THURSDAY, Oct. 16, 2008 (HealthDay News) -- Being fat increases the level of inflammatory activity in the body, while being physically fit decreases it, according to a new U.S. study.
The study included 452 healthy men who had levels of different groups of blood cells measured during exercise. A high total white blood cell count is a marker of inflammatory activity and is a strong and independent risk factor for coronary heart disease-related illness and death, according to background information in a news release from the researchers at the Pennington Biomedical Research Center in Baton Rouge, La.
None of the participants smoked or had been diagnosed with a serious disease or chronic condition, all of which are known to be associated with a higher white blood cell count. The men were weighed and measured and had their blood pressure taken before their level of cardio-respiratory fitness was assessed using a standard treadmill test.
Blood tests showed that levels of all groups of white blood cells were lowest in the most physically fit men and higher in men who had a combination of higher body fat and lower levels of fitness.
In general, the more body fat, the higher the white blood cell count. However, the study did find that a high level of physical fitness negated the effect of extra body fat.
The researchers noted that white cell counts tend to increase after a session of vigorous exercise, but regular exercise may condition the body to respond more efficiently when doing physically demanding activities.
The study was published in the British Journal of Sports Medicine.
The National Institute of Diabetes and Digestive and Kidney Diseases explains the health risks of being overweight.