Diner enters restaurant, is seated, and peruses the menu.  

He places the menu on the table, indicating that a decision has been made.  The server greets the diner and takes the Diner's order, but what's this?  Red wine with fish?  The Cardinal Sin!  Not on my watch!  

The Server, aghast:  "One moment sir, I'll fetch the sommelier."

Diner:  "That won't be nec..."

Server:  "One moment sir, just one moment."

Sommelier enters scene, corkscrew a blazin':  "May I make some recommendations, sir?"

Diner:  "I'll have the Argentinian Malbec with my Mackerel please."

Sommelier:  "Instead Sir, may I recommend a New Zealand Savignon Blanc?"

Diner:  "The terrior at this particular Château, mon frier, has a very low iron content.  I will have the Malbec and I will wallow in my own decanal and heptanal if the case may be, thank you."

Sommelier:  "Um, but, um.  But the tannins, sir, the tannins.  Um.  Very well."

What did the diner know that the sommelier didn't?  What's this about iron?  In a recent article published this past August in the Journal of Agricultural and Food Chemistry, a team of crack-shot food scientists broke open the door to pairing red wine with fish... and it's not the tannins.

According to The Economist