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Sugars and Health
Dental Health
Oral health is integral to overall health and well-being. Tooth decay
or dental caries, an infectious disease, is a common cause of poor dental
health, especially in children. Although sugars have been associated with
dental caries, all types of fermentable carbohydrates can promote cavity
formation. What's more, proper dental hygiene is more effective in preventing
tooth decay than changes to nutrition habits.
"In short, dental health problems do not require any dietary recommendations,
in addition to, or other than, those required for maintenance of general
health" -WHO/FAO joint report, "Carbohydrates in Human Nutrition."
Causes of Tooth Decay
The etiology of tooth decay is complex and multi-factorial. Nutritional
status, oral hygiene, fluoride exposure, dietary habits, heredity, socioeconomic
status, general health and use of medications can all play a role.
However, a direct relationship between diet and dental caries is accepted.
All fermentable carbohydrates, including sugars and starches, contribute
to dental caries formation. Starches are broken down to sugars in the
mouth by salivary amylase. Thick plaque bacteria, present on tooth surfaces,
metabolize sugars to form organic acids. These acids lower the pH of plaque.
Although tooth enamel is generally hard and wear resistant, it is slightly
soluble in acids. Thus, the presence of these organic acids causes the
tooth enamel to begin to dissolve or demineralize. The longer the pH remains
low or acidic, the more likely enamel erosion will occur.
Teeth surfaces are repeatedly attacked by acids and then repaired by
the action of saliva. Saliva contains many cario-protective components
that help defend teeth against erosion including calcium and phosphate,
fluoride, buffers and anti-microbial agents. It therefore neutralizes
acids, dilutes sugars in food as well as assists in repairing losses to
teeth surfaces through remineralization. Unfortunately, this 'normal'
remineralization process is very slow. Thus, if demineralization of enamel
exceeds the remineralization repair process, caries formation will occur.
The frequency and severity of attacks on teeth surfaces can be influenced
by a number of factors. For example, "grazing" on food and drink for long
periods of time increases exposure of bacteria to fermentable carbohydrate
and therefore increases the exposure of teeth to acids. Similarly, foods
that stick to teeth will increase exposure of teeth to acids since they
remain in the mouth longer. Other factors include the amount and virulence
of bacteria present, the abundance and make-up of saliva, the inherent
resistance of teeth to acid and the type of food ingested. Back to top »
Caries Prevention
Oral Hygiene and Fluoride Use
Though sugars and other fermentable carbohydrates contribute to tooth
decay, they are not the most important factor in the etiology of the disease.
Several studies have shown that in countries where proper oral hygiene
is followed and adequate fluoride exposure exists, caries prevalence has
decreased despite increases in sugar consumption. Furthermore, if carbohydrate-containing
foods are eaten frequently but oral hygiene is maintained and fluoride
used, caries are not likely to form. Therefore, prevention should focus
on proper oral hygiene and adequate fluoride use, rather than fermentable
carbohydrates alone.
The Canadian Dental Association encourages Canadians to brush after
meals, floss regularly and visit a dentist every six months for a check-up.
When brushing is not possible, rinsing with water can help limit the effect
of cariogenic bacteria on teeth.
Fluoride helps protect teeth in three ways: it inhibits plaque,
it defends tooth enamel from demineralization, and it speeds-up
and improves remineralization. Thus, Health
Canada endorses the fluoridation of drinking water at the optimum
range of 0.8 to 1.0 mg/L, as a safe and effective way to reduce
tooth decay. In fact, addition of fluoride to municipal water supplies
has been shown to reduce the rate of dental caries in children by
35-50%, and by 30 % in adults. However, the ingestion of too much
fluoride can result in fluorosis --a cosmetic condition that appears
as white specks on teeth -- which occurs predominantly in younger
children. For recommendations for the use of fluoride in infants
and children, visit the Canadian
Pediatric Society.
Sugars and Other Carbohydrates
Frequency
Although proper oral hygiene and fluoride use are the primary tools for
preventing tooth decay, dietary changes can help. The goal should be to
limit the frequency and severity of acid attacks on teeth. It is not the
total amount of sugars and starches ingested that matters most in caries
formation but the frequency of carbohydrate consumption. Sugars and starches
can be consumed without deleterious effects when they are ingested as
part of main meals rather than eaten continuously throughout the day.
Thus, spacing meals at least two hours apart allows dental plaque pH time
to return to neutral.
Source
All fermentable carbohydrates, whether from the sugar bowl, fruits,
vegetables, milk or grain products, break down to sugars in the mouth
and can lead to tooth decay. In fact, an expert report by the Food and
Agricultural Organization (FAO)/World Health Organization (WHO) states
that it would be irrational to advise limiting consumption of sucrose
as a means to prevent tooth decay if consumption of milk and fruit were
not also limited.
Though the mechanism is unclear, chewing on high-protein foods in combination
with fermentable carbohydrates may protect against dental caries. Also,
the chewing action as well as the combination of raw and cooked foods
in the mouth can increase salivary production, which minimizes the effect
of fermentable carbohydrates on teeth.
Form
Carbohydrate-containing foods that are sticky and that adhere to teeth
are potentially more cavity-causing because they are difficult to brush
away and may remain in the mouth for longer periods of time. Examples
of foods that stick to the teeth include caramels and dried fruit, while
foods such as bread, potato chips and crackers are more likely to stick
between the teeth.
Other Dietary Recommendations
Infants: Tooth decay can develop in infants who are given a bedtime-bottle
filled with fermentable-carbohydrate containing fluid such as fruit juice
or milk. This condition, commonly called early childhood tooth decay,
can also result from mothers allowing infants to nurse at the breast while
sleeping. It can lead to loss of baby teeth, crowded or crooked permanent
teeth and speech difficulties. To prevent this, a baby should never be
put to bed with a bottle. However, if the baby is accustomed to this practice,
the bottle's contents should be replaced with water.
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References
Carbohydrates in Human Nutrition, FAO/WHO, 1998
Carbohydrates and Dental Health, Carbohydrate News, Canadian Sugar Institute, 2002
Caries Preventive Strategies, International Life Sciences Institute, 1995
Diet - Guidelines for sugar consumption in Europe: is a quantitative approach justified? European Journal of Clinical Nutrition, 53:503-513, 1999
Diet and dental caries: cariogenicity may depend more on oral hygiene using fluorides than on diet or type of carbohydrates. Van Loveren, C. European Journal of Paediatric Dentistry, 1:55-62, 2000
Healthy Living, Children, Early Childhood Tooth Decay, Health Canada
Fluorides and Human Health, Health Canada
Flouride - The Use of Fluoride in Infants and Children, Canadian Paediatric Society, 2009
Carbohydrates: Nutritional and Health Aspects, International Life Sciences Institute, 2003
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