Re: A ______ a day keeps the doctor away!
Onion..
Raw, not a whole one, just a few slithers.. It's said to boost your immune system.
I remember a few years ago, I was always getting colds and chest infections and a friend suggested I eat more onions. So I always have onions in my sandwhiches for lunch at work and it has helped me loads. Gone from getting colds/coughs every few months to once or twice a year..