Guinness and Mackeson are said to be 'nourishing' - B vitamins(?). Red wine contains anti-oxidants which are supposed to be beneficial.
I know this doesn't apply to you, but the midwife told me to drink Mackeson when I was breast-feeding. It supplies calories and B vitamins and the alcohol relaxes you and so promotes easier feeding of the baby.
Of course, she only meant to drink one or two a day not a whole crateful! That is the key with alcohol ........ it is only beneficial when taken in moderation.