The Horrifying Tooth/Sugar Experiment at Vipeholm Mental Institution (1945-1949)

During the early 20th Century, an epidemic was taking place in the country of Sweden as people, both adults and children, suffered from serious dental health issues. Even children as young as 3 were suffering from tooth decay and cavities, requiring false teeth. Dental health was generally poor across the globe during this time, and typically, rotting teeth were simply pulled. Although dentistry had existed for centuries, the modern practice was in its infancy and most normal people could not afford advanced procedures such as cavity fillings and root canals.

No one agreed on the root cause. Even dentists were not in agreement. Some thought it was simply bad genetics. Others thought the modern diet was the cause as our ancestors ate more natural weeds with antibacterial properties. At that time, it was not even known whether or not sugar was a part of the problem. Politicians got involved as well and argued over whether or not publicly funded dental care should be introduced. The costs of such a program would have been astronomical with so much tooth decay and every one agreed that solving the epidemic should be the first course of action.

So, the Swedish government decided to focus on preventing tooth decay – but to do so, they needed to know what caused it, so that people could avoid it. In 1938, the National Dental Service of Sweden was established and one of their first missions was to determine whether or not sugar had anything to do with tooth decay. But to do this, they would need to experiment on living human beings. Where would a group of humans be that would consent to such a study? As it turned out, they found a place where the people might not even need to consent – the Vipeholm Mental Institution, a facility for people with “severe intellectual and developmental disabilities.”

The institution held over 1,000 individuals, all separated from society and included children and adults. Most of the patients remained there for the duration of their lives. At least half of the patients could not communicate in a way that could be understood and about a third were unable to leave their bed – some because they had to be tied to it. The head of the institution was a physician named Hugo Froderberg. He kept notes on each of the patients and gave them each a grade 0-6 based on their intelligence. Those in the zero group he considered equal to vegetables, biologically lower than animals. Only those rated at least 2 were given any medical attention.

However, at least 1/3rd of the patients were rated 4 and above and these were the ones would could typically walk around, chew and eat food for themselves and even work jobs at the facility. They would be the focus of this experiment. Sponsored by companies from the sugar industry, the experiment began in 1945 with an examination of the current condition of the patients teeth. It was noted at the start that most of the patients, especially the children, had teeth in relatively good condition – perhaps because they were not given candy and sweets like normal kids. The first phase of the experiment focused on prevention was mostly ethical as the patients were fed about half the amount sugar the normal population consumed, but were also given vitamins A, C and D, along with fluoride tablets. No food was allowed in between normal meals. This went on for two years, and the teeth seemed to respond well, with very few new cavities forming.

However, just because cavities did not form with less sugar didn’t prove that sugar caused them. So, they wanted to find out what lots of sugar would do to the teeth and the experiment took a dark turn when, in 1947, the next phase began and the patients would now be given twice the amount of sugar that the general population consumed. The patients had no choice in the matter and the ethical considerations at this time were simply ignored. Three groups were formed – one that ate sweet and sticky bread with extra sugar with their meals, a second that drank sugary beverages that contained as much as sugar as 9 cans of Pepsi, and a third that were forced to eat various candies including super sticky toffees in-between meals. Why super sticky? So that the sugary candy would stick to the teeth and continue to stay there even after the candy had been consumed. In fact, the Swedish chocolate company Mazetti was asked to produce the stickiest possible toffee they could so it would cling to the teeth and be very difficult to get rid of. And to make extra sure the sugar did the most damage possible, toothbrushes were forbidden. They eventually created multiple groups of children who ate the toffee, one group given 8 per day and another who ate 24. To keep them from getting bored of the same food, they changed up the flavors and any patients who tried to throw away their candy or discard of it somehow were punished.

You might be shocked to learn that the sugar in fact caused some tooth problems. There were over 2,000 cases of extensive tooth decay. Nearly half of the teeth of these patients were completely rotten. One child needed to have 10 of his teeth extracted. As would be expected, the groups who were fed more sugar had more tooth decay. The results stated that:

- Sugar consumption increases decay activity; when sugar is withdrawn, activity goes down

- The risk of developing decay is greatest if the sugar is sticky and retentive in form; and when it was eaten frequently especially between meals.

Since none of the patients were offered dental care during this study, many experienced severe pain and suffering, which for most of them was only finally alleviated by extracting the rotten teeth. The candy companies that sponsored the study were understandably upset at the results and tried to delay the release of the data, which proved beyond a doubt that sugar contributed to tooth decay.

The researchers at the time considered the study a success and most did not even consider the ethical violations that were committed. At this time, people with disabilities were largely considered subhuman and they had almost no rights. Many believed that because the state took care of them at the institution, they had a responsibility to give back to the community through experiments such as this one. After the results were finally published in 1953, there was some public outrage but mostly it was concentrated on why the study took so long to become public as well as why corporate interests were involved. Very few people questioned the ethical aspects of what was done.

It wasn’t until the 1990’s when widespread studies began to appear questioning the ethics of the Vipeholm experiments. In 1997, the story made headlines, finally highlighting the negative aspects of the methods used to perform the investigation. Although the experiments were successful in linking the intake of sugar to tooth decay, the unethical human experimentation was finally recognized, although much too late to punish any of those involved or apologize to the victims. Later studies confirmed that some of the scientists involved in the experiment were under massive pressure from political and economic interests. Although it was certainly a different time in the 1940’s, it’s incredible to think that back then humans with mental disabilities were considered subhuman and could be experimented on without consent and with no regard to their pain and suffering, offering no compensation whatsoever.