Since the sugar content is quite high in sports drinks, when consumed in excess amounts it can lead to obesity, diabetes, and cardiovascular disease (Raizel et al. 2019). However, these conditions tend to be seen in the non-athletic population who over-consume sports drinks while living a sedentary lifestyle (Raizel et al. 2019).
Adverse effects of sports drinks can become more pronounced if mixed with alcohol and for that reason, it is important not to consume both too close together (Raizel et al. 2019). Regarding children, research for sports drinks optimizing athletic performance in youth is sparse (Pound & Blair, 2017). Sweat rates for children tend to differ when compared with adults thus it is rare for children to exercise in a dehydrated state (Pound & Blair, 2017).
Although sports drinks may be warranted for youth athletes performing a vigorous activity, it appears their use is unnecessary for the average child partaking in physical activity or daily play-based physical activity (Pound & Blair, 2017). The main adverse effect associated with sports drinks appears to be their effect on dental health.
Tooth erosion is the dissolution of tooth mineral caused by external sources as opposed to tooth decay caused by internal sources such as plaque and bacteria (Kaye, 2017). Erosion starts with an initial softening of the enamel surface and eventually leading to permanent loss of tooth volume and thinning of the tooth surface (Arnauteanu et. al. 2015). Erosion will occur if the solution around the enamel has a pH lower than 5.5 (Kaye, 2017). Most sports drinks have a pH normally between 2.5 to 4.5 (Jena et al. 2019).
One study assessed 795 participants and found concerning results. Tooth erosion was present in 26% of people who were considered “low consumer” with a daily sports drink intake of less than 250ml and a staggering 77% of people who consumed greater than 750ml per day were affected by tooth erosion (Sovik et al. 2015). This is a grave concern, considering that is not out of the ordinary for athletes to consume higher than 750ml of sports drinks per day, especially during intense training sessions or events (Sovik et al. 2015).
In the 2012 London Olympics, 30% of medical visits to athletes were dental consultations and were only second to musculoskeletal problems (Vanhegan et al. 2013). Interestingly other factors aside from sports drinks such as race pace, training frequency, and gastroesophageal reflux contribute to tooth erosion too in endurance runners (Antunes et al. 2017). During intense and long-duration endurance activities athletes can experience changes in saliva flow and pH, also leading to tooth erosion (Antunes et al. 2017).
A serious problem for athletes who drink sports drinks is the hyposalivation that occurs during exercise (Kaye, 2017). As mentioned earlier, athletes in prolonged events or hot conditions lose a lot of fluid through perspiration. Increased perspiration rate decreases saliva and causes dryness in the mouth, also known as xerostomia (Kaye, 2017).
Saliva aids in neutralising the acid contained in foods and drinks and reduces harmful effects by quickly clearing food and drink from the mouth (Kaye, 2017). Saliva can also provide calcium and phosphorus to help protect tooth enamel (Kaye, 2017). However, with less saliva in the mouth, the athlete loses its tooth protection mechanism, and they are going to tend to drink more of a sports drink to counteract xerostomia leading to a potent remedy for tooth erosion.
Sports drink companies are looking to counteract this, and sometimes calcium can be added as an ingredient, aiming to increase the pH of the drink thus reducing the erosion potential of the drink (Milosevic, 2004). Adding calcium and phosphate to isotonic drinks may keep saliva at a normal pH, inhibiting tooth demineralisation (Antunes et al. 2017).
However, current ingredients already in sports drinks cause the opposite effect such as citric acid which is added to sports drinks for flavour. When citric acid is in the mouth it binds to calcium and phosphorus reducing teeth defence and increasing the erosion capabilities of a sports drink (Kaye, 2017). Perhaps, focusing on potentially reduces or lessening the effects of current ingredients in some sports drinks rather than added more ingredients to counteract the harmful effects may be a better solution.