The COVID-19 pandemic has made us painfully aware of the fragility of life. More than a half-million Americans have died of the virus, and deaths worldwide now number more than 3 million. It again is raging in India.
Despite this catastrophic health crisis, scientists predict that human life expectancy will continue to increase, as will world population. Indeed, the average life expectancy of the human has jumped from about 28 years to 77 since 1800, and it keeps rising.
What caused this phenomenon? To answer that question, I interviewed some two dozen people in the health care profession. Dr. Peter Buckley, dean of Virginia Commonwealth University’s School of Medicine, helped in my project by posing my question to many of his department heads.
My survey should not be considered comprehensive nor as a rigorous scientific exercise. Nevertheless, I was impressed with the thought the respondents gave to my question.
Many of the suggestions I received overlapped enough for me to determine five fundamental developments that led to a longer life expectancy and quality of life for humans. Some of these advances originated outside of the United States, but they eventually profoundly affected Americans.
The answers to my question are as follows (arranged chronologically):
1) Acceptance of the germ theory (1860s)
Until the mid-19th-century, numerous reasons were given for the causes of illness and death. The most common was the miasma theory that held that infectious diseases such as cholera, malaria, typhoid fever and the Black Death were attributed to “bad air,” composed of decomposed matter carried by mists.
Even when surgery initially was deemed successful, patients frequently died from postsurgical infections such as gangrene and sepsis. No one understood the causes of these infections or their complications, and how they spread.
French scientist Louis Pasteur proved infectious diseases were a result of an invasion of microscopic organisms (germs) into living hosts. Furthermore, the spread of germs in the body could explain infectious diseases.
Known as the germ theory, Pasteur never tested the concept. Instead, Glasgow University Professor Joseph Lister studied Pasteur’s theory and tried it in surgery. In the 1880s, he applied a “chemical barrier” (that he called antiseptic) using germ-killing carbolic acid. His techniques seemed to work, despite initial mixed reaction within the medical profession.
Despite initial reluctance by many doctors to endorse his methods, by the turn of the 20th century the number of surgery-related deaths significantly fell, providing solid evidence that his antiseptic worked.
Also, sterilizing surgical instruments, wearing gloves during surgery and dressing wounds with antiseptic solutions became standard procedure for doctors, resulting in the saving of untold numbers of lives ever since.
2) Internal imaging (1895)
This development changed the practice of medicine almost overnight. German physicist Wilhelm Rontgen was experimenting with electrical currents through glass cathode-ray tubes and discovered that X-rays could provide images inside the body. X-ray machines allowed doctors to examine broken bones, tumors, internal injuries and other irregularities that are not visible to the eye alone.
Later medical imaging such as computerized tomography (CT) scanners and magnetic resonance imaging (MRI) created even sharper images within the body and have become fundamental diagnostic tools in modern medicine. Rontgen’s early work using electrical currents eventually opened a whole new therapeutic element.
3) Penicillin, the world’s first antibiotic (1928)
Scottish biologist Alexander Fleming accidentally discovered mold in a petri dish that killed deadly bacteria on contact. Most doctors were slow to recognize penicillin’s significance until World War II, when it went into mass production. This crucial development has saved tens of millions of lives but over the years, certain bacteria have become increasingly resistant to antibiotics and raise the fears of some scientists about the ability to stop their spread.
4) Antiviral drugs (1960s)
We only have to look at the past year to comprehend the devastation that viruses can cause. From smallpox, to influenza, to hepatitis, to polio, to the coronavirus, these microorganisms at times nearly have destroyed whole populations.
Scientific journalist Charles Mann notes that on the eve of Christopher Columbus’ first visit to the New World in 1492, the total native population in the Western Hemisphere is estimated to have numbered some 100 million.
Yet within a century, that figure had plummeted to only about 10 million. The native population had been isolated from the rest of the world’s population and had not developed immunities like the invading Europeans who practically were germ- and virus-spreading machines.
The development of antivirals did not take off until the 1960s. Medical scientists found it difficult to conquer viruses because of their complex structure and their ability to mutate to other forms. The development of several different types of antiviral drugs that stimulate the body’s immune system to attack the coronavirus has been a game saver during the past year. Medical scientists, however, constantly are watching for any new virus strains that could prove more devastating than any seen before.
5) Stem cell therapy (1970s)
When stem cells were discovered inside the cord blood of infants, therapy under certain circumstances could be used to make any type of human cell, giving it huge potential to treat various blood cancers, as well as bone marrow transplantation.
Two things make stem cells unique: They can renew themselves through cell division and they can be used to make any kind of human cell. This discovery has great potential for the future of medicine and already is being used to treat leukemia and other blood disorders. Research is underway to use stem cells to treat spinal cord injuries, Alzheimer’s disease, Parkinson’s disease, strokes and other afflictions.
Other significant developments
Respondents to my question suggested a number of other factors that easily could be listed in the five mentioned above. They include:
- The public health movement calling for, among other things, clean drinking water, proper sewage disposal, food inspections, regulation of drugs, personal sanitation and hygiene, particularly in urban environments (mid-to-late 19th century), and the building of hospitals and clinics throughout the country.
- The professionalization of the practice of medicine, requiring educated, licensed medical personnel and the elimination of quackery.
- Organ transplants.
- First tried in the 1840s, anesthesia enabled doctors to perform both minor and major surgery on patients without pain.
- Acceptance of mental health as a legitimate medical concern deserving treatment.
- Immunotherapy, especially in the treatment of cancer.
It would be interesting to see the list of developments 50 years from now, such as the application of focused ultrasound in a variety of ways. As VCU’s’ Buckley observes: “Thanks to the tireless work of today’s medical scientists who stand on the shoulders of others before them, we can anticipate the eventual end of , Parkinson’s, Alzheimer’s and various cancers, among other debilitating scourges.”
For some of us, those developments cannot come soon enough.
Charles F. Bryan Jr., Ph.D., is president and CEO emeritus of the Virginia Historical Society. Contact him at: email@example.com