"Many battles have been fought and won by soldiers nourished on beer, and the King does not believe that coffee-drinking soldiers can be relied upon to endure hardships in case of another war." -- Frederick the Great, 1777
If there was ever a truly great endorsement of beer over coffee in the two large camps of Western drinking pastimes, Frederick the Great certainly issued it. And the King of Prussia died peacefully in his study at age 74, so we have to assume he won all the fights that mattered with beer as his guide.
That story has been the same throughout much of history. The Sumerian "Hymn to Ninkas" was both the first beer recipe and the first drinking song, and it was thousands of years ago. Beer and humans have a long, symbiotic history -- and for good reason. That is why beer perhaps should have been included in the recently-issued nutritional guidelines, at least for adults.
1. Beer keeps us safe from harmful bacteria
Lots of harmful microbes survive just fine in water, and so beer became popular because water was often unsafe. Yeast in the beer-fermentation process breaks down simple sugars, which produces alcohol and carbon dioxide, and lots of nasty microbes can't handle the acidity of CO2 and organic acids produced by yeast. Or survive in alcohol. Beer has both, so it was the product of choice when you were unsure about the sanitation of the water nearby.
Thus, beer saves lives. That is why beer yeast is way over near us on the Tree of Life.
2. Dark beer is a good source of vital free iron
Iron is essential to the human diet and studies of 40 brews found that dark beer has more free iron than pale beer. Using the differential pulse adsorptive stripping voltammetry technique, they found that beers with the highest iron content were a dark Spanish beer (165 ppb) and a dark Mexican beer (130 ppb). Those that had the lowest levels of iron were from The Netherlands and Ireland (41 ppb and 47 ppb, respectively).
This is why you should never drink Heineken, even on a dare.
3. Beer may prevent neurodegenerative diseases
Xanthohumol, a compound in hops, has gotten the attention of researchers for its antioxidation, cardiovascular protection and anticancer properties. In lab tests of brain cells, they found it could potentially help slow the development of brain disorders, which might make it a good candidate for fighting Alzheimer's, Parkinson's disease and other neurodegenerative conditions.
Microbiological safety, nutrients and protective potential are all great reasons beer should be your friend.
Finally, I will close with a little known fact that older generations know well, but that young people don't easily learn on the FaceySpaceys or the Tweetypages or whatever. Red Solo cups are designed to show you exactly how much nutrition you are getting: