Version classiqueVersion mobile

Nutrition and Performance in Sport

 | 
Christophe Hausswirth

Chapter 2. Nutrition, sport and health

Topic 4. Nutrition and oral hygiene

Julien Louis et Christophe Hausswirth

Résumé

High-level sports performance requires rigorous and intense training, which significantly increases energy expenditure. Consequently, the athlete must ingest large amounts of food several times during the day to cover their energy requirements. Because carbohydrates in all forms (solid or liquid) provide rapid and sustained energy, they are the preferred food type of athletes, and are eaten before, during and after training. However, a high-carbohydrate intake combined with chronic dehydration creates a significant risk for oral health, and can promote the formation of cavities and tooth erosion. These effects on the teeth can have disastrous consequences on performance. Because of this, athletes should choose their food based on energy content, and also on its effect on oral health. The foods of choice are alkalizing foods, which help to neutralize acid attacks. These foods include dairy products, mineral waters, starch-and fibre-rich carbohydrates. Some strategies can also be applied during meals, snacks, or training when consumption of high-risk foods increases. Finally, because athletes are particularly exposed to the risk of tooth decay and dental erosion, they should take care to regularly consult their dentist for a dental health check-up.

Texte intégral

1. Introduction

1Nutrition in the elite athlete is different to nutrition in the mainstream population. This difference stems from increased energy expenditure (a few hundred to several thousand calories per day) due to repetition of daily – or even twice-daily – training sessions, which must be balanced by an increased energy intake. Food plays a major role in an athlete’s life and an inadequate intake could expose them to a risk of fatigue, injury or underperformance. Thus, if the diet is not balanced – e.g. lacks essential compounds or contains excess quantities of some foods – disorders can develop, including at the level of oral hygiene. The main problems encountered with oral hygiene in athletes are cavities and tooth erosion. These problems are promoted by the consumption of foods which are high in sugar and by acidity associated with exercise-related dry mouth. Within this context, the purpose of this chapter is, first, to generally assess food consumption patterns in elite athletes, and then to present the main food hazards and how they can be avoided. Finally, we will propose practical recommendations for good oral hygiene in athletes.

2. Specificities of an elite athlete’s diet and its consequences for oral hygiene

2Diet plays an important role in the lifestyle, performance and recovery of athletes and directly influences their oral hygiene. To facilitate food ingestion, physical well-being and performance, the mouth and teeth need to be operational and healthy. Because dental problems such as tooth decay or dental erosion significantly affect performance (Piccininni and Fasel, 2005), athletes should be careful to monitor the quality of the food they eat on a daily basis.

3Little is known about the relationship between the dietary practices of elite athletes and their oral hygiene (Bryant et al. 2011). However, it is commonly acknowledged that athletes are particularly prone to dental problems related to the combined effect of intense training and their “sports” diet. The main risk factors for athletes are: high energy supply, repeated food intake and/or drinks, consumption of acidifying foods, ingestion of sugary foods, and dehydration (Sirimaharaj et al. 2002; Bryant et al. 2011; Frese et al. 2014).

4For example, Figure 1 shows the eating habits of a cohort of 265 athletes participating in 20 Olympic disciplines. The data indicate that, although the diet of these athletes is not bad, it is not optimal, and it would be wise to correct some habits. For example, nearly 60% of these athletes do not eat enough fibre-rich foods which are essential for good digestion and which limit the eroding effects of acidic foods; 53% consume too many sweet products; 48% are inadequately hydrated; and 62% admit to snacking between meals, all of which increase the risk of problems with oral hygiene.

5Furthermore, 94% of athletes questioned reported drinking during training, with 12% consuming energy drinks; this can be compared to 96% of athletes who drink during competitions, 31% of whom consume energy drinks. In addition to fluid intake, 18% of athletes systematically consume some solid food during a competition, as opposed to just 2% during training. Most of the food eaten during exercise is rich in simple sugars. Of course, whether food or drink is consumed during sport largely depends on the type of sport practised; the highest level of consumption is generally observed in endurance athletes who need a constant energy supply to balance their energy expenditure over a long period. According to a recent study of 31 highly trained triathletes, nearly 84% of them regularly consumed sports drinks during training (one to six times per week) of which 16% consume them at least six times per week; 94% ingest solid foods, of which 58% only during the cycling leg of training. This data suggests that endurance athletes may be more exposed to risks related to the repeated ingestion of sweet foods, and to greater drying of the mouth (Bryant et al. 2011).

6The intense training the elite athlete undertakes requires a performance-oriented diet. In many sporting disciplines, the main objective is to maintain energy supply to the muscles to allow their immediate contraction, or in the longer term to build up energy reserves. Athletes often consume mostly carbohydrate-based foods, which are often acidifying, and tend to omit certain classes of foods. However, this may not be wise in the long term as a high-carbohydrate and acidifying diet, associated with chronic drying of the mouth due to intense effort/stress could promote the development of dental hygiene problems.

Figure 1: Food habits of 256 elite athletes participating in 20 different Olympic sports (source INSEP).

Figure 1: Food habits of 256 elite athletes participating in 20 different Olympic sports (source INSEP).

3. The main dental problems encountered in athletes

7The main dental problems encountered by athletes are cavities (3.1) and dental erosion (3.2):

3.1 Dental cavities

8Dental cavities correspond to a demineralization of the tooth, which can lead to cavitations, i.e. the formation of hollows in the tooth, often accompanied by pain. Cavities are formed when the acid produced by a specific oral bacterium dissolves the enamel in the tooth. The risk of cavities is very high when food is eaten frequently, when saliva production is reduced, and when dental care is neglected (Tahmassebi et al. 2006). Sugars are the source of energy most associated with the formation of cavities. The bacteria found in the mouth degrade sugars to produce acids, reducing the pH in dental plaque and damaging the tooth enamel. The following diagram presents a simplified summary of the mechanism behind the development of cavities.

3.2 Dental erosion

9Dental erosion corresponds to a loss of dental enamel due to a chemical process (acidification) which involves bacteria. As enamel is lost, the tooth becomes exposed to mechanical wear and becomes very sensitive. Any acidic element (pH<5.5) can potentially dissolve tooth enamel (Sirimaharaj et al. 2002; Bryant et al. 2011). Thus, dental erosion may be caused by exogenous or endogenous acids, or by a combination of both. Exogenous acids are present in food, beverages, medicines (Table 1) and the environment, e.g. in chlorinated swimming pools; whereas endogenous acids are mainly stomach acids which may come into contact with the teeth during vomiting or regurgitation (Jarvinen et al. 1991).

Table 1: Food factors representing a risk of dental erosion (adapted from Nunn, 2001).

Food

Drug

Acidic soft drinks

Iron-rich supplements

Lemon juice

Vitamin C tablets

Other fruit juices

Aspirin

Acidic sports drinks

Wines

Cider

Herbal teas

Citrus fruits

Other acidic fruits and berries

Foods preserved in vinegar

Sweet candies

10The risk of tooth decay and dental erosion are increased in high-level athletes (Milosevic et al. 1997). Repeated and/or long duration training may reduce salivary flow due to dehydration and to breathing through the mouth (Horsewill et al. 2006). In addition, energy consumption is high among elite athletes and often involves an intake of large proportions of carbohydrates and acidic drinks (Sirimaharaj et al. 2002; Slater et al. 2003). Risks are also increased by the frequency and duration over which food or acidic drinks are consumed. The risk is even greater in younger athletes as their tooth enamel is not yet fully mature, and is more porous and readily dissolved by acids (Tahmassebi et al. 2006). Under normal conditions, the enamel is bathed in saliva containing protective ions, and becomes progressively stronger, less permeable and more resistant to acid attacks. However, this maturation takes time, and so young athletes are particularly exposed to dental problems.

4. Food and oral hygiene

11The mouth is considered to be the “mirror” of the body, in that many diseases related to unhealthy diets can be detected at the level of the mouth. A predominantly acidic diet can have harmful consequences for the body, causing progressive demineralization of various tissues. The body extracts the minerals it needs from the skin, hair, nails, bones, joints, and teeth, which then tend to become less resistant to decay. When blood pH falls, the calcium phosphate stored in tissues is released to help neutralize acidity. During chronic acidosis the alkaline reserves are pillaged, resulting in demineralization causing many problems: tooth decay, spontaneous bone fractures, joint and bone pain, broken hair and nails. Acidification of the body is also experienced in the mouth in the form of a drop in salivary pH. When the saliva becomes acidic, dental erosion and tooth decay can occur (Lussi et al. 2004).

12The measurement of pH is considered a valid method to assess the erosive potential of a food or beverage (El-Khatib et al. 2001). PRAL (potential renal acid load) is also used to classify different types of food. The pH corresponds to the hydrogen potential (i.e. acidity) of a food when it comes into contact with the teeth, whereas the PRAL provides information on the acidifying power of a food once it has been digested and metabolized. Foods are thus classed as acidic or basic, depending on the nature of their residue after digestion. The higher the PRAL, the greater the acidifying potential of the food. In general, whether we take into account the pH value measured for a food or its PRAL, the acidifying foods most damaging to the teeth are sweet products (containing simple sugars) such as cakes, ice cream or other sweet desserts, animal products (red meat), alcoholic beverages, soft drinks (cordials, fruit juices, energy drinks, sports drinks, etc.) and sodas (containing sugar and acidic compounds). Carbohydrate-rich foods (sweet and acidic) are certainly the most deleterious to oral health, and greatly promote the development of cavities. However, among carbohydrate-rich foods, starchy foods, such as rice, bread, potatoes and pasta, represent a much less significant threat than simple sugars (i.e. foods that taste sweet).

13In contrast, some low-acid, or even alkalizing, foods can help protect against tooth decay and dental erosion. These foods include cow’s milk (containing ~ 5% sugar, but of a type which is not very cariogenic) and dairy products in general (cheese, yoghurt, and cottage cheese). The protective effects of dairy products mainly stem from the presence of lactose (which is much less cariogenic than other types of sugar) and protective elements such as calcium, phosphorus and casein (Nunn, 2001). For example, cheese helps protect against dental cavities as it contains few carbohydrates, but is high in calcium and phosphorus. In addition, its strong flavour causes significant secretion of saliva which helps to neutralize acid attacks and quickly removes food residues from the mouth.

14Finally, to help limit the harmful effects of sugar on the teeth, sugar-free sweeteners may be used. Sweeteners, also known as “sugar substitutes” or “fake sugars” are food additives which have a sweet taste. Sweeteners are increasingly used in food products to replace sucrose (common table sugar), because they provide fewer calories, and are non-cariogenic. Sweeteners include, for example, aspartame (artificial), xylitol (from birch bark) or rebaudioside A, better known as Stevia (the name of the plant from which it is extracted). The advantage of sweeteners is that they are not, or are rarely, used by oral bacteria, thus they do not cause the formation of acid and cavities. Chewing sugar-free xylitolcontaining gums after meals when it is not possible to brush the teeth can effectively protect teeth (Ribelles et al. 2010; Hanson and Campbell, 2011; Mickenautsch and Yengopal, 2012).

4.1 Sodas and other sweet drinks

15Almost half of the drinks consumed in Western countries are sodas (Tahmassebi et al. 2006). Excessive consumption of acidic and sugary drinks increases the risk of acid demineralization leading to dental erosion and the development of cavities. This risk is increased in children whose teeth are not yet fully mature, in athletes, and in those practising poor dental hygiene. Numerous studies have confirmed the acidifying nature of sodas and other sugary drinks, for both “industrial” (with added sugar) drinks and so-called “natural” (no added sugar) drinks (Milosevic, 1997; Marshall and al. 2003; Cairns et al. 2002; Hooper et al. 2005; Wongkantee et al. 2006). Only maltodextrins (glucose polymers) have been shown to be a little less acidifying than other forms of sugar (glucose, fructose) (El-Khatib et al. 2001; Marshall et al. 2003; Al-Dlaigan et al. 2001). In addition to their high sugar content, soft drinks contain various forms of acids, which give the beverage a low pH. Some acids are inevitable in drinks, due to the presence of natural elements such as fruits (orange, lemon), citric acid from oranges, tartaric acid from grapes, or malic acid or from apples (Tahmassebi et al. 2006). Even fruit teas, made from dehydrated fruits, have an acidifying power (Phelan and Rees, 2003). However, other acids are artificially added during manufacturing to improve the organoleptic characteristics (taste, appearance) of beverages. These acids include, for example, carbonic acid generated by incorporating carbon dioxide into the beverage. However, it should be noted that even when the soda bottle has been open for a long time and no longer contains any bubbles of gas, the pH remains low. This indicates that other acids are present to improve taste, including phosphoric acid in cola beverages (Tahmassebi et al. 2006). Finally, preservatives added to soft drinks, such as vitamin C (ascorbic acid), may also contribute to their acidity (Grobler et al. 1985).

16The “light” form of sodas have become very popular in recent years. These drinks contain artificial sweeteners to reduce their calorie content and avoid inducing weight gain. However, these sodas nevertheless contain acidic substances which may cause enamel demineralization and represent a significant erosive potential. Moreover, light drinks do not trigger the satiety reflex, thus drinking them may lead to food intake late at night or overconsumption of this type of drink.

17Some steps can be taken to limit the negative impact of soft drinks on oral health. Several studies have demonstrated a beneficial effect of adding calcium and phosphate salts to counteract the effects of the acidity of soft drinks (for review, see Tahmassebi et al. 2006). However, these compounds altered the taste of the beverage. Similarly, adding fluoride to drinks could reduce the prevalence of cavities by 30%. Finally, other strategies exist to reduce the negative effect of sodas or sugary drinks, such as choosing smaller units (small cans, 150 to 250 ml), using a straw to prevent excessive contact with the teeth leading to tooth erosion, selecting the least sugary sodas, diluting drinks, and avoiding prolonged sipping. Other recommendations to limit the negative effect of sodas are presented in Table 2.

Table 2: Practical recommendations to help reduce the deleterious effects of drinking sodas (adapted from Tahmassebi et al. 2006).

Recommendations to reduce the negative impact of consuming sodas

Dilute the drink by adding still water

Consume the drink at mealtime

Drink rapidly

Use a straw as often as possible

Cold sodas are less erosive

Do not store sodas in bottles or containers to limit their ingestion

Do not sip sodas, or allow them to remain in contact with the surface of teeth for a long period

Avoid brushing teeth immediately after consuming acidic drinks

End meals with a food which helps to neutralize acid attacks (e.g. cheese or milk)

Favour drinks with a low erosive power (e.g. milk drinks) rather than acidic sodas

4.2 Sports drinks

18“Sports” or “energy” drinks are frequently used by athletes during training. These drinks provide energy (generally 6 to 10% carbohydrates in various forms: glucose, glucose polymers, fructose) and electrolytes to compensate for losses due to sweating. In a recent study, Bryant et al. (2011) studied the consumption of energy drinks in 31 triathletes (18 to 36 years of age) from New Zealand. The results indicate that 84% of triathletes regularly consumed a sports drink during training, and 16% consumed this type of drink six or more times per week, 16% even consumed these drinks on non-training days, and 48% consumed large quantities of sports drinks contained in bottles. The highest energy consumption was noted during the cycling leg of an event (58%), with intake divided into five to seven portions during the session.

19Most sports beverages have a cariogenic and erosive effect on the tooth enamel because of their acidity (low pH) and the high level of fermentable carbohydrates they contain (Table 3). Consuming sports drinks during training, associated with decreased salivary secretion (related to dehydration), creates a combination of conditions favouring the development of cavities and dental erosion. Indeed, the dry mouth frequently encountered during exercise can increase the erosive potential of sports drinks. In this context, some sports (which involve a long duration of breathing through the mouth) or situations (hot climate, dry conditions) appear to promote the development of oral hygiene problems.

Table 3: Acidity levels of several commercially available sports drinks (adapted from Milosevic, 1997), compared to other commonly consumed drinks.

Energy-rich “sports” drinks

pH

Other drinks

pH

Carbo lode

3.74

Coffee

5.00

Gatorade

3.05

Tea

5.50

High5

2.52

Cola

2.70

Isostar

2.38

Still water (Hépar, Volvic)

7.00

Lucozade Sport (Lemon, Orange)

3.05

Sparkling water (Badoit, Quézac)

6.00

Maxim

4.46

Orange juice

3.75

PSP22

2.60

Cow’s milk

6.50

20Recent studies have attempted to provide recommendations to help prevent, or solutions to reduce the negative impact of sports drinks on oral health. Adding calcium associated with maltodextrins (glucose polymers) to drinks as a substitute for simple sugars could reduce the erosion of tooth enamel (Hooper et al. 2004). Min et al. (2011) also showed a significant reduction in erosion of bovine enamel samples when 0.25% hydroxyapatite nanoparticles (rich in calcium and phosphate compound) was added to a well-known sports drinks.

21Finally, some practical recommendations can be made to help limit the deleterious effects of sports drinks on the teeth, such as diluting drinks well, reducing their consumption (saving them for intense efforts), choosing maltodextrinbased beverages, systematically rinsing the mouth with plain water (preferably rich in calcium and phosphate) after each sip of sports drink.

5. Recommendations to preserve oral hygiene in athletes

22When involved in an intense sporting activity, it is impossible to completely avoid exposure to risk factors associated with poor oral health. Indeed, athletes need to frequently consume significant amounts of carbohydrate-rich foods and beverages to maintain the energy levels needed for their activity. However, athletes should keep in mind and implement, on a daily basis, certain recommendations to maintain their oral health.

23■ Regularly consume alkaline foods (fibre-rich foods, dairy products, eggs, nuts and seeds, water, etc.).

24■ Take time to chew food to increase the flow of saliva to the mouth.

25■ Do not sip sweet or soft drinks (sodas, fruit juices, sports drinks, etc.); any contact between the teeth and sugary foods and/or acid should be as short-lived as possible (a straw can be used).

26■ Systematically rinse the mouth with plain water immediately after ingesting sweet and/or acidic foods or drinks.

27■ Brush teeth after every meal (two to three times per day).

28■ Chew sugar-free gum (containing xylitol) after meals when brushing is not possible.

29■ Have regular dental check-ups to verify the condition of the teeth.

Bibliographie

6. Bibliographic references

Al-Dlaigan A, Shaw L, Smith A. 2001. “Dental erosion in a group of British 14 year-old school children. Part II: influence of dietary intake.” In British Dental Journal. 190:258-61.

Bryant S, McLaughlin K, Morgaine K, Drummond B. 2011. “Elite Athletes and Oral Health.” In International Journal of Sports Medicine. 32:720-724.

Cairns AM, Watson M, Creanor SL, Foye RH. 2002. “The pH and titratable acidity of a range of diluting drinks and their potential effect on dental erosion.” In Journal of Dentistry. 30:313-317.

El-Khatib TR, Duggal MS, Toumba KJ. 2001. “An evaluation of the acidogenic potential of maltodextrins in vivo.” In Journal of Dentistry. 29:409-14.

Frese C, Frese F, Kuhlmann S, Saure D, Reljic D, Staehle HJ, Wolff D. 2014. “Effect of endurance training on dental erosion, caries, and saliva.” In Scand J Med Sci Sports. In press.

Grobler SR, Jenkins GN, Kotze D. 1985. “The effects of the composition and method of drinking of soft drinks on plaque pH.” In British Dental Journal. 158:293-7.

Hanson J, Campbell L. 2011. “Xylitol and caries prevention.” In Journal of Massachusetts Dental Society. 60(2):18-21.

Hooper S, West NX, Sharifa N, Smith S, North M, De’Ath J, Parker DM, Roedig-Penman A, Addy A. 2005. “A comparison of enamel erosion by a new sports drink compared to two proprietary products: a controlled, crossover study in situ”. In Journal of Dentistry. 32:541-545.

Hooper SM, Hughes JA, Newcombe RG, Addy M, West NX. 2005. “A methodology for testing the erosive potential of sports drinks.” In Journal of Dentistry. 33:343-348.

Horswill CA, Stofan JR, Horn MK, Eddy DE, Murray R. 2006. “Effect of exercise and fluid consumption on salivary flow and pH.” In International Journal of Sports Medicine. 27(6):500-4.

Jarvinen V. Rytomaa I Heinonen OP. 1991. “Risk factors in dental erosion.” In Journal of Dental Research. 70:942-7.

Lussi A, Jaeggi T, Zero D. 2004. “The Role of Diet in the Aetiology of Dental Erosion.” In Caries Research. 38:34-44.

Marshall TA, Levy SM, Broffitt B, Warren J, Eichenberger-Gilmore JM, Burns TL, Stumbo PJ. 2003. “Dental caries and beverages consumption in young children.” In Pediatrics. 112:184-91.

Mickenautsch S, Yengopal V. 2012. “Anticariogenic effect of xylitol versus fluoride–a quantitative systematic review of clinical trials.” In International Dental Journal. 62:6-20.

Milosevic A. 1997. “Sports drinks hazard to teeth.” In British Journal of Sports Medicine. 31:28-30.

Min JH, Kwon HK, Kim BI. 2011. “The addition of nano-sized hydroxyapatite to a sports drink to inhibit dental erosion–In vitro study using bovine enamel.” In Journal of Dentistry. 39:629-635.

Nunn J. 2001. “Nutrition and Dietary Challenges in Oral Health.” In Nutrition. 17:426-427.

Phelan J, Rees JS. 2003. “The erosive potential of some herbal teas.” In Journal of Dentistry. 31:241-6.

Piccininni PM, Fasel R. 2005. “Sports dentistry and the Olympic Games.” In Oral Health. 95:52-71.

Ribelles Llop M, Guinot Jimeno F, Mayné Acién R, Bellet Dalmau LJ. 2010. “Effects of xylitol chewing gum on salivary flow rate, pH, buffering capacity and presence of Streptococcus mutans in saliva.” In European Journal of Paediatric Dentistry. 11(1):9-14.

Sirimaharaj V, Brearley Messer L, Morgan MV. 2002. “Acidic diet and dental erosion among athletes.” In Australian Dental Journal. 4:2 28-236.

Slater G, Broad EM, Haukka J, Modulon S, Hopkins WG. 2003. “Eating patterns and meal frequency of elite Australian athletes.” In International Journal of Sports Nutrition. 13:521-538.

Wongkhantee S, Patanapiradej V, Maneenut C, Tantbirojnb D. 2006. “Effect of acidic food and drinks on surface hardness of enamel, dentine, and tooth-coloured filling materials.” In Journal of Dentistry. 34:214-220.

Table des illustrations

Titre Figure 1: Food habits of 256 elite athletes participating in 20 different Olympic sports (source INSEP).
URL http://books.openedition.org/insep/docannexe/image/1829/img-1.jpg
Fichier image/jpeg, 456k
URL http://books.openedition.org/insep/docannexe/image/1829/img-2.jpg
Fichier image/jpeg, 88k

© INSEP-Éditions, 2015

Conditions d’utilisation : http://www.openedition.org/6540

Rechercher dans OpenEdition Search

Vous allez être redirigé vers OpenEdition Search