Fasting increases inflammatory response

This interventional study examined participants who fasted for 5, 10, 15, or 20 days. The statistical analysis has some concerns—the 20-day group showed higher levels of C-reactive protein levels before starting the fasting, and reported significant potassium changes despite nearly identical values across groups. I reanalyzed the data and found that C-reactive protein increased after 5-10 days of fasting, but not after 15-20 days. However, the longer fasting groups had less than half the participants, limiting reliability. Based on this analysis, fasting for 5-10 days may increase C-reactive protein levels, indicating increased inflammation.

This study had participants complete a 10-day high-calorie feeding period and a 10-day fast, separated by a two-week stabilization period. While the study is cited to support that fasting increases C-reactive protein, the protein increased during both the fasting and high-calorie periods. This makes it unclear what effect, if any, fasting specifically has on C-reactive protein levels.

This study involved participants undergoing 14 days of fasting. C-reactive protein increased at day 7 but returned to baseline levels by the end of the fasting period. Therefore, it is misleading to use this paper to support the claim that fasting increases inflammatory markers, as the elevation appears to be temporary.