While the immune system usually works in a concerted effort to handle a pathogen, the immune response that generates histamines in the body can actually be countered by the antioxidant and immune effects of vitamin C. Essentially, vitamin C can speed up the reduction of inflammation caused by histamines, so the symptoms disappear. Vitamin C can be found in high concentrations within Indian gooseberry, oranges, kale, spinach, kiwi, berries, tomatoes and other readily accessible food sources.