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Study: Multivitamins may lower cancer risk in men


5 Star

Study: Multivitamins may lower cancer risk in men

Our Review Summary

In lots of little ways, this AP piece exemplifies the difference between very good and outstanding health reporting. Compared with the solid effort from Reuters, the AP’s take was just a little more thorough in its evaluation of the evidence and its implications for readers. Some examples:

  • The story breaks down benefits in terms of absolute, not just relative, risk.
  • There is a clear differentiation between observational studies and randomized, controlled, trials.
  • The involvement of commercial support, small though it may be, is acknowledged.
  • The story cautions that specific groups of people may be at risk of harm from vitamin supplements

The AP did require about 100 more words to deliver these details, and we realize that space is always a concern. Sometimes it does take a little more space to thoroughly address all of our criteria.


Why This Matters

Current evidence is unclear as to whether vitamin supplements help prevent chronic diseases, and they’ve been shown to cause harm in some cases. That’s why, with the exception of people suffering from a vitamin deficiency, most of us are advised to get our vitamins from food instead of supplements. The current consensus, however, is based on studies that typically used high doses of a single vitamin. The low-dose multivitamin used here doesn’t seem to cause the same problems seen in other research, and may even offer a benefit for men similar to those in this study. That’s good news, of course, but it’s hard to get too excited considering the very small size of the reduction, which is barely outside of the range that would be considered statistical noise. It’s the kind of finding that could easily be reversed when the next study comes around–and readers should be warned accordingly.


Does the story adequately discuss the costs of the intervention?

Not Applicable

Not applicable.  Most people know that multivitamins are inexpensive.

Does the story adequately quantify the benefits of the treatment/test/product/procedure?


The story was very cautious in its framing of the results, quoting a researcher who called the effect “very mild” and who said he wasn’t sure it’s significant enough to recommend to anyone. The story also took the time to explain exactly what the benefit looked like in absolute terms: “After about 11 years, there were 2,669 new cancers, and some people had cancer more than once. For every 1,000 men per year in the study, there were 17 cancers among multivitamin users and more than 18 among those taking the placebo pills. That worked out to an 8% lower risk of developing cancer in the vitamin group.” The competing Reuters coverage didn’t provide these details.

Does the story adequately explain/quantify the harms of the intervention?


The story states that side effects were similar between vitamin and placebo group participants, with the exception of their being more rashes among vitamin users. The story also touches on potential harms from dietary supplements in general (e.g. they are minimally regulated and not subject to strict testing for purity) and for specific groups (e.g. people on blood thinners or with cancer, whose vitamin use might interfere with their treatment).

Does the story seem to grasp the quality of the evidence?


The story provides a solid explanation of where this study fits in the hierarchy of vitamin research. It explains how the study differs from previous trials that looked at the effects of individual vitamins in higher doses. It also differentiates the new research from previous observational studies of vitamin users, which “can’t give firm conclusions.”

Does the story commit disease-mongering?


No disease-mongering. The story is clear that the results apply to older, relatively healthy men who don’t smoke.

Does the story use independent sources and identify conflicts of interest?


We hear from an expert who wan’t involved with the study, and we receive a complete description of the study’s funding sources. The story notes that while NIH paid for most of the study, Pfizer supplied the pills. That’s a detail we didn’t hear about in the competing Reuters piece.

Does the story compare the new approach with existing alternatives?


The story says that multivitamins are “less effective than a good diet, exercise and not smoking, each of which can lower cancer risk by 20% to 30%, cancer experts say.” We’ll call this good enough for a satisfactory, but we do quibble with the story’s broad assertions regarding the effectiveness of these lifestyle recommendations. With the exception of smoking cessation, which is certainly effective for preventing cancer, it’s never been conclusively proven that dietary changes or exercise can reduce cancer risk. In fact, recent research suggests that fruits and vegetables — long thought to be strong cancer fighters — actually have little or no effect on cancer risk. Obesity is emerging as the main diet-related culprit when it comes to cancer, something the story could have been more precise about.

Does the story establish the availability of the treatment/test/product/procedure?

Not Applicable

The availability of multivitamins is not in question.

Does the story establish the true novelty of the approach?


The story is clear about where this study stands in context with previous research.

Does the story appear to rely solely or largely on a news release?


It’s clear that this story wasn’t based on a press release.

Total Score: 8 of 8 Satisfactory

Comments (3)

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Carl from PA

October 23, 2012 at 12:47 pm

I haven’t been able to determine how a reduction from 18 cancers per 1000 men to 17 cancers per 1000 men constitutes an 8% reduction. That looks like a 5% reduction to me.


Gregg in SD

October 24, 2012 at 7:21 am

Carl, From the quantify criterion above: “…17 cancers among multivitamin users and more than 18 among those taking the placebo pills.” This statement says “more than 18”, so assuming that means a number between 18 and 19, I checked the percent reduction values for 18.1 to 18.9 incrementing by 0.1. I get an approximate 8% reduction for 18.5.


Chris Turner

October 31, 2012 at 9:54 pm

The impression I got from this study was that it seems to be primarily an an endorsement (advertisement) for a particular multivitamin, that is, Pfizer’s Centrum. The study details disclose that Pfizer provided all the product -for free- over the 10+ years of the study duration. Furthermore, right after the news about this study hit the media outlets Pfizer used the data to promote its multivitamin.

Nevertheless, the subtle implications put forth by some study authors is that the public is best off to rely on multivitamins (e.g., Centrum) that are designed containing RDA levels of nutrients, and products containing ingredients at levels above the RDA are supposed to be unsafe.

But much sound data exists (but is mostly disregarded by the medical profession) showing it is high dose supplements, including multis, that are most beneficial -while still being very safe. The problem with those therapeutic supplements is that they interfere with the medical/pharmaceutical industry’s’ main objective: making profits from ongoing diseases with their products.

Reports that denounce the efficacy and safety of high dose supplements are usually acts of scaremongering over vitamins (see ). Politics isn’t far away…