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5 Articles in this Series
Diet “Cheat” Days Negatively Impact Recovery From Inflammatory Injury
Ketogenic Diet Prevents and Rescues Mechanical Allodynia Induced by a High Fat Diet
Prolactin Linked to Sex Differences in Migraine
Toward Automated Pain Intensity Estimation in Mice: Finding Structure in Complex Data
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Diet “Cheat” Days Negatively Impact Recovery From Inflammatory Injury

Presentation by Stacie Totsch, graduate student, working with Robert Sorge, PhD

Obesity and chronic pain, both serious health problems in the United States, frequently co-occur in the same patients.1 People with obesity have pain not only in their weight-bearing joints but also in non weight-bearing joints, suggesting that another factor besides excess body weight is influencing the relationship between pain and obesity.

One such factor may be diet. The high levels of carbohydrates, saturated fat, and omega-6 fatty acids that characterize a poor diet lead to activation of the innate immune system and the induction of a pro-inflammatory state.2 Researchers at the University of Alabama at Birmingham hypothesize that this inflammation predisposes individuals to chronic pain.

In a new study3 presented at this year’s meeting, the researchers examined how diet quality affects behavioral and physiological measures of pain. This project was selected as one of the meeting’s most promising abstracts by the Scientific Program Committee and was presented as both a poster and a talk in a session on meeting highlights. The work was led by Robert Sorge, PhD, assistant professor at the University of Alabama at Birmingham, and presented by graduate student Stacie Totsch.           

In an earlier study4 conducted by Dr. Sorge and colleagues, animals were fed the Total Western Diet (TWD),5 a model of the high fat diet consumed by Americans. After mice consumed the diet for 14 weeks, a chronic inflammatory injury was induced using Complete Freund’s Adjuvant (CFA). Mice that consumed the TWD took much longer to recover than animals that consumed a regular control diet.

The TWD was based on median macronutrient values from the CDC’s National Health and Nutrition Examination Survey (NHANES). The researchers reasoned that many Americans’ don’t eat this average diet, but instead eat at the 2 extremes, very unhealthy and very healthy. They developed the Standard American Diet (SAD) and the Anti-Inflammatory Diet (AID) to mimic these extremes.

The SAD is high in fat, carbohydrates, sugar, and trans and saturated fats, while the AID contains several components (including resveratrol, curcumin, and ginseng) with known anti-inflammatory properties. In the current study, the team investigated how alternating between the 2 diets would affect pain and recovery from inflammatory injury.

New research in mice suggests that people who cheat on their diets on the weekend undo the benefits of healthy eating during the week.

The researchers fed mice a SAD, AID, or control diet for 14 weeks prior to the administration of CFA. Some of the AID and control animals were switched to SAD chow only on Saturdays and Sundays, mimicking the weekend cheat days found in many Americans’ diets.

Animals on the SAD 7 days per week took almost twice as long to recover from mechanical sensitivity as those fed the control diet. In contrast, mice who received the AID every day of the week recovered as fast or faster than those on the regular diet.

Unexpectedly, the animals that were switched from the AID to the SAD on weekends took just as long to recover from the inflammatory injury as those who ate the SAD diet the entire week. The mice that were switched from the regular diet to the SAD took even longer to recover than the mice who only ate the SAD.

When the researchers examined the animals’ gut microbiota, as expected, mice on the SAD had higher levels of proteobacteria that are associated with an inflamed gut than mice on the AID. Conversely, the anti-inflammatory actinobacteria were more prevalent in the gut of mice on the AID. The animals that switched between the 2 diets had intermediate levels of both types of bacteria.

“These results aren’t promising for people who have cheat days, and suggest that even acute exposure to the SAD is detrimental. However, there is good news: the AID does confer some benefit to the gut,” Ms. Totsch said.



1.     Okifuji A, Hare BD. The association between chronic pain and obesity. J Pain Research. 2015;8:399-408.

2.     Giugliano D, Ceriello A, Esposito K. The effects of diet on inflammation: emphasis on the metabolic syndrome. J Am Coll Cardiol. 2006;48(4):677-685.

3.     Totsch S, Lopez S, Quinn T, Meir R, Sorge R. The SAD weekend: a perilous North American tradition. Poster presented at: Annual Meeting of the American Pain Society; May 17-20, 2017; Pittsburgh, PA. Poster #121.

4.     Totsch SK, Waite ME, Tomkovich A, Quinn TL, Gower BA, Sorge RE. Total Western Diet Alters Mechanical and Thermal Sensitivity and Prolongs Hypersensitivity Following Complete Freund's Adjuvant in Mice. J Pain. 2016;17(1):119-125.

5.     Hintze KJ, Benninghoff AD, Ward RE. Formulation of the Total Western Diet (TWD) as a basal diet for rodent cancer studies. J Agric Food Chem. 2012;60(27):6736-6742.





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