Simple comparative observation:  muslims make over 20% of word population. There are only 12 muslim Nobel laureates. 7 of those were for peace,not exactly the field requiring high cognitive functions (one awarded to a known terrorist actually). More than half were awarded in the 21st century.

Dostoyevsky,Van Gogh,Hemingway, Churchill, Buzz Aldrin, Magellan (no navigation difficulty for him),Tesla. And many more. All drunks. Any of them had weak brain cognitive functions?

Your liver will give up well before your brain.