Risks to oral health

Diet & nutrition

Today the world faces two kinds of malnutrition, one associated with hunger or nutritional deficiency and the other with dietary excess. Urbanization and economic development result in rapid changes in diets and lifestyles. Market globalization has a significant and worldwide impact on dietary excess leading to chronic diseases such as obesity, diabetes, cardiovascular diseases, cancer, osteoporosis and oral diseases. Diet and nutrition affects oral health in many ways. Nutrition, for example, influences cranio-facial development, oral cancer and oral infectious diseases. Dental diseases related to diet include dental caries, developmental defects of enamel, dental erosion and periodontal disease.

The nutrition transition is a relevant example on how common risks influence public health, including oral health. The public health community involved with oral health should gain an understanding of the health effects of these complex developments in order to prevent or control oral diseases.

The major challenges are:

• To implement nutritional counselling, covering not only the general health aspects of having good nutritional behaviour but also emphasizing the aspects directly linked with oral health. The post-eruptive effect of diet in terms of sugar consumption is one of the aetiologic factors for dental caries.
• To facilitate awareness-raising activities to promote breastfeeding. Among other important health benefits, breastmilk prevents the occurrence of rampant early childhood caries. Early childhood caries is caused by frequent and prolonged exposure of the teeth to sugar and is often the result of a child going to bed with a bottle of a sweetened drink or drinking at will from a bottle during the day.
• To advise on decreasing the consumption of sugary soft drinks which is a major risk factor in dental caries. Also, dental erosion seems to be a growing problem and in some countries an increase in erosion of teeth is associated with an increase in consumption of beverages containing acids.
• To promote a rational and healthy diet among people living in deprived and more remote areas of low- and middle-income countries by encouraging the use of natural products with good nutritional values instead of refined, industrialized food.
• To advocate a healthy diet which can also help prevent oral cancer. Fresh yellow-green fruits and vegetables have been identified as beneficial as are vitamin A, C and E supplements. Excessive consumption of alcohol is an important risk factor in the aetiology of oral precancerous and neoplastic lesions and such habits should be modified.

WHO/FAO recently published a Global Strategy on Diet, Physical Activity and Health, based on the analysis of the best available evidence on relationship between diet and physical activity patterns and the major nutrition-related chronic diseases. The strategy aims at reducing the growing burden of noncommunicable diseases in both developing and developed countries. Recommendations are made to facilitate formulate regional strategies and national guidelines to reduce the burden of nutrition-related chronic diseases. Among other recommendations, free (added) sugars should remain below 10% of energy intake and the consumption of foods/drinks containing free sugars should be limited to a maximum of four times per day.

In order to minimize the occurrence of dental erosion which particularly seems related to consumption of acidic beverages, the amount and frequency of intake of soft drinks and juices should be limited. Elimination of undernutrition prevents enamel hypoplasia and other potential effects of undernutrition on oral health (e.g. salivary gland atrophy, periodontal disease, oral infectious disease).

The WHO Oral Health Programme contributes to the implementation of the Global Strategy on Diet, Physical Activity and Health. The intervention activities at national level are multiple but the following areas should be addressed:

• Oral health services
• Schools: Curricula, school lunches and school health
• Food industry, supermarkets
• Restaurants, catering, etc.
• NGO's (health related and others)
• Legislation and policy
• Media
• Monitoring, surveillance and research

The Ministry of Health should ensure that the mechanisms for intersectorial collaboration are carefully considered. Strategies include taxation and pricing, food labelling, school lunch policies and support to nutrition programmes.

Fluorides

Research has shown that fluoride is most effective in dental caries prevention when a low level of fluoride is constantly maintained in the oral cavity. The goal of community-based public health programmes, therefore, should be to implement the most appropriate means of maintaining a constant low level of fluoride in as many mouths as possible. Fluorides can be obtained from fluoridated drinking-water, salt, milk, mouthrinse or toothpaste as well as professionally applied fluorides, or from combinations of fluoridated toothpaste with either of the other two fluoride sources. There is clear evidence that long-term exposure to an optimal level of fluoride results in diminishing levels of caries in both child and adult populations.

However, there are some undesirable side-effects with excessive fluoride intake. Experience has shown that it may not be possible to achieve effective fluoride-based caries prevention without some degree of dental fluorosis, regardless of which methods are chosen to maintain a low level of fluoride in the mouth. The public health administrators must seek to maximize caries reduction while minimizing dental fluorosis.

Fluoride is being widely used on a global scale, with much benefit. More than 500 million people worldwide use fluoridated toothpaste, about 210 million people benefit from fluoridated water, salt fluoridation is used for some 40 million people while other forms of fluoride applications (clinical topical fluorides, mouth-rinses, tablets/drops) are administered to about 60 million people. Meanwhile, populations in many developing countries do not have access to fluorides for prevention of dental caries for practical or economic reasons.

In the WHO Technical Report Series No. 846 on "Fluorides and oral health" (1994) the recommendation on use of fluoridated toothpastes reads as follows:

One of WHO’s policies is to support the widespread use of affordable fluoridated toothpaste in developing countries. This is particularly important in light of the changing diet and nutrition status in these countries. Recent local studies have shown that affordable fluoridated toothpaste is effective in caries prevention and should be made available for use by health authorities in developing countries. The WHO Global Oral Health Programme is currently undertaking further demonstration projects in Africa, Asia and Europe in order to assess the relevance of affordable fluoridated toothpaste, milk fluoridation and salt fluoridation.

Tobacco

Prevalence of tobacco use has declined in some high-income countries but continues to increase in low- and middle-income countries, especially among young people and women. Undoubtedly, the increasing number of smokers and smokeless tobacco users among young people in different areas of the world will considerably affect the general and oral health of future generations. The prevalence of tobacco use in most countries is the highest amongst people of low educational background and among the poor and marginalized people.

Tobacco use is a major preventable cause of premature death and of several general diseases. In addition, cigarette, pipe, cigar and bidi smoking, betel quid chewing (pan), guhtka use and other traditional forms of tobacco have several effects in the mouth. Tobacco is a risk factor for oral cancer, oral cancer recurrence, adult periodontal diseases and congenital defects such as cleft lip and palate in children. Tobacco suppresses the immune system's response to oral infection, compromises healing following oral surgical and accidental wounding, promotes periodontal degeneration in diabetics and adversely affects the cardiovascular system. Moreover, tobacco greatly increases the risk when used in combination with alcohol or areca nut. Most oral consequences of tobacco use impair quality of life be they as simple as halitosis, as complex as oral birth defects, as common as periodontal disease or as troublesome as complications during wound healing.

The WHO Oral Health Programme aims to control tobacco-related oral diseases and adverse conditions through several strategies. Within WHO, the Programme forms part of the WHO tobacco-free initiatives, with fully integrated oral health-related programmes. Externally, the Programme encourages the adoption and use of WHO tobacco-cessation and control policies by international and national oral health organizations. Primary partners are WHO Collaborating Centres in Oral Health and NGOs who are in official relations with WHO, i.e. the International Association for Dental Research (IADR) and the FDI World Dental Federation. A number of projects have been initiated in Canada, European Union countries, Japan, New Zealand and the United States, and more programmes are being considered in India and China.

There are several ethical, moral, and practical reasons why oral health professionals should strengthen their contributions to tobacco-cessation programmes, for example:

• They are especially concerned about the adverse effects in the oropharyngeal area of the body that are caused by tobacco practices.
• They meet, on a regular basis, children, youth and their caregivers, thus providing opportunities to influence individuals to entirely avoid, postpone initiation or quit using tobacco before they become strongly dependent.
• They often have more time with patients than many other clinicians, providing opportunities to integrate education and intervention.
• They often treat women of childbearing age, thus are able to inform such patients about the potential harm to their babies from tobacco use.
• They are as effective as other clinicians in helping tobacco users quit and results are improved when more than one discipline assists individuals during the quitting process.
• They can build their patient's interest in discontinuing tobacco use by showing actual tobacco effects in the mouth.

The tobacco-related goal of the WHO Oral Health Programme is to ensure that oral health teams and oral health organizations are directly, appropriately and routinely involved in influencing patients and the public at large to avoid and discontinue the use of all forms of tobacco.

The aim of cancer control is a reduction in both the incidence of the disease and associated morbidity and mortality. This requires not only knowledge of the natural history of the disease but also an understanding of the underpinning social, economic and cultural factors. Screening and early detection can save lifes. Several developed and developing countries are in the process of implementing cancer prevention programmes, including oral cancer prevention. It is essential to educate people to recognize the early signs and symptoms of oral cancer. Particularly in developing countries, primary health care workers trained in the detection of oral cancer will become a considerable force for prevention through early detection and health promotion to raise awareness in the community. An effective referral system must be identified to ensure vital actions are taken.

The WHO Oral Health Programme supports the inclusion of oral cancer prevention as part of national cancer control programmes, based on careful planning, monitoring and evaluation, and partnership-building.