Immunity is the body's built-in protection mechanism
Immunity is the body's defense mechanism against pathogenic bacteria and viruses that enter the body. In other words, immunity is the human body's built-in ability to protect itself and affects our overall health. Our immunity decreases as we get older. In addition, hard exercise and excessive stress can lower our immunity.
A study was done to examine the benefits of taking cystine and theanine for preventing colds during the winter when people often catch colds. The study examined 176 adult males and found that in the group that took cystine and theanine fewer people caught a cold. There were also fewer complaints of cold symptoms such as chills and fever. This shows that taking amino acids can increase immunity and prevent colds as well as reduce the symptoms if you do catch a cold.
Kurihara et al., Japan Society for Amino Acid Sciences Industry-University Joint Symposium (2008)
Miyagawa et al., Geriatr. Gerontol. Int., 8, 243-250 (2008)