A well balanced, nutritious diet is essential for maintaining a healthy immune system. Eat plenty of whole grains, fresh fruit and vegetables, as well as lean meat and fresh fish, which provide protein and micronutrients while being relatively low in saturated fat. Omega-3 fatty acids (found in freshwater fish like salmon and mackerel), complex carbohydrates, yogurt, and seaweed are believed to increase the activity of T cells and their escort cells, and to increase the production of antibodies and fighting cells.

To give your immune system the best chance of fighting off an invader, reduce your intake of alcohol and caffeine, found in tea, coffee and cola. Cut down on smoking, or give up altogether. You should also try to make sure that you get plenty of rest and try to avoid stress if you can. Chronically high levels of stress hormones such as adrenaline act as suppressants of the immune system.

It is well known that moderate amounts of exercise can boost one’s immune system.