Dr. Andrea Middleton - Is It Bad For You? Approved by Dr. Andrea Middleton

Is Phosphoric Acid Bad For You?

Also Known As: Orthophosphoric acid, E338



Short answer

Phosphoric acid, commonly found in colas and processed foods, is safe in moderation. Consuming high amounts can lead to bone demineralization, tooth enamel erosion, and kidney health issues. It’s advisable to consume a balanced diet with calcium-rich foods and limit intake of foods with added phosphoric acid.



Long answer

The Role of Phosphoric Acid in Food and Beverages

Phosphoric acid, a colorless and odorless inorganic mineral acid, plays a multifaceted role in the food and beverage industry. As a tangy ingredient, it's quite popular in various consumables. Here's an overview of the ways phosphoric acid can interact with our foods and drinks:

  • Flavor Enhancer: In beverages, especially colas and other soft drinks, phosphoric acid is a key flavor component that provides a characteristic sharpness or tanginess, which balances the sweetness of sugar or high-fructose corn syrup.
  • Acidity Regulator: It's commonly used to adjust and maintain the acidity, which can help control the growth of microbes, extending the shelf life of products. This property also helps preserve the desired texture and appearance of food.
  • Leavening Agent: In baking powders and prepared doughs, phosphoric acid reacts to form carbon dioxide gas, which helps dough rise. This can contribute to the fluffy texture of baked goods.
  • Clarifying Agent: It's used in the production of sugar and cheese, where it assists in the clarification process by removing impurities and contributing to the desired final product quality.

Despite its prevalence in the industry, the addition of phosphoric acid in food and beverages raises questions about its health implications. Among the concerns is the potential for phosphoric acid to contribute to bone demineralization when consumed in high quantities, as it may interfere with calcium absorption. Peer-reviewed studies, including a narrative review in the "Journal of Bone Mineral Metabolism" (2000), suggest that this could be a pertinent issue, particularly for individuals at risk of osteoporosis. Additionally, there's conjecture about its potential link with tooth enamel erosion, referenced by research in "The Journal of the American Dental Association" (2004).

However, it is integral to distinguish between the additive's role as a food component and overconsumption, which could tip the scales towards negative health outcomes. As with many ingredients, moderation is key, and understanding the extent of phosphoric acid's involvement in our diet is crucial. The general consensus among regulatory agencies like the FDA is that phosphoric acid is "Generally Recognized as Safe" (GRAS) when used in accordance with good manufacturing practices.

From a culinary and consumption standpoint, the role of phosphoric acid is a double-edged sword. It offers functional benefits to food and drink products, enhancing flavors and prolonging shelf life, but at the same time, mindful consumption is critical. It beckons consumers to be vigilant about the quantities ingested and to be aware of the potential health implications associated with excessive intake.

Potential Effects of Phosphoric Acid on Bone Health

Exploring the impacts of phosphoric acid on bone health is crucial, especially considering it's a common ingredient in soft drinks and processed foods. The body needs phosphorus to build and repair bones and teeth, manage energy, and reduce muscle pain after exercise. However, the form of phosphorus as phosphoric acid might not boast the same advantages as naturally occurring phosphates in food.

One area of concern is the potential link between phosphoric acid and bone density. Studies suggest that excessive intake of phosphoric acid, particularly from soda consumption, may be associated with lower bone density, increasing the risk of osteoporosis. Here's a breakdown of what science says:

  • Bone Mineral Density: A study published in The American Journal of Clinical Nutrition found that cola beverages were associated with significantly lower bone mineral density in women. This observation was not made with other types of carbonated drinks, pointing toward the possible role of phosphoric acid, prevalent in cola drinks, as a contributing factor. Tucker et al., 2006
  • Caffeine Content: It's essential to note that the caffeine content in some phosphoric acid-containing beverages may also play a role in bone health. Caffeine has been shown to potentially interfere with calcium absorption, which is necessary for optimal bone health. Massey & Whiting, 1993
  • Calcium-Phosphorus Ratio: The balance of calcium and phosphorus is vital for bone health. High phosphorus intake, particularly in the form of phosphoric acid without adequate calcium, can disrupt this balance and might contribute to bone demineralization and the development of osteoporosis. Calvo, 2014
  • Phosphate Additives vs. Natural Phosphorus: The absorption of phosphorus from phosphate additives is much higher than from natural food sources, potentially exacerbating the imbalance between phosphorus and calcium levels in the body. This factor makes the type of phosphorus a meaningful consideration when examining bone health. Calvo & Uribarri, 2013

While understanding the intricate impacts of phosphoric acid on bone health is ongoing, it's prudent for individuals to be mindful of their phosphoric acid intake from processed foods and beverages. Maintaining a diet that emphasizes a variety of calcium-rich foods and natural sources of phosphorus, such as dairy products, fish, and nuts, can help support bone health. Always consider the synergy of nutrients in your diet and the balance that leads to optimal wellness.

The ongoing debate emphasizes the necessity for further research to fully understand the relationship between phosphoric acid and bone health. Nevertheless, nutrition experts often suggest that moderation in consumption of phosphoric acid, particularly from sources such as soda, can be a prudent approach to ensuring long-term skeletal health.

Correlations Between Phosphoric Acid and Kidney Health

When it comes to the impact of phosphoric acid on kidney health, the conversation gets a bit nuanced. This common food additive, which adds a tangy taste and prevents discoloration in beverages and food products, has been under scrutiny for its potential effects on renal function. Let's unravel these implications piece by piece.

Phosphoric Acid and Kidney Stone Formation

One of the major concerns with phosphoric acid consumption is its association with the formation of kidney stones. Research has suggested that high intake of phosphoric acid, which is prevalent in sodas and processed foods, can lead to an increased risk of developing kidney stones. A study published in the American Journal of Epidemiology found that consumption of cola, which is high in phosphoric acid, is associated with an elevated risk of chronic kidney disease and kidney stones due to its potential to alter urinary pH levels and increase urinary calcium excretion.

Impact on Chronic Kidney Disease

Not only has phosphoric acid been linked to kidney stones, but it also has potential ties to the progression of chronic kidney disease (CKD). A diet high in phosphorus, which includes food additives like phosphoric acid, can strain already weakened kidneys. As kidneys are responsible for filtering out excess phosphorus, too much of this mineral can put additional stress on these vital organs. This theory is supported by a study in the Clinical Journal of the American Society of Nephrology where researchers noted an association between high phosphorus intake and CKD progression.

Dietary Phosphorus vs. Additive Phosphorus

An important distinction to make is between dietary phosphorus and additive phosphorus. Natural phosphorus, found in foods like seeds, nuts, and legumes, is vital for health and much less readily absorbed by the body. Conversely, phosphorus in the form of food additives like phosphoric acid is almost completely absorbable, posing a greater risk for phosphate build-up in the body which can be harmful for individuals with compromised kidney function.

Recommended Intake and Kidney Health

The recommended dietary allowance (RDA) for phosphorus for healthy adults is between 700 mg to 1,250 mg a day, depending on age, sex, and life stage. Patients with renal conditions are typically advised to consume less than this amount. It is crucial for individuals with kidney issues or at high risk to manage their phosphoric acid intake vigilantly and opt for natural sources of phosphorus over additive forms when possible.

Professional Guidance Suggested

Because the correlation between phosphoric acid and kidney health can vary based on an individual's overall health and diet, consulting with a healthcare professional or registered dietitian is advisable. This is particularly important for individuals who have kidney issues or a family history of renal diseases. Personalized dietary recommendations and regular monitoring can help mitigate any potential risks associated with excessive consumption of phosphoric acid.

In conclusion, while phosphoric acid serves its purpose in food preservation and flavoring, mindfulness around its consumption is necessary, especially for those concerned about kidney health. By staying informed and making dietary choices guided by professional advice, we can minimize any adverse effects and promote renal well-being.

Phosphoric Acid's Impact on Dental Enamel

Phosphoric acid, often found in soft drinks and processed foods as a flavor enhancer and preservative, has raised concerns among dental health professionals. This is due to its potential erosive effect on dental enamel, the hard, protective outer layer of our teeth. Dental enamel is critical in protecting teeth from decay, but it is also susceptible to demineralization, particularly from acidic substances.

When we consume foods and beverages containing phosphoric acid, this compound can temporarily lower the pH level in our mouths, creating an acidic environment. It's in this environment where the risk lies; the acidity can initiate the demineralization process of tooth enamel. If demineralization exceeds saliva's natural remineralization process, this can lead to enamel erosion, making teeth more vulnerable to cavities and sensitivity.

A study by the Journal of Dentistry for Children found that prolonged exposure to drinks containing phosphoric acid can lead to significant enamel erosion. The reason is simple: the phosphoric acid can dissolve the calcium phosphate that dental enamel is primarily composed of. As enamel wears down, teeth can become discolored, taking on a yellowish tint because of the underlying dentin becoming more visible.

The impact of phosphoric acid on dental health doesn't stop there. Once enamel is weakened, the teeth can become more susceptible to bacteria, leading to further dental problems such as decay and even tooth loss in severe cases.

It is important to note that not all exposure to phosphoric acid will cause enamel erosion. Factors that contribute to its impact include:

  • The concentration of phosphoric acid in the product
  • The duration and frequency of exposure to phosphoric acid
  • The presence of other compounds in food and drinks that may either enhance or mitigate the acid’s effects
  • Individual saliva production and its natural capacity to neutralize acids

Dentists recommend several strategies to minimize the potential harmful effects of phosphoric acid on dental enamel:

  • Rinsing the mouth with water after consuming acidic foods or drinks to neutralize the acid levels
  • Using a straw when drinking acidic beverages to limit contact with teeth
  • Chewing sugar-free gum to stimulate saliva production, which helps in the remineralization of the enamel
  • Waiting for at least 30 minutes before brushing teeth after consuming acidic foods or drinks, as brushing too soon can cause more enamel erosion

It's essential to understand that occasional consumption of foods and drinks with phosphoric acid is less likely to cause significant damage to dental enamel. However, regular and excessive intake should be a concern, especially in the absence of proper dental care routines. To ensure the health of your teeth, it's always a good practice to maintain a balanced diet with a limited intake of highly acidic foods and beverages. Pairing this with diligent oral hygiene can help mitigate the adverse effects phosphoric acid may have on dental health.

When seeking to protect your smile, being informed and proactive goes a long way. So next time you reach for that soda can, remember your pearly whites and treat them kindly!

Balancing pH: Phosphoric Acid's Influence on the Body's Acid-Base Balance

The human body meticulously maintains a tightly controlled pH balance, which is crucial for proper physiological function. The normal blood pH range is between 7.35 and 7.45, which is slightly alkaline. Any disruption to this balance can have significant health implications. When we consume substances like phosphoric acid, commonly found in dark colas and processed foods, it introduces additional acid into our system.

This additive may affect the body's acid-base balance, and the kidneys have to work harder to excrete the excess acid. Overconsumption of phosphoric acid through diet can lead to a condition known as acidosis, which occurs when the body's fluids contain too much acid. Acidosis can reduce the body’s ability to absorb minerals and may result in bone demineralization. Let’s explore the potential impacts phosphoric acid can have on the body’s pH balance:

  • Mineral Absorption: Phosphoric acid can bind with minerals like calcium, magnesium, and zinc in the digestive tract, potentially leading to reduced absorption rates of these essential nutrients. This is particularly concerning as it can contribute to a reduction in bone mineral density, possibly increasing the risk of osteoporosis over time.
  • Impact on Kidney Function: The kidneys are responsible for maintaining acid-base homeostasis by adjusting the pH of blood and excreting hydrogen ions and reabsorbing bicarbonate from urine. High intake of phosphoric acid challenges the kidneys' ability to maintain this balance, which could potentially lead to chronic kidney disease if the dietary pattern is sustained long-term.
  • Buffering Systems: The body has three major buffering systems: bicarbonate, phosphate, and protein. While the phosphate buffer system uses phosphates to neutralize strong acids and bases, an excess of phosphoric acid from dietary sources could potentially overwhelm this system, leaving the body less equipped to neutralize other acids.

Research on the role of phosphoric acid in diet and its effects on acid-base balance has yielded varying results. Some studies suggest that habitual intake of beverages containing phosphoric acid can be associated with lower urinary pH levels, indicating a more acidic environment (Fenton et al., 2009). Conversely, a review published in the American Journal of Clinical Nutrition found that dietary acid load was not significantly associated with systemic pH levels or clinical outcomes (Fenton & Huang, 2016).

While the body is equipped to handle small amounts of phosphoric acid, individuals who consume significant amounts through their diet should consider the potential impacts on their body's pH balance. It's essential to ensure you're also getting enough foods that can help counteract the acid load, like fruits, vegetables, and legumes which are naturally alkaline-forming and provide a rich source of minerals to support the body's buffering capacity.

As with many things in nutrition science, balance is key. Modest consumption of foods and drinks containing phosphoric acid, paired with a diet rich in minerals and alkalizing foods, can help maintain the body's delicate acid-base equilibrium. It's also advisable to consult a healthcare professional or a registered dietitian if you have concerns about your dietary acid load, especially if you have existing conditions that might be affected by an altered pH balance, like osteoporosis or kidney diseases.

Understanding Daily Intake Limits for Phosphoric Acid

When it comes to diet and nutrition, moderation is key – and the same holds true for phosphoric acid. Known by the chemical designation E338 and commonly found in soft drinks, processed foods, and some cleaning agents, phosphoric acid can be part of a regular diet but should be limited to ensure overall health. The reason why moderation is necessary revolves around the effects phosphoric acid can have on bone health, kidney function, and digestive balance.

The acceptable daily intake (ADI) for phosphoric acid is determined by various organizations around the globe. The European Food Safety Authority (EFSA), for instance, has classified phosphoric acid as a group '3' substance, which translates to "not classifiable as to its carcinogenicity to humans". Nevertheless, this categorization stresses the importance of adhering to agreed upon intake levels to mitigate any potential risks.

Although a definitive ADI for phosphoric acid has not been uniformly agreed upon, different bodies like the Food and Drug Administration (FDA) in the United States offer guidance on phosphate compounds collectively. It's generally recommended that phosphorus intake from all sources – food, beverages, and supplements – should not exceed 700 milligrams per day for adults, based on the Dietary Reference Intakes (DRIs) established by the Institute of Medicine (IOM).

  • For infants (0-6 months): the adequate intake (AI) is 100 mg/day.
  • For infants (7-12 months): the AI is 275 mg/day.
  • For children (1-3 years): the recommended dietary allowance (RDA) is 460 mg/day.
  • For children (4-8 years): the RDA is 500 mg/day.
  • For children (9-18 years), the values increase with age, up to 1250 mg/day.
  • For adults (19 years and older): 700 mg/day.
  • For pregnant and lactating women: 700 mg/day.

It's worth noting that the actual intake of phosphoric acid specifically would be a fraction of the total phosphorus intake. Still, careful consumption is advised since foods and drinks with added phosphoric acid can quickly elevate phosphorus levels in the body. In particular, consumption of phosphate additives like phosphoric acid is higher in Western diets due to the prevalence of processed foods and sodas.

Considering the potential link between high phosphate levels and health issues such as cardiovascular disease and weakened bones, particularly in populations with compromised kidney function, it's recommended to pay close attention to phosphorus intake from all sources.

It's important to assess your diet, especially if you consume multiple products containing phosphoric acid or other phosphates. Ensuring a variety of nutrient sources can help maintain balance and prevent exceeding recommended levels. If you have specific health concerns or dietary restrictions, consulting a dietitian or healthcare professional is a crucial step to personalize your dietary needs.

Lastly, those with renal issues or conditions that affect the metabolism of phosphorus should be particularly vigilant about their phosphoric acid intake. Since phosphorus levels are closely regulated by the kidneys, any impairment can lead to an accumulation in the bloodstream, exacerbating health problems.

The overarching theme in assessing your daily phosphoric acid intake is one of balance and awareness. By staying informed and making mindful choices, you can enjoy a varied diet without overstepping these important nutritional boundaries.

Frequently asked questions

Yes, natural sources of phosphorus, such as dairy, nuts, and legumes, are less acidic and thus safer for dental health. Phosphoric acid in beverages can contribute to enamel erosion, while natural phosphorus is essential for healthy teeth without the adverse acidic effects.

Yes, dietary adjustments can improve kidney health. Reducing phosphoric acid intake by avoiding sodas and processed foods in favor of foods with natural phosphorus can decrease the risk of kidney stone formation and progression of chronic kidney disease.

Phosphoric acid may pose a higher risk of bone demineralization for individuals already at risk of osteoporosis due to its potential interference with calcium absorption. In those with healthy bones, the effect is less pronounced, but it is still advisable to consume it in moderation to avoid any negative long-term impact on bone health.

Alkaline-forming foods include most fruits, vegetables, and legumes. These foods can help balance out the acidity from phosphoric acid and support the body's natural buffering systems to maintain a healthy acid-base equilibrium.

Ask a question about Phosphoric Acid and our team will publish the answer as soon as possible.

Possible short-term side effects

  • enamel erosion
  • altered urinary ph
  • digestive disturbance

Possible long-term side effects

  • bone demineralization
  • increased risk of osteoporosis
  • kidney stones
  • chronic kidney disease
  • dental decay
  • tooth sensitivity
  • acidosis
  • reduced mineral absorption

Commonly found in

  • soft drinks
  • baked goods
  • processed foods

Ingredients to be aware of


  • enhances flavor
  • improves food texture
  • extends shelf life
  • leavening agent
  • clarifying agent

Healthier alternatives

  • natural sources of phosphorus (dairy, fish, nuts)
  • calcium-rich foods
  • alkaline-forming foods (fruits, vegetables, legumes)

Thank you for your feedback!

Written by Rachel Adams
Published on: 12-27-2023

Thank you for your feedback!

Written by Rachel Adams
Published on: 12-27-2023

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