The Optimum ph for human body cell, just over neutral towards base at 7.5ph (potential hydrogen (this is about electricity really))) tap water = 6 or 6.5 ph.
Your stomach and gallbladder produce 250g of bi-carb salt a day to balance the sugars (acids), carbohydrates (complex sugar chains or lots of acids), Lipids (fats and oils also mostly acidic) and finally proteins (what do proteins break down into? Amino acids, some of the strongest (or "hydrogen potential" polarised) acids that occur in nature. In short everything we ingest for survival is acidic.
The list of diseases associated with mild, acute or chronic Acidosis are all pretty horrifying and all notably prevalent in western populations where we have a particularly sugary diet! If you over lay that with the classic work of Western A Price regarding bone demineralisation back in the day, you get a good reinforcement from another branch of unrelated health study.
As humans age the stomach and gall bladder produce less salt through degradation and also relative to your increases size as you grow. In fact according to Bruce Lipton, the discoverer of Epigenetics, the immune system is actually packed up and "set" by late adolescence. So you cant cope with the all the forms of acid you need to eat to survive as well in childhood and your immune responses are far weaker and less adaptable in adulthood.
Did you know the primary medical use of sodium bicarbonate solution? To "buffer" toxic chemical treatments, my father had it with his Chemo. So by putting a tea spoon of bi carb in a pint of tap water you are giving your stomach and gall bladder lower work load so they can up production of pepsin and other necessary (acidic) digestive factors, more energy from the same food.
Lastly it's the main salt used in neuron to axon synapse gap charge relay. It is like that film limitless with Bradley Cooper. Answers come quicker without cognitive recall effort.
Highly Recommended!
Read the book "Sodium Bicarbonate" by Dr Marc Sircus for much more info