One of the promising findings of that past decade of research is that physical activity and exercise lower inflammation.   

Wake Forest University recently studied 87 overweight people who had knee pain and osteoarthritis.  Specific inflammatory chemicals were measured, which had the cryptic names of IL-6, TNFα, sTNFR, and C-reactive protein (CRP).  Also measured was the 6 minute walking performance and quality of life based on a questionnaire.  After six months on the exercise program, levels of the inflammation chemicals were reduced significantly. This coincided with improvements in the distance individuals could walk in six minutes.

[Miller, GD, Nicklas, BJ, Loeser, RF. Inflammatory biomarkers and physical function in older, obese adults with knee pain and self-reported osteoarthritis after intensive weight-loss therapy. J Am Geriatr Soc 2008;56(4):644-51.] 

These positive results are echoed by another study that looked at how the amount or the degree of exercise affected inflammation.  This study showed that those who exercised the most had the lowest levels of the inflammation chemical CRP, while those who exercised the least had CRP levels that were significantly higher.  You can see the difference by comparing the low exercise with the high exercise group in the graph  below.

These are but a couple of studies that show how exercise lowers inflammation. There are hundreds of inflammatory molecules we could discuss.  We’ve chosen these few, such as CRP, to demonstrate a principle.  The importance of lowering something like CRP with exercise can be understood from the following recent study regarding CRP in osteoarthritis.

Fifty-four people with osteoarthritis were preparing to undergo surgery.  Doctors measured their blood levels of CRP in addition to the levels of CRP (and other inflammatory chemicals) in their joint fluid.  They found that the levels of CRP in blood were strongly linked to another inflammation molecule (IL-6) in joint fluid.  More studies like this are beginning to show the troublesome role of these circulating inflammation molecules.  Anything you can do to reduce these molecules could have important effects on preventing the development or the progression of joint irritation.

[Pearle, AD, Scanzello, CR, George, S, et al. Elevated high-sensitivity C-reactive protein levels are associated with local inflammatory findings in patients with osteoarthritis. Osteoarthritis Cartilage 2007;15(5):516-23.]

The importance of these studies is that they show how exercise can help lower inflammation chemicals that pose known risks to your joint tissue.  These same chemicals also cause harm to blood vessels, brain tissue, heart muscle, the immune system, thyroid, and a wide range of systems throughout the body.  There are certainly drugs available that block the release or the action of some of these chemicals.  But the drugs can be harsh and any simple means, such as exercise, that could lower these chemicals is truly welcome.

It should also be noted that specific nutrients can also contribute to lowering some of these inflammation chemicals.  For example, dietary fiber has been shown to lower C-reactive protein (CRP) in women. Intake of fruits and vegetables has been shown to lower a family of chemicals called isoprostanes.  This discussion can be seen at the following link.

<Foods that Fuel Joint Inflammation>

Contraction of insulin-resistant muscle normalizes insulin action in association with increased mitochondrial activity and fatty acid catabolism.