Prior epidemiologic studies have suggested that long-term physical activity protects against the onset of IBD. With this in mind, the chosen article primarily focuses on long-term voluntary exercise on the expression of pro- and anti-inflammatory cytokines in mice. Moreover, side objectives of the study included analysis of intestinal lymphocyte (IL) expression of apoptotic proteins and inflammatory cytokines following a brief session of high intensity exercise.
Figure 1 on pg. 1108 provides a great schematic representation of the experiment layout.
As the authors predicted, the mice that regularly exercised expressed lower pro-inflammatory cytokine levels (TNF-a & caspase 7) and higher anti-inflammatory cytokine levels (IL-6 & IL-10) than the sedentary mice. In addition, it was found that an acute session of intense activity caused increases in pro-inflammatory cytokines and pro-apoptotic protein (caspase 3).
The results suggest that long-term physical activity can provide an 'anti-inflammatory effect' by promoting higher levels of “good” anti-inflammatory cytokines. In contrast, acute sessions of intense exercise promoted a temporary state of inflammation and destruction that eventually returned to basal levels.
My analysis of the article suggests that regular light intensity sessions of exercise such as walking is the best intervention for all individuals regardless of their health. This is because less vigorous sessions of activity provide an 'anti-inflammatory effect' on the body in addition to other health benefits without taxing the CNS and promoting inflammation. I do believe high intensity bouts of exercise are beneficial to overall health; however, I see it as a 'trigger' to those suffering from IBD. This is because IBD results from a chronic state of inflammation and intense exercise would contribute further to the imbalance of pro-inflammatory cytokines.
Do others believe high intensity bouts of exercise should be avoided by IBD patients too?
The article discussed can be found at: http://www.sciencedirect.com/science/article/pii/S0889159110001054
Although I didn't find an article about high intensity exercise, I found another study that tested the effect of walking 3 times a week for 12 weeks on sedentary patients with Crohn's disease. There were statistically significant improvements in the Inflammatory Bowel Disease Quality of life score, Inflammatory Bowel Disease Stress Index, and body mass index (BMI). This study shows low intensity exercise didn't cause any flare ups of the disease, and in fact improved patients conditions. I liked this study because it used human patients instead of mice.
ReplyDeleteI would think that high intensity exercise may cause too much stress on the body and make the IBD symptoms flare up, but more studies should be done in order to determine what patients with IBD should avoid and what may help their symptoms.
Link where the study can be found: http://www.nature.com/ajg/journal/v94/n3/abs/ajg1999153a.html
I was definitely interested in learning more about the mechanism behind why different types of exercise can have such different effects on our bodies. I found a good article that reviews all of the effects of exercise on immune function.
ReplyDeleteThe article mentions that regular performance of about 2 hours of moderate exercise per day is associated with a 29% reduction in risk of picking up upper respiratory tract infection (URTI) compared with a sedentary lifestyle. In contrast, the article shows that there is a 100–500% increase in risk of picking up an infection in the weeks following a competitive ultra-endurance running event! This just goes to show the immense difference in the effects that exercise can have on our immune system's ability to function.
An acute session of intense physical activity cause responses very similar to those that occur during sepsis, infection, or trauma. There is a large increase in the number of circulating lymphocytes and neutrophils, increases in inflammatory cytokines such as TNF-alpha, MIP-1, and IL-1beta, and increases in anti-inflammatory cytokines such as IL-6, IL-10, and IL-1ra.
IL-6 is responsible for an increase in cortisol and epinephrine release, which are major stress hormones. Cortisol and epinephrine suppress Type-1 T cells, which decreases the cell-mediated response. This causes a decrease in the magnitude of protection against viruses and may explain why athletes may be more prone to get sick.
Following prolonged, strenuous exercise, the production of antibodies by B cells is inhibited, and delayed-type hypersensitivity responses to subdermal antigen injection (a marker of the cell-mediated immune response) are diminished. These changes seem to weaken the immune response to pathogens and allow for infection to take hold more easily. This is another reason why athletes are more susceptible to infection immediately following intense bouts of exercise.
Even though there are some bad effects immediately following intense bouts of exercise, it is important to note that these risks are minor, and the long term benefits definitely outweigh these risks.
http://jap.physiology.org/content/103/2/693.full