Another important factor that further establishes the superiority of fruits, vegetables and leaves over other foods is their ability to maintain the blood in a slightly alkaline condition, which is necessary for the very life of man.
The acids in fruits are finally converted into alkaline salts, chiefly carbonates, which help to maintain normal alkalinity of the blood. Increased acidity of the blood is the precursor of numerous diseases.
Fruits, vegetables and leaves, which keep the blood in a mildly alkaline condition, help to maintain a healthy and vital body by preventing undue strain on the liver and kidneys. In addition, they facilitate excretion of toxic substances.
Fruits, vegetables and leaves produce mostly carbonic acids in the blood, which is fully oxidized into carbon dioxide and water. The carbon dioxide is easily exhaled from the lungs and produces absolutely no strain on the kidneys.
Fruits, vegetables and leaves neither produce aceto-acetic acid in the blood nor do they contain proteins having sulphur. Other foods, more or less, contain amino acids like methionine and cystine, which produce strong acids like sulphuric acid that is responsible for high acidity of the blood. As these acids cannot be completely oxidized, the lungs fail to exhale them. Further, as the alkalinity of the blood has to be maintained, an extra burden and strain is passed on to the kidneys for their excretion. It has been proven that most of the carbonic acid added to the blood appears not as acid, but as bicarbonates (Alkaline ion). This fully establishes that fruits, vegetables and leaves efficiently help to maintain the normal alkalinity of the blood. The kidneys are thus saved from strain, which keeps the body in a healthy and vital condition.
The following quotation amply proves the desirability and necessity of maintaining the blood in a mild alkaline condition:
“Life is possible only if the blood is kept within a range of alkalinity, and a healthy physiological hydrogen ion concentration of 36-44 mmol/l corresponding to a pH between 7.37 and 7.45 is maintained by two widely different mechanisms, which are closely integrated. The blood is alkaline because it contains bicarbonate phosphate and proteins, which are quite strong bases. It also contains carbonic acid and the pH of the blood depends principally upon the ratio of the main acid component carbonic acid and the main base bicarbonate. The concentration of carbonic acid in the plasma is determined by the partial pressure of carbon dioxide in the alveoli. The alveolar partial pressure of carbon dioxide is itself maintained steady by the equality between its rate of production in the tissues and the rate at which ventilation eliminates it from the body. On the other hand, the concentration of bicarbonate is regulated by the tubular epitelium of the kidneys and in good health is kept at about 22 to 24 mmol/l.
A great many metabolic processes result in the production of acids and these must be eliminated from the body if the reaction of the tissue and blood is to remain within the normal range. The route of disposal of acids depends upon whether or not they are capable of being oxidized completely to carbon dioxide and water. Carbonic acid within the body is eliminated as carbon dioxide by ventilation. Other acids such as aceto-acetic or sulphuric, which are derived from oxidation of the fatty acids or sulphur containing proteins, respectively, are excreted by the kidneys. At the site of their production in the tissues and during their carriage in the blood, all acids increase the hydrogen ion concentration. Its extent is minimized by the stabilizing power of the blood and tissues. Carbonic acid is produced by metabolic reactions far greater than any other acid. A greater part is converted into carbonic acid in the red cells. The hydrogen ions of carbonic acid are taken up by the haemoglobin in the red cells while the bicarbonate ion moves out from the red cells to the plasma in exchange for chloride ions (chloride shift). Most of the carbonic acid added to the blood, therefore, appears not as acid, but as bicarbonate ion. When the blood passes through the lungs and the haemoglobin is re-oxygenated, the process is reversed and the carbon dioxide formed is expelled by ventilation. In health, a small amount of inorganic acid produced each day and being nonvolatile requires to be excreted by the kidneys. The excreting power of the kidneys is the limiting factor in the body to rid itself of ions derived from inorganic acid and organic acids other than carbonic acid.”
(Davinson’s “Principles and Practice of Medicine”- Twelfth Edition-1977, page 164-65.)