Whey Protein Supplementation Improves Nutritional Status, Glutathione Levels, and Immune Function in Cancer Patients: A Randomized, Double-Blind Controlled Trial

Clinical side effects from medical therapy play an important role in causing malnutrition among cancer patients. Whey protein isolates (WPIs) have the potential to improve the nutritional status of cancer patients. The present study determined the effects of whey protein supplementation on nutritional status, glutathione (GSH) levels, immunity, and inflammatory markers in cancer patients in Thailand. A total of 42 cancer patients (41-63 years old) who received intravenous chemotherapy were randomized in a double-blind controlled trial at the National Cancer Institute in Thailand. Patients received 40g of WPI plus zinc and selenium (intervention group, n=23) or a maltodextrin oral snack (control group, n=19) every day during the daytime for 12 weeks. Nutritional status, GSH levels, immunity, and inflammatory markers were assessed at baseline, 6, and 12 weeks. Whey protein supplementation significantly increased albumin (2.9%) and immunoglobulin G (4.8%) levels compared to the control group at week 12. Controls showed a significantly lower percent change in GSH levels (6.0%), whereas there was a significant time-dependent increase in the intervention group (11.7%). Whey protein supplementation improved nutrition status scores in the intervention group compared to the control. These data indicate that whey protein supplementation can increase GSH levels and improve nutritional status and immunity in cancer patients undergoing chemotherapy. These results will facilitate implementation of malnutrition risk prevention strategies and improve protein status, including immune function, during chemotherapy.