Physicians have often turned to food ingredients to help keep everyone’s immune system as healthy as possible.
Although not a proven cure, doctors in the 1400s recommended their patients include horseradish, mint, vinegar, and applesauce in their diets to ward off the bubonic plague. These ingredients do have some immune-boosting properties, including vitamin C, antioxidants, flavonoids, fiber, and water. Perhaps this is the origin of “an apple a day?”
