I’m pretty sure I recall first hearing Dr. Steven Novella in his Medical Myths, Lies, and Half-Truths: What We Think We Know May Be Hurting Us for the The Great Courses series talk about the bogus claim we often hear about a lot of “natural” products being sold out there that they can improve or boost the immune system. Its nonsense…

Well this article in Slate follows up and reinforces that thinking…

Boost your immunity: Cold and flu treatments suppress innate immune system
Natural remedies that claim to “boost your immune system” don’t work, and it’s a good thing they don’t.