(RxWiki News) About a third of Americans take a multivitamin with minerals — the most commonly used type of dietary supplement in the US. A new study looked at the impact of this use on breast cancer survival.
Being careful not to state a clear cause-and-effect relationship, the researchers did find that older breast cancer survivors who took supplements containing both multivitamins and minerals had lower risks of dying from the disease than women who didn’t take the supplements.
The postmenopausal women who took the supplements before their breast cancer diagnosis had a 30 percent lower risk of death than non-users, the study discovered.
"Tell your doctor about all supplements that you take."
Sylvia Wassertheil-Smoller, PhD, distinguished university professor emerita of epidemiology and population health at Albert Einstein College of Medicine of Yeshiva University, and colleagues examined data from the Women's Health Initiative (WHI) Clinical Trials and the Women's Health Initiative (WHI) Observational Study to determine if multivitamin/mineral (MVM) supplements impacted mortality rates.
The WHI enrolled 161,608 postmenopausal women between the ages of 50 and 79 in 40 clinical centers throughout the US during the years 1993 to 1998. During the study, participants were continually monitored about their health and lifestyle habits, including supplement use.
The current research studied information on the 7,728 women who were diagnosed with invasive breast cancer during the WHI.
Breast cancer that spreads beyond its original location into the breast tissue is considered invasive.
The researchers learned that 37.8 percent of the breast cancer survivors reported MVM use at the time they enrolled in WHI. Within this group, 76.7 percent of the women said they were taking MVM at the WHI visit closest to their breast cancer diagnosis.
The survivors were followed for just over seven years after their cancer diagnosis.
The researchers found that compared to non-users, women who took the MVM supplements had the following characteristics:
- slightly older
- more likely to be white
- higher income and education levels
- lower body mass index (BMI) — a measure of body fat
- more active with better overall health
- less likely to have a history of diabetes
The women were also more likely than non-users to take additional vitamin supplements, along with the MVM.
The researchers’ analysis determined that women who took multiple vitamin/mineral supplements before their breast cancer diagnosis were 30 percent less likely to die of their cancer than were women who did not take MVM.
This protective benefit held even after accounting for a number of other factors, including the following:
- age at diagnosis
- smoking stauts
- weight and BMI
- physical activity levels
- alcohol use
Despite these findings, the authors stressed that this study did not prove that MVM supplements were the cause of the lowered mortality risks.
dailyRx News spoke with Deborah Gordon, MD, nutrition and preventive medicine expert, about this study.
"Because I always include nutritional counseling, I would be curious to know if the women studied were eating junk food and compensating with a vitamin or eating mindfully and adding a multi-vitamin in their nutritional planning!" said Dr. Gordon, who is an integrative physician at Madrona Homeopathy in Ashland, Oregon.
"My takeaway from this article is that nutrition counts for survival after a breast cancer diagnosis, and that good nutrition should include all the basic nutrients, whether by dietary choice or by regular supplementation as required," Dr. Gordon said.
“The results suggest a possible role for daily MVM use in attenuating breast cancer mortality in women with invasive breast cancer but the findings require confirmation,” the authors concluded.
Results from this study were published in the October issue of Breast Cancer Research and Treatment.
The Women’s Health Initiative is funded by the National Heart, Lung, and Blood Institute of the National Institutes of Health.
No conflicts of interest were reported.