Weight Loss Reduces Inflammation in Postmenopausal Women
“Both obesity and inflammation have been shown to be related to several types of cancer, and this study shows that if you reduce weight, you can reduce inflammation as well,” said Anne McTiernan, MD, PhD, of the Fred Hutchinson Cancer Research Center, Seattle, WA.
To examine the effects of a caloric restriction weight loss diet and exercise on inflammatory biomarkers, the investigators randomized 439 overweight and obese postmenopausal women to a 1-year caloric restriction diet (goal of 10% weight loss, n=118), aerobic exercise (225 minutes per week of moderate-to-vigorous activity, n=117), combined diet + exercise (n=117), or control (n=87).
Baseline and 1-year high-sensitivity C-reactive protein (hs-CRP), serum amyloid A (SAA), interleukin-6 (IL-6), leukocyte, and neutrophil levels were measured by investigators blind to group. Models were adjusted for baseline body mass index (BMI), race/ethnicity, and age.
At the end of 1 year, compared with controls, hs-CRP decreased by geometric mean 0.92 mg/L (36.1%; P<0.001) in the diet alone and 0.87 mg/L (41.7%; P<0.0001) in the diet + exercise groups. IL-6 decreased by 0.34 pg/mL (23.1%; P=0.001) in the diet alone and 0.32 pg/mL (24.3%; P<0.001) in the diet + exercise groups. Neutrophil counts decreased by 0.31 × 109/L (P=0.006) in the diet alone and 0.30 × 109/L (P=0.005) in the diet + exercise groups.
Diet and diet + exercise participants with 5% or more weight loss reduced inflammatory biomarkers (hs-CRP, SAA, and IL-6) vs. controls. The diet and diet + exercise groups reduced hs-CRP in all subgroups of baseline BMI, waist circumference, CRP level, and fasting glucose.
McTiernan and colleagues found a mild dose response, as there were greater reductions in these measures among women who lost at least 5% of their body weight. They also found that exercise alone, without a dietary weight loss component, had little effect on inflammation markers.
“This study adds to the growing understanding we have about the link between obesity and cancer, and it appears we can affect inflammation directly through nonpharmaceutical means,” said McTiernan.