This
week, a study made the news suggesting there’s a substantial benefit to breast
cancer patients who take multivitamin-multi-mineral supplements. This study definitely warrants a closer look.
Dr.
Sylvia Wassertheil-Smoller of Albert Einstein College of Medicine, Yeshiva
University in New York, together with her colleagues, analyzed data from the
Women’s Health Initiative (WHI) clinical trials and observational study on the
use of supplements as it relates to mortality due to breast cancer. The WHI trials included 7,728 patients who
were diagnosed with breast cancer during the course of the studies, and were
followed for an average of 7 years after their diagnosis. At the start of the study, a thorough
assessment of diet, lifestyle and clinical condition was conducted. We think a particularly interesting feature
of the assessment was that information on what supplements were used was
obtained by having patients bring their bottles of vitamins and other
supplements to the clinic, so they could be accurately recorded by the
researchers (as opposed to the participants providing this information to the
researchers, which may not be as reliable).
The researchers tracked mortality in this population of breast cancer
patients, and compared mortality of those who used versus those who did not use
multivitamin-multi-mineral supplements.
At
the start of the study, 37.8% of the women reported using these
supplements. For those women using
supplements, breast cancer mortality was 30% lower than those who did not
report using multivitamin-multi-mineral preparations. The researchers tried adjusting this figure
with many different variables that could have otherwise accounted for the
difference in mortality, including age at the time of cancer diagnosis,
physical activity, alcohol use, diabetes, smoking, education level,
race/ethnicity, and weight. They also
used other sophisticated statistical analyses that accounted for the propensity
of the subjects to take multivitamin-multi-mineral preparations. After all this adjustment, the researchers
still found that women taking these supplements were 24% less likely to die
from breast cancer, a statistically significant figure.
Now,
of course, a study in which patients are observed over the course of many years
is not the same as a randomized, controlled trial. Nevertheless, the design of this study is
considered the “gold standard” of observational studies: thousands of patients who are monitored
starting even before they are diagnosed with a disease, and whose outcomes are
tracked after diagnosis as well.
Interestingly, in the last few years, there have been three other
studies of breast cancer patients with similar designs that report similar
results about supplements.
In
2011 researchers from Kaiser Permanente in California published a study of
2,236 early stage breast cancer patients whose diet and supplement use were
reported to researchers every year after they were diagnosed with breast
cancer. Their mortality and recurrence
rates were analyzed. 72% of these women
used supplements after their diagnoses.
In this study, multivitamin use after recurrence in the entire study population
was not associated with mortality, though use of multivitamins both before and
after diagnosis decreased recurrence and mortality, although the results were
non-significant. However, among women
treated with radiation alone, or women who were treated with both radiation and
chemotherapy, the decrease in recurrence and mortality was significant. This means that the women who had more
serious disease did benefit from taking multivitamin supplements. Those women whose disease was mild enough,
for instance, to be treated with only surgery and hormone therapy did not have
any further benefit from multivitamins.
It’s possible that since the latter group of patients has a very good
prognosis in general, the extra contribution of multivitamins would be too
small to be detected in a group of this size.
This study also noted that pairing multivitamin use with eating more
fruits and vegetables, along with physical activity, also contributed to better
overall survival.
Columbia
University researchers studied this same group in more detail in a study
published in 2012. Specifically, they
examined the use of antioxidant supplements by these breast cancer
patients. In this case, they found that
the use of vitamins C and E were associated with 27% and 29% reductions in
breast cancer recurrence, and vitamin E use predicted lower overall
mortality. These researchers found,
however, that the use of combination carotenoids was associated with higher
mortality risks. It’s hard to figure out
what this finding means. Were these
supplements used mainly by a subpopulation that had particularly serious
disease? Or, was there, perhaps, some
risk factor that wasn’t assessed in the statistical analyses done by the
researchers? As an example, what was the
quality of the supplements used by these patients? The effect of a high quality supplement
versus a poor quality supplement will be profoundly different. Unfortunately, in studies that simply observe
patients, it’s difficult to discern what additional variables may have
influenced the outcome; it’s necessary to do a randomized trial to resolve
questions like these.
Finally,
in a study that appeared in June of 2013, researchers at Harvard analyzed
12,019 breast cancer patients who were tracked in four separate studies, 3
studies in the US and one in China. They
examined supplement use, and adjusted their analyses for smoking and hormone
status (menopausal or not). They also
adjusted each of the supplements for use of other supplements, so that they
could more easily determine which supplement was responsible for which
effect. When they were done with the
adjustments, the use of antioxidant supplements, including multivitamins, and
vitamins C and E, were associated with a 16% decreased risk of death. Vitamin D use was linked to a decreased risk
of recurrence in patients who had estrogen-receptor positive tumors, although
not those with estrogen-receptor negative tumors. A particular strength of this study is the
diversity of the populations that were studied, which makes it easier to
generalize to the diverse population of women who are diagnosed with breast
cancer.
While
these observational studies do not give us the kind of information that
randomized trials do, and while there are still questions that can be raised
about data that they include, these very large and diverse studies are sending
us a message: use of multivitamins and
other antioxidant supplements by breast cancer patients can contribute to a
positive outcome. At the Block Center,
we recommend tailoring supplement regimens to your specific clinical needs,
based on detailed testing of your biochemical terrain.
For more information on The Block Center for Integrative Cancer Treatment, call (847) 230-9107 or visit BlockMD.com.