Citric acid is a commonly used ingredient in various food products, beverages, cleaning agents, and personal care items. Known for its tangy flavor, it also offers a range of health benefits. However, there are some misconceptions and myths surrounding this organic compound.
In this article, I’ll review the uses, sources, chemistry, and health benefits of citric acid. I’ll also address the myths and hysteria some online “gurus” have spread surrounding this safe and useful food ingredient.
What is Citric Acid?
Citric acid is an organic acid, specifically a weak acid, that occurs naturally in citrus fruits like lemons, limes, oranges, and grapefruits. It is widely used as a food additive due to its sour taste, as well as for its preservative and flavor-enhancing properties.1Penniston, K. L., Nakada, S. Y., Holmes, R. P., & Assimos, D. G. (2008). Quantitative assessment of citric acid in lemon juice, lime juice, and commercially-available fruit juice products. Journal of endourology, 22(3), 567–570. https://www.ncbi.nlm.nih.gov/pubmed/
Citric acid is also found in other natural sources like tomatoes and bell peppers, and it can be mass-produced using organisms like Aspergillus niger, a black mold fungus.2Cairns, T.C., Nai, C. & Meyer, V. How a fungus shapes biotechnology: 100 years of Aspergillus niger research. Fungal Biol Biotechnol 5, 13 (2018). https://doi.org/10.1186/s40694-018-0054-5
I’ll get back to this below, but to be clear, this black mold produces citric acid. That does not mean citric acid contains black mold, which is what several fear-mongering nutrition elitists have suggested.
The Chemistry Behind Citric Acid
Citric acid, with its chemical formula C6H8O7, is part of a group of organic compounds known as tricarboxylic acids.
It plays a crucial role in the citric acid cycle, also known as the Krebs cycle, which is a series of chemical reactions that occur in our bodies to generate energy from carbohydrates, fats, and proteins.
With its unique structure, citric acid acts as an intermediate compound in this cycle, facilitating the conversion of nutrients into a usable form of energy.
Is Citric Acid the same as Vitamin C?
While citric acid and vitamin C, also known as ascorbic acid, are related, they are not the same. It is a weak acid found in citrus fruits, while vitamin C is an essential nutrient for our health.
Although citrus fruits are a good source of both citric acid and vitamin C, they serve different functions in our bodies. Citric acid is often added to foods and beverages for flavor enhancement, while vitamin C is involved in various physiological processes, including immune function, collagen synthesis, and antioxidant protection.
Sources of Citric Acid
Citric acid can be found naturally in food as well as created by other organisms. The chemical structure is identical in both cases, so it offers the same health benefits either way.
Food sources include citrus fruits and some vegetables. Fruits rich in citric acid include lemons, limes, oranges, and grapefruits, whereas vegetables such as tomatoes and bell peppers also contain it.
On the other hand, citric acid can be produced by other organisms, the most common being Aspergillus niger, a black mold fungus. This method is commonly used to produce citric acid on a large scale. Contrary to the fear-mongering social media “influencers” who suggest that citric acid contains mold because of where it comes from, it does not. It is pure citric acid, C6H8O7.
Mass-produced citric acid is widely used as a food additive, flavor enhancer, and preservative in various processed foods and beverages and nutritional supplements. It is found in products like ice creams, candies, and snacks, where it provides a tangy flavor, and in powdered products like supplements and drink mixes.
Citric acid is also used in cleaning products due to its acidity, as it helps remove stains and mineral deposits.
Uses of Citric Acid
Citric acid has a wide range of applications in various industries. They include:
Food and Beverages
Citric acid is commonly used as a food additive and preservative, as it helps extend the shelf life of packaged food items. It also acts as a flavor enhancer in beverages, giving them a pleasantly tangy taste.
Citric acid is added to fruit juices, such as lemonade and orange juice, to enhance flavor and balance acidity and many carbonated sodas and fruit-flavored drinks also contain citric acid.
In food products, citric acid can help prevent the browning of cut fruits and vegetables.
Dietary Supplements
Citric acid is used in dietary supplements for various purposes. It adds a sour taste, which can improve the palatability of some supplements. It also serves as an antioxidant, helping to protect cells from oxidative stress and free radicals.
And it can enhance the absorption of certain nutrients, such as calcium, by increasing solubility.
Cosmetics and Medications
Citric acid is utilized in cosmetic and personal care products due to its various properties.
It helps remove dead skin cells, promoting smoother and brighter skin tone, so it’s great for exfoliation.
It is also used as a pH adjuster in skincare products, ensuring the formulation stays at the desired pH level.
Citric acid acts as a preservative in cosmetics and medications, preventing microbial growth and enhancing product stability. And some skin care products use citric acid for its brightening effects, helping to improve skin tone and reducing the appearance of dark spots.
Cleaning Products
Citric acid is a natural cleaning agent, making it a popular ingredient in eco-friendly cleaning products. Its acidity helps break down mineral deposits, soap scum, and hard water stains.
It is effective in removing limescale and rust from various surfaces, including kitchen appliances, bathroom fixtures, and coffee makers. It can be found in dishwashing detergents, laundry detergents, and all-purpose cleaners.
The pH-adjusting properties of citric acid make it an excellent choice for cleaning products, as it helps maintain the desired pH level for optimal cleaning performance.
Health Benefits of Citric Acid
Apart from its various uses, citric acid offers several significant health benefits.
Improved Skin Health
The use of citric acid in skin care products can contribute to better skin health by promoting even skin tone and reducing the appearance of dark spots.3Green, A. K., & Roudsari, A. H. (1996). Effects of alpha-hydroxy acids on photoaged skin: a pilot clinical, histologic, and ultrastructural study. Journal of the American Academy of Dermatology, 34(2), 187-195.
It helps exfoliate the skin, removing dead skin cells, and revealing a brighter complexion.
Interestingly, citric acid contributes to the production of glycolic acid, which is known to improve skin texture and reduce the signs of aging.
Overall, it plays a role in maintaining healthy, radiant skin when used in appropriate concentrations and formulations.
Protection Against Kidney Stones
Citric acid helps reduce the risk of kidney stones, primarily due to its ability to increase urinary citrate levels and potentially urine volume, which can reduce the risk of stone formation.4Penniston, K. L., Steele, T. H., & Nakada, S. Y. (2015). Medical and Dietary Therapy for Kidney Stone Prevention. Korean Journal of Urology, 56(12), 775–779.
Citric acid can bind to calcium in the urine, which reduces the amount of free calcium available to form calcium oxalate or calcium phosphate stones, the most common types of kidney stones.5Doizi, S., Poindexter, J. R., Pearle, M. S., Blanco, F., Moe, O. W., Sakhaee, K., & Maalouf, N. M. (2018). Impact of Potassium Citrate vs Citric Acid on Urinary Stone Risk in Calcium Phosphate Stone Formers. The Journal of urology, 200(6), 1278–1284.
It also increases the level of citrate in the urine. Citrate is a known inhibitor of kidney stone formation because it can prevent the growth of crystals by forming a protective coating around them and preventing small stones from becoming larger.6R. Caudarella, F. Vescini, A. Buffa, et al. (2003). Citrate and mineral metabolism: kidney stones and bone disease. Frontiers in bioscience : a journal and virtual library.
Citric acid metabolizes into bicarbonate, leading to an increase in urine pH. A higher urine pH can increase the solubility of certain stone-forming salts, such as calcium oxalate, and reduce their crystallization. It can also inhibit the agglomeration of calcium oxalate crystals, which is a key step in stone formation.7Li Ruiling (2011). Application of Citric Acid Improving Phosphorus Utilization in Diet. Feed Review.
Enhanced Nutrient Absorption
Citric acid has been shown to enhance the absorption of essential nutrients in the body, leading to improved overall health. Here’s how it works.8Hanle Zhang, Lina Yi, R. Sun, et al. (2016). Effects of dietary citric acid on growth performance, mineral status and intestinal digestive enzyme activities of large yellow croaker Larimichthys crocea (Richardson, 1846) fed high plant protein diets. Aquaculture.
By increasing acidity in the stomach, it aids in the breakdown of food, facilitating better nutrient digestion and absorption. It promotes the solubility of minerals like calcium, iron, and zinc, making them more accessible for absorption.9Sara Arefhosseini, Helda Tutunchi, S. Nomi-Golzar, et al. (2022). The effect of hydroxy citric acid supplementation with calorie-restricted diet on metabolic, atherogenic and inflammatory biomarkers in women with non-alcoholic fatty liver disease: a randomized controlled clinical trial. Food & function.
Also, citric acid’s antioxidant properties help reduce oxidative stress, which can damage cells and impair nutrient absorption.
Reduced Inflammation
Citric acid may help reduce inflammation through its antioxidant properties, which help neutralize free radicals that contribute to inflammation. The citrate in citric acid can have anti-inflammatory effects, reducing the production of pro-inflammatory molecules in the body.10Mebratu Melaku, R. Zhong, Hui Han, et al. (2021). Butyric and Citric Acids and Their Salts in Poultry Nutrition: Effects on Gut Health and Intestinal Microbiota. International Journal of Molecular Sciences.
Including citric acid-rich foods in the diet may help manage inflammation, benefiting overall health and potentially lowering the risk of chronic diseases.
Enhanced Gut Health
Citric acid helps create an acidic environment in the stomach, aiding digestion and facilitating the breakdown of food. It supports the growth of beneficial bacteria in the gut, contributing to a balanced microbiome.11El-Senousey, H. K., Fouad, A. M., Yao, J. H., Zhang, Z. G., & Shen, Q. W. (2021). Dietary citric acid enhances growth performance, nutrient digestibility, intestinal microbiota, antioxidant status, and immunity of Japanese quails. Poultry Science, 100(8), 101269. https://doi.org/10.1016/j.psj.2021.101269
The acidity of citric acid also helps inhibit the growth of harmful bacteria, potentially reducing the risk of gastrointestinal infections.
Is Citric Acid Harmful?
In a short answer, no, it is not harmful. But like anything else, some people may be more sensitive than others.
Though it contains numerous health benefits, it’s possible to overdo the amount you consume. It’s unlikely you’ll do so through a healthy diet and use of nutritional supplements, but for people who eat only processed foods for every meal and consume excessive amounts of soda and juice, their citric acid intake can become excessive. Chronically high intakes may lead to:
- Tooth enamel erosion: Citric acid in beverages may erode tooth enamel over time, leading to dental issues. We’re talking about multiple sodas and juices every day.
- Skin irritation: Some people with sensitive skin may experience irritation or allergic reactions when using citric acid-containing skin care products.
- Citric acid intolerance: Some people may experience intolerances or sensitivities to citric acid when consumed in large amounts. Symptoms may show up as digestive issues or skin irritation. However, it’s also quite likely that these symptoms are triggered by other foods or ingredients in the diet, as citric acid is found in many modern-day prepared and packaged foods. In many cases, it is guilty by association, not causation.
Read also: Don’t Drink Your Calories, Even if They’re From “100% Juice”.
The Black Mold-Citric Acid Hysteria
As I explained above, citric acid can be mass-produced by using Aspergillus niger, a black mold fungus. This fungus produces it as a byproduct of its metabolism. The citric acid is removed and purified, leaving the pure citric compound, C6H8O7, and no remnants of the fungus. It’s similar to getting xylitol from birch bark or corn. You end up with pure xylitol. You don’t ingest tree bark.
That said, numerous social media influencers recently started suggesting people were eating black mold whenever they bought food products or supplements containing citric acid. As you’d expect, their social media posts got viral levels of attention and left many people anxious about the foods they consume.
This kind of “fear porn” is becoming all too common across all sorts of media, even in health and fitness.
Other Interesting Facts about Citric Acid
Apart from its uses and benefits, citric acid has some intriguing aspects worth mentioning.
Synthesis of Other Organic Compounds using Citric Acid
Citric acid can serve as a precursor for the synthesis of other organic compounds, such as:
- Itaconic acid: Produced from citric acid through a microbial fermentation process, itaconic acid finds applications in industries such as plastics, adhesives, and textiles.
- Acetonedicarboxylic acid: Derived from citric acid, acetonedicarboxylic acid is used as a starting material for the synthesis of pharmaceuticals and agrochemicals.
- The versatility of citric acid enables it to be utilized not only as an additive but also as a raw material in the production of various organic compounds.
Does Citric Acid Offer More than Just Tanginess?
Citric acid’s tangy flavor is well-appreciated, but it offers more than just taste. Here are a couple of additional benefits it offers:
- Preservation: It acts as a natural preservative, helping food products stay fresh for longer periods. It inhibits the growth of certain bacteria and molds, contributing to food safety.
- Antioxidant properties: It exhibits antioxidant effects, aiding in the neutralization of free radicals, which can cause cellular damage. This makes it a valuable ingredient for dietary supplements and food products, promoting overall health and well-being.
Conclusion
Though citric acid isn’t considered a dietary supplement, it does offer a number of health benefits. It also makes other dietary supplements and certain foods and beverages taste better.
In extreme excess, it could lead to some minor health issues, but in all likelihood, the health issues could be more related to the consumption of highly processed junk food than the citric acid itself.
In the grand scheme of the Standard American Diet, citric acid isn’t the problem ingredient that many fear-mongering social media influencers have made it out to be, and it could, in fact, offer many people a nutritional edge.
