Review published in Advances in Nutrition finds pro-inflammatory diets are associated with the development of several diseases
Studies have shown that chronic low-grade inflammation is associated with the development of a number of chronic diseases. In particular, it is associated with an increased risk of mortality from all causes, as well as an increased risk of cancer, type 2 diabetes, neurodegenerative disease, and cardiovascular disease. In addition to physical diseases, chronic inflammation is implicated in the development of mental illness, including depression, schizophrenia, and bipolar disorder.
Diet plays a key role in inflammation. For example, Mediterranean dietary patterns, which are rich in fruits, vegetables, fatty fish, poultry, extra virgin olive oil and whole grains, are associated with lower systemic inflammation. On the other hand, Western dietary patterns, which are characterized by low consumption of fruits and vegetables and high consumption of ultra-processed high-calorie foods, are associated with increased levels of inflammation.
Published in Advances in Nutrition, the international review journal of the American Society for Nutrition, “The Dietary Inflammatory Index and Human Health: An Umbrella Review of Meta-Analyses of Observational Studies” took a critical look at the current body of evidence in order to determine the association between the inflammatory properties of different dietary patterns and 38 different disease outcomes. More specifically, authors Wolfgang Marx et al. looked at the relationship between the Dietary Inflammatory Index™ and human disease. Based on 45 food parameters, the Dietary Inflammatory Index is a tool used to estimate the inflammatory potential of particular dietary patterns.
In order to conduct their research, the authors performed a comprehensive search of the scientific literature, leading them to 15 relevant meta-analyses of observational studies that collectively tracked the diets and disease outcomes of more than 4.3 million study subjects. Following the authors’ analyses, they found pro-inflammatory dietary patterns, as judged by a higher Dietary Inflammatory Index score, were associated with a higher likelihood of a range of chronic disease outcomes. Specifically, a dietary pattern with a high Dietary Inflammatory Index score was associated with an increased risk for 27 of the 38 health outcomes under investigation. “Convincing (Class I) evidence” was found for myocardial infarction only. “Highly suggestive (Class II) evidence” was found for all-cause mortality, overall cancer risk, and site-specific cancers such as colorectal cancer, pancreatic cancer, respiratory cancers, and oral cancer.
Overall, the results of this umbrella review provide “further evidence for the role of anti-inflammatory dietary patterns in the prevention of chronic diseases, as well as inflammation as a mechanism of action in the genesis of adverse health outcomes.”
The authors did acknowledge that the strength of the evidence was not uniformly strong for all chronic disease outcomes. For 31 of the 38 disease outcomes, for example, the evidence was rated as either “suggestive” or “weak or no association.” Looking to the future, the authors believe, “further prospective evidence is required to explore this association in health outcomes where current studies are limited (e.g., pancreatic, endometrial, and urological cancers), to address the large degree of heterogeneity, and to explore potential subgroup populations that are particularly susceptible to diet-induced inflammation.”
Wolfgang Marx, Nicola Veronese, Jaimon T Kelly, Lee Smith, Meghan Hockey, Sam Collins, Gina L Trakman, Erin Hoare, Scott B Teasdale, Alexandra Wade, Melissa Lane, Hajara Aslam, Jessica A Davis, Adrienne O’Neil, Nitin Shivappa, James R Hebert, Lauren C Blekkenhorst, Michael Berk, Toby Segasby, Felice Jacka. The Dietary Inflammatory Index and Human Health: An Umbrella Review of Meta-Analyses of Observational Studies. Advances in Nutrition, nmab037 (Epub ahead of print; DOI: https://doi.org/10.1093/advances/nmab037).
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