Soypeptide supplementation attenuates weight loss and improves quality of life among brain cancer patients in a pilot study

Inability to meet nutrition needs resulting from multiple diseases-related, and individual factors contribute significantly to malnutrition and poor disease outcome among cancer patients. Strategies capable of delivering metabolically efficient nutrients with less digestive and metabolic stress without adding bulk to the diet of patients may be suitable for dealing with cancer-related malnutrition and quality of life (QoL). We sought to test the hypothesis that peptide supplementation could attenuate weight loss and improve QoL among brain cancer patients compared to conventionally treated controls. In a non-blind pilot study, brain cancer patients received 9 g soybean peptide supplementation twice per day (peptide group, n = 9) and compared with conventional treatment (control group, n = 10) over two chemotherapy cycles of 42 days. Compared to the controls, soypeptide supplementation attenuated weight loss with 5.4% increase in weight. Moreover, QoL, assessed using the European Organization for Research and Treatment of Cancer QLQ-C30, revealed that physical (8.1 +/- 15.6, p < .047) and emotional (7.5 +/- 3.5, p < .033) functioning as well as summary scores (7.1 +/- 2.4, p < .048) improved, whereas others remain stable. Molecular docking simulation suggested that the peptides could induce body weight through the inhibition of angiotensin-converting enzyme (ACE) upon digestion. Daily soypeptide supplementation could enhance weight gain and improve QoL among brain cancer patients possibly by inhibiting ACE activity. However, a follow-up study with a larger sample size in a double-blind randomized trial is required to validate these preliminary findings.