Oranges or kiwifruit (kiwis)
Oranges and kiwis are an excellent source of vitamin C, which is the vitamin that many people turn to when they feel a cold developing. The both relatively low on calories with a low glycemic index and very high on nutrients and vitamins. While scientists are still not sure exactly how it helps, vitamin C may reduce the duration of common cold symptoms and improve the function of the human immune system.
More amazing facts about kiwis; it can help protect your DNA from oxygen related damage and they are highly recommended for people dealing with asthma thanks to the high levels of vitamin C who helps the respiratory system.