Draft Australian Dietary Guidelines (PDF, 3MB) - Eat For Health

2.6.2.3 Other conditionsDental caries and bone strength: The evidence suggests that consumption of soft drinks isassociated with increased risk of dental caries in children (Grade C, Section 15.14 in EvidenceReport [14]) and increased risk of reduced bone strength (Grade C, Section 15.3 in EvidenceReport [14]) [458, 476-479] (see Chapter 4).Oral health is also affected by fluids. Fluoride added to tap water provides protection againstdental caries [480]. The mildly alkaline nature of saliva is the key protective element againstcorrosion of teeth by acids. If dehydration occurs after exercise or from particular medications, anadequate intake of water is essential for maximising the protective effect of saliva on oral health[481]. Dehydration also causes loss of salivary protection against attrition, erosion and abrasion.The Australian Dental Association reports that 68% of Australian school students have at leastone tooth eroded [482]. Erosion is related to the acidity of drinks, whether sweetened with sugaror artificial sweeteners, as well as the bacterial fermentation that can occur with consumption ofsugar (see Section 4.3). The relationship between the acidity of sweetened drinks and dentalerosion is also supported by the American Academy of Pediatrics Committee on School Health[483].Blood pressure: Recent evidence is inconclusive in regards to an association between coffeeconsumption and systolic blood pressure (Section 15.14 in Evidence Report [14]).2.6.3 How drinking water may improve health outcomesFor oral health, water has an advantage over many commercially available drinks, including sugarsweetenedor low-kilojoule soft drinks, ‘sports’ and ‘energy’ drinks. As well as the potentiallyadverse direct effects of sugar (see Section 3.3) the carbonation process creates an acidicenvironment that contributes to the erosion of tooth enamel [481].The mechanism by which coffee consumption may protect against type 2 diabetes is not clear. Ithas been reported that insulin resistance is increased in peripheral tissues after exposure tocaffeine [484] and conversely, the effect of caffeine on thermoregulation has been suggested as amechanism by which glucose homeostasis is improved [485]. Other components of coffee,possibly magnesium, may also assist by benefiting insulin sensitivity and reducing risk of type 2diabetes [486]. Tea contains polyphenols known as catechins which have been reported to reducehypertension, atherosclerosis and thrombogenesis [487]. Polyphenols also play a part in nitricoxide production from the vascular endothelium, enhancing endothelial health and reducing therisk of cardiovascular diseases and stroke [487].DRAFT Australian Dietary Guidelines- December 2011 71