Throughout the semester most of the diseases we have looked at have been linked to chronic inflammation, often due to obesity. One of the many recommendations by many websites, etc. was for people to exercise to reduce weight and thus inflammation. But what if exercise itself is an anti-inflammatory? A review I found explains how exercise could be just that.
Entitled The anti-inflammatory effects of exercise: mechanisms and implications for the prevention and treatment of disease, this review was published in Nature Reviews Immunology (Impact Factor of 35!!) in September 2011. It describes some of the known ways that exercise affects the immune system, although it is still a relatively small field with a need for more precise scientific methods. I have summarized some of it below for you.
Aside from the known benefits of exercise, which would be a reduction in fat mass and a change in cholesterol types (LDL to HDL), exercise also increases the production of immunomodulatory molecules. The first, most well studied to date is our old friend IL-6. An increase in IL-6 has been linked to almost every disease state we have looked at this semester. What has been found in exercise is that it transiently stimulates IL-6 production through a fall in muscle glycogen. But what is critically important is that this transient increase causes the expression of IL-10, IL-1RA and cortisol. These anti-inflammatory cytokines combat IL-6 and IL-1β, while cortisol is anti-inflammatory systemically.
As we have already discussed in class exercise can change the phenotype of macrophages in the adipose tissue. But it also decreases the number of inflammatory monocytes in the blood, thought to be due mainly to the activity of cortisol, but the exact mechanism is unknown. It has also been seen that increased intense activity can increase the number of regulatory T cells present in the blood as well. The decrease in inflammatory cells and an increase in regulatory cells, could help to balance the body systemically, leading to not just a decrease in weight, but an overall decrease in inflammation with each exercise bought.
While there is still a lot of questions on what type, intensity, and duration of exercise is most beneficial there is no doubt that it is doing something to the inflammatory state of the body. The exact mechanisms also need to elucidated, but overall the outlook is promising. So, if you weren’t already thinking it, go out for a run already!!
Great summary-
ReplyDeleteI just have a general question about why exercise is considered anti-inflammatory when we are seeing a pro-inflammatory response with the release of Il-6. Is the anti-inflammatory cytokine response longer lasting or/and greatly amplified to neutralize Il-6 effects AND produce additional anti-inflammatory effects; what is the source that tips the scales into a pro-inflammatory effect, rather than anti-inflammatory and inflammatory being equally leveled with no net benefit?
http://www.lanimuelrath.com/bar-method/the-anti-inflammatory-effects-of-high-intensity-exercise-more-reason-to-go-for-the-burn/
ReplyDeleteThe article attached breaks down how exercising with high intensity has an anti-inflammatory effect. We know that inflammation is good and is necessary for our survival. It is chronic inflammation that is harmful. During intense exercise IL-6 is released and has a pro-inflammatory effect; however, there are anti-inflammatory inhibitors released at the same time. From this article, I do like that they point out those suffering from chronic inflammation may have different inflammatory responses with acute and chronic exercise.
Very interesting post, I think that people often underestimate the power of strengthening the body through exercise. My mom has Addison's disease which causes her adrenal glands to be unable to produce sufficient amounts hormones such as cortisol. Her primary care doctor has prescribed her with steroid replacements for years and it was not until she began to supplement those with a regular exercise routine that her cortisol levels normalized.
ReplyDeleteThe last sentence of my comment was not stated correctly, so I would like to adjust for any further comments.
ReplyDelete*What is the source that tips the scales into an anti-inflammatory effect, rather than an anti-inflammatory and pro-inflammatory being equally leveled (neutralization) with no net benefit on the system?
Interesting point of view. Throughout the semester I don't ever recall exercise being an anti-inflammatory. Exercise has always just been envisioned as a long-term "solution" for most illnesses and even though it is an essential lifestyle to obtain, I don't think people are truly aware of its importance.
ReplyDelete@MicheleF495:
ReplyDeleteI was not clear on the source of IL-6 release. Most of the IL-6 release during exercise is from muscle and is relatively local. There is very little increase in IL-6 levels in the blood, but in muscle biopsies the IL-6 level is significantly increased. Also, the IL-6 levels in the muscle cause a release of systemic anti-inflammatories, especially cortisol. So overall, the systemic release of anti-inflammatories would benefit the whole body, not just the localized IL-6 production in the muscle. Does that help to answer your question?
The effects of exercise on various systems has always interested me. Since exercise is only one stressor that can effect the body and it is winter time, I looked further into exercise in extreme temperatures. In searching I found an interesting review in Wilderness and Environmental Medicine, Immune Responses to Exercising in a Cold Environment. Just from reading about all the contradictions between studies in this paper, I definitely agree that the field is relatively small and needs much more research to give more confidence in the results. Despite this, I found the paper very helpful, demonstrating the effects of cold weather on NE, cortisol, and other factors that effect the immune system. It seems that the intensity of the cold measured may change the effect on the immune system, just as with the intensity of exercise. As suggested by the authors, intense exercise in extreme cold may lead to immunosuppression and possibly lead to higher infection rates in athletes, military personnel, and others who are subject to these kind of stressors. This may be just another reminder that although we often see inflammation as bad, without we are in trouble.
ReplyDeleteLaVoy et. al. Immune Responses to Exercising in a Cold Environment. Wilderness and Environmental Medicine. 2011. 22:343-351
I am amazed at what exercise does to the human body. The modifications of the systems of the body when stressed at high intensity levels are astonishing in my opinion, and I believe that exercise is the coveted 'fountain of youth.' I do recall on several occasions in which I have been recommended not to workout while having a cold because it suppresses the immune system. I don't know the validity of this statement and I cannot seem to find anything supporting this. Does anybody know how valid this statement is?
ReplyDeleteGreat topic about immunity and exercise. I was also considering this topic and found a couple papers that generally talked about the topics you discussed in your post, with more emphasis on training intensity and it’s effect on the immune system. They propose/discuss the idea post-exercise immunodepression in subjects with very high intensity training (mainly professional athletes). In one study, Th1 cytokine levels are down regulated due to increased levels of glucocorticoids and catecholamines. In another study, levels of saliva IgA were significantly lower in athletes when compared to sedentary matched controls, measured after intense training (a soccor match) and periodically during a 7-month season. Both propose that too much training without adequate rest can create ‘windows’ of imuunodepression, thus increasing risk for post exercise infection. But since these studies apply more to professional athletes, you all should still go do that run!
ReplyDelete1. http://www.nsca-lift.org/HotTopic/download/Immune-Function.pdf
2. J Strength Cond Res. 2009 Oct;23(7):1968-73
3. http://well.blogs.nytimes.com/2009/10/14/phys-ed-does-exercise-boost-immunity/