Dietary inflammatory index

The Dietary Inflammatory Index (DII) is a numerical score that assesses a diet for its effect on several biomarkers linked to inflammation. Its theoretical bounds are −8.87 to +7.98, and it is oriented such that negative scores are more anti-inflammatory and more positive scores are pro-inflammatory. The DII has been linked to many chronic diseases, including arthritis, many types of cancer, cardiovascular diseases, inflammatory bowel diseases, and diabetes. Variants include an energy-adjusted E-DII and a children's C-DII.

History and development
The development of the DII began in 2004, and the first version of the DII debuted in December 2009. However, this older version was never used in a published paper. It had several drawbacks, such as being statistically biased, omitting the impact of flavonoids, and being reversed (scoring inflammatory diets as negative). A new, revised DII was released in 2014. This version quickly gained favor as a research tool for the study of diet-associated inflammation and health-related outcomes, and is the version commonly referred to as the DII. The E-DII was developed later. At the request of the USDA, a children's DII was developed in 2018.

Validation
The DII has been subjected to construct validation. It is correlated with several inflammatory markers, including interleukin 1 beta, interleukin 4, interleukin 6, interleukin 10, tumor necrosis factor TNFα-R2, C-reactive protein, and homocysteine, both individually and as a combined inflammatory biomarker score.

Health linkages
The DII has been associated with a large number of actual health outcomes, including metabolic syndrome, asthma and lung function, lung cancer, esophageal cancer, colorectal cancer, breast cancer, prostate cancer, pancreatic cancer, endometrial cancer, cardiovascular disease, depression, telomere length, bone mineral density, obesity, and overall mortality.

Availability
The weights of the DII are published in the 2014 paper. However, computing DII scores requires a nutrition database and normalizing dietary scores relative to the world standard food intake, and the original authors observed significant errors in the published literature. The E-DII and C-DII require unique comparative databases which are products of Connecting Health Innovations and are not publicly available.