TTR and head and neck cancer: An RCT on colorectal cancer surgery found that PN with alanyl-glutamine in combination with ω-3 fish oil fat emulsion helped improve patients’ postoperative nutritional status and immune function and reduced the overall incidence of adverse effects.[26] An RCT on head and neck cancer conducted by Sittitrai et al[27] revealed that a perioperative oral glutamine- and fish oil-rich diet not only significantly reduced surgical complications, length of stay, and hospitalization costs, but also improved patients’ nutritional status, including body weight, prealbumin, and transferrin levels.