Lean Meats
Why they’re cold/flu fighters: Maintaining good iron levels is necessary for maintaining a healthy immune system, and eating lean red meat and poultry, as well as fish and shellfish, provides a type of iron that is easily absorbed by the body. Zinc is another important mineral that these food sources provide—it serves many functions, one of which includes activating a white blood cell that helps fight off infections.

In some studies, zinc nasal sprays and lozenges have been shown to reduce the duration of a cold and the severity of symptoms, but overall, the research is inconsistent. Some people have also reported that they lost their sense of smell after using zinc nasal sprays. In addition, ingesting too much zinc could be harmful.

瘦肉
保持鐵的攝入量對維持健康的免疫功能非常重要。瘦肉、家禽、魚類和貝類食物里含有的鐵很容易被人體吸 收。這些食物里也都含有另外一種重要的礦物質-鋅。鋅在人體內參與多項重要生理功能，如激活白細胞幫助抵抗感染等。

一些研究結果顯示：鋅的鼻腔噴霧劑和含片能縮短感冒病程、緩解感冒癥狀。不過另有報道發現鋅鼻腔噴霧劑引起嗅覺喪失。而且鋅攝入過多是有害的。