Phosphoric acid is an inorganic mineral acid having the chemical formula H3PO4. It is also known as orthophosphoric acid and is manufactured through chemical synthesis, available as colorless, transparent syrupy liquid or in very light color.

It is widely used as an acidity regulator. It is affirmed by US FDA as GRAS (generally recognized as safe) and generally approved as a safe food additive in many countries with E number E338.

This acid exists naturally in the human body and in foods. But high amounts of this acid are found in colas, particularly brown carbonated drinks that are flavored with extracts of cola nuts.

Phosphoric acid uses

The acid is used in beverages such as various colas and acidify foods, but not without dispute as to its health effects. It provides a spicy taste, and being a mass-produced chemical, is available in large quantities and cheaply. The bulk availability and low cost is unlike more expensive natural seasonings that give comparable flavors, such as citric acid for sourness, or ginger for tanginess, obtainable from limes and lemons.

It is intentionally added to soft drinks to give them a sharper flavor. This acid also slows the growth of bacteria and molds, which would otherwise multiply rapidly in the sugary solution.

E338 is also an ingredient in over the counter anti-nausea medications which also include high levels of sugar (fructose and glucose). It should not be used by diabetics without consulting a doctor. In addition, it is also used as a catalyst in the synthesis of aspirin because it provides a bigger number of hydrogen ions with less contamination when compared to sulfuric acid and hydrochloric acid.

Moreover, it is used in orthodontics and dentistry as an etching solution, to roughen and clean the surfaces of teeth where dental fillings or appliances will be placed. This acid is also used in many teeth whiteners to eliminate plaque that may be on the teeth before application. Also, it is used as a pH adjuster in skin-care products and cosmetics and in the manufacture of fertilizers or other chemicals.

Side effects of phosphoric acid

It’s been associated with kidney disease and kidney stones. Because kidneys cannot store acids or completely filter them, these acids accumulate and form kidney stones in mixture with other salts. Phosphate chemical compounds are also found naturally in dairy and meat products, which helps explain why dairy, meat, and sodas similarly cause inflammation in the human body.

Repeated exposure to this acid may cause bronchitis to develop with phlegm, cough or shortness of breath. Long-term exposure to the liquid may cause cracking and drying of the skin.

The following short-term health effects may occur shortly or immediately after exposure to this acid:

  • Contact can burn and irritate the eyes.
  • Breathing this acid can irritate the throat and nose, causing wheezing and coughing.

Teeth

A report published in General Dentistry found that E338 can be as damaging to teeth similar to battery acid. The acid breaks down the enamel that coats your teeth. Your tooth enamel is a hard tough layer coating your teeth, protecting them against tooth decay and against general usage. This makes you more exposed to cavities and can also lead to loss of tooth mass.

„Drinking any type of soft drink poses risk to the health of your teeth.” – Kenton Ross, a dentist and spokesman for the Academy of General Dentistry.

Bones and osteoporosis

The American Journal of Clinical Nutrition explains how phosphoric acid chemically robs the bones, lowering human bone density. Numerous reasons have been given to account for the effect of consumption of this acid on bone mineral density.

First, it is known to bind to magnesium (Mg) and calcium (Ca) in the digestive tract. Salts of calcium and phosphorus (E341 – calcium phosphate) are known as apatites and they make up the bulk of the bone. Hence, such salts are only good for bone health as long as they are formed in the bone.

However, the salts of calcium and phosphoric acid created in the gut are not readily absorbed in the intestine. Thus, the consumption of this acid may reduce the absorption of magnesium and calcium.

Because both minerals are important to bones’ health, orthophosphoric acid can potentially lower the amount of magnesium and calcium available for bone mineralization.

Secondly, the increased consumption of E338 from cola drinks may lower the body’s calcium-phosphorus ratio. This means that less Ca is available for bone mineralization than phosphorus. Since both phosphorus and calcium are needed to form the basic units of the bone, a lower Ca-P ratio does not improve bone formation.

Lastly, the acidifying effect of the acid has also been mentioned as a cause of bone loss.

„Soft drinks have long been suspected of leading to lower Ca levels and higher phosphate levels in the blood. When phosphate levels are high and Ca levels are low, Ca is pulled out of the bones. The phosphate content of cola drinks is very high, and they contain virtually no calcium.” – quote from Encyclopedia of Natural Medicine, by Joseph Pizzorno ND & Michael Murray ND.

In the 2006 Tufts University study, lead by Katherine Tucker, looked at data from 2,500 osteoporosis patients and found that people, particularly women, who regularly drank dark soda had lower bone densities than those who did not usually consume these beverages. But women who drank non-cola soft drinks didn’t appear to have lower bone density.

Osteoporosis is especially frequent in women and for a precise reason; women’s bones are generally smaller than men’s, thus the phosphoric acid affects the bones of women more directly.

„This disease causes an estimated 2 million broken bones each year and usual results in pain, immobility, placement in a nursing home, isolation and other health problems.” – Amy Porter, executive director and CEO of NOF.

Healthier options

First off, an individual should never have any reason to want to have phosphoric acid. It is a product that is only used in the medical, industrial and agricultural fields. Thus, it has no health benefits that can be attained on a personal level. In other words, no one would want to drink phosphoric acid directly or apply it to their skin. After all, it is an acid, so it burns. It does not have any beneficial health benefits.

Instead of consuming sodas that are high in E338, consume cold drinks that aren’t as likely to damage your teeth. Most sparkling waters don’t contain this acid and you can mix them with a small amount of juice for a refreshing fizzy acid-free beverage.

You can also try non-carbonated drinks, including plain water and iced tea with a bit of lemon.

Sources: here, here, here and here.