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.
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