Inflammation is needed to repair injured muscle
There’s growing recognition that anti-inflammatory drugs aren’t always the best response to muscle soreness or injury. In that light, the press release accompanying a new study in the FASEB Journal is overstating things when it says “the study shows for the first time that inflammation actually helps to heal damaged muscle tissue, turning conventional wisdom on its head.” Still, the results are interesting:
The research report shows that muscle inflammatory cells produce the highest levels of IGF-1 [insulin-like growth factor-1], which improves muscle injury repair. To reach this conclusion, the researchers studied two groups of mice. The first group of mice was genetically altered so they could not mount inflammatory responses to acute injury. The second group of mice was normal. Each group experienced muscle injury induced by barium chloride. The muscle injury in the first group of mice did not heal, but in the second group, their bodies repaired the injury.
The paper itself makes it clear that researchers already knew that inflammation was important to muscle repair, but the mechanism (i.e. the role of macrophages in producing IGF-1) was unclear. So does this mean that anti-inflammatories are a bad idea after muscle injury? Not necessarily — too much inflammation can still cause problems (for reasons that aren’t entirely clear to me). What the authors propose is that, when a muscle injury is being treated with anti-inflammatories, it may make sense to also administer supplemental IGF-1 to compensate for what the anti-inflammatories are blocking.