In response to the published study, "Dietary Supplements and Mortality Rate in Older Women," published in the Archives of Internal Medicine (a publication of the American Medical Association), the Council for Responsible Nutrition (CRN), the leading trade association representing the dietary supplement industry, issued the following two-part statement:
Statement by Duffy MacKay, N.D., vice president, scientific and regulatory affairs, CRN:
"Dietary supplements are used by more than 150 million Americans in combination with other healthy lifestyle habits such as trying to eat a healthy diet and exercising regularly. Research consistently shows that dietary supplement users are higher educated, have higher income levels, and are more likely to engage in other healthy practices than non-supplement users. This study did not discount those facts, and expressly noted that supplement users were more likely to be physically active, more likely to have a lower BMI and waist-to-hip ratio, and have a lower prevalence of smoking, high blood pressure, and diabetes mellitus.
The authors note in their article that '...dietary supplements are commonly taken to prevent chronic disease...' The statement would be more accurate with the addition of one word: dietary supplements are commonly taken to help prevent chronic disease. In other words, dietary supplements should not be expected, in and of themselves, and without the synergy of other healthy habits, to prevent chronic disease.
This study, however, attempts to tease out one piece of the healthy equation for good health—dietary supplements. CRN maintains that nutrients may be robbed of their beneficial effects when viewed as if they were pharmaceutical agents, with scientists looking to isolate those effects, good or bad.
It's important to keep in mind that this is an associative—not a cause and effect—study. Further, the authors themselves have noted additional limitations. In fact, when the authors did their initial [minimum adjusted] analysis, it appears they actually found benefit for many of the supplements, not just calcium; yet instead of stopping there, they went on to 'further adjust' the data, possibly until they found statistics worthy of this publication's acceptance. The study may make for interesting scientific water cooler discussion, but certainly does not warrant sweeping, overstated concerns for elderly women.
Further, the authors show their own bias with this statement: 'We recommend that they [dietary supplements] be used with strong medically-based cause, such as symptomatic nutrient deficiency...' which basically means these researchers would rather wait till we all get scurvy before acknowledging any need for supplemental nutrients.
Our advice to consumers: your best chance for living a long and healthy life is to engage in healthy lifestyle practices, and many in the scientific community maintain that rational, reasonable use of vitamins and other supplements is part of that equation. Talk to your doctor, or other healthcare practitioner, if you have concerns—but read between the lines of individual studies and don't make your decisions—either for or against supplements—based solely on hype."
Statement by Steve Mister, president and CEO, CRN:
"Consumers continue to look for the best way to live long and healthy lives, and as much as we would like for science to easily give us answers, the fact is that science is not black and white. But even more concerning is the recent drive to combine political agendas with what should be pure science. The supplement industry regularly gets accused of this practice—in some cases rightly so—yet medical journals seem to be given a pass, as if somehow they held no bias whatsoever.
Let's look at some of the facts in this publication.
First, within the article itself are a number of opinions including this one: 'Also, cumulative effects of widespread use, together with food fortification, have raised concern regarding exceeding upper recommended levels…' It's quite popular these days to talk about overnutrification, but in fact research consistently shows that most people are falling short in several key nutrients such as potassium, calcium, vitamin D, and fiber while certain subpopulations fall short in folate, vitamin B12, and iron.
Second, the authors advise that dietary supplements only be used 'with strong medically-based cause, such as symptomatic nutrient deficiency...' Given the high dosages of iron reportedly being used by the women in the study— iron is the supplement for which there was the strongest negative association—it is highly likely the participants were taking the high dosage of iron reported in the study under a physician's care for an iron deficiency which may itself have resulted in a shortened lifespan. But the piece purports to warn against over-the-counter use of vitamins.
Next, the publication invited a commentary from a scientist whose opinion on supplements and their potential role in good health is already well-known, and whose own work has been the subject of controversy in scientific circles. In the spirit of true scientific discourse, wouldn't it have been more appropriate to invite a commentary from a researcher who might have looked at the data in its entirety, with sufficient lead time, and provided a different perspective?
The commentary states: '...Therefore, we believe that politicians and regulatory authorities should wake up to their responsibility to allow only safe products on the market.' Critics of dietary supplements will continue to advocate that vitamins and minerals should be regulated like drugs, but even they should realize that although drugs undergo rigorous RCT testing, many safety issues for drugs still do exist. Furthermore if nutrients were regulated like drugs, the cost and availability of supplements would make it difficult for average consumers to make these products part of their healthy lifestyle.
The editors add their own 'editorial note,' using this study as an opportunity to bemoan the fact that 'A better investment in health would be eating more fruits and vegetables, among other activities.' This recommendation comes despite the fact that we don't see a lot of RCTs for fruits or vegetables either. Even without RCTs, we agree that people should be eating more fruits and vegetables; however, in a practical world, consumers are not doing that, and dietary supplements are an option—not a substitute—for getting some (not all) of the health benefits from fruits and vegetables.
It's time scientific journals acknowledge they have some biases, just like industry."
Council for Responsible Nutrition