(121) The SAD weekend: a perilous North American tradition

Obesity and chronic pain are often comorbid. It is known that poor quality diet and/or obesity contribute to a chronic inflammatory state that may lead to susceptibility to chronic pain. Previously, we developed a Standard American Diet (SAD) and an Anti-inflammatory Diet (AID) to investigate the effects of diet on pain. The SAD is high in refined sugar, carbohydrates, trans and saturated fatty acids. The AID includes EGCG, sulforaphane, resveratrol, curcumin, and ginseng; all known to have anti-inflammatory properties. In the current study, we were interested in how alternating between the diets would affect pain and recovery from inflammatory injury. Male and female mice were fed a SAD, AID or regular (REG) chow diet for 14 weeks Monday to Friday. On Saturday and Sunday, some animals from the AID or REG groups were switched to the SAD diet. Mechanical sensitivity was assessed weekly, glucose tolerance was assessed at weeks 8 and 16, and body weight was measured every Monday and Friday. Microbiome analysis was performed at week 14. Following 14 weeks of diet exposure, chronic pain was induced through intraplantar injection of complete Freund’s adjuvant (CFA). Following CFA injection, the SAD prolonged recovery while the AID shortened recovery time. Interestingly, animals that were switched to the SAD on weekends had further protracted recovery, comparable to animals who solely consumed the SAD. Of clinical interest, animals that consumed the SAD had more proteobacteria and less bacteroidetes, while animals that consumed the AID had more actinobacteria and less proteobacteria. Animals that switched between diets had a mixture of the two. These data suggest that acute exposure to SAD has similar detrimental effects on recovery than long term exposure but that consuming AID remains beneficial in terms of gut microbiota.