Aug. 12, 2008 -- Dietary supplement use among long-term cancer survivors
aged 65 and older is very common, according to a new study. But researchers say
the practice may pose risks, even though the goal is often to prevent cancer
"When you supplement, particularly one specific type of nutrient, you
can upset the metabolic balance, how the body processes those nutrients,"
says Denise Snyder, RD, the clinical trials manager at the Duke University
School of Nursing and a study co-author. "Maybe you have too much of one
thing, not enough of something else, and that may put your cells at
For the study, published online in the Journal of Cancer
Survivorship, Snyder and colleagues asked 753 cancer survivors who were
five years or more out from their diagnosis of breast, prostate, or colorectal
cancer to answer questions by telephone about their dietary habits and
their use of supplements.
Supplements for Cancer Survivors
Seventy-four percent of the survivors reported taking dietary supplements.
80% took a multivitamin.
50% took calcium, vitamin D, or both.
41% took antioxidants such as vitamins C and E, carotenoids, selenium, and
29% took fish oil or fatty acid supplements.
19% took glucosamine, chondroitin, and combinations.
18% took botanicals or herbs.
Ninety percent of those who used supplements reported using at least one
formulation for more than a year.
The numbers taking supplements were a surprise, Snyder says. "We kind of
expected it would be at least half," she tells WebMD.
Supplement use was tied into diet habits and other lifestyle factors,
Snyder's team found. In general, the healthier the lifestyle, the more
likely the survivors were to take supplements.
Those who ate a high amount of fruits, vegetables, and fiber and less
saturated fat than the others tended to use supplements. Nonsmokers and the
more highly educated participants were also more likely to report supplement
Supplements for Cancer Survivors: Analysis
Turning to dietary supplements after cancer treatment is understandable,
says Snyder. Cancer survivors tend to look for something they hope will reduce
the odds of recurrence or a new cancer, she says.
"They have often reached out to supplements as a backup to a healthy
diet," she tells WebMD. The researchers didn't ask why the cancer
survivors took the supplements, she says.