October 25, 2021

I, Science

The science magazine of Imperial College

Ten thousand years ago, human life expectancy was only 30 years. The discovery of new medicines has extended this life expectancy ...


Medicine has been a part of human culture for thousands of years. Modern medicine now allows us to cheat death more often and for longer than ever before. So what have been the most important advances to date.

Life Expectancy

The most common way to measure the extension of life in a population is life expectancy. For most of human history, the average life expectancy for a population didn’t deviate much from 25–35 years, although individual life spans were often much longer than this. Even by 1850, when the advance of modern medicine had truly started,—life expectancy was still below 40 years of age. Since then, average life spans have almost doubled in many countries, including the UK. While much of this improvement can be attributed to public health changes such as improved sanitation, medical advances have had a big impact on how long we live.


Meningitis. Tuberculosis. Malaria. Pneumonia. Thanks to advances in infection control, all of these diseases that were once so deadly can now be controlled, if not cured completely. Preventing death from infections is an important way medicine cheats death every day. Three crucial paradigm changes in medicine have allowed this to happen: vaccinations, antimicrobials, and the use of antiseptic conditions.


Although some form of vaccination has been used for over a thousand years in the form of small pox inoculations in India and China, the wide range of vaccinations now available is a recent phenomenon. From Edward Jenner and the use of cowpox to vaccinate against smallpox in 1796, through to Louis Pasteur and the discovery of bacteria, and onto the first genetically engineered vaccine for Hepatitis B in 1986, vaccination has only increased as a method to prevent disease and so extend life. Perhaps the best example: a total of 80 percent of infected children died from smallpox at the beginning of the last century, as well as 30 percent of adults. Finally eradicating this disease in 1979 was a large step forward and provides hope that it might be possible for other infectious human diseases.


Penicillin, discovered in 1928 by Alexander Fleming, was developed as an antibiotic in 1940. Penicillin and its derivatives have been instrumental in preventing death from bacterial diseases and kick-started the antimicrobial revolution in medicine. Though plant- based antimicrobials had already been in use since the 15th century, the search for antibiotics didn’t begin in earnest until World War II.


Developed by Pasteur in 1864, germ theory is the idea that microscopic cells are all around us and can be deadly. As a result, germ theory is a main cause of the widespread adoption of antiseptic techniques. In 1847, Ignaz Semmelweis, a physician from Hungary, had shown that hand-washing could save the lives of women giving birth. At the time, up to a third of women would die from childbed fever, spread by the doctors delivering babies without washing their hands.

Following this in 1867, Joseph Lister’s sterilisation of air and instruments in surgical theatres with carbolic acid was also an important move towards the antiseptic conditions that save lives today. But we still have much further to go; infection rates in hospitals are still high, and often allow the spread of increasingly antibiotic-resistant infections like MRSA.


The use of anaesthetics has allowed surgery to become far more sophisticated in the last 150 years. Ether, laughing gas, and chloroform were all discovered in the 1840s, and more effective anaesthetics have since been developed, as well as better monitoring techniques. The use of an anaesthetic also prevents post- operative shock, a major cause of death among early surgical patients.


From the chemical reactions of life to the discovery of cells, many medical advances would not have been possible without our increasing knowledge of the biology of the human body. The huge range of drug treatments at the moment owes a lot to our understanding of the cellular basis of diseases, including cancer. While many types of cancer are still almost untreatable (melanoma and lung cancer as two examples), we are now coming close to being able to cure people of other types, including some breast and testicular cancers. Our understanding of immunology has led to increased use of transplant operations, saving multiple lives from just one donor. One of the next big questions is how to slow the ageing process itself. With new advances year after year, we can look forward to continuing to extend many more lives.

Giving life

It doesn’t end at extending life. In vitro fertilization (IVF) treatment has allowed around 5 million babies to be born worldwide since the birth of the first test tube baby in 1978. TTo put that figure in perspective, that’s roughly twice the urban population of Birmingham. Fertility treatments are bringing new life to more and more families around the world.

The flipside

The flipside to this coin is the massive healthcare disparity throughout the world. While life expectancy in Western countries is high, it remains just above Victorian levels in many places (such as the 46 year average in Sierra Leone). Every five seconds a child somewhere in the world dies of a preventable cause—usually pneumonia, diarrhoea, or malaria. These deaths could still be prevented.

While medicine is continuing to advance, our own lifestyles are starting to get in the way, and might cause life expectancy to start to decrease for the first time in 150 years. Our propensity for unhealthy diets, a sedentary life, and a fondness for cigarettes and alcohol are all levelling the playing field. By doing nothing about these common health issues, we’re starting to let death back in too.

Image: pharmaceutical drug on Wikipedia.com