If you’re a label reader, you may notice that“citric acid” is an ingredient in many packaged foods. As its name implies, this compound naturally occurs in citrus fruits and is an effective preservative. It’s also a cleaning agent, an emulsifier, and lends a subtle sour flavor to foods.
Isolated by a chemist in the 18th century, citric acid came to be used as a mold inhibitor to prevent food spoilage. Oddly enough, since the early 20th century, the mold-fighting acid has been chemically manufactured from–wait for it- mold!
What Is Citric Acid?
You may be surprised to learn that almost all organic life forms contain citric acid. This antioxidant is used in a variety of metabolization processes in the body. (1)
In an average human, the body produces and metabolizes about 2 pounds of the acid every day. It then eliminates excess citric acid through urine. (2) The acid found in higher concentrations in citrus fruit (lemon and lime especially), hibiscus, cocoa, pineapple, and kiwi fruit.
What is Citrate?
Citrates is a derivative of citric acid. Sometimes, the two names are used interchangeably on food labels. It can be used as an anticoagulant because it binds to calcium. (3)
Citrate levels are higher in fruits than in other produce. But this natural substance has its downfall: routinely high levels of citrate in the body can lead to kidney stones, renal dysfunction, and bone disease (binding to calcium and weakening bone structure). The prostate, however, benefits from citrate, and produces high levels of the substance. (4)
Manufactured citrates, on the other hand, are commonly mixed with other chemicals or minerals to create the following:
- alverine citrate – a medication used for treating gastrointestinal disorders
- calcium citrate – used in medications to treat low calcium levels in blood and bones
- fentanyl citrate – an injectable analgesic (highly addictive)
- gallium citrate – a radioactive compound for medical diagnostic procedures for cancer
- magnesium citrate – used in laxatives and as a pre-operative colon cleanser
- potassium citrate – used in medication to reduce the risk of kidney stones
- sodium citrate – a preservative, emulsifying agent, and acidity regulator
- zinc citrate – a dietary supplement and personal care ingredient for odor reduction.
The Modern Citric Acid Formula
When citric acid was fist used a couple hundred years ago, it was derived from lemons. Due to rising costs, the formula has since changed. Today, it’s manufactured from black mold. Yes, black mold—the same stuff that can cause a whole host of illnesses and even death.
Here are the details of the commercial acid formula:
“Black mold is able to efficiently (and cheaply) convert sugars into citric acid. By feeding sucrose or glucose—often derived from corn starch—to the black mold, a citric acid solution is created. Corn is highly likely to be genetically modified (GMO). The resulting solution is filtered out from the mold, and the citric acid is precipitated from the solution and processed into the final, usable form using lime and sulfuric acid.” (5)
Black mold, outside of the body, damages its environment (buildings and their contents). (6) When inhaled or ingested, black mold can cause respiratory irritation, asthma, chronic fatigue, headaches, nausea and vomiting, and bleeding from the nose and lungs. (7)
Some people experience an allergic reaction to it, which isn’t exactly straightforward to diagnose. (8, 9) Unfortunately, the potential exists that some traces of the mold may remain in synthesized citric acid after processing. Hence, citric acid can create allergy-like symptoms in some people.
Also, the ingestion of any genetically modified organism (GMO) is the subject of tremendous controversy. Strictly from a health perspective, until the jury is out there is no evidence for the definitive safety of GMO in our diets or environment. Since the FDA allows it, even “organic” products can be a source of the chemical. How, may you ask? Well, Citric acid was long produced by Pfizer, a company with very loose morals and even larger pockets (10).
Citric Acid Uses
Here are a few reasons why citric acid are found in so many products:
- preserves and stabilizes active ingredients thanks to its antioxidant properties
- as a weak acid to adjust pH balance
Processed foods and home goods
- flavoring agent (sour) – soft drinks, candy
- preservative – baby food, jam, hummus, salsa, mayonnaise
- fermenting agent – cheese, wine
- emulsifying agent – ice cream, sorbet
- laundry and dishwasher products
- personal care products – lotion, shampoo, soap, cosmetics, bath bombs, etc.
- water treatment products
You’ll also find citric acid in the following products:
- bleaching agents
- corrosion inhibitors
- agricultural chemicals
- cleaning solvents
- printer toner and ink
- automotive products
Citric Acid vs. Ascorbic Acid
These two acids are often mistaken for one another. Both acids naturally occur in foods as discrete substances.
Ascorbic acid is the chemical name for vitamin C and the term “ascorbic acid’ is even used interchangeably with vitamin C. However, they are not necessarily the same thing. Essentially, ascorbic acid is a component of vitamin C.
Vitamin C is an essential antioxidant that the body needs to: support the immune system; form and maintain skin, connective tissue, muscle, and bones; regulate blood vessels and capillaries; and contribute to proper organ function.(11)
Unfortunately, the ascorbic acid used as an additive in foods and beverages is synthetic. While synthetic ascorbic acid is molecularly the same as naturally-occurring vitamin C, it is fermented from corn starch, corn sugar, or rice starch instead of vitamin c-rich fruits. Much of the corn grown in the world is genetically modified, making corn starch another source of GMO contamination.
Additionally, although synthetic vitamin C may be chemically the same as what’s found in nature, its shape is not. Cell receptors are of a certain shape and attach to nutrients in their expected (natural) shape. Synthetic vitamins are not identical to naturally-occurring nutrients. Therefore, synthetic vitamins (not just C) don’t work the same in the body as what you get from food. (12)
Lots of people pop vitamin C tablets or powders like they’re going out of style, thinking they’re doing a good thing for their health. On the contrary: in addition to the non-medicinal ingredients found in vitamin supplements (including sugars, preservatives, and artificial colors and flavors), getting too much ascorbic acid in one dose can actually cause adverse reactions. These include kidney stones, organ damage, cancer, interference with other (natural) enzymes, and increased risk for heart disease. (13)
In contrast, naturally occurring vitamin C occurs in small doses within produce and contains all the necessary enzymes and complementary nutrients for the body to appropriately absorb and metabolize it.
Is Citric Acid Bad For You?
Yes and no.
Natural citric acid is important to metabolize fats, carbohydrates, and proteins. Citric acid is an effective aluminum detoxifier. (14) Juice from lemons and limes can preserve foods and keep them from oxidizing (for example: squeezing lime juice into your guacamole will prevent the avocado from turning brown).
The synthetic citric acid found in innumerable manufactured products, however, is another story.
The U.S. government’s database of chemicals lists the following hazards of citric acid (15):
- May be corrosive to metals
- Harmful if swallowed
- Causes skin
- May cause an allergic skin reaction
- Causes eye irritation
- May cause allergy or asthma symptoms or breathing difficulties if inhaled
- May cause genetic defects
- Suspected of causing genetic defects
- May cause cancer
- Suspected of causing cancer
- May damage fertility or the unborn child
- Causes damage to organs through prolonged or repeated exposure
- Very toxic to aquatic life
- Very toxic to aquatic life with long lasting effects
Specific Hazard of Citric Acid
Inhaling citric acid can cause respiratory constriction, resulting in coughing, sore throat, shortness of breath, and upper respiratory system illness, including cumulative lung disease. Skin contact with citric acid can cause dermatitis. (16)
Additionally, eating too much citric acid inhibits the body’s absorption of calcium and iron. High concentrations of citric acid used in water treatment have been found a factor in bladder cancer. (17)
On the other hand, citrates used as medical coagulants can negatively interact with medications. If undergoing any medical procedure (including donating blood or dialysis), make sure to inform your health practitioner of any medications you are taking, including citrate. (18, 19)
Soft drinks contain the acid as a flavoring agent and preservative. One study showed that citric acid deteriorated tooth enamel within an hour of exposure. (20) At high concentrations, citric acid can cause immediate cell death within dental pulp. (21)
Perhaps lesser known still, is that citric acid can cause gastroesophageal reflux disease. Even some canned baby food contains citric acid, causing acid reflux in babies. You can find a list of tested baby foods here. (22)
Worse yet, both citric acid and ascorbic acid are often found alongside sodium benzoate in processed foods.The combination of either of the acids with the salt creates benzene, a known human carcinogen.
- do not take during pregnancy
- do not take if kidney, heart, or any other medical issues exist
- avoid if taking any other medications, including over-the-counter drugs and herbal remedies
- may cause upset stomach (23)
- allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
- bloody, black, tarry stools
- confused, dizzy, lightheaded, faint
- irregular heartbeat, chest pain
- numbness or tingling in hands or feet
- pain on swallowing
- stomach pain
- unusual bleeding or bruising
- unusually weak or tired
- loose stools
- nausea, vomiting (24)
Citric Acid Substitutes
There are valid, practical uses for citric acid and alternatives to synthetics or those made from mold do exist.
- You can buy non-GMO citric acid powder or citric acid crystals that originate from fermenting sugar rather than mold. Use it to flavor foods or regulate pH. (25)
- Cream of tartar is an acid (tartaric acid)—it’s what settles at the bottom of a wine barrel after aging wine. Sold in a powder, you can substitute 1 tablespoon of cream of tartar for ¾ tablespoon of citric acid in do-it-yourself beauty products.
- You can use lemon juice to replace citric acid, since it’s a natural source.
- 1 ounce of lemon juice for 1 ½ grams of citric acid
- 2 tablespoons of lemon juice for ½ teaspoon of powdered/crystal acid (for canning)
- 16 ounces of lemon juice mixed with 16 ounces of water equals 1 teaspoon of citric acid dissolved in a quart of water (for drying produce)
- 1/8 cup of lemon juice equals ½ teaspoon of acid (for making cheese)
Citric acid is remarkably useful in many contexts. The balance lies in its source and measure. Natural sources are always preferable to synthetics in terms of quality, reliability, bioavailability, and avoidance of potential adverse side effects.