ABSTRACT
BACKGROUND: Insulin-like growth factor I (IGF-I) and other markers of insulin resistance (IRm) might influence the penetrance of BRCA gene mutation. In a demonstration project on BRCA mutation carriers we tested the effect of the 'Mediterranean diet', with moderate protein restriction, on serum levels of IGF-I and IRm. METHODS: BRCA mutation carriers, with or without breast cancer, aged 18â»70 years and without metastases were eligible. After the baseline examinations, women were randomized to an active dietary intervention or to a control group. The intervention group attended six full days of life-style intervention activities (cookery classes followed by lunch, sessions of walking for 45 min and nutritional conferences) over the next six months. RESULTS: 213 BRCA mutation carriers completed the six-month study. Women in the intervention group (110) showed major changes in all the parameters under study. They significantly lost weight (p < 0.001), fat mass (p = 0.002), with reduced hip circumference (p = 0.01), triglycerides (p = 0.02) and IGF-I (p = 0.02) compared with controls. They also had a significantly higher levels of insulin-like growth factor-binding protein 3 (IGFI-BP3) (p = 0.03) and a lower IGF-I/IGFI-BP3 ratio (p = 0.04). The reduction of serum levels of IGF-I was significantly associated with the reduction in the consumption of animal products (p = 0.04). CONCLUSIONS: Women in the intervention group showed significant improvements in IGF-I and in other IRm that might influence the penetrance of BRCA mutations.
ABSTRACT
BACKGROUND: Insulin resistance is associated with higher breast cancer (BC) penetrance in BRCA mutation carriers. Metabolic syndrome (MetS), an insulin resistance syndrome, can be reversed by adhering to the Mediterranean diet (MedDiet). In a dietary intervention trial on BRCA mutation carriers, we evaluated adherence to the MedDiet, and the association with the MetS, by analyzing data from the Mediterranean Diet Adherence Screener (MEDAS). METHODS: BRCA mutation carriers, with or without BC, aged 18 to 70 years, were eligible for the trial. After the baseline examinations, women were randomized to a dietary intervention or to a control group. Both groups completed the MEDAS at baseline and at the end of the dietary intervention. RESULTS: A total of 163 women completed the 6 months of dietary intervention. Compared with controls, the women in the intervention group significantly reduced their consumption of red meat ( P < .01) and commercial sweets ( P < .01) and their MEDAS score rose significantly (+1.3 vs +0.55, P = .02). The number of MetS parameters decreased with increasing points of adherence to the MEDAS score ( P = .01). In the intervention group, there was a significant association with the greater reduction of MetS. CONCLUSION: BRCA mutation carriers in the intervention group experienced greater improvement in their MedDiet and MetS parameters.
