Vitamins and Cancer: What About Taking Diet Supplements and Vitamins
Should I consider taking vitamins and nutritional supplements before, after,
or during chemotherapy?
Ask your physician, nurse, or dietitian about using nutritional supplements such
as Boost, Ensure, and Carnation Instant Breakfast to help meet nutritional needs
and maintain or gain weight. There are many products available that can't
be purchased at the grocery store. Call 1-877-4WebMed to order products for
home including those that are found at the grocery store. A dietitian can
help you add commercial supplements to your current diet, or if necessary, comprise
your entire diet to meet all your estimated nutritional needs.
Will taking vitamins during chemotherapy help?
Diet vs. supplements - the preferred choice to meet nutritional
needs is from the diet. The vitamins, minerals and phytochemicals (a variety
of compounds produced by plants) needed to help our bodies fight cancer are found
in a well-balanced diet emphasizing plant-based foods. According to the nutrition-based
literature available, an inverse association has been noted between fruit and vegetable
consumption and cancer risk. In other words, eating more fruits and vegetables
may lower your cancer risk.
It is difficult to determine if a specific nutrient is protective, or a specific
combination and ratio of phytochemicals. The ultimate goal is to maintain
a well-balanced, plant-based diet, low in fats and sugars to help lower the risk
of cancer. Recommendations include at least 5 servings per day of a variety
of fruits and vegetables with breads and starch consumption including 2-3 servings
of whole grains.
In cancer research, the intake of individual vitamin supplements,
as opposed to consuming fruits and vegetables, has not shown increased protection
from these supplements. In fact, three clinical studies were done examining
the protective effects of beta-carotene and lung cancer, two of which found a higher
association among cigarette smokers when beta-carotene was supplemented. The
third study showed neither benefit nor harm from the beta-carotene.
Phytochemicals refer to a wide variety of compounds produced
by plants. They are found in fruits, vegetables, beans, grains, and other
plants. There are thousands of phytochemicals and they fall into groups such
as the polyphenols (subgroup flavonoids), antioxidants (including
carotenoids), and sulfides. Phytochemicals have either antioxidant
or hormone-like actions.
Flavonoids are found in soy beans, soy products, garbanzo
beans, chickpeas, licorice, and tea. These are estrogen-like substances from
plants called phytoestrogens.
Antioxidants are commonly found in vegetables such as
broccoli, brussel sprouts, cabbage and cauliflower. There are many phytochemicals
that fall into this category including carotenoids which are founds in carrots,
yams, cantaloupe, butternut squash, and apricots. The term antioxidant is
often associated with vitamins and cancer protection. Antioxidants include vitamin
C, vitamin E, selenium, and carotenoids. These nutrients are associated with
a reduced cancer risk due to their ability to scavenge free radicals from our body.
Free radicals are reactive compounds that can damage normal cells.
Sulfides are found in garlic and onions and may have a
role in reducing risk of stomach cancer. These nutrients are found naturally
in many fruits and vegetables. Due to their protective association in food,
researchers are trying to determine if this benefit exists with supplemental phytochemicals.
Herbs have been used for hundreds of years to treat disease.
Many are safe, and others may have severe and harmful side effects, and possibly
interfere with cancer therapies such as chemotherapy, radiation therapy and recovery
from surgery. A recent example has been the discovery that levels of chemotherapy
were reduced in the body in people who were using the herb St. John's Wort.
Safety considerations are to tell your health care team
about any herbal products you are using or are planning to use before, during,
or after chemotherapy. Ask your physician, nurse, or dietitian
for reliable information about dietary supplements. Stop taking the products
immediately and contact your physician if you experience side effects such as wheezing,
itching, numbness, or tingling in limbs.
The jury is still out regarding supplementation of various phytochemicals and herbs
to help prevent or fight cancer. There are many studies being conducted regarding
supplementing and/or megadosing different phytochemicals or herbs. It appears
that much of the encouraging herb / vitamin / cancer data
has been seen in animal studies, which do not necessarily cross over to human studies.
There isn't enough consistent and significant data at this point to draw any strong
conclusions or associations to recommend the use of supplements.
Vitamins, Minerals, Herbs and Chemotherapy / Radiation Therapy for Cancer
Research is underway to determine the safety and possible benefits in using herbs,
antioxidants, vitamins, and minerals during treatments.
Megadoses - The literature available has not proven that
taking vitamins in small or large doses helps to prevent or reverse cancer.
Megadoses of vitamins can prove to be toxic or harmful in some instances.
Water-soluble vitamins are generally harmless due to our
body's ability to excrete the excess vitamins as waste. In some instances
there can be negative effects, for example, high doses of Vitamin C can increase
the risk of oxalate kidney stones, posing an increased risk for individuals with
renal failure. B6 (pyridoxine), even in moderate dosages, could result in
Quite the opposite of fighting diseases such as cancer, fat-soluble vitamins
in large doses can become toxic, because they are stored in the body. Vitamin
A toxicity can lead to changes in bone development, an enlarged liver, anemia, and
loss of hair. High doses of Vitamin D can produce high calcium levels with
calcifications in the kidney and blood vessels, and possibly result in osteoporosis.
Note: We strongly encourage you to talk with your health care professional
about your specific medical condition and treatments. The information contained
in this website is meant to be helpful and educational, but is not a substitute
for medical advice.