A new study has reported that a high quality diet after treatment for breast cancer can reduce inflammation among survivors who do not exercise. Inflammation and immune response may affect the prognosis of breast cancer survivors. The study was designed to investigate how diet quality is related to markers of inflammation and fat tissue-derived hormones among breast cancer survivors. The study also sought to determine how physical activity or body size influenced any observed associations. The study included 746 women diagnosed with stage 0 to IIIA breast cancer who completed food frequency questionnaires 30 months after diagnosis. Diet quality was scored with the Healthy Eating Index (HEI)-2005, a measure of diet quality that assesses conformance to federal dietary guidance. The HEI-2005 translates recommendations in the 2005 dietary guidelines into specific, quantified recommendations for consumption of fruits, total vegetables, dark green and orange vegetables, grains and whole grains, and calories from solid fat, alcohol, and added sugar, among other dietary elements. Participants provided fasting blood samples, which were used to measure serum concentrations of C-reactive protein (CRP), serum amyloid A, leptin, and adiponectin.

Women with better versus poor quality postdiagnosis diets (defined as HEI-2005 scores in the highest fourth of the study group versus the lowest fourth) were found to have lower concentrations of CRP (1.6 mg/L versus 2.5 mg/L). However, when the influence of exercise was examined, the association between high quality diet and low CRP held for women who did not exercise after diagnosis but was not significant for those who did. In other words, exercise may have served to reduce inflammation in those with poor quality diets. The authors conclude that a better-quality diet appears to be associated with lower levels of chronic inflammation among breast cancer survivors. Lower levels of chronic inflammation have been associated with improved survival after breast cancer.