Full-scale experiment designed to bring about tooth decay

In 1947-1949 a group of mental patients in Sweden were used as subjects in a full-scale experiment designed to bring about tooth decay. They were fed copious amounts of candy, and many of them had their teeth completely ruined. But, scientifically speaking, the experiment was a huge success.

The National Dental Service in Sweden was started in 1938. The dental health of Swedes at that time was atrocious, nearly everyone had cavities. It was suspected that diets rich in sugar caused tooth decay, but there was no scientific proof. In 1945 the then Medical Board commissioned a study. This was the start of the Vipeholm experiments.

Vipeholm, outside Lund, was the country’s largest facility for ‘uneducable retards’ and was chosen to be the site of the largest experiment ever run on humans in Sweden at that time.

Elin Bommenel is a historian and doctoral student at Theme: Technology and Social Change, Linkoping University. In her dissertation she performs a thorough study of the Vipeholm experiments.

She is the first researcher to gain access to the original documents from the experimental period at Vipeholm. She describes how the scientists found themselves in the interstice between research and care, and under great pressure from political and economic interests. The confectionery industry donated huge sums of money and tons of chocolates and caramels to the experiments.

The experiments had started in 1945, with government-sanctioned vitamin trials, but they were converted in 1947 without the knowledge of the government. The researchers decided, in consultation with the Medical Board, to start to use sugar instead, to cause tooth decay by using an extremely sweet and sticky diet. Up to that point, Vipeholm employees had been part of the experiment too, but this was stopped, since it was soon found that there was no way of monitoring their intake of sweets.

The sugar experiment lasted for two years. In 1949 the trials were revised again, now to test a more ‘normal’ carbohydrate-rich diet. By then about 50 of the 660 subjects in the experiment had had their teeth completely ruined.

The confectionery industry was not pleased with the results, and the researchers delayed their publication. When they were finally made public in 1953, a critical debate arose about why they had been held back so long.

The scientists were accused of having been bought by the industry. However, there was never any public debate about the ethics of the experiments as such. Not until the 1990s did a couple of studies appear about the ethical aspects of the Vipeholm experiments, by two Linkoping scholars, among others: Bo Petersson and Bengt Erik Eriksson.

Elin Bommenel highlights in her thesis the interplay between politics and research. Even though, or perhaps precisely because, the research emanated from a political commission, it was important for the scientists to obtain credible results. They did so, on the one hand, by being incredibly meticulous in their methodology and, on the other hand, by clearly demarcating themselves from the government and the industry.

“While science had to profile itself as being shielded from political interests in order to be credible, it was not objective in practice. It is part of politics and society. This was politically commissioned research. In scientific terms the results were sound, and they were politically useful. In 1957 a major campaign was started to prevent tooth decay. The Vipeholm researchers’ findings still hold up. In fact, we have them to thank for the excellent dental health that Swedes now enjoy. The price was paid by the patients with rotten teeth.”