A low glycemic index Mediterranean diet reduced the Dietary Inflammatory Index scores in patients with breast cancer

ABSTRACT (word count 263)

Background: Inflammation is directly associated with breast cancer (BC) incidence and mortality, dietary inflammatory index (DII®) and dietary glycemic index (GI) scores, and inversely associated with Mediterranean diet (MD). We therefore investigated the DII in women diagnosed with BC, randomized in a trial to follow either a MD diet or MD with low-GI (MDLGI) carbohydrates.

Methods: Data were derived from 223 women living in Italy, mean age of 59±9.3 years, within 12 months of BC surgery (stages I-III). Dietary data from 7-day food records, the Mediterranean Dietary Assessment Screener (MEDAS) and serum high sensitivity C-reactive protein (hsCRP) levels were collected at baseline and after 12 months of treatment. Student’s t-test, two-way ANOVA, Spearman correlations, Pearson correlation and regression analyses were conducted.

Results: Adherence to the Mediterranean diet increased after 12-months of treatment in both MD and MDLGI groups, MEDAS from 8.1 to 9.1 and from 8.3 to 9.9, respectively (p<0.001); dietary GI decreased from 55.5 to 52.4 and from 55.1 to 47.6, respectively (p<0.001); and DII decreased from 2.08 to 1.49 and from 1.60 to 0.81, respectively (p<0.001).  No treatment difference in hsCRP levels and no significant correlation between CRP levels and DII scores were found. The analysis of variance suggested that low GI may independently contribute to lowering the DII (beta-coefficient 0.08, p<0.001).

Conclusions: The DII decreased after 12 months (4 sessions) of dietary counseling on a traditional MD. This effect was particularly stronger when carbohydrates were of low GI. These results are relevant given that lowering the inflammatory potential of the diet may have implications in cancer prognosis and overall survival.