History of Medical Discoveries: From 1900 to Now

By: Dakota Behrman

At the start of the 1900s, life expectancy in America was just a short 48 years. By the end of the century, it would jump to 76 years (Statista). These leaps in how long the average human spends on this planet can be attributed to many things, but we wanted to particularly take note of the ways advances in medicine have helped extend the human life span and the history behind each discovery that would change the world.

1921 – Insulin Production 

In the United States, 10.5% of the population (34.2 million) has diabetes, a disorder that left untreated can lead to death (CDC). In 2019, approximately 4.2 million worldwide deaths were attributed to diabetes (NCBI.NLM.NIH). Diabetes is caused by the body’s incapacity to regulate the production of a protein hormone, insulin. Prior to the 1920s, diabetes was practically a terminal disease, the life expectancy for patients with acute onset diabetes was less than 4 years from diagnosis. In 1921, a team of scientists at the University of Toronto successfully crafted a method to extract the insulin hormone for synthetic production. After a slew of experiments on dogs with diabetes, they were ready to plan for human subjects (Diabete Quebec).

The team added a new member, biochemist, James Collip, who developed a method to purify insulin from the pancreas of a cow. This purer, more concentrated insulin allowed the team to work toward human trials. In January 1922, 14-year-old Leonard Thompson, who was afflicted with type 1 diabetes, became the first person to be injected with insulin. Within the day, his blood sugar levels dropped, and the team was able to work out an even better synthesis of insulin. By the end of the month, he was given a second injection which led to his successful treatment. By mid-1922, mass production of insulin was underway, paving the road for the worldwide treatment of diabetes (Diabete Quebec).


1928 – Penicillin  

The history of treating infections could warrant an entire article of its own. From draining of the blood to moldy bread to mercury IVs, the process which we used to treat infections was widely ineffective and lead to serious side effects that were not much better than the infection being treated (The Conversation).

In the most well-known case of medical discoveries comes Scottish physician, Alexander Fleming. He famously left for a month-long vacation, leaving an experiment involving various culture plates behind at his office. The Petri dishes contained colonies of Staphylococcus, the bacteria that causes Staph infections. Upon return, he discovered one of the dishes had colonies of bacteria, except for a spot in the dish that had begun growing a strange mold. Fleming and his team would develop this mold into the world’s first antibiotic: penicillin. However, Fleming and his team did not fully understand the applications that could occur with their newfound antibiotic.

It wasn’t until men at Oxford University focused on this strange find into a complete life-saving medicine. In 1939, this team would concert their efforts into the higher production volume of penicillin to conduct their research, effectively turning Oxford into a penicillin manufacturer. In 1940, they successfully showed that the drug could protect miss from Streptococcus, commonly known as Strep Throat, which, without proper medication and luck, could be deadly. This led to the human trials, where a police officer was given the drug to treat a life-threatening infection that attacked his eyes, face, and lungs. Within a few days, the infection was treated, and his recovery was underway. Sadly, he passed due to the penicillin supply being depleted. It took many years and many complications, but by 1949, 133 billion units of penicillin were being produced in the US (ACS)

Thanks to these two teams, Fleming’s team, and the men at Oxford University, an estimated 200 million lives have been saved (New World Encyclopedia). This paved the way for the development of other antibiotics which ushered in a current era in which some of the greatest threats to our health can be solved by a simple shot.  

1977 – In Vitro Fertilization  

On this list, we have discussed the history of medical discoveries that have saved lives, so let’s talk about one that has created lives. About 6.1 million women between 15-44 years old have difficulty getting or staying pregnant (CDC). In vitro fertilization (IVF) is a process in which an egg is combined with sperm in an environment outside of the organism; then, the fertilized egg is implanted into the mother or surrogate’s uterus for further development (Mayo Clinic). While the ethics of the process is long debated, the medical knowledge to develop this procedure was nothing short of groundbreaking. As with most medical advancements, our understanding came from the way of testing on animals. Attempts at successful IVF date back to the 1870s by the Viennese embryologist, Samuel Schenk, who worked on rabbits and guinea pigs. He was one of the first to observe that cell division can occur in cultures after sperm was added to an ovum, a female reproductive cell (Arizona State University).

For the next 50 years, more attempts were made by scientists across the globe, until 1951 when American biologist, Min Chueh Chang, proved that sperm must first mature through particular stages before developing the capacity to fertilize. Eight years later in 1959, Chang would be the first to successfully use IVF with rabbits being his test subjects. With most medical advancements, the work between success in animals and success in humans has a very wide gap. In 1968, English gynecologist, Patrick Steptoe, and British physiologist, Robert Edwards, started their journey towards the first successful human IVF. They made progress throughout the next decade, having successful fertilization and cell division of eggs in a petri dish. However, once implanted, the pregnancy would not take hold. In 1976, the team was working with an infertile couple and transferred a fertilized egg into the mother, who coincidentally had the optimal hormone levels for the eggs to take hold. The team later discovered that these diurnal cycles of hormone levels were a key factor for successful implementation (Arizona State University).

 On July 25th, 1978, Louise Joy Brown was born, the first human ever to be born via in vitro fertilization. Now, hormone therapy is given prior to IVF to increase the chances of success, and over an estimated eight million humans have been born as a result of in vitro fertilization (Reproductive Biomedicine Online).

From the prehistoric era of herbalism to the modern age of stem cell research, medicine has always been evolving, changing, and advancing in the pursuit of healthier living. We hope you enjoyed this deep dive into a few of the medical discoveries that helped shape the world as we know it and allowed us to experience it more. We are excited to see what the future holds, and what medical advances have yet to be discovered.

Interested in contributing to the Krucial Kollective? Send us an e-mail at marketing@krucialrr.org and let us know what you would like to write!

From the prehistoric era of herbalism to the modern age of stem cell research, medicine has always been evolving, changing, and advancing in the pursuit of healthier living.

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