Most Wanted Supplements:
Are They Cancer Killers or Frauds? What You Need to Know
Marketing claims for nutritional
supplements can be lofty -- and misleading.
What's lurking inside those
bottles -- cancer killers? Or con
artists?
University of Michigan Comprehensive Cancer Center dietitians Joan Daniels, R.D.,
and Nancy Burke, R.D., say the best bet for cancer prevention is a healthy diet. Nevertheless,
we know many of our patients have questions about supplements. Here's the lowdown
on 10 commonly linked to cancer prevention.
Suspect: Fish Oil
Charge: Fish oil contains omega-3 fatty
acid, which helps the body absorb nutrients
and fend off inflammation. Some studies
indicate that omega-3s may prevent cancer
and heart disease.
Verdict: Inconclusive.
Like all supplements,
researchers don't know whether fish
oil acts alone or with other food chemicals
to provide cancer protection. Most people
can tolerate up to 3,000 milligrams per day
of fish oil. But higher doses may impair the
immune system and increase bleeding and
stroke risk. Instead of using fish oil, include
oily fish, such as salmon and tuna, in your
diet.
Suspect: Flaxseed
Charge: Flaxseed contains lignans,
which may be helpful in reducing cancer risk.
Lignans are phytoestrogens, plant chemicals
that mimic the hormone estrogen. Flaxseed is
also rich in omega-3 fatty acid.
Verdict: Laboratory research has shown
flaxseed may slow colon, skin, lung and
breast cancer growth, but results haven't
been confirmed in humans.
Some people
take flaxseed oil, but it does not contain
lignans and lacks the antioxidant properties
of ground flaxseed. Instead of oil, consider
sprinkling ground flaxseed, which is high in
fiber and omega-3s, over cereal or yogurt.
But use caution: Flaxseed may cause stomach
upset. Drink fluids to prevent bowel obstruction.
Flaxseed may also interact with blood
thinners, including pain medications such as
aspirin.
Suspect: Ginger
Charge: Laboratory research at the U-M
Cancer Center has shown that ginger may
be effective in killing ovarian cancer cells.
Ginger is known to control inflammation --
which may play a role in cancer -- and
nausea.
Verdict: It's too early to know whether
ginger will help treat or prevent cancer.
Ginger supplements are not recommended. However, adding fresh ginger root to your
diet or chewing candied ginger for nausea may be helpful. Excessive
amounts of ginger should be avoided, as it may interact with blood-thinners and
cause lower blood sugar levels in people who take diabetes medications.
Green Tea
Charge: People who drink green tea
seem to have a lower cancer risk, particularly
for cancers of the bladder, esophagus,
ovaries, pancreas and possibly breast. Green
tea contains plant chemicals called polyphenols
that act as antioxidants and anti-inflammatories.
Verdict: Drinking up to three cups of
green tea per day is probably safe for most
people and may have anticancer effects.
However, green tea extracts or pills are not recommended. Be aware that green tea
contains caffeine, which may interact with medications and
keep you awake.
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Make an appointment with Cancer Center Nutrition Services by calling 734-647-8902.
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