Introduction: Despite the potential benefits of ketogenic diets (KDs) for cancer, evidence of its effects on quality of life is lacking. This study has aimed to find out whether KD has adverse effects on quality of life, physical activity, and biomarkers in patients with breast cancer.
Method: A total of 80 patients with locally advanced or metastatic breast cancer were randomly assigned to either a KD or a control group for this 12-week trial. Concurrent with the first, third, and fifth chemotherapy sessions (12-week), the quality of life, physical activity, and biomarkers (thyroid function tests, electrolytes, albumin, ammonia, ALP, lactate and serum ketones) were assessed. Dietary intake was also recorded on admission and the end of the treatment.
Results: No significant differences were seen in the quality of life or physical activity between the two groups after 12 weeks; however, the KD group showed a better global quality of life compared to the control group at 6 weeks (P=0.02). Also, serum lactate and ALP levels decreased significantly in KD group compared to the control group after intervention (10.7±3 vs 13.3±4, 149±71 vs 240±164, P=0.02 and P=0.007, respectively). KD did not have any negative impact on thyroid hormones, electrolytes, or physical activity. Compliance among KD subjects ranged from 66.7% to 79.2% as assessed by dietary intake and serum ketones levels of >0.5.
Conclusion: According to our results, chemotherapy combined with KD does not negatively impact the quality of life, physical activity, or biomarkers tracked during our study. Ketosis may improve the effectiveness of chemotherapy in patients with breast cancer in part by decreasing lactate and ALP.