The health of the Thymus gland is directly related to the health of the immune system. The Thymus gland naturally undergoes involution, or shrinkage, as you age. If you consume a diet rich in fruits and vegetables that provide nutrients, such as vitamin C, vitamin E, Selenium, Zinc, and Beta Carotene, you will be supporting your Thymus gland nutritionally. Get plenty of rest and sleep. Drink lots of liquids.
Liquids help dilute solutions in the blood and help keep the respiratory tract from dehydration.
Avoid intake of sugar. Decreased Vitamin C levels, due to excessive sugar consumption, can result in significantly reduced white cell function. Increase your Vitamin C intake. If your body does not have adequate Calcium to draw on, it will literally rob your bones to provide sufficient levels for the blood - hence the aches and pains often associated with colds and flu.