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
保持铁的摄入量对维持健康的免疫功能非常重要。瘦肉、家禽、鱼类和贝类食物里含有的铁很容易被人体吸 收。这些食物里也都含有另外一种重要的矿物质-锌。锌在人体内参与多项重要生理功能，如激活白细胞帮助抵抗感染等。

一些研究结果显示：锌的鼻腔喷雾剂和含片能缩短感冒病程、缓解感冒症状。不过另有报道发现锌鼻腔喷雾剂引起嗅觉丧失。而且锌摄入过多是有害的。