Arginine Deficiency May Weaken Immune System's Cancer Defense, Study Finds

A new Rockefeller University study found that low levels of the amino acid arginine can impair the immune system's ability to detect and fight cancer and viruses, potentially explaining worse outcomes in these conditions. The research, published in Cell, showed that arginine deficiency stalls production of MHC-1 proteins, which display abnormal cells to the immune system. Supplementing arginine in mice reduced flu and COVID-19 severity and fewer colon tumors, even when given 24 hours after infection. Arginine levels naturally decline with age, which researchers suggest may explain increased cancer and infection risk in older adults. The study used doses equivalent to about 10 grams daily, though clinical trials are still needed before recommending supplementation.