Citric acid is found in citrus fruits, especially lemons and limes. This is what gives them a sour taste.
An industrial form of citric acid is commonly used as a food supplement, as a cleaning agent and as a food supplement. However, this industrial form is different from that found in citrus fruits. For this reason, you may wonder if there is any benefit to the body from citric acid.
This article explains the differences between natural and industrial citric acid, and discusses its beneficial properties and possible harm.
What is citric acid?
Citric acid was first obtained from lemon juice by a Swedish researcher in 1784 ( 1 ).
The composition was odorless and colorless made from lemon juice until the early 1900s, when researchers found that it can also be made from black mold, Aspergillus niger , which creates citric acid when it feeds on sugar ( 1 , 2 ).
Due to its acidic nature, citric acid is primarily used as a flavoring and preservative, especially in soft drinks and sweets.
It is also used to stabilize or preserve medicines and as a disinfectant against viruses and bacteria.
Citric acid is a compound originally derived from lemon juice. Today it is made from a certain type of mold and is used in various fields.
Natural Food Sources of Citric Acid
Citrus fruits and their juices are the best natural sources of citric acid. In fact, the word lemon comes from the Latin word citrus .
Examples of citrus fruits include:
Other fruits also contain citric acid, but in smaller quantities. They include:
- a pineapple
Drinks or foods that contain these fruits – such as ketchup in the case of tomatoes – also contain citric acid.
Although citric acid is not found in nature, it is also a by-product of the production of cheese, wine and sourdough.
Citric acid, indicated in food ingredients and food additives, is not produced in the same way as in citrus fruits ( 4 ).
This is because the production of this citrus supplement is too expensive, and demand far exceeds supply.
Lemons, limes and other citrus fruits are the predominant natural sources of citric acid. Other fruits that contain much less include certain berries, cherries, and tomatoes.
Artificial Sources and Uses
Characteristics of citric acid make it an important supplement for various industries.
About 70% of the produced citric acid is used in food and drinks, 20% in pharmaceutical and dietary supplements, and the remaining 10% goes to cleaning products.
Manufactured citric acid is one of the most common nutritional supplements in the world.
It is used to increase acidity, enhance taste and preserve ingredients ( 5 ).
Carbonated drinks, juices, powdered drinks, sweets, frozen foods, and some dairy products often contain industrial citric acid.
It is also added to canned fruits and vegetables to protect against botulism, a rare but serious disease caused by the toxin-producing bacteria Clostridium botulinum .
Medicines and nutritional supplements
Citric acid is a staple in medicine and nutritional supplements.
It is added to medicines to stabilize and preserve the active ingredients and is used to enhance or mask the taste of chewing and syrup-based products.
Mineral supplements, such as magnesium and calcium, may contain citric acid – in the form of citrate – as well as to improve absorption.
Disinfection and cleaning
Citric acid is a useful disinfectant against various bacteria and viruses ( 7 ).
In vitro studies have shown that it can be effective in treating or preventing human norovirus, the main cause of foodborne illness ( 10 ).
Citric acid is sold as a general disinfectant and cleaning agent for descaling, stains of hard water, lime and rust.
It is seen as a safer alternative to conventional disinfectants and cleaners, such as kvat and chlorine bleach.
Citric acid is a universal supplement for foods, drinks, medicines and food additives, as well as detergents and disinfectants.
Benefits for the body
Citric acid has many impressive health benefits and features.
Citrate, a closely related molecule of citric acid, is the first molecule to form in a process called the citric acid cycle.
These chemical reactions in your body, also known as the tricarboxylic acid cycle (TCA) or the Krebs cycle, help convert food into usable energy ( 11 ).
Humans and other organisms derive most of their energy from this cycle.
Improves nutrient absorption
The main benefit of citric acid for the human body is that it significantly increases the bioavailability of minerals.
Mineral supplements are available in various forms today. But not all forms are absorbed by the body in the same way, because your body uses some more efficiently. Citric acid increases the bioavailability of minerals, allowing your body to absorb them better ( 12 , 13 , 14 ).
For example, calcium citrate does not require stomach acid to be absorbed. It also has fewer side effects – such as gas, bloating, or constipation – than another form called calcium carbonate ( 15 ). Therefore, calcium citrate is the best option for people with less stomach acid, like older people.
Citric acid also improves the absorption of zinc supplements ( 20 ).
Can protect against kidney stones
Citric acid – in the form of potassium citrate – prevents the formation of new kidney stones and breaks down already formed ones ( 21 ).
Kidney stones are solid masses of crystals that usually come from your kidneys.
Citric acid protects against kidney stones, making your urine less favorable for stone formation ( 24 ).
Kidney stones are often treated with citric acid as potassium citrate. However, consuming foods high in this natural acid, such as citrus fruits, can bring similar benefits in preventing stone formation ( 25 ).
Citric acid helps in energy metabolism, absorption of minerals and the prevention or treatment of kidney stones.
Citric acid: possible harm, contraindications and side effects
Manufactured citric acid is generally recognized as safe (GRAS) by the U.S. Food and Drug Administration (FDA) ( 5 ).
There are no scientific studies studying the safety of industrial citric acid when consumed in large quantities over long periods.
However, there have been reports of diseases and allergic reactions to the supplement.
In one report, joint pains with swelling and stiffness, muscle and abdominal pain, and shortness of breath in four people were found after they consumed products containing industrial citric acid ( 4 ).
Researchers admitted that they could not prove that the manufactured citric acid was responsible for these symptoms, but recommended that its use in foods and drinks be further studied.
In any case, the scientists suggested that the symptoms were most likely due to the mold used to make citric acid, and not to the compound itself.
A small report suggests that mold residues from produced citric acid can lead to allergies and other illnesses, but this has not yet been proven.
Citric acid is naturally found in citrus fruits, but synthetic versions derived from molds are usually added to foods, medicines, supplements, and cleaning products. The main benefit of citric acid for the human body is that with it, the absorption of minerals is many times more effective. This applies to minerals such as magnesium, calcium, zinc and others.
Although mold residues during production can cause allergies in rare cases, citric acid is generally considered safe.