Sports and Energy Drinks: Dental Aspects to Consider

Introduction

Sports and energy drink consumption has become popular in recent years among athletes and the young.¹ In addition, the industrialists are targeting children by promoting a misleading relation between their products, healthy lifestyles and sporting skills in their marketing campaigns.² Sports drink ‘Glucozade’ gained fame in 1927, while the era of energy drinks began in 1962 with a brand named Lipovitan D.³ The reasons for manufacturing each of these drinks are different, and the ingredients are mostly unique.⁴ The main goal of sports drinks is to hydrate the body and sustain endurance performance, while energy drinks promote attention, alertness perception and also serve as refreshers and boosters.⁵

Dental problems related to the overwhelming ingestion of these drinks have become a major public health issue. Since the drinks are mostly carbohydrates, dental caries may be potentiated in subjects who do not maintain a standard plaque control. Dental erosion caused by low pH from extrinsic dietary sources includes fruits, acidic carbonated beverages, sports & energy drinks, many of which contain citric acid.⁶ Intake of these drinks during dehydration reduces the clearance of acids and sugars from the tooth surface and the buffering capacity is also inhibited due to lower salivary flow which increases the risk of dental erosion and dental caries.⁷

Moreover, due to their high erosive potential, such drinks can have an impact on the endurance of restorative materials. Eventually, this damages the interface between the tooth surface and the restorative material.⁸ A low pH can also affect the surface integrity of the restoration by softening the matrix and further leading to the loss of structural ions from the dental material.⁹

This review reflects the impact of sports and energy drinks on the tooth structure and dental restorative materials. It also includes various preventive measures to restrict the usage and minimize the dental effects of such drinks.

Sports Drinks

Sports drinks are manufactured to quickly replace fluids and electrolytes lost through sweating, as well as offer carbohydrates to refill glycogen stores and maintain performance.⁵ Three main types of sports drinks are: Isotonic, Hypotonic, Hypertonic. Isotonic drinks contain salt and sugar levels that are comparable to those found in the human body. Similarly, the levels of salt and sugar are high in hypertonic drinks and low in hypotonic drinks than that of the body.⁵ The sports drinks contain carbohydrates, electrolytes such as sodium, potassium, magnesium and calcium, vitamin A, B complex, C & E, minerals such as sodium bicarbonate, selenium and green tea extract.⁵ Commonly available sports drinks are All Sport Body Quencher, All Sport Naturally Zero, Gatorade, Gatorade Propel, Gatorade Endurance, Powerade Zero, Powerade, Powerade Ion4 and Accelerade.¹⁰ Few in vitro studies reported pH of sports drinks ranging from (2.38- 4.46),⁶ (2.38- 4.46),¹¹ (2.52),¹² (2.7),¹³ (2.84),¹⁴ (2.9),¹⁵ (2.93),¹⁶ (2.99- 3.75),¹⁷ (3.04).¹⁸ Isostar is the most acidic with a pH 2.38 and the least acidic is Maxim with a pH 4.46.^6,11 It is estimated that the Indian sports drink market is expected to expand at a compound annual growth rate of 4% during the forecast period of 2021-2026. Growing demand among athletes and new age sports enthusiasts is projected to propel the market forward.¹⁹

Energy Drinks

Energy drinks are intended to promote mental attention, readiness, and anaerobic capacity.⁵ Caffeine, guarana, taurine, ginseng, L-carnitine, niacin, riboflavin, folic acid, cyanocobalamin, pyridoxine hydrochloride, pantothenic acid, creatine, and/or glucuronolactone, yerba mate, sugars such as glucose, sucrose and fructose are commonly used ingredients in energy drinks.²⁰ Java Monster, Java Monster Lo-Ball, Monster Energy, Monster Low Carb, Red Bull, Red Bull Sugar Free, Power Trip Original Blue, Power Trip “0”, Power Trip the Extreme, Rockstar Original, Rockstar Sugar Free are some of the most popular energy drinks in the market.¹⁰ The pH of these drinks reported in various in vitro studies ranged from (2.52),⁶ (2.52),¹¹ (2.6-3.3),²¹ (2.69-3.81),¹² (2.76),¹⁴ (3.03-3.81),⁸ (3.16-3.23),¹⁷ (3.24),¹⁶ (3.32),¹⁸ (3.42- 3.54).²² High Five is the most acidic with a pH 2.526,¹¹ and the least acidic is Red Bull with a pH 3.81.8,¹² The majority of energy drinks have approximately 11%–15% (21–34 g/237 mL) sugar concentration more than the other sports drinks.²⁰ The Indian energy drink market is predicted to increase at a compound annual growth rate of 9.22% between 2020 and 2025.²³

Impact of Sports and Energy Drinks on Tooth Structure

Dental Erosion

Dental erosion is defined as the irreversible loss of dental hard tissue by a chemical process that does not involve bacteria.²⁴ Acids from the diet or stomach regurgitation are one of the most common etiological agents for dental erosion.²⁵ Most citrus fruits, as well as sports and energy drinks are extremely acidic.²⁴ Its acidity is much lower than the critical plaque pH of 5.5, which can cause dental erosion.²⁶ Citric acid is the widely used organic acid in sports and energy drinks. It erodes tooth structure more quickly than other acids of similar concentration. This detrimental effect is attributed to their acidic nature and the capability to chelate calcium at higher pH.²¹

The erosive potential may also be explained by the calcium and phosphate content in the drinks. In the literature, there are reports of acidic drinks modified by added calcium which demonstrated a reduced erosive potential.²⁷ The presence of nano-hydroxyapatite¹⁵ and casein phosphopeptide stabilized amorphous calcium phosphate¹³ in the drinks release more calcium and phosphate than traditional microparticles. In vitro studies^{28,17-15,21-27,11} reported a loss of hard dental tissue which is considerably more on exposure to sports and energy drinks. Though many in vitro studies support their relationship with dental erosion, many clinical studies have failed to find this relationship.²⁹

Effect of sports & energy drinks on enamel

When enamel is exposed to acidic drinks, the interface between rods and inter-rods enamel as well as between the enamelin and hydroxyapatite crystallites represent the pathways for acid conduction. This further leads to dental erosion which starts with the weakening of enamel and progresses to the loss of the tissue volume while leaving a fine layer above the resting enamel. Enamel dissolution will progress and become irreversible if exposed to acids for an extended period. Enamel erosion is initiated when plaque pH drops below 4.0, although the enamel demineralization occurs below 5.5 when the oral environment becomes undersaturated for hydroxyapatite.³⁰

Effect of sports & energy drinks on dentin and cementum

Dentin has plate-like crystallites of 3 nm thickness, which mineralizes the collagen fibrils arranged in parallel arrays. The dentine crystallites are smaller than those in enamel and as a result, the dissolution might appear over a shorter period.

Because of changes in the chemical composition, the root cementum/dentin is more prone to erosion when compared to enamel. Small size apatite crystals, reduced mineral and more organic content make the root surface susceptible to erosion.³⁰

Dental Caries

Dental caries is an irreversible microbial disease of the calcified tissues of the teeth, characterized by demineralization of the inorganic portion and destruction of the organic substance of the tooth, which often leads to cavitation.²⁴

Effect of sports & energy drinks on the dental caries process

A diet enriched with fermentable carbohydrates has a strong link to dental caries, as does the excess consumption of sports and energy drinks, which are essential for the development of dental caries. The quantity, type of carbohydrate and presence of calcium, phosphate, fluoride content in the drinks play a major role in the dental caries process. Due to the presence of carbohydrates in the drinks, too much intake can alter the matrix of the biofilm and favour the accumulation of Streptococcus mutans and other cariogenic bacteria, making the tooth structure more porous and susceptible to dental caries. According to the American Dental Association (ADA), the frequency and amount of sugar exposure in the form of food and sugar-sweetened drinks intensify the risk of dental caries and is a significant factor for cariogenicity.³¹

Impact of Sports and Energy Drinks on Dental Restorative Materials

Marked pH variations in the oral cavity lead to degradation of the restoration surface. The acidic tendency of sports and energy drinks may prompt irreversible changes over the external structure of restorative materials.³² Restorative materials can absorb water and are capable of absorbing other fluids with pigments such as sports & energy drinks, resulting in discoloration.⁹ Evidence from a few in vitro^8,9,33,22-34 studies reveals a loss of surface hardness, roughness and discoloration of composite materials on prolonged contact with these drinks.

Surface wear

The acidogenic potential of the drinks can physiologically subject the oral cavity to pronounced pH fluctuations, combined with the masticatory forces resulting in restorative material wear. Composite based materials with low filler content have evidenced a greater surface loss on exposure to acidic drinks. When compared to other restorative materials, glass ionomer cement loses more hardness on immersion in such drinks. This occurs due to the higher solubility of the glass ionomer cement compared to composite-based materials. Microhardness test and scanning electron microscopy reveals that when these drinks are in contact with both resin-modified and conventional glass ionomer cements, there is an increase in surface roughness compared to other dental materials.³⁵

Microleakage

Sports and energy drinks create an acidic environment in the oral cavity which causes enamel decalcification, leading to microleakage around the restoration. Microorganisms and other molecules penetrate between the tooth and the restorative material, compromising the durability of the restoration.³⁵

Discoloration of composite restorative materials

Composite materials can absorb water and other pigments present in drinks. Water acts as a conductor for the pigment and penetrates the resin matrix. When there is an excessive absorption, it leads to expansion, plasticization of the material and hydrolyzation of the silane resulting in micro-crack formation. Micro-cracks create a gap at the interface between the filler and matrix resulting in discoloration.⁹

Prevention Strategies to Reduce the Dental Effects of Sports and Energy Drinks

Avoid supplements during sporting activities

When water is adequate and there is no necessity for supplements containing sugars during post-workout and sporting activities, these drinks can be avoided. A twobottle strategy such as a sports supplement followed by water can be used.

Modify the oral environment

Athletes who regularly consume acidic drinks can be advised to use high concentration fluoride toothpaste and mouth rinses. They are recommended to spit but do not rinse after toothbrushing to exploit the advantage of fluoride availability.

Reduce the dental plaque biofilm

Dental plaque biofilm formation may be more in athletes due to reduction in salivary flow during times of dehydration and stressful training. As a result, maintaining good oral hygiene is essential. To achieve this:

• Athletes should be responsible for their own selfcare
• Interdental cleaning before tooth brushing
• Athlete self-monitoring by using plaque-disclosing agents
• Technique coaching and guidance from a dental specialist on a one-to-one basis

Routine dental check-ups

Examination of the oral cavity, screening for dental diseases and additional instructions concerning the dental effects of sports and energy drinks must be given by dentists and also periodic dental visits must be suggested.³⁶

Interdisciplinary approach

The sports medicine team should have adequate knowledge of the oral health component of the athlete’s health profile. In case, if any dental diseases are noted, they can be referred to the sports dentistry team.³⁷

Natural sports drinks

Sugarcane juice: Its rehydration capacity is almost equal to sports drinks. In addition, sodium chloride combination with sugarcane juice enhances performance during any physical activity. Golazo natural sports drink brand, contains about 33 g of cane sugar which is less sweeter than commercial sports drinks.

Milk: Milk is enriched with calcium, proteins and fat content. It retains the calcium content in the body and facilitates muscle contraction. Sport Shake is a milkbased energy drink available in the market.

Coconut water: Coconut water is enriched with potassium. It helps in combating dehydration and maintains the blood sugar in the body. ZICO, Vita Coco and O.N.E are some of the well-known coconut water brands.

Personalized sports and energy drink

The quantity of carbs and electrolytes required for an individual depends on the body weight. Two individuals with different body weights performing the same intensity of exercises would require different compositions of sports drinks. Therefore, depending on one's physical activities and body weight, the drinks must be taken.³

Restrict the usage of sports and energy drinks

Manufacturers are manipulating the products to increase acceptance and the market is misleading and targeting vulnerable groups. Similar to the Framework Convention on Tobacco Control (FCTC), there is a need for guidelines at an international level, based on which government can enact legislation and restrictions on the usage of these products.²

Conclusion

Sales of sports and energy drinks have increased exponentially. The consumption of these drinks can cause detrimental effects leading to dental erosion, dental caries and progressive deterioration of restorative materials. Taking this into consideration, oral health promotion activities should be reinforced among people to create awareness about the impact of these drinks on oral health. Any social media or cinema advertising these should be made to include clear warning messages to avoid unnecessary intake of acidic drinks.

Conflict of interest

The authors declare that they have no conflict of interest.

Financial support and sponsorship

Nil