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 recurrence.
"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 risk."
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.
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 use.
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.