This news release describes a randomized, controlled clinical trial designed to learn whether adding vitamin D supplements to substantial weight loss regimens would have a synergistic effect in reducing inflammatory chemicals in the bodies of overweight, older women with levels of vitamin D considered too low. The study, published in Cancer Prevention Research, has potential relevance for cancer prevention because inflammatory cytokines have been implicated in the genesis and progression of some cancers, as well as heart disease and other disorders. The release offers substantial details about the design, metrics and outcomes of the clinical trial and does a pretty good job of defining the possible reasons for the effects of chronic inflammation and weight loss on cancer development. It goes to some lengths to narrowly define the results and avoid overstatement. That said, the release ends on a sour note by encouraging readers to talk to their doctors about vitamin D testing — a recommendation not consistent with U.S. Preventive Services Task Force guidelines and which is not supported by this research. Readers might also have been better informed if the release had offered more context regarding the many conflicting and sometimes confusing studies that have previously looked for links among vitamin D, inflammatory responses, diet, overweight, sun exposure and cancer.
News releases that include the words “diet,” “overweight,” “vitamin,” and “cancer” are almost narrative nuclear events, often guaranteeing an explosion of coverage, souped up vitamin sales pitches, and lots of negative fallout whose half-life seems forever. Cancer remains the second biggest killer disease overall of Americans, and some experts believe that it will soon push heart disease and stroke out of first place. Thus cancer prevention is a deservedly hot topic, and it is no surprise that Americans are eager for information about ways to limit their risk. News releases that describe research on these topics have enormous power to inform and misinform.
There was no mention of the potential costs of screening women for vitamin D levels (as encouraged in the release in a statement from the principal investigator) or the cost of supplementation.
The release does a good job of comparing data and providing explanations for the measurements used. We’ll award a Satisfactory for that precision, but as noted below under “Evidence,” there was no explicit caution regarding the fact that measurements of interleukin-6 (IL-6) are only surrogates for the effects of weight loss and vitamin D on clinical outcomes related to inflammation (e.g. cancer diagnoses). IL-6 levels dropped in both the placebo and vitamin D arms, and it’s not clear whether the statistically significant additional decline in IL-6 observed in the vitamin D group is clinically important.
Because some of the participants were vitamin D-deficient and the dose of vitamin D provided was modest (2000 IU/d), this was a tough call. But supplementation is often so misunderstood, overhyped and oversold that some statement cautioning readers to pay attention to the specifics of this study and not apply its recommendations to everyone seems prudent.
For the most part, the release provides a cautious and accurate description of what appears to be a well-conducted clinical trial in a well-defined population. For example, it notes that weight loss and vitamin D lowered inflammation LINKED to cancer — not that these things reduced cancer risk itself (something this study couldn’t establish). But as noted above, we would have appreciated an explicit acknowledgment that IL-6 is a surrogate marker for the clinical outcomes that people care about. And more importantly, we’re concerned about the closing comment that women should talk to their doctors about measuring their vitamin D levels to determine the most appropriate dose. The problem is there is no evidence supporting screening or treating to a level — and certainly not from this study. The US Preventive Services Task Force has concluded that evidence is insufficient to recommend routine vitamin D screening and the IOM has said that while there are data supporting the benefits of vitamin D supplementation with bone health and fall prevention, there is no evidence supporting benefits for cancer. While testing may be warranted in those with signs or symptoms of clinical deficiency, the statement made here implies that everyone should be tested so that an appropriate dose of vitamin D can be selected. That goes beyond the available evidence.
It’s hard to argue that overweight, vitamin deficiency, chronic inflammation and cancer are not real threats, so no mongering apparent here.
Funding sources are well documented.
The study didn’t discuss alternative preventive measures or genetic causes of increased cancer risks. But this is such a broad and expansive topic that we don’t think the release should have been expected to address those myriad issues. We’ll rate this Not Applicable.
Primary care physicians and other health providers are well positioned to monitor blood levels of vitamin D, along with dietary and exercise regimens. The news release makes that clear, albeit indirectly. As noted above, we think the release goes too far in suggesting that people ask their doctors about having their vitamin D levels checked. But we’ve already docked points for that, so we’ll award a Satisfactory rating here.
The release makes a case for this being the first clinical trial of its kind; although it’s always difficult to make that statement absolutely, the writer of the release attributes the statement to the study author. As a general rule, it’s probably best to say “believed to be the first.” While the release meets our standard here, we also wish it had delved a bit into the background of previous vitamin D research and the conflicting and confusing messages that research has generated. Without that context, the typical reader might wrongly jump to the conclusion, based on the wording of the lede and other parts of the release, that this study of vitamin D supplementation — because it was a controlled clinical trial — has somehow settled the important questions about the role of vitamin D and inflammation in cancer risk. The debate remains alive and well.
None detected.
Systematic, Criteria-Driven
The @nytimeswell effort is shown to be unwell once again.
There's pervasive media bias toward hyping treatment benefits while neglecting negative results & harms.
Big part of this is reliance on experts with financial &/or intellectual conflicts of interest.
Att'n journalists: Use this list 100 independent experts to correct imbalance https://t.co/Twzc1Sp8Vw
Comments
Please note, comments are no longer published through this website. All previously made comments are still archived and available for viewing through select posts.
Our Comments Policy
But before leaving a comment, please review these notes about our policy.
You are responsible for any comments you leave on this site.
This site is primarily a forum for discussion about the quality (or lack thereof) in journalism or other media messages (advertising, marketing, public relations, medical journals, etc.) It is not intended to be a forum for definitive discussions about medicine or science.
We will delete comments that include personal attacks, unfounded allegations, unverified claims, product pitches, profanity or any from anyone who does not list a full name and a functioning email address. We will also end any thread of repetitive comments. We don”t give medical advice so we won”t respond to questions asking for it.
We don”t have sufficient staffing to contact each commenter who left such a message. If you have a question about why your comment was edited or removed, you can email us at feedback@healthnewsreview.org.
There has been a recent burst of attention to troubles with many comments left on science and science news/communication websites. Read “Online science comments: trolls, trash and treasure.”
The authors of the Retraction Watch comments policy urge commenters:
We”re also concerned about anonymous comments. We ask that all commenters leave their full name and provide an actual email address in case we feel we need to contact them. We may delete any comment left by someone who does not leave their name and a legitimate email address.
And, as noted, product pitches of any sort – pushing treatments, tests, products, procedures, physicians, medical centers, books, websites – are likely to be deleted. We don”t accept advertising on this site and are not going to give it away free.
The ability to leave comments expires after a certain period of time. So you may find that you’re unable to leave a comment on an article that is more than a few months old.
You might also like