The Nutrition Nuggets Newsletter is brought to you quarterly by The Abramson Cancer Center of the University of Pennsylvania Registered Dietitians, Katrina Claghorn and Ellen Sweeney. Katrina and Ellen provide nutrition counseling to The Abramson Cancer Center of the University of Pennsylvania outpatients.
The Best Disease Protection: supplements or synergy?
What is the best way to protect your body against disease? Should we take herbs, antioxidant supplements, and green tea? Or is there something even better? For now, researchers agree that most studies suggest that people who consume more antioxidants in their diets, not in pill form, have a lower cancer risk. A diet high in fruits and vegetables might therefore be beneficial in improving cancer survival as well. Research implies that the benefits of eating fruits and vegetables might be much greater than the effects of the vitamins, including antioxidants, they contain.
The protective benefit is believed to be from the many vitamins and phytochemicals (natural disease fighting plant substances) in whole foods acting together (in synergy) to reduce cancer risk. Most experts recommend eating at least five servings of fruit and vegetables daily. A serving size is equal to 1/2 cup cooked vegetables, 1 cup raw vegetables, 1/2 cup chopped fruit, 1/4 cup dried fruit, one piece fresh fruit, or 6 ounces fruit juice. For more information, visit the American Institute for Cancer Research web site.
Too Much Of A Good Thing: Safe Upper Limits Established for Vitamins and Minerals
A Recommended Dietary Allowance (RDA) is the amount of a vitamin or mineral required by a healthy person to prevent deficiencies. The first RDAs were published in 1941 and have been revised about every five years based on a review of scientific literature. Over the decades, the Food and Nutrition Board of the National Academy of Sciences' Institute of Medicine has changed their approach in presenting dietary guidelines. They recognized that many people are taking nutrients in amounts well beyond the RDAs. To protect the public from toxicity that can be caused by taking too much of some nutrients, an additional reference value was created. This new category, Tolerable Upper Intake Limits (ULs), is defined as "the highest level of daily nutrient intake that is likely to pose no risk of adverse health effects".
ULs have been established for vitamins A, B6, B12, D and E and for the minerals iron, magnesium, selenium, and zinc. The UL for vitamin A has been set at 10,000 IU per day. Taking doses of vitamin A greater than the UL regularly can cause irreversible liver damage and birth defects. This is just one example. The National Institute of Health has posted information about all the new ULs on their website.
Coping with Cancer Treatment: Preventing Dehydration
Cancer treatment can increase the amount of fluid a person needs to flush the bladder and kidneys. Signs of dehydration include weakness, dizziness, decreased urination, thirst, headache, and possible fever. These symptoms can occur quickly if you lose fluid due to diarrhea, vomiting, or fever. An intake of 48-64 ounces (6-8 eight ounce glasses) of fluid per day is recommended. These fluids should be non-alcoholic and caffeine free since both substances tend to increase fluid loss.
Remember, "fluid" does not just mean water. Broth, juice, fruit drinks, Jell-O, water ice, milk, Ensure, and decaf teas all count as fluid.
Cancer Prevention Pantry: Time For Summer Blues!!
Adapted from the Environmental Nutrition newsletter, March 2001.
It is blueberry season and there is nothing like fresh blueberries to top off a bowl of cereal, bake in a pie, or just enjoy on their own. These are just a few tasty ways to celebrate summer. The juicy berries are also tiny antioxidant powerhouses. Anthocyanins, the blue pigments from the blueberry skin, are powerful antioxidants with potential cancer preventing power. In a recent study comparing 40 fruits and vegetables, blueberries had the highest antioxidant capacity, mostly due to the anthocyanin. More good news is that frozen blueberries are just as nutritious. So enjoy the health benefits year round! Look below for an antioxidant packed summer snack.
Ask The Dietitian
Should I take Antioxidant supplements, during my cancer treatment?
Antioxidant supplements, which would include vitamins A, C, and E, beta-carotene, co-enzyme Q10, and minerals such as selenium, may interfere with these treatments. The concern is that antioxidants may reduce oxidizing free radicals created by the treatments and consequently reduce the effectiveness of the therapy. There have been inconclusive studies in this area but our knowledge about how chemotherapy and radiation therapy work leads us to predict that antioxidants may interfere with therapy.
Food sources of antioxidants are generally safe since it would be difficult to consume a large enough amount of antioxidants from food sources, like fruits and vegetables, to negatively impact treatments. A safe supplement to take during therapy is a standard (Centrum type brand) multivitamin which generally provides a safe amount and balance of nutrients.
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