In this very narrow discussion of a small study in mice, the suggestion is that someday maybe walnuts (or some nutritional element of walnuts) could help people by slowing the growth of colon cancer. But while the study doesn’t mention how much (or how little) such a therapy might cost, we think this criterion is Not Applicable here for two reasons: 1. the cost of walnuts is generally well known, and 2. the research is at early enough stage — and the release establishes the preliminary nature of the study — that it’s hard to know what any walnut-related therapy might cost. Furthermore, while the criteria of cost is integral to what we all agree is good reporting about health outcomes, incorporating information about the potential cost of walnuts — or any other foodstuffs — in a release about a study that’s so preliminary might actually reinforce the suggestion of a useful therapy. Including that info wouldn’t improve anyone’s understanding of the importance of the research. The research on a small group of mice showed slowing of the growth of colon cancer tumors. The research proved that tumors in mice fed walnuts had “10 times the amount of total omega-3 fatty acids, including plant-based alpha-linolenic acid (ALA), in the tissue compared to the mice fed the control diet.” Although the quantification here is limited, we’ll give the story credit for accurately reporting the outcomes in broad strokes. The detailed results of what happened in a mouse study have limited use for the average human reader anyway. But while the release does not state that the mouse study could lead to prevention for humans, we’re worried that a normal reader may see the suggested effects of an enhanced walnut diet — increased anti-inflammatory activity, reduced angiogenesis, increased protective lipid content — and assume that these affect actual cancer outcomes. Set aside the major caveat that it is an animal study for a moment — the release says that walnuts “may” slow the growth of colon cancer. It also equally may not. The limited study did not appear to investigate potential harms, and the release didn’t comment on them. For humans, consumption of too many calorie-dense walnuts could precipitate weight gain. But the equivalent of two ounces a day doesn’t sound like it could be very harmful. We’ll rate this Not Applicable. While the main headline was not upfront about the fact that the study involved mice, the body of the release itself was carefully worded and did a fair job of describing the evidence. It’s always helpful to see “animal” in the very first sentence of a study involving mice. microRNAs are a complicated topic, as are changes in gene expression, which is at the root of the questions that the study addressed. The release adequately describes the evidence drawn from the work but does so sparsely. The eight-page paper is reduced to an eight-paragraph release, only three paragraphs of which actually convey an explanation of the work. What the release offers is acceptable by our standards but more information, properly couched, could aid readers in assessing the study’s true value. There was no disease mongering. Funding sources were identified, netting this release a Satisfactory rating, but when a fundor is integrally related to the substance of the research, that mention belongs higher up in the story or release, rather than tagged onto the end, allowing readers to consider the context of the funding early in their reading of the material. The release discusses the chemistry of inflammation and the growth of tumors in the mice. It briefly mentions “diet and lifestyle changes” as means to reduce risk, but does not discuss what specific changes are shown to be helpful. It also does not discuss screening and polyp removal, arguably the best-supported intervention for catching colon cancer before it spreads. We accept that walnuts are widely available. There has already been research on the potential protective influence of omega-3 fatty acids for inflammation. The release clearly explained the novelty of this specific mouse study investigating underlying chemistry and how it may work. While we aren’t happy with the headline, we think this release squeaks by because the main text is accurate and we applaud the first sentence clearly labeling it an “animal study.” The release clearly avoids any sensationalized verbiage, a feat to be lauded in cases like this when an inference of a simple activity — like eating nuts — might lead a reader to jump to wrong conclusions.
New Harvard research finds walnuts may help slow colon cancer growth A walnut-enriched diet may cause beneficial genetic changes in animal cancer cells, affecting inflammation, blood supply and growth of tumors