Bacteria are tiny one-celled living organisms that have a remarkable ability to flourish in inhospitable conditions, from the iciest regions on earth to the hottest vents beneath the ocean floor. Some bacteria are pathogenic, or capable of causing disease, and have the potential to make us very sick; bacteria cause illnesses like cholera, tuberculosis, and gonorrhea. Many harmful bacteria can be killed simply by washing your hands with soap and warm water. But before the middle of the 1800s, people only washed their hands when they looked dirty – not because they suspected that an invisible bacterial army could really ruin their day.
Until the modern era, in the war between humans and microbes, the microbes were winning. In order to push the limits of life expectancy, doctors first had to understand that much of human illness could be traced to the bacteria and viruses that creep onto and into our bodies. To create medicines that killed germs and saved lives, they had to see what had been unseen.
And once they figured out all of that, there was another battle to win: they had to convince people that they were right.
THE REVOLUTIONARY IDEA OF WASHING YOUR HANDS
In mid-nineteenth-century Europe, one in two hundred women who had a baby did not survive the year after giving birth. It was basically taken for granted that after childbirth, a lot of women would catch something called puerperal fever, an infection of the reproductive organs that often leads to death.
One physician wanted to know why. In 1860, Ignaz Philipp Semmelweis, a doctor at a Viennese hospital, noted that in the hospital’s two delivery rooms, the rates of infection were skewed. Women in the delivery room where medical students assisted births were three times more likely to come down with puerperal fever than the women in the delivery room staffed by midwives.
Though the chief of his hospital urged him to leave the matter alone, Dr Semmelweis wanted to investigate the discrepency. Why were so many women and babies dying? Why did more women survive when their babies were delivered by midwife?
Dr Semmelweis figured out that while the midwives did have better training and more experience than the students, skill wasn’t the only reason the patients survived. Remember, nobody understood how germs spread yet. The medical students weren’t thinking twice about where they were before they stepped into the room to help deliver babies. But Dr Semmelweis noted where they were: in class, dissecting diseased cadavers. That’s right. The students would go straight from the dissection room to the delivery room without washing their hands. They were transmitting bacteria, and ultimately, infection.
LONGEVITY VOCABULARY
• LIFE EXPECTANCY: How long you can be expected to live if you are born in a certain time and in a certain environment
• LIFE SPAN: How long an individual actually lives
• MAXIMUM LIFE SPAN: The longest recorded life span for the species (122.5 years for a human female)
• HEALTH SPAN: The healthy years of your life
• LONGEVITY: How long you can live
• STRONGEVITY: How strong you are over the course of your long life
When Dr Semmelweis instructed students to wash their hands before each examination, the maternal and infant mortality rates from puerperal fever dropped sharply. Once one of the top causes of postpartum infection, this disease is now barely seen in the developed world.
Dr Semmelweis is credited with introducing the idea of antisepsis: sanitizing your hands and keeping surfaces free of germs. His discovery changed our entire understanding of germs and illness. This was a crucial shift for the human life span, because it gave more women and more children a fighting chance at survival. Dr Semmelweis’s investigation is the reason why there are signs in public toilets around the world today reminding people to wash their hands.
Another breakthrough for the human life span was the introduction of antibiotic drugs like penicillin. Before the mid-twentieth century, simply trimming your rose garden could be a dangerous pastime. The discovery of antibiotics changed the way people lived their lives. As researchers beat back the bacteria, children, young adults, and women were all afforded a better chance of living longer. After penicillin was invented, the human life span jumped another ten years.
As more people aged, the ratio of what was killing us shifted from infectious diseases to the illnesses that accompany ageing, like heart disease. By the 1950s, as people started living through infections and making it to their seventies in record numbers, cardiovascular diseases became the number one killer in the country for men and women. It is still the number one killer today, partially because the technological advances that increased life expectancy also led to modern conveniences that can undermine it: innovations like processed foods and devices that enable us to live sedentary lifestyles.
HOW WE GOT HEART SMART
Until the middle of the twentieth century, the causes of heart disease were an utter mystery to the medical community. Most theories were based on speculation; there was not enough meaningful data to provide any real insight into how to prevent the disease that was killing so many people in Western societies. Then in 1948, in the United States, the National Heart Institute (a part of the NIH) launched a study that is still recognized as one of the most important medical accomplishments of the era: the Framingham Heart Study. More than five thousand men and women between the ages of thirty and sixty-two from the town of Framingham, Massachusetts were selected to participate in the longitudinal study, which assessed the health of these individuals every two years over the course of several decades. (The study is still running; in 1971, another group of more than five thousand participants enrolled, the children of the original group; in 2002, the grandchildren of the original group signed up.) Through tracking such a large sample of participants over time, researchers learned that the common denominators of heart disease included high blood pressure, smoking, and high cholesterol levels. A model for later longitudinal studies, the Framingham study gave doctors a way to identify possible heart disease candidates and to develop preventative measures. It was also the first major study that included women, an important qualification that we will discuss in more detail later.
At the time that the Framingham study began, treatments for age-related diseases were mainly aimed at easing the symptoms and making the patient comfortable, not actually curing the disease. But in the 1950s, doctors gained new ground in surgery. Insights gleaned from surgeons in World War II allowed surgical procedures to become more specialized. Doctors better understood and had better access to diagnostic tools, anaesthesia, and blood transfusions. And the widespread availability of antibiotics made high-risk surgeries safer. Surgeons were more confident than ever, and their first order of business was the heart.
By the 1960s, heart transplant surgery was on its way. In the middle of the decade, a chimpanzee’s heart was put into a man. In the late 1960s, the first human heart was transplanted. Revolutionary techniques like these, along with the rise of coronary care units, the treatment of high blood pressure, and the improved medical response to coronary disease, were