Citric Acid: Uses, Benefits, and Risks

Synthetic citric acid is one of most common food additives in the world

Citric acid is an organic compound found in high amounts in citrus fruits. It's what gives lemons and limes their distinctive sour taste.

Many manufacturers add citric acid to packaged foods and beverages to keep them fresh. However, this citric acid is synthetic, unlike naturally occurring citric acid in fruits.

This article discusses citric acid's benefits, safeness, and potential uses.

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In its pure form, citric acid is colorless and odorless but has a strong acidic taste.

Citric acid's history dates back to 1784 when Swedish chemist Carl Wilhelm Scheele crystallized it from lemon juice. In 1917, food chemist James Currie discovered that he could produce citric acid using a strain of the black mold Aspergillus niger. This method is still in use today.

It is commonly used in food production as a flavor enhancer and preservative. Due to its antioxidant properties, it is also an ingredient in medications to improve stability and act as a preservative.

Although both antioxidants in citrus fruits share similar properties, they are not the same. It's also important to mention that citric acid does not contain vitamin C, also known as ascorbic acid.

The richest source of naturally occurring citric acid is citrus fruits and their juices. Natural sources of citric acid include:

The following fruits and vegetables contain smaller amounts of citric acid:

Although citric acid can be manufactured from citrus fruits, the process is not cost-effective and, therefore, no longer carried out on an industrial level.

Manufactured citric acid is a common additive in:

Citric acid's unique characteristics make it useful in many applications.

An estimated 70% of global citric acid production is accounted for by the food and beverage industry, with 20% used by the cosmetic and pharmaceutical industries. The remaining 10% is in cleaning products and detergents.

Citric acid is the most common additive in the food industry. In addition to preserving a food's color, texture, and taste, citric acid can increase the acidity of foods. This can help prevent the growth of mold, mildew, bacteria, and fungus.

Many canned and jarred foods contain citric acid to prevent the growth of Clostridium botulinum, a dangerous bacterium that can cause botulism, a life-threatening illness.

Manufactured citric acid is used in the preparation of:

Citric acid is added to numerous personal care products, including shampoo, hair spray, and cosmetics to help them last longer. It's also present in many skin care products to help increase skin elasticity and firmness.

In the pharmaceutical industry, citric acid is a pH corrector used as an antioxidant to preserve vitamins and minerals. Citric acid can improve the palatability of medications by masking the bitter taste of active ingredients.

Citric acid may have some disinfectant properties. Research suggests it effectively protects against many viruses, including the human norovirus.

As a metal chelating agent (a compound that binds tightly to metal ions), a citric acid cleaner can effectively remove hard water stains, calcium deposits, rust stains, and soap scum.

In addition to its traditional uses, citric acid has several other interesting health benefits.

Citric acid is an alpha-hydroxy acid (AHA). AHAs are chemical exfoliators commonly added to skin care products to help peel away dead skin cells, revealing fresh new skin.

Low concentrations of citric acid may help improve skin tone and texture and unclog pores by promoting cell turnover.

However, high doses may have adverse effects and cause skin irritation.

Citric acid, as potassium citrate, can often treat or prevent chronic kidney stones. It helps increase urine citrate to avoid calcium stones and decrease urine acidity, preventing uric acid and cystine stones.

You may also consume citrus fruits or diluted lemon juice concentrate as a natural remedy for stone prevention.

Citric acid is often added to minerals to help improve their absorption. Magnesium citrate is made by combining citric acid with magnesium oxide. One study noted that magnesium citrate is absorbed better than magnesium chelate and magnesium oxide.

Another study noted that calcium citrate is the most easily absorbed calcium supplement. You can also take it on an empty stomach because its absorption does not require stomach acid.

Naturally occurring citric acid is an antioxidant. This means it can help protect your cells from damage caused by free radicals. Antioxidants also help protect against inflammation and signs of aging.

Citric acid is a generally recognized as safe (GRAS) food additive. Though research hasn't established a link between citric acid created from black mold, many worry that it may cause allergies, respiratory problems, and chronic diseases.

Some people have reported increased inflammatory symptoms after consuming foods or medications with manufactured citric acid. However, more research is necessary to determine the presence or absence of harm.

Aspergillus niger is a known allergen. Therefore, you may react to foods containing citric acid if you have a mold allergy. The sugar used to produce citric acid often comes from corn, so you may also react to citric acid if you have a corn allergy.

The high acid content of natural and manufactured citric acid may erode tooth enamel over time, especially if you don't practice good dental hygiene.

Skin products with citric acid may irritate some people, particularly those with sensitive skin.

Citric acid is an organic compound naturally found in citrus fruits. Manufactured citric acid, created from a type of black mold, is one of the most common additives in the world. It is found in everything from foods to dietary supplements and cleaning agents. Though citric acid is considered safe, it may trigger a reaction in those with allergies.

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By Lindsey DeSoto, RD, LDLindsey Desoto is a registered dietitian with experience working with clients to improve their diet for health-related reasons. She enjoys staying up to date on the latest research and translating nutrition science into practical eating advice to help others live healthier lives.