What really alkalizes the blood?

Let's break down step by step why adequate amounts of protein and ATP are critical for preventing acidosis (blood acidification), and why the alkalizing effect of fruits and vegetables is a myth when viewed from a biochemical perspective.

Acid-Base Balance and the Role of Protein

The pH of blood in the body is strictly regulated within the range of 7.35–7.45. Disruption of this balance can be dangerous and indicates pathological processes.

Protein is not just an "acidic" product. It contains both acid-forming amino acids and alkalizing ones. With sufficient protein intake, the body finds it easier to maintain its buffering system—especially with the involvement of protein amino acids in the synthesis of glutamine, which neutralizes excess protons (H⁺) in the kidneys.

With insufficient protein, the synthesis of enzymes, albumins, and buffering systems (especially the phosphate and ammonium buffers) is disrupted, reducing the body's ability to maintain pH within normal limits.

ATP as the Key to Maintaining Alkalinity

ATP is not just energy; it is the currency for ion pumps, in particular:

• Na⁺/K⁺-ATPase: maintains membrane potential and pumps protons out of the cell.
• H⁺-ATPase in the kidneys and mitochondria: participates in the removal of excess hydrogen ions (acidifying agents) and the reabsorption of bicarbonates (the alkaline component of blood).

If there is a lack of ATP:

• The kidneys cannot effectively excrete H⁺, which quickly leads to metabolic acidosis.
• The blood's buffering systems become depleted, especially the bicarbonate buffer.

ATP is primarily synthesized from fats and B vitamins:

• Fats, especially saturated ones, provide the highest yield of ATP per unit mass (1 g of fat → up to 9 kcal).
• During β-oxidation of fatty acids, acetyl-CoA is formed, which enters the Krebs cycle and produces the majority of ATP in the mitochondria.
• B vitamins (B1, B2, B3, B5, B7) are coenzymes in the metabolism of fats, proteins, and carbohydrates (e.g., NAD⁺, FAD, coenzyme A, TPP); without them, energy metabolism literally comes to a halt.

Why Lemon, Fruits, and Vegetables Do Not Alkalize the Blood

Indeed, many vegetables and fruits leave an alkaline ash residue during metabolism (mainly due to potassium, magnesium, calcium), but:

• This does not directly affect blood pH, but only reduces the burden on the kidneys for acid excretion.
• Urine pH may become more alkaline, but blood will remain at the same level provided that buffers and kidney function are maintained.

Vegetables and fruits, even despite their high content of organic acids (citric, oxalic), do not alkalize the blood and do not directly participate in the creation of ATP or buffers. They may play a supportive role, but are not decisive in combating acidosis.