Lemon, orange and grapefruit (beware with beta blockers, pain meds, anticonvulsives and a few other categories or meds) are agrumes and contain a certain category of acids that actually turn alkaline in our bloodstream (don't ask, I still haven't figured it out yet!) ...lemons help us not to demineralize our bones, oranges can kickstart our vit C levels (along with other fruits) and grapefruit are just fun to eat...
They have the virtue of cutting our appetite, stimulating our bowels and hydrating us well...
So, I do not know why, but I do love them...
Sharon