Vipeholm experiments
The Vipeholm experiments or Vipeholm Study (Swedish: Vipeholmsexperimenten) were a series of human experiments where patients of Vipeholm Hospital for the intellectually disabled in Lund, Sweden, were fed large amounts of sweets, including "extra sticky toffee" to provoke dental caries (1945–1955). The experiments were sponsored both by the sugar industry and the dentist community, in an effort to determine whether carbohydrates affected the formation of cavities. The experiments provided extensive knowledge about dental health and resulted in enough empirical data to link the intake of sugar to dental caries. However, today they are considered to have violated multiple principles of medical ethics. History 
The National Dental Service of Sweden was established in 1938. The state of dental health was not well-studied at the time, and cavities were widespread. It was suspected high sugar diets caused tooth decay, but there was no scientific proof. In 1945, the Medical Board commissioned a study on the subject, which would then become the Vipeholm experiments. Vipeholm was Sweden's largest facility for "uneducable retards" and was chosen to be the site of the largest experiment ever run on humans in Sweden at the time. Initially, Vipeholm employees were also a part of the experiment. What began in 1945 as government-sanctioned vitamin trials were converted in 1947 without the knowledge of the government. In consultation with the Medical Board, the researchers decided to substitute sugar for the vitamins. From 1947 to 1949, a group of patients were used as subjects in a full-scale experiment designed to bring about tooth decay. They were fed copious amounts of sweets, including toffee and chocolate. 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, the teeth of about fifty of the 660 subjects in the experiment had been completely damaged. Nonetheless, the researchers felt that, scientifically speaking, the experiment was a success. One of the practical results of the study was the recommendation that it was better for children's teeth to eat sweets once per week, compared to a smaller total amount spread out over most of the week. This practice established itself in Swedish society, and still today many parents only allow their children sweets on Saturdays, known as  (Saturday candy). Delayed results 
The confectionery industry supported the experiments through donations of money and sweets. Because the experiments had shown a clear link between sugar intake and dental cavities, the industry was not pleased with the results, and researchers delayed publication. When the study was finally made public in 1953, public debate arose over why the results had not been published earlier. The scientists were accused of having been bought by the industry. However, at the time there was not any public debate about the ethics of the experiments themselves. Modern attitudes in the dental profession are very different: a participant in the Vipeholm study, Bo Krasse, writes "It is obvious that a research ethics committee would not accept a project like the Vipeholm Study today." He explains "The need for the study was obvious to us as dentists" and states that the Swedish Parliament and then the news media debated the ethics of the study as early as 1953. Revelations 
It was not until the 1990s that studies appeared about the ethical aspects of the Vipeholm experiments. In 2000, the Swedish ombudsman for the disabled reported that the "excesses" of the study were not justified by the results. Elin Bommenel, a historian and doctoral student at Linköping University, performed a thorough study of the Vipeholm experiments in her dissertation, published in 2006. She was the first researcher to gain access to the original documents from the experimental period at Vipeholm. Her research describes how the scientists found themselves caught between the divergent goals of research and patient care as well as being under immense pressure from both political and economic interests. References 

Social history of Sweden
History of dentistry
History of sugar
Human subject research in Sweden
Medical ethics
Intellectual disability