From Volume 46, Issue 11, December 2019 | Pages 1044-1049
Taking sports supplements is an increasing trend within the population and regular consumption of these supplements may increase the risk of developing caries. This paper focuses on identifying current evidence relating to caries risk and sports supplements, and also aims to investigate the sugar content of current sports supplements available in the UK.
The bodybuilding industry has been expanding since its unofficial birth in 1890. The industry saw an exponential increase in popularity in 1980 with the likes of Arnold Schwarznegger taking to the stage. The global sports nutrition market accounted for 28.37 billion dollars in 2016 and is expected to reach 45.27 billion dollars by 2022, growing at a compound annual growth rate of around 8.1% between 2017 and 2022. Following the recognition of the sport by the International Olympic Committee in 1997, bodybuilding competitions became televised and, not surprisingly, the public has been influenced by this sport. Behaviours are changing, influenced by urbanization and a growth in fitness centres. Individuals want to improve the way they look and are influenced by advertising and social media.
What does this mean for the dental profession? The WHO has issued guidelines that recommend intake of free sugars should provide ≤10% of energy intake, and suggest further reductions to <5% of energy to protect dental health throughout life.1 A systematic review showed that lower dental caries was found when free sugar intake was <5% of energy.1 According to the Dietary Supplement Health and Education Act 1994, dietary supplements are defined as ‘products that are designed to be taken by mouth’. Any substance that enters the mouth will react with enzymes in saliva, changing the environment in the oral cavity and therefore have the potential to cause dental caries.
A literature search yielded limited research in this area. However, studies by Morgan et al and Needleman et al do demonstrate a link between the ingestion of sports supplements and dental disease.2,3 Needleman et al showed 55.1% of 278 athletes studied at the London 2012 Olympics had dental caries, focusing on their reduced salivary flow rate, and need for oral health promotion, whereas Morgan et al focused on dental caries caused by sports drinks due to their high sugar content and low pH.2,3 These articles have also been supported by Ali et al and Broad and Rye.4,5
This information from the most visited bodybuilding and fitness website in the world, Bodybuilding.com was used to produce a comprehensive list of the most commonly purchased supplements worldwide, including protein supplements, sports drinks, carbohydrate supplements and weight gainers.6
In the case of each supplement, the nutritional information was independently verified and the carbohydrate content and the sugar content of each type of supplement was examined. It has been shown that carbohydrates are the energy source for oral bacteria to ferment into acid products, which can lead to tooth tissue breakdown, and therefore carbohydrates are one of the main causes of dental caries.7,3
Protein supplements have been a staple of the bodybuilding industry as protein provides building blocks for muscle growth.8 According to the NHS daily reference intake guidelines of 2017, 50 g of protein is the recommended value per day. For muscle synthesis and maintenance 1.2–1.7 g of protein per kilogram of body weight is recommended.4,9 For the average 70 kg athlete, this equates to 84–119 g of protein daily and, to achieve these targets, it becomes more convenient using protein supplements rather than a dietary source.
Protein supplements can be found in the form of powder (whey protein and casein) or in the form of snack foods such as protein bars. Protein in the form of whey and casein both provide the necessary amino acids to stimulate and aid muscle synthesis in the body.10Table 1 shows popular protein supplements in the UK and the sugar content. It is important to note that consuming protein supplements before and after a workout have an advantageous effect on muscle synthesis, which leads to the assumption that many supplement users will be consuming these protein shakes at least twice a day on the days that they are working out.11
| Protein powder supplement name | Carbohydrate content per serving (g) | Sugar content per serving (g) |
|---|---|---|
| Optimum Nutrition Gold Standard 100% Whey™ | 2.4 | 1.4 |
| BSN Syntha-6® | 6.0 | 1.6 |
| Dymatize® ISO100 | 2.7 | 0.5 |
| MuscleTech NITRO-TECH® | 4.0 | 1.0 |
| Optimum Nutrition Gold Standard 100% Casein™ | 3.5 | 1.5 |
| EVLUTION NUTRITION Stacked Protein® | 4.0 | 3.0 |
| Cellucor® COR-Performance Whey | 4.0 | 3.0 |
| Universal Nutrition® Animal Whey | 3.0 | 2.0 |
| Optimum Nutrition Platinum Hydrowhey™ | 2.2 | 0.4 |
| Kaged Muscle Re-Kaged® | 5.0 | 3.0 |
From the data in Table 1, it can be seen that the sugar content of these 10 protein powder supplements are fairly low, with the highest being 3.0 g of sugar found per serving. However, as stated, these protein powders are recommended to be consumed before and after workouts, which therefore doubles the sugar content and also the frequency of sugar intake. Therefore, if a patient were to be taking Kaged Muscle Re-Kaged® twice a day, the sugar intake would be 6 g over two servings within approximately 2 hours (the average workout time). It is important to note here that taking these supplements in a workout period means also taking them in between meals. As shown by the Vipeholm study, the increase of frequency and type of sugar can increase the caries prevalence.12
Athletes also supplement their protein intake with the use of protein bars to diminish cravings for other snacks like chocolate or crisps.13Table 2 presents the carbohydrate and sugar data for the 10 best-selling protein bar products. These protein bar supplements shown have a range of sugar content from 1–15 g.
| Protein bar supplement name | Carbohydrate content per serving (g) | Sugar content per serving (g) |
|---|---|---|
| Quest Nutrition® Quest Whey Protein Bars | 24.0 | 1.0 |
| MusclePharm® Combat Crunch Bars | 28.0 | 7.0 |
| Grenade® Carb Killa Protein Bars | 14.8 | 2.0 |
| MuscleTech® NITRO-TECH Crunch Bar | 24.0 | 7.0 |
| Lenny and Larry's® The Complete Cookie | 27.0 | 15.0 |
| Dymatize® Elite Protein Bar | 19.0 | 2.4 |
| Grenade® Reload Protein Flapjacks | 31.5 | 8.1 |
| OhYeah!® Nutrition OhYeah! Bars | 27.0 | 8.0 |
| CNP Professional Pro Flapjacks | 38.5 | 5.2 |
| SCI-MX Nutrition® PRO2GO Cookie | 30.5 | 4.0 |
Sports drinks have been the topic of controversy over recent years due to their availability to the general public; in particular adolescents and young adults aged 15–24.14 The popularity of sports drinks arises from the industry advertising these drinks with the use of role model athletes and promoting their use to the public. A survey completed in South Wales in 2016 showed that 89.4% of a sample of 160 children aged 12–14 years-old consumed sports drinks after physical activity due to the ‘nice taste’.1 It is concerning that the consumers are unaware of the harmful side-effects these sports drinks can have on oral health and also general health.15 The survey by Morgan et al also showed that Lucozade™ and Powerade™ were the most common sports drinks consumed (Table 3).2 The sugar content of these drinks is very high, and they also have a pH below 5.5, the critical value of enamel dissolution which leads to enamel breakdown and initial lesion formation.16 Both of these factors, combined with regular consumption, makes sports drinks highly cariogenic.17
| Sports drink name | Carbohydrate content per serving (g) | Sugar content per serving (g) |
|---|---|---|
| Lucozade™ Sport 500 ml | 32.5 | 18.5 |
| Lucozade™ Sport Lite Low Cal 500 ml | 10 | 5 |
| Lucozade™ Sport Elite 45 ml gel | 30 | 10 |
| Lucozade™ Energy 380 ml | 31.9 | 17.1 |
| Powerade™ ION 4® 600 ml | 35 | 35 |
| Powerade™ Zero™ 600 ml | 0.6 | 0 |
| Powerade™ Original® 600 ml | 24.6 | 24.6 |
Carbohydrate supplements have been cited to be used in conjunction with protein supplements in the recovery period after a workout.18 This is firstly to restore energy levels and glycogen levels to an athlete but also stimulate an insulin response on a physiological level, which greatly decreases rates of muscle breakdown and causes an anabolic response.19 By decreasing the amount of muscle breakdown, more energy and amino acids can be used for creating new muscle as opposed to repairing broken muscle post-workout.20 The best-selling carbohydrate supplements are shown in Table 4. As can be seen from this table, these carbohydrate supplements are very high in carbohydrate content, specifically in sugar content. As stated, these supplements are used to stimulate an insulin response to stimulate muscle synthesis, which is why the high sugar content is required.20
| Carbohydrate supplement name | Carbohydrate content per serving (g) | Sugar content per serving (g) |
|---|---|---|
| CNP Professional Pro Recover | 46.0 | 43.0 |
| High 5 Protein Recovery | 40.0 | 20.0 |
| PhD® Nutrition Recovery 2:1 | 46.1 | 21.4 |
| Extreme Nutrition™ Build and Recover | 45.0 | 29.0 |
| Nutrisport® ATP Muscle Fuel | 24.0 | 12.0 |
| Optimum Nutrition Recover 2:1™ | 35.0 | 18.0 |
| Sci MX Recover 2:1 Isolate™ | 51.0 | 25.0 |
| Universal Torrent™ | 52.0 | 27.0 |
| JYM Supplement Science Post JYM Carb® | 30.0 | 29.0 |
The idea of most workout plans, based on increasing muscle, is to increase the overall daily caloric intake of an individual to above their basal metabolic rate, with room for adjustment dependant on activity levels.21 One way of doing this is the incorporation of meal replacement products, such as ‘mass gainers' of high caloric value to replace one or two meals during the day which would usually be lower in calories.22 A general weight gainer consists of superior protein and carbohydrate content, to provide a high concentration of calories in one go through the form of an oral suspension created from the addition of the weight gainer powder to a fluid of the consumer's choice; in most cases this is either water or milk. Table 5 presents the nutritional value for the ten best-selling weight gainers. As can be seen here, the weight gainers contain between 0–20.88% sugar content per serving. (It is important to note for each supplement the recommended serving is not the same size.) The NHS states that the daily reference intake (RFI) of sugar is 90 g for the average adult aged 19–64 years-old. In the case of Mutant Mass®, one serving contains 23.2% of the daily reference intake of sugar.23 If we take into account that many users consume these supplements more than once a day, this can account for just under 50% of the daily reference intake of sugar in just two servings.24
| Weight gainer name | Carbohydrate content per serving (g) | Sugar content per serving (g) |
|---|---|---|
| Optimum Nutrition Serious Mass™ | 252.1 | 21.3 |
| BSN True Mass® | 84.8 | 15.7 |
| MuscleTech® MASS-TECH | 131.0 | 8.0 |
| Dymatize® Super Mass Gainer™ | 242.0 | 18.0 |
| Universal Nutrition® Real Gains | 87.0 | 5.0 |
| MuscleMeds Carnivor Mass™ | 125.0 | 0.0 |
| BSN True Mass 1200® | 210.0 | 19.0 |
| Optimum Nutrition® Gold Standard Gainer | 105.0 | 10.0 |
| Mutant Mass® | 182.0 | 38.0 |
| Dymatize Elite Mass Gainer™ | 75.0 | 8.0 |
Workout regimes for an athlete can consist of multiple rounds of supplement consumption. Some of these consist of pre-, trans- and post-workout protein bars and drinks, appetite-reducing supplements, a recovery drink or shake, and possible weight gainers, depending upon the fitness goals of the athlete. All these are often consumed spaced throughout the day.
Even with a low amount of sugar intake, the frequency of this sugar intake is increased compared to a consumer who does not take supplements. Based on the conclusions from the Vipeholm study, the frequency and type of sugar is important in the development of caries.12 As well as this, some supplements are in the form of drinks, and have a pH of less than 5.5, which can accelerate the breakdown process of enamel and initiate the caries process.25
Within the food industry itself there are management systems put in place by the government to educate the public on the nutritional values. This comes in the form of the traffic light system for nutritional information, which shows green for a safe amount, amber for moderate and red for a high amount of sugar, fat and salt. A similar system could be used for all sports supplements (currently this is not the case). This would provide a simple and easy way for consumers to see the amount of sugar contained in these supplements.
Recently, there have also been government plans in England to ban the sale of energy drinks to under 16-year-olds, with some supermarkets already voluntarily adopting these changes.26 Fuse, the Centre for Translational Research in Public Health, stated that popular energy drinks contain on average 160 mg of caffeine. However, the European Food Safety Authority of 2015 recommended maximum intake for school children aged 11–12 is 105 mg. These supplements can also contain high levels of sugar and there should be caution when selling to adolescents owing to the risk of caries and erosion which can occur from the acidity and sugar content.
There is a need for more research on the effects of sports supplements on the oral cavity, particularly as the demand for these supplements is producing a rapidly expanding market. Dentists need to be aware of the potential for sports supplements to be a factor in the development of dental caries, as consumption of these supplements leads to an increase in the frequency and quantity of sugar consumed daily. However, other factors also need to be considered, eg oral hygiene practises and the rest of the diet. Dentists should routinely ask patients about their supplement consumption, especially patients presenting with multiple lesions. Furthermore, details such as frequency and type consumed should contribute to their caries risk assessment, thereby enabling the dentist to advise the patient appropriately.
