The debate about a sugar tax has focussed on the effect such a measure would have on rising rates of overweight and obesity in our community. However, taxing sugar would also have an impact on oral health and could be an effective way of addressing the current high rate of tooth decay among some population groups.
In this latest installment of the ‘Talking Teeth‘ series, Winthrop Professor Marc Tennant and co-Authors Professor Kate Dyson and Professor Estie Kruger look at some early seminal research studies into the relationship between sugar and dental decay, including one undertaken at an orphanage in Bowral, run by an eccentric philanthropist.
This fascinating (and deeply unethical by modern standards) study has informed our understanding of the role sugar plays in tooth decay and is still relevant in debates over current public policy issues, such as the sugar tax.
Professors Tennant, Dyson and Kruger write:
Dental professionals the world over will recall studying ‘Dental Public Health 101’, a subject which invariably makes reference to two quintessential sugar and dental decay studies from “back in the day’ – ‘Vipeholm’ [Ref 1] and ‘Hopewood House’. As a dutiful student of the 1980’s, I learned them by rote, passed the exam (just), and with a gaze affixed on the future, promptly burned all my notes in the ritualistic manner of many a university student.
Hopewood House ‘experiment’
Now, ironically, some 35 years later, as lessons from ‘Dental Public Health 101’ rise like Lazarus amid discussions of a sugar tax, I am fascinated to (re)learn that the Hopewood House experiment is actually Australian. Reacquainting myself with the story of Hopewood House, I dig a little deeper second time around and am surprised by some intriguing revelations.
Amazingly, Hopewood House still stands as an actual house in Bowral, New South Wales. Currently a wedding and event venue, it was recently on the market (if you have a lazy $7.5million, perhaps you could still obtain this slice of dental public health history).
During WWII, Lesley Owen Bailey, a wealthy philanthropist, opened a somewhat unconventional “orphanage” system, with its primary base at Hopewood House. Some 86 children lived their lives, from before birth until the coming of age, in the care of Owen and his staff. The key word here is unconventional; it’s a complex story and has been described elsewhere as a social experiment and Eugenics.
I can be sure few of us would want to go so far as adopting the dietary regime of the Hopewood House experiment. In fact, it has been troubling to discover on revisiting Hopewood, that the total calorific intake of the children was reportedly below recommended levels for extended periods and the children were below average in growth percentiles.
A grand vision
Although there were attempts by authorities to intervene, this is certainly not a story of pure altruisim and the story certainly has many elements that are out of step with contemporary values. Indeed, the Hopewood children, now of mature age, have suffered schisms in their views of their own upbringing, with some pointing to abuse, both physical and sexual.
Bailey’s grand vision was raising strong healthy people able to protect Australia. One of Bailey’s focuses was the benefit of a strict, healthful diet. The children’s diet was tightly controlled and high in fresh foods, salad, nuts and vegetables and very low in refined carbohydrate and sugars [Ref 5]. Bailey had experts, including a group of dental experts, regularly assessing the health of the children.
Lower levels of decay
Despite the Hopewood children having poor oral hygiene, they had far less tooth decay than similar aged children attending NSW State schools. As 12 year olds, almost two thirds of Hopewood children had decay-free adult teeth at a time when nearly all State school children had decay (For teeth enthusiasts, Hopewood’s 12 year olds averaged 1–2 decay-affected adult teeth whilst State school children averaged over five times these levels with 9–10 teeth affected by decay [Ref 2].
As the children grew older and began earning wages, their adherence to a strict low-sugar diet waned and decay levels rose sharply (6–7 decayed teeth by age 15 and 12–13 decayed teeth by 18 years of age [Ref 3].).
The Hopewood House story forms part of the foundation underpinning the principle of reducing dietary refined carbohydrates to enhance health, and more specifically dental health. The current sugar tax debate is focused on reducing obesity, and rightly so, with developed countries, and now developing countries facing this epidemic.
However, reducing refined carbohydrate intake would also be expected to improve dental decay levels which remain high among some groups. However, it must be remembered that the effect will never be as dramatic as that seen with the Hopewood House children living in an era prior to widespread fluoride exposure.
Footnote: For a more in-depth understanding of the overall nature of the ”experiment” a thesis and subsequent article by Dr. Deborah Ambery are excellent reading [Ref 4]. None of which I have any recollection of being told about as a student! And it is far more important than the dental story.
- GUSTAFSON, B. E., QUENSEL, C. E., SWENANDER LANKE, L., LUNDQUIST, C., GRAHNEN, H., BONOW, B. E., and KRASSE, B. The Effect of Different Levels of Carbohydrate Intake on Caries Activity in 436 Individuals Observed for Five Years, Acta odont. 11:232–364, 1954.
- SULLIVAN, H. R., and HARRIS, R. The Biology of the Children of Hopewood House, Bowral, N.S.W. I. Observations Extending over Five Years (1952–1956). 2. Observations on Oral Conditions, Aust. dent.J.,3:311–17, 1958.
- HARRIS,R. Biology of the Children of Hopewood House, Bowral, Australia. 4. Observations on Dental-Caries Experience Extending over Five Years (1957–61). JDR, 42;1387–99, 1963.
- ADJ 1958:378–382
Professors Marc Tennant, Kate Dyson and Estie Kruger are from the International Research Collaborative – Oral Health and Equity, Department of Anatomy, Physiology and Human Biology, The University of Western Australia.