Thanks to a sweet accident, saccharin is one of the oldest and most popular synthetic sweeteners in the world. It is used as a sugar substitute in many food and pharmaceutical products, especially for people suffering from diabetes or who want to control their weight. However, few people know that saccharin was discovered by chance, in a chemistry laboratory, more than a century ago.
The protagonist of this story was Constantin Fahlberg, a Russian chemist working at Johns Hopkins University in the United States under the direction of Ira Remsen. In 1878, the two were researching the properties of coal tar derivatives, a type of coal. One day, after a long day’s work, Fahlberg went home without washing his hands and sat down to dinner with his wife.
When he tasted the bread, he noticed that it tasted very sweet. Thinking it was some special seasoning, he asked his wife what she had put on it. She said nothing, that it was the same bread as usual.
Fahlberg then realised that the sweet taste came from his own hands, which were impregnated with some chemical substance. Intrigued, he went back to the lab and tested one by one the compounds he had used that day. Finally, he found the culprit: it was an o-sulphobenzoic amide, which he had obtained by oxidising a molecule called ortho-toluenesulphonamide. Fahlberg found that this substance was able to sweeten up to 300 times more than sugar, without adding calories or affecting the metabolism.
Fahlberg communicated his finding to Remsen and together they published an article in 1879, entitled “Über die Oxydation des Orthotoluolsulfamide” (On the Oxidation of Orthotoluolsulfonamide), in which they described the structure and properties of the new substance, which they called saccharin. However, differences soon emerged between the two scientists. While Remsen was engaged in academic research, Fahlberg saw the enormous commercial potential of saccharin and decided to patent it and manufacture it industrially, without acknowledging Remsen’s role in its discovery. This led to a fierce dispute between the two, which lasted until the end of their lives.
Saccharin quickly became very popular, especially among people with diabetes and those concerned about their figure. It was also used as a sweetener in times of war and sugar shortages. However, it was not all good things. In the 1970s, it was discovered that saccharin could cause bladder cancer in rats subjected to very high doses. This led to its use being banned or restricted in some countries, such as Canada and the United States. However, subsequent studies showed that the mechanism by which saccharin caused tumours in rats was not applicable to humans, and that moderate consumption of saccharin posed no health risk.
It is currently obtained by chemical synthesis from toluene or other petroleum derivatives.
Today, saccharin remains one of the most widely used and consumed sweeteners in the world, along with others such as aspartame and stevia. Its history is an example of how a fortuitous accident can lead to a great scientific discovery and a revolutionary product.
As a curiosity, another sweetener, sucralose, was also discovered by chance, when researching how to synthesise holgenated sugars. Sucralose is produced from sugar molecules, known in Spain as E955 and widely used in soft drinks and processed foods. It has a similar taste to sucrose, but is 600 times sweeter than sucrose, which is why it is used in very small quantities.
