This news release describes the results of an observational study that looked at the association of a scoring system called the dietary inflammatory index (DII), which aims to measure the inflammatory potential of certain foods, with risk of bone fractures in postmenopausal women. Researchers also looked at changes in bone mineral density (BMD) and compared them with DII scores. Over 160,000 women completed food frequency questionnaires at baseline and then again 3 years later, and information on bone fractures was reported at least every year. A smaller group of women (about 10,000) also had a procedure that measured their bone mineral density (BMD), which is an important factor in risk for osteoporosis and fractures.
Overall, the study did not find an association between a diet higher in inflammatory foods (based on the DII) and fracture risk. However, a higher DII score was associated with increased risk for hip fracture — but only in White women younger than 63 years. Women with the least inflammatory DII scores had less loss of hip BMD despite having a lower BMD at the start of the study, when compared with women that had the most inflammatory DII scores.
This release places the research into context for readers and provides important cautions about the observational and retrospective nature of the study design. Its language is measured, and it takes care not to hype the findings. We also liked how the release references a positive finding from a subgroup of the study without presenting the finding as if it were the main result. The release would have been improved with the addition of some measurement of benefits and some mention of the costs associated with a diet that would potentially lead to fewer bone density problems in older age.
Chronic inflammation plays an important role in the development of many chronic diseases and some dietary patterns have been shown to be associated with inflammation. However, the evidence of the association between dietary patterns and inflammation is still inconsistent. Some research suggests that bone loss, which can lead to osteoporosis, and fracture risk are associated with higher levels of inflammatory markers in the body, and that this can be potentially changed through adopting certain eating patterns.
The Dietary Inflammatory Index (DII) was developed to assess the overall quality of the diet, on a spectrum of anti- to pro-inflammatory. This index was created by assigning a score for each food that has been reported to positively or negatively affect levels of specific inflammatory markers in the body. The DII was designed to look at the impact of overall diet on inflammation, rather than looking at one or two specific food components. Examining exposure to diet patterns and their links to bone health in postmenopausal women may lead to developing diet recommendations for women at risk for fractures and osteoporosis.
The release does not discuss costs. This is not a typical intervention but more of a dietary lifestyle choice, but because the study in question talked about diets that were both high and low in inflammatory foods, it would be worth even a reference to what the costs associated with a more beneficial diet might be.
We were disappointed to see little actual quantification of the benefits found in the study. Most of the numbers in the release were numbers quantifying the number of women being studied in different ways and the number of dietary components that were studied. One sentence said this:
“Higher scores were associated with an almost 50 percent larger risk of hip fracture in Caucasian women younger than 63, compared with the risk for women in the group with the lowest inflammatory scores.”
It’s very hard to know what to make of that sentence without knowing the actual number of women who saw a benefit or did not see a benefit. This is an issue of reporting relative risk (which this study did) versus absolute risk, which would give us actual numbers of women that were affected. (See our primer on writing about absolute vs relative risk.)
There is no mention of harms in the release but it’s hard to envision harms that could occur from an improved diet.
This is where the release really does provide a model for other releases. It nicely describes the structure of the study, the period of time it covered, its weaknesses, and other relevant details. It references a positive finding from a subgroup of the study but does not treat that finding as if it were the main result of the study. And it may seem a small thing, but the release uses the term “inflammation markers.” Use of the term “marker” is a caveat that gives it some distance from the actual cause or definitive proof. A marker is an indicator of a possible disease or condition and not a sign of the disease or condition itself.
There is no disease mongering in the release.
The release explains that the study was funded by the National Heart, Lung and Blood Institute and the U.S. Department of Health and Human Services.
The release does not go into any depth about the different diets being studied, but it does explain that different diets with different levels of inflammatory components had different degrees of impacts on bone density.
It states early in the release that “vegetables, fruits, fish and whole grains” are beneficial but it would be nice to see more focus on specific foods and even specific diets considered to be pro- or anti-inflammatory so that readers could compare and contrast different diet patterns.
These different food types were not described in the research publication either, but in these cases, we encourage PR staff to seek clarification from the investigators.
We are giving this a pass here because the release makes mention of “a diet higher in beneficial fats, plants and whole grains,” which includes foods that are widely available.
The news release established that this was the first study to look at dietary information from this large group of participants, assign their diet patterns an inflammation score based on previously established research, and determine the relationship between their diet, bone mineral density, and risk for bone fracture. The release nicely fit the current research into the larger body of research on inflammation and bone density. It said:
“Previous studies have connected high levels of inflammatory markers in the blood to bone loss and to fractures in older women and men, which prompted Orchard and her colleagues to wonder what they’d find if they took one more step back – to the dietary choices that contribute to inflammation in the body.”
There is no unjustifiable language in the release.