Your immune system is your body's defense against disease-causing agents such as bacteria, parasites, germs and viruses. A weak immune system can make you prone to diseases. This is why you need a strong immune system to keep you from getting sick easily.

Citrus fruits such as oranges, grapes and apples, and vegetables such as broccoli, tomatoes and red bell peppers are rich in vitamins and minerals. But to further enhance a healthy immune system, the study says our body will need the mineral zinc, which is more than just a remedy for cold symptoms. Zinc is vital for a variety of reasons, including strengthening the immune system.