As we enter cold and flu season, it’s time to strengthen our immune systems to face the onslaught of sniffles, coughs and sneezes. Research shows that tea possesses compounds which can enhance the immune system and offer added defense against illnesses that tend to occur more often this time of year. These compounds include catechins (a chemical found in plants, especially green tea), amino acids (important in building proteins that help the immune system) and polyphenols (an antioxidant).