I rarely drink beer these days. However, when I was down on The Wirral, my brother and I called into the Irby Mill pub on the way home (I'd been drinking too much coffee and needed the pub's facilities and CJ wanted to photograph the pub's sign). We decided to enjoy the pub's ambience
and I decided to have a non-alcoholic beer. I rarely drink beer these days and non-alcoholic beers that I've sample have not been to my liking apart, I should add, from a John Smiths bitter that ceased production aeons ago. I was given a
which turned out to be rather enjoyable.
However the fact that it was a 'refreshing isotonic drink' had CJ and I wondering what the relevance of isotonic was. The usual meaning of the word relates to a solution having the same osmotic pressure as some other solution, especially one in a cell or a body fluid. We all know from our biology lessons that osmosis is a process by which something passes through a
semipermeable membrane from a less concentrated solution into a more
concentrated one. So if the pressure was the same surely the liquid was about to drink would just pass straight through me without permeating any of my digestive etc organs and therefore couldn't have any effect on me.
Thinking about this I discovered that sports drinks (I've never had one) are isotonic as well but they are all supposed to be good and energy-giving and that presumably requires the transfer of goodness through my bodily membranes.
I'm confused. Can anyone enlighten me.