Weight loss reduces inflammation related to cancer

Postmenopausal women who were overweight or obese and lost at least 5 percent of their body weight had a measurable reduction in markers of inflammation, according to a study led by Dr. Anne McTiernan and published May 1 in Cancer Research, a journal of the American Association for Cancer Research.

"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 corresponding author McTiernan, of the Public Health Sciences Division.

Women in the trial who were assigned to a weight loss intervention had a goal of 10 percent weight reduction during the course of one year achieved through a diet intervention, with or without aerobic exercise.

"This program was highly achievable and reproducible. We are not talking about drastic weight loss," said McTiernan.

The researchers measured levels of five inflammation markers in 439 Seattle-area women: C-reactive protein, serum amyloid A, interleukin-6, leukocyte and neutrophil.

At the end of one year, C-reactive protein reduced by 36.1 percent in the diet-alone group and by 41.7 percent in the diet and exercise group. Interleukin-6 decreased by 23.1 percent in the diet group and 24.3 percent in the diet and exercise group.

Exercise alone showed little effect on inflammation

McTiernan and colleagues-including Liren Xiao and Drs. Ikuyo Imayama, Neli Ulrich, Catherine Duggan, Caitlin Mason, and Ching-Yun Wang, all of PHS, and Carolyn Bain of the Vaccine and Infectious Disease Division-found greater reductions in these measures among women who lost at least 5 percent 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," McTiernan said.

Researchers from the University of Washington, National Cancer Institute, University of British Columbia, University of Illinois at Chicago, Beth Israel Deaconess Medical Center and Colorado State University also contributed to the findings. The National Cancer Institute funded the study.

[Adapted from an AACR news release]