A moderately high protein diet and 4’ isometric exercises efficacy in breast cancer patients treated with antiestrogenic medication

Abstract

Many breast cancer patients gain weight during treatment increasing recurrence, oncology specific mortality and general mortality risks. Breast cancer diagnosis and treatment overthrow patients’ lifestyle aggravating sedentariness and any preexisting weight gain causes like insulin and leptin resistance, dysbiosis and dyslipidemia. The aim of this study is to evaluate the efficiency of a moderately high protein diet – based on foods naturally high in proteins, omega-3 fatty acids, calcium, probiotics and prebiotics – and of an isometric exercise protocol to generate fat loss without muscle loss in ER+ breast cancer patients taking antiestrogenic treatment. We randomized 50 ER+ breast cancer patients – taking either Tamoxifen or Aromatase Inhibitors (AI) after surgery and chemotherapy – to follow a high protein diet, or a high protein diet and 4’ isometric exercises for 12 weeks. Patients were instructed to eat only when hungry and to keep a food journal. We measured weight and body composition with a bioelectrical impedance scale after checking for hydration status. The diet group lost 2.17 ± 2.42% subcutaneous fat (p = 0,000) with no muscle loss, and there was no statistical difference between patients taking Tamoxifen or AI regarding body composition evolution. The diet + isometric exercise group lost 2.2 more pounds than the diet group and 0.66 ± 0.91% visceral fat (p = 0,001) also with no muscle loss. AI patients from the diet and exercise group did not improve muscle mass – maybe because of the musculoskeletal impact of AI medication. In conclusion, a moderately high protein diet can decrease body fat in ER+ breast cancer patients on anti-estrogenic medication. Adding a daily minimal exercise protocol to a high protein diet decreases visceral fat – which is more hormonally active. And resistance-training exercises are more appropriate than isometric exercises for patients on AI.

Keywords

• oncology nutrition
• breast cancer
• weight gain in breast cancer patients
• antiestrogenic treatment
• isometric exercises