer survivors should also strive for a plant-based diet.
View Optimal Diet Plan
However, the average American consumes just 1.5 servings of vegetables and less than 1 serving of fruit per day. Only 22 percent of our population eats the recommended 5 or more servings of fruits and vegetables daily. However, Americans spend $18.7 billion annually on dietary supplements, including vitamins, despite limited and inconclusive scientific evidence of effectiveness in disease prevention and treatment.
It is worth mentioning that a known risk of over-supplementation with Folic acid is that it can mask a Vitamin B12 deficiency, which can lead to permanent nerve damage. Deficiency of Folic Acid and Vitamin B12 results in a form of anemia known as pernicious anemia. The current tolerable upper intake level (UL) for folate of 1000 mcg for adult men and women, and a UL of 800 g for pregnant and lactating (breast-feeding) women less than 18 years of age. The current tolerable upper intake level (UL) for folate is:
- 1000 mcg for adult men and women
- 800 g for pregnant and lactating (breast-feeding) women less than 18 years of age
Supplemental folic acid should not exceed the UL to prevent folic acid from masking symptoms of vitamin B12 deficiency. However for those with precancerous polyps, the UL may in fact be much lower.
What should you do?
Speak with your nutritionist to create an individualized supplementation plan based on your medical history and current diet.
Eat folate-rich fruits and vegetables such as: dark leafy greens, broccoli, asparagus, avocado, sweet potato, peanuts, legumes, soybeans, sunflower seeds, orange juice, oranges, wheat germ, rye, buckwheat, semolina, eggs and brewer's yeast.
View Recipe Archive
If you are a woman of child-bearing age please continue to eat folic-acid rich foods, fortified foods and take your multivitamin.
If you are over 40 or have a history of pre-cancerous colon polyps use caution with taking folic acid supplements or B-Complex vitamins and high dose multivitamins.
If you are over 40 or have a history of pre-cancerous colon polyps limit your intake of processed, packed foods that are supplemented with folic acid, including certain cereals and breads.
If you are a breast cancer survivor or are at risk for breast cancer, and drink alcohol, please speak with your physician about balancing risk and benefits of folic acid supplementation. Four hundred mcg of folic acid can help attenuate the risk of breast cancer in women who drink alcohol.
Folic Acid is not included in the vitamin percentages listed on the food label. Read the ingredients of breads, cereals and other grain based foods: look for the words Folic Acid to indicate it's fortified. The folic acid is usually added to the flour and typically found in unbleached enriched wheat flour used in many packaged foods.
Be aware that many new beverages including vitamin-enriched waters, juices and sodas may include supplemental folic acid.
Reference:
Mason JB, Dickstein A, Jacques PF, Haggarty P, Selhub J, Dallal G, Rosenberg IH. A Temporal Association between Folic Acid Fortification and an Increase in Colorectal Cancer Rates May Be Illuminating Important Biological Principles: A Hypothesis. Cancer Epidemiol Biomarkers Prev 2007;16(7):1325-29.
Healthy eating and exercise promotes greater breast cancer survival rates
Eating fruits and veggies plus being physically active can help women who have survived early stage breast cancer live longer, even if they are overweight.
Breast cancer survivors who combined healthy eating and exercise had greater survival rates than if they adhered to just one of these lifestyle behaviors. A recent study revealed that making both of these strategies a daily reality promoted survivorship, even if the women remained obese. This research study, published earlier this month in the reputable Journal of Clinical Oncology, looked at almost 1500 women with an average age of 50 years, living in western states within the U.S. Almost all of the women were nonsmokers.
The 30 percent of women in this study who fell into the high vegetable-fruit/high physical activity group had about half the risk of death from breast cancer compared with women in any of the other three groups (high vegetable-fruit/low physical activity, low vegetable-fruit/high physical activity, low vegetable-fruit/low physical activity). Women with a history of estrogen-receptor positive breast cancer gained the most benefit from integrating these healthy lifestyle behaviors. Even though combining both health behaviors provided the greatest benefit, women whose habits were either high fruit and vegetable intake or high physical activity still had better outcomes compared with the women who did neither.
High vegetable-fruit intake was defined as at least 5 servings per day, and the women in the highest consumption group ate an average of 7.6 servings per day.
A serving is defined as:
- 1 cup leafy greens, berries, melon
- 1/2 cup cooked or cut vegetables and fruit
- 1 medium piece of fruit or vegetable
- 1/4 cup dried fruit
- 6 oz. 100 percent fruit juice
High physical activity was defined as walking 30 minutes at a moderate pace, 6 days per week.
The Bottom Line:
Including more fruits, vegetables and walking in your daily life can help promote survival from breast cancer, even without significant weight loss in those who are obese. Eating a plant-based diet and being physically active can also protect against heart disease, diabetes and other chronic illness.
Maintaining a healthy weight is still very important. This study helps show that making gradual changes in your everyday life is the best place to start making positive health changes. Following a plant-based diet and adding physical activity will naturally lead to weight loss in most individuals over time. The good news is you may get benefits from the behaviors even before the weight comes off.
Make your goal this summer to eat more plant foods and get moving. You'll feel good and may reap some significant health benefits. Remember that every little bit counts.
Reference:
Pierce JP, et al. Greater Survival after Breast Cancer in Physically Active Women with High Vegetable-Fruit Intake Regardless of Obesity. Journal of Clinical Oncology 2007; 25(17):2345-2351.
How you cook may be as important as what you cook
An international group of scientists met in Lyon, France, to review data on the cancer-promoting potential of high-temperature frying methods. Their findings were published in the December 2006 issue of the peer-reviewed journal, The Lancet Oncology. They analyzed evidence from animal studies and human research conducted in China.
Heating oil to high temperatures may lead to the development of cancer causing compounds in the air. This includes cooking techniques such as stir-frying, deep-frying and pan-frying. Researchers found a significant increase in the risk of lung cancer in non-smoking women who regularly prepare their meals using these methods. The risk of cancer increased proportionately with the amount of exposure to the fumes produced from frying. The type of cooking oil used in frying did not make a difference in cancer risk.
The unhealthy byproducts of frying are thought to occur through a process of oxidation, or creation of free radicals. Free radicals take electron molecules from the fats in cell membranes which results in cell damage. Another way frying can be detrimental to health is through the creation of polycyclic aromatic hydrocarbons in the emissions of oil heated to high temperatures.
The Bottom Line:
Choose cooking methods such as baking, broiling and steaming and limit frying of any kind.
Reference:
Straif K, Baan R, Grosse Y, Secretan B, El Ghissassi F, Cogliano V., Carcinogenicity of household solid fuel combustion and of high-temperature frying. Lancet Oncology 2006;7:977-978.
