When you think about inflammation, you probably think about the type of swelling that occurs in a sore knee after a hard run.  But this is only one type of inflammation.  Knee swelling after a hard run is an example of acute or local inflammation.  But there’s also another, very different type of inflammation known as chronic or systemic inflammation.  

Systemic inflammation is inflammation of the blood and/or artery walls caused by bacterial infection and other factors such as free radicals and high levels of blood lipids.  Systemic inflammation is closely linked to atherosclerosis, or the stiffening of arteries through the formation of fatty plaques.  When free radical-damaged blood lipids or other factors create a lesion in the artery walls, an inflammatory response results.  As such lesions accumulate, inflammation becomes chronic and actually accelerates the formation of fatty plaques that stiffen the arteries, increasing the risk of heart attack and stroke.

Inflammation is also linked to diabetes.  A study by researchers at Brigham and Women’s Hospital in Boston found that those with the highest blood levels of two inflammatory compounds—interleukin-6 and c-reactive protein—were six times as likely to develop type 2 diabetes as women with low levels of the compounds.  Even Alzheimer’s disease and some cancers have an apparent inflammation link.

Exercise significantly reduces biomarkers of systemic inflammation such as c-reactive protein.  It appears that the repeated low-grade inflammatory response that exercisers experience after workouts stimulates a larger increase in the production of anti-inflammatory compounds and antioxidant defenses that protect against systemic inflammation.  One study by researchers at Auburn University found that markers of systemic inflammation were 76 percent lower in subjects with a high aerobic fitness level than in their moderately fit counterparts.  This is one reason why runners are much less likely than non-runners to suffer heart attacks and strokes.

Maintaining a healthy diet will also help your body manage inflammation better.  Some nutrients when consumed in excess tend to increase production of pro-inflammatory cytokines and other compounds while others limit their production.  Studies have shown that diets high in starches, sugars, saturated fat and trans fat are associated with high levels of systemic inflammation markers.  Diets high in natural antioxidants and fiber and with moderate amounts of alcohol and caffeine and a balanced ratio of omega-6 and omega-3 fats are associated with low levels of inflammation. 

For example, a new study from Penn State University provides evidence that a diet rich in whole grains may promote weight loss and reduce the risk of chronic diseases such as diabetes by reducing inflammation. Participants in the study were 25 men and 25 women with metabolic syndrome.  All 50 subjects were placed on the same weight-loss diet for 12 weeks, except that half of them were counseled to get all of their grains in the form of whole grains.  Members of both groups lost weight—8 to 11 pounds—but those in the whole grain group lost more abdominal fat. In addition, members of the whole grain group exhibited a 38 percent decrease in C-reactive protein, whereas C-reactive protein levels remained unchanged in members of the control group. 

Specific foods believed to increase inflammation include processed meats and sugar-sweetened beverages.  Foods that may reduce inflammation are fruits and vegetables, whole-grain foods, soy foods and good sources of omega-3 fats such as salmon and flaxseeds.  

The so-called Mediterranean diet happens to be heavy on anti-inflammatory foods (and beverages) and light on pro-inflammatory foods.  A study by researchers at the University of Athens, Greece, looked at the relationship between the Mediterranean diet and levels of c-reactive protein and other inflammatory biomarkers.  This study was done as part of the ATTICA study, which tracked the eating patterns of more than 3,000 men and women over a two-year period.  The study found that participants with the closest adherence to the traditional Mediterranean diet had, on average, 20 percent lower C-reactive protein levels, 14 percent lower white blood cell counts, 17 percent lower interleukin-6 levels, 6 percent lower fibrinogen levels, and 15 percent lower homocysteine levels compared to those who adhered least to the Mediterranean diet. 

Fish consumption alone accounted for much of these differences.  Inflammation markers were up to one-third lower in those individuals who consumed at least 10 ounces of fish each week.  Naturally, fish that are rich in omega-3 fats, such as wild salmon, herring, and mackerel, are especially beneficial.

Perhaps the most effective dietary measure you can take to reduce systemic inflammation is to avoid overeating so that you’re able to maintain a lean body composition.  That’s because fat cells produce inflammatory cytokines that stimulate the production of c-reactive protein.  Different levels of body fat, especially in the abdomen, account for a sizeable fraction of individual differences in systemic inflammation.  So anything you can do diet-wise to reduce your body fat percentage will also reduce your inflammation level.

This entry was posted on Thursday, September 4th, 2008 at 10:35 am and is filed under Nutrition. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.