Multivitamins May Not Cut Cancer Odds

Feb. 9, 2009 -- Taking a multivitamin may not lower the risk of cancer, heart disease, or death from any cause for postmenopausal women.

That's according to a new study published in the Archives of Internal Medicine.

Here are highlights from the study, which included 161,800 postmenopausal U.S. women followed for about eight years:

• About 42% of the women reported taking multivitamins.
• During the study period, new cases of certain cancers (including breast cancer, lung cancer, and colorectal cancer), heart disease, and deaths from any cause were similar in women taking multivitamins and those not taking multivitamins.

Adjusting for the women's age, race, BMI, physical activity, alcohol use, smoking, and other factors didn't change the results. But the researchers couldn't adjust for every possible influence.

Data came from the Women's Health Initiative (WHI), a long-term women's health study. Because the WHI only included postmenopausal women, it's not clear if the findings apply to other groups of people.

Researcher's Advice

In a news release, researcher Marian Neuhouser, PhD, says that it was a "surprise" to find that "multivitamins did not lower the risk of the most common cancers and also had no impact on heart disease."

Neuhouser recommends getting nutrients from foods, not supplements.

"Whole foods are better than dietary supplements. Getting a wide variety of fruits, vegetables, and whole grains is particularly important," says Neuhouser, who works in Seattle at the Fred Hutchinson Cancer Research Center.

Supplements Industry Responds

Andrew Shao, PhD, is the vice president for scientific and regulatory affairs at the Council of Responsible Nutrition, a trade group for the dietary supplements industry.

In a statement responding to Neuhouser's study, Shao says that "multivitamins, like all other dietary supplements, are meant to be used as part of an overall healthy lifestyle; they are not intended to be magic bullets that will assure the prevention of chronic diseases, like cancer."

Shao points out that most Americans don't get the recommended amounts of various essential nutrients from their diets. "Consistently taking a multivitamin over the long term could help fill these nutrient gaps and may help consumers lead healthier lives," Shao says.