We are all alkaline naturally, but our individual organs have different pH because they are components of a wholistic system called ‘the body’ which uses all organs and elimination systems to maintain a blood level of approximately pH 7.35 at all times.
They are both products of advertising and have no real meaning. However the true ‘natural alkalinity’ of the human body is usually referring to the blood pH, which is optimally pH 7.35.
Excess alkalinity is, according to most commentaries, a temporary state, brought about by overdosing of alkaline substances in one event. This contrasts dramatically with the practice of substituting alkaline water for acid water. We have completed a meta study of scientific studies on the use of alkaline water all over the world in the last 100 years. The overall conclusion is that the consumption of calcium and magnesium-rich water gives better health than non-alkaline water.