Nutrition, Diet, and Anti-aging: Dietary Inflammatory Index (DII) and Anti-aging

Chronic inflammation in vivo has been reported to be a risk factor for lifestyle-related diseases such as cancer and cardiovascular disease. There are various lifestyle factors that can contribute to an inflammatory state, and diet is considered one of them. There are many dietary nutrients that can affect inflammation, and food contains both inflammation-suppressing and promoting components. Since people do not eat single food, it is necessary to evaluate the overall impact of diet on inflammation. In recent years, the Dietary Inflammatory Index (DII), which evaluates the overall impact of diet on inflammation, has been developed from about 2000 previous studies on 45 types of nutrients and foods. It is used internationally, mainly in Western countries, and its association with diseases has been reported. That is, the lower the DII score (negative value), the more the diet is considered to suppress inflammation, and the higher the score (positive value), the more the diet is considered to promote inflammation (Table 92.1). Also, it has been shown in multiple studies that there is a correlation between the DII score and inflammatory biomarkers such as C-reactive protein (CRP), interleukin-6 (IL-6), and TNF-α (tumor necrosis factor-α). Examples of nutrients and foods that make up the DII score and have proven anti-inflammatory effects include polyphenols, ω3 unsaturated fatty acids, and dietary fiber. The higher the intake of polyphenols, the more it is associated with a decrease in inflammation markers through antioxidant pathways. Also, dietary fibers are suggested to bring about anti-inflammatory effects through short-chain fatty acids mediated by gut bacteria. It is thought that a high DII score is associated with anti-aging, as there are reports that it leads to a decrease in the blood concentration of klotho protein, which is considered an anti-aging hormone.