OK, try this.
Blood uses a substance called a buffer, plus an enzyme to greatly speed up the process, to remove acidity from the blood as soon as it arrives in the bloodstream. A buffer is a substance that keeps acidity from running rampant by merging with it so that it cannot try to eat through something else. And what a happy coincidence it is that the buffer used eats up acid to form the very same things our body produces when it breaks down sugars for energy: water and carbon dioxide. Human bodies excel at ridding themselves of carbon dioxide and water, so eliminating acids from the bloodstream is pretty trivial, too. As long as there's enough of the buffer material and the enzyme in the bloodstream, acidity doesn't stand a chance there.