1.    Oranges

Oranges are jam-packed with vitamin C. And studies show that vitamin C can actually reduce the duration of a cold.  In one study, vitamin C was shown to reduce the length of a cold by eight percent in adults and 13.6 percent in children.

Even more beneficial is orange juice. According to Fox News, the average cup of orange juice has about 120 milligrams of vitamin C, which exceeds the recommended daily allowance of this necessary nutrient.  Just make sure to pick a brand of OJ that’s not loaded with sugar. Look for a “no sugar added” option.

2.    Beef

In recent times, we’ve been told to limit our consumption of beef. But as it turns out, beef and a strong immune system may go hand in hand. Beef has about one milligram of zinc per ounce. This makes beef a go-to option when it comes to fighting colds.

A macronutrient, zinc is needed by the body for immune function. However, experts say that about 12 percent of Americans don’t get enough zinc. And in those over the age of 64, that number climbs to almost 40 percent.

Researchers at Oregon State University recently analyzed this concept to find out how zinc deficiency correlates to increased inflammation in older adults. They found that inadequate zinc causes improper immune cell activation as well as dysregulation of a protein called cytokine Il-6, which affects cell inflammation.