Special Feature

doi:10.1038/nindia.2017.30 Published online 10 April 2017

Roadblocks to reducing oral health inequalities in New Zealand

[Nature India Special Issue: Oral Health Inequalities and Health Systems in Asia-Pacific]

W. Murray Thomson1

Policy Recommendations

• Continued limits on marketing of high-sugar foods.

• Use of objective data rather than ideology in health policy-making. 

• Explore ways to reduce the cost of oral care and self-care.

W. Murray Thomson

Social and ethnic inequalities in the tooth decay experience have long been apparent in New Zealand (NZ) and elsewhere1, noticeably among adults and preschool children. Having much in common with other chronic non-communicable diseases, decay can easily be labelled as a “wick­ed” health problem. Such complex problems are difficult to solve: they have a number of causes, are continually developing and changing, and there is no universal solution2.

Dental caries is a multifactorial disease with several causes and influenc­es3. Earlier predictions of it disappearing as a public health problem are far from accurate. There is much evidence suggesting that it’s a lifelong, highly prevalent disease4-6 which has no single solution. At the individual level, there is now good longitudinal evidence that sustained, long-term plaque control is achievable7, and topical fluorides such as fluoride toothpastes are effective8. However, effective self-care needs to be sustained over the long term7. At the community level, water fluoridation is effective9, but it shifts the population disease distribution, rather than eliminating it. Sugar intake is the most im­portant person-level risk factor for tooth decay10, and the marketing and con­sumption of sugars is increasing11.

There are three main challenges in reducing inequality in tooth decay in NZ: (1) the poor oral health of low- socio-economic status (SES) adults; (2) a rhetorical and policy focus on individual behaviour; and (3) individuals’ sus­ceptibility to the marketing of high-sugar products and their lack of control over the cariogenic (and obesogenic) environment.

Poor oral health among low-SES adults

One of the striking findings of the most recent NZ national oral health sur­vey was the nature and extent of adult oral health inequalities by deprivation level and ethnicity12. Despite universal access to free oral healthcare from in­fancy to age 17 (which aims to ameliorate disparities during that particular developmental period), there is inequality in adults’ tooth decay experience. Adults pay for their own dental care (although treatment for orofacial and dental trauma is covered by a unique social insurance scheme, the Accident Compensation Corporation). So, the re-emergence of inequalities, after enti­tlement to State-provided care ends at age 18, is as steady as it is inevitable. By their late 30s, people who have been low SES all their lives have three times the experience of missing teeth due to decay than those who have remained high SES. Those differences are magnified in their impact upon sufferers’ day-to-day lives13.

A focus on individual behaviour

The dominant discourse in oral health centres on individual behaviour and choices, ignoring wider influences. Those suffering from tooth decay are deemed to be at fault, implying that better attention to self-care and avoid­ance of cariogenic food and drinks could have averted their predicament. Peo­ple are labelled “non-compliant” if they fail to follow dentists’ instructions, or if their way of using dental care is anything other than asymptomatic, routine visiting.

Lack of control over the carcinogenic environment

The current lack of control over the cariogenic environment is a result of social and economic policy decisions. Since the 1970s, neoliberalism has become the organising principle of modern society. The promotion of globalisation has led to a reduction in nations’ self-determination, with bodies such as the World Bank and the International Monetary Fund being major proponents. The over-riding agenda is facilitating the accumulation of global capital by transnational corporate interests in the absence of any legal obligation to en­sure the welfare of citizens. Neoliberalism uses instruments such as changes to fiscal policy, reductions in public spending, tax reforms, trade liberalisation, privatisation of State enterprises and institutions, and deregulation14. Most of these end up being injurious to public health and welfare. For example, three key social policy changes in New Zealand in the early 1990s were shown to have led to a rapid widening of ethnic inequalities in child oral health in the subsequent five years15.

The health effects of social policy were recently highlighted14 in an anal­ysis of the provenance and effects of mass consumption of an energy-dense and nutritionally compromised “industrial diet” — highly processed and con­venient “junk” food. Such food is high in sugar (much of which comes from high-fructose corn syrup), salt and fat, and has low nutritional value. Being cheap, readily available and requiring minimal preparation, it tends to be con­sumed by those on low and/or insecure incomes, whose numbers are steadily rising.

Sugar intake is known to be the most important dietary risk factor for dental caries11, yet the marketing of sugar-laden food and drinks continues unabated, with the true sugar content unapparent to most consumers. An analysis of NZ supermarket shopping data a decade ago showed that some of the most popular supermarket products sold were less healthy, such as full-fat milk, white bread, sugary soft drinks, butter and sweet biscuits. Moreover, two of the 10 most purchased items were cola drinks. Soft drinks comprised six of the 30 most popular items16. A replication of that study today would likely show no change. A recent review highlighted the effects of food marketing on children, summarising the findings of a number of systematic reviews of the issue and underlining the effectiveness of promoting low-nutrition foods among children (and their families)17. Little progress has been made in curbing such practices.

Another problem is the reluctance of government health bodies to look beyond the narrow confines of the health sector, their failure to adequately take into account the wider structural and social determinants of oral health, their continued focus on individual behaviour, and an institutional reluctance to challenge the neoliberal assumptions behind contemporary government policy. The steady contraction of the NZ public sector18 and an associated de­crease in its job security19 have further consolidated this.

Reducing inequalities in dental caries experience is a laudable objective, but the many influences and actors make it a “wicked” problem indeed. Mak­ing meaningful progress towards such a goal will require innovative and sus­tained actions at a number of levels ranging from the personal to the geopo­litical. Whether the system has the capacity and the will remains to be seen.

1Professor, Sir John Walsh Research Institute, Faculty of Dentistry, The University of Otago, Dunedin, New Zealand (murray.thomson@otago.ac.nz).


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