August 16, 2006

Since the history of mankind, the sweet taste has been much sought after, both for basic survival and for enjoyment. Indeed, we have been pre-programmed to like the sweet taste since infancy when the first sugar we tasted was in the milk (lactose) we drank. A moderate consumption of sweet foods is fine, providing consumption is not too frequent throughout the day, and a routine of teeth cleaning at least twice a day is adhered to. Alternatively, low calorie sweeteners can provide the desired sweetness without any risk of plaque build-up.

Diet plays an important role in oral health. Nutrition influences the craniofacial development and dental diseases including dental caries (decayed teeth), enamel defects, dental erosion and periodontal disease. In some cases, tooth loss also could impair speech as teeth do play an essential role in communication. Subsequently, dental healthcare costs can also prove to be a burden for many governments and individuals alike.

The following table indicates the trends in levels of dental caries in 12 year olds in selected countries in the Western and Asian regions in selected years.

The data on the level of dental caries in the development of teeth of 12 year olds show two distinct trends. Firstly, a decline in the dental caries in the developed countries and secondly, an increase in the prevalence of the disease in some developing countries that have increased their consumption of refined carbohydrates (cane sugar, sweets, sticky bakery goods for example) and do not benefit from adequate amounts of fluoride in foods, water and/or toothpastes.

* DMFT: Decayed, missing, filled permanent teeth
Source: CAPP - the WHO Oral Health Country/Area Profile Programme
 

DMFT describes the amount or the prevalence of dental caries in an individual. DMFT is a numerical measure of dental health in a given population and is obtained by calculating the number of Decayed (D), Missing (M), Filled (F), Teeth (T). It provides a useful indicator of the level of tooth decay in the country.

Dental Caries – How Do They Develop?
Dental caries result in tooth decay and cavities. It is the most common disorder affecting the teeth. The main factors determining the risk of dental caries are oral hygiene; exposure to fluoride and frequency of consumption of foods which promote the development of plaque, which can in turn result in dental caries. Dental caries occur when acids produced by bacteria dissolve the teeth. Bacteria set off a sticky film, known as dental plaque, on the surface of the tooth. The bacteria use fermentable carbohydrates such as sugars or starches in food and drinks consumed, to form acids. The acids formed dissolve minerals such as calcium and phosphate from the tooth. This is called demineralization.

However, our saliva is super-saturated with calcium and phosphate which promotes remineralization. Saliva also clears food debris from the mouth and neutralizes the acids produced from the bacteria. At the same time, saliva acts as a reservoir for fluorides from toothpaste or from fluoridated water. Fluoride helps control dental caries by remineralising the teeth and inhibiting bacterial acid production. Tooth decay only happens when the process of demineralization exceeds remineralization over a period of time.

This explains why the frequency of eating carbohydrates, both sugars and starches, influence the development of dental caries. If food or drinks are taken too frequently, our saliva does not have sufficient time to re-mineralize the tooth enamel, thus allowing the decay process to begin.

Sugar Substitutes – What Are They and How Do They Work?
Sugar substitutes such as aspartame, saccharin and xylitol have been widely available for several years now. These are sweeteners that not only give us the sweet taste that we seek and enjoy, but also allow us to minimize any negative repercussions to our oral and physical health. For example, sweeteners do not cause tooth decay because they do not contain fermentable carbohydrates which can be turned into harmful acids by oral bacteria. In fact, sweeteners are also used to improve the flavour of products for dental and oral hygiene, which contain fluoride, thus contributing to dental carries
prevention. For example, research has shown that xylitol can exert positive effects on the dental health of young children via the maternal consumption of xylitol-sweetened chewing gum. The children of the mothers who consumed the chewing gum exhibited 70% less tooth decay than the children of the mothers who did not consume xylitol (SÖderling and Isokangas, 2000).

Sugar substitutes can be broadly divided into two categories – intense sweeteners and bulk sweeteners. Intense sweeteners are generally many times sweeter than table sugar (sucrose) and hence are only used in very small amounts to provide the same sweetness as table sugar, with few or no accompanying calories. Examples of intense sweeteners include: aspartame, acesulfame K, saccharin and cyclamate.

Bulk sweeteners contain significant amounts of carbohydrates and calories compared to intense sweeteners although most bulk sweeteners provide only half the calories of table sugar. Bulk sweeteners are mainly composed of sugar alcohols (polyols). The hydrogenated nature of the sugar alcohols also causes them to be less prone to fermentation. It is for this reason that sugar alcohols have a reduced calorific value and can be used in “tooth friendly” products such as chewing gum. In fact xylitol, a polyol widely used in chewing gum is more effective in preventing tooth decay than any other polyols. Sugar alcohols are also used in many sugar-free candies, cookies and other food products. Examples of bulk sweeteners include: sorbitol, lactitol, maltitol and xylitol.

Although there has been controversy regarding the health effects of intense sweeteners, they are amongst the most extensively researched food substances in the world. The general conclusion is that approved sugar substitutes when used in normal consumption, present no significant or measurable risk. For example in April 2006, US FDA and then in May 2006, the European Food Safety Authority reconfirmed that aspartame is safe for human consumption and that there are no problems for its continued use as an additive in ready prepared foods and as a table top sweetener.

Although there has been controversy regarding the use of sweeteners due to allegations of adverse health effects, they are amongst the most extensively researched food substances in the world. The general conclusion is that approved sugar substitutes when used in normal consumption, present no significant or measurable risk. In April 2006, US FDA and then in May 2006, the European Food Safety Authority reconfirmed that aspartame is safe for human consumption and that there are no problems for its continued use as an additive in ready prepared foods and as a table top sweetener.

Protecting Oral Health – Some Simple Steps
While sweeteners can provide the sweet taste with less calories and lower risk of dental caries, there are additional simple steps that we can all take to promote good oral health.

1. Start dental care early for children
A baby’s teeth and gums can be wiped using a soft cloth after each feed. This will ensure the removal of any residual substances that could lead to tooth decay. At the same time, the action promotes gum health and gets the baby used to the sensation of having its mouth cleaned.

2. Encourage regular brushing and flossing of teeth
Establishing the habit of tooth brushing at least twice daily with fluoridated toothpaste and using dental floss or tooth picks will assist in the removal of dental plaque and thereby reduce the chance for dental caries to develop. If possible, cleaning the teeth after each meal is ideal. Chewing tooth friendly gum after a meal is another alternative as it helps increase saliva flow and clears food debris from the mouth. However, most importantly teeth should be cleaned before going to sleep at night and every night.

3. Visit the dentist every 6 months
Getting a thorough dental check up every 6 months allows the dentist to monitor and evaluate the condition of your teeth and allow for early detection and treatment of any oral health problems should it be required.

4. Do not eat food or sip drinks continuously
Allowing sufficient time between meals enables saliva to neutralize acids and remineralize teeth. Avoiding continuous eating and drinking also reduces the chances of obesity and other health problems from over eating.

5. Good nutrition
The caries prevention action of cheese has been reported in some studies. Cow’s milk contains calcium, phosphorus and casein, all of which inhibit caries. Foods that stimulate salivary flow, including wholegrain foods, peanuts, as well as tooth friendly chewing gum also can protect against tooth decay.

Good oral health is in the hands of each of us. While governments and health authorities can play a role in encouraging good oral health practices and also through the fluoridation of water supply, the responsibility of preventing

Further Reading:

1. SÖderling, E., et al (2000): Journal of Dental Research 79 (3): 882 – 887
2. Isokangas, P., et al (2000): Journal of Dental Research 79 (3): 1885 – 1889
3. Recommendations for preventing dental diseases, 105 – 119, Diet, Nutrition and The Prevention of Chronic Diseases, WHO Technical Report Series 916.