The ability of food to affect the acidity of blood is still highly debated in the world of nutritional science, but the idea that acidic blood harms the body is universally agreed upon.
Acidity of the blood, measured in pH, stays in the very small window of 7.35-7.45 for optimal health. If blood becomes too acidic, either through stress or from what you eat, the body must neutralize it.
These natural acid buffers take calcium from the bones and can lead to osteoporosis and kidney stones. By eating alkaline foods instead of acidic foods, your bones can stay strong and you waste less energy on those buffer systems.
The more processed a food is, the more acid it will form when ingested. This refers to processed meats and refined sugars.
Chlorophyll is a hallmark of alkaline-forming foods. Chlorophyll is the lifeblood of plants and is found in abundance in edible greens. Generally, the greener the food, the better it will be for your blood pH. This makes dark leafy greens like kale and spinach prime contenders for alkalizing your blood.
The validity that ingested food can affect the pH of blood is not agreed upon on the grounds that stomach acid has a pH of 2, or is highly acidic, and thus any food you ingest gets bathed in this acid. But the broader idea that green plants serve the body better than corned beef and butter gives a little more weight to this idea.