It is easy to be smug about the blindspots of the past. Lead paint, cigarettes, cocaine in Coca Cola—could they really not have known? Such are the things we think, as we heedlessly Juul, pump ourselves with radiation, and fill prescriptions for pills whose long-term side effects have yet to be determined. All of these things might turn out to be fine; and we are, in any case, more attuned than ever to the ways we might be killing ourselves, whether or not we choose to do anything about it. But the killers of the future—the causes and the sicknesses themselves—may not arrive in a form we’re expecting. For this week’s Giz Asks, we reached out to a number of experts for a clearer sense of what we’ll be dying from in the future.
Associate Professor, Population Health & Disease Prevention, University of California-Irvine
Mostly the same as now: heart disease and cancer. These two diseases have been the leading two causes of death in the United States for a very long time, accounting (together) for over half of all deaths. These patterns change slowly. So, even twenty years from now, I fully expect heart disease and cancer to be, by far, the two leading causes of death in the United States.
They might flip-flop: cancer (currently in second place) may become the leading cause of death, with heart disease sinking to second. Heart disease has been on a fifty-plus year decline in importance, so it would not surprise me if it finally loses its place.
The population is becoming grayer, with boomers approaching 75. So causes of death that are common among the elderly will become more common, particularly accidents (falls), and possibly influenza/pneumonia. And Alzheimer’s disease, which was formerly outside the top-10 but is now the sixth-leading cause of death in the United States.
Similarly, diabetes deaths have increased in importance recently; currently its the seventh-leading cause of death. Increasing obesity will buttress the importance of diabetes as a cause of death.
But demographers are keenly aware of what we call, in jargon, “competing risks.” Put simply, you can only die of one thing. So the above-mentioned causes of death cannot all triumph. To the extent to which one rises, another one will not. This, combined with the large lead that heart disease and cancer have, means that the future of leading causes of death looks much like the present: heart disease and cancer.
Assistant Professor, Sociology, Indiana University Bloomington, whose research focuses on the structural forces that contribute to social inequalities in health
To predict the leading causes of death in the U.S. we need to consider the larger structural and social forces shaping mortality. During the 20th century, we witnessed a significant rise in life expectancy, driven primarily by public health advances coupled with advances in medicine. At the start of the 20th century people most often died from infectious diseases, but at the start of the 21st century people most often died from chronic diseases. Today, the two leading causes of death are heart disease and cancer.
Looking to the future, it is likely that chronic diseases will still top the list of the leading causes of death. Cancer is complex and elusive to treat. And it is unlikely that population level behaviors—and the broader social forces that shape them—will shift enough to cause heart disease to decline as a leading cause of death in the next 10 or 20 years. Even more, we can look at the rise in obesity among younger adults to predict the types of disease (i.e., diabetes, heart disease) that will haunt them as they age.
There are also newer trends emerging that will affect mortality over the next 20 years. First, among those who are in some way socially or economically privileged we are observing delayed mortality. People are living longer and dying from diseases of old age, such as Alzheimer’s and dementia. As those born after WWII age (i.e., baby boomers), we will continue to see this as a leading cause of death. Second, the gap between the rich and the poor is greater than it has been in 50 years. This inequality has significant population health effects, making the “American dream” of upward mobility even more elusive, and potentially contributing to rising infant mortality rates. One result is a rise in “deaths of despair” or deaths due to drug or alcohol overdose and suicides. Third, epidemiologists have long been cautioning us about reemerging infectious diseases, of which an influenza pandemic tops the list of concerns. But antibacterial and antifungal resistance will pose clear public health threats in the near future. Finally, we are starting to observe the effects of climate change on population health. Even small temperature changes are associated with a rise in violence, cardiovascular deaths, and will likely shift our experiences of autoimmune diseases triggered by the changing environment (e.g., allergies). The leading causes of death over the next two decades depends largely on the way humans to respond to these larger structural causes of mortality.
Professor, Population, Family and Reproductive Health, Johns Hopkins, whose primary research interest is the economics of public health practice
The way writers and readers always frame this question reflects the bio-power of the health care industry. I am pretty sure the responses you got to your question were the names of diseases. The implied action agenda would be to spend money on the medical experts who could develop marketable commodities to prevent or cure the named disease. We have given over our understanding to the paradigm that what causes ill health is disease and what improves ill health is bio-medicine powered by wet-bench lab research. But in reality look at any one of these diseases on a spatial map and you quickly see that what causes ill health is the social and cultural conditions in a place. The higher death rates from heart disease, cancer, stroke, and obesity consistently line up inside places and social groups. What really causes ill health are places that reinforce life-styles and choices and keep people under constant stress. What we have discovered this decade is an overwhelming willingness of Americans to be divided inside their communities, to exclude whole groups of people into otherness.
What will rise up more as an American cause of death in the future will be “otherness.” Those individuals being cast out of belonging to their cities and neighborhoods and families as well as those who cast them out will experience a cascade of physiology known as allostatic load. The physiology flows through prolonged elevated blood levels of corticosteroids and adrenalin. This leads to heightened susceptibility to atherosclerosis and cancer. Is the solution really cardiologists and oncologists though?
Groups that this will happen to are millions of lonely old men who started getting divorced during the uptrend in 1980s and failed to reform families—they are now entering their 70s. If LGBTQ communities fail to be mainstreamed, they will be othered. The LatinX community has traditionally been paradoxically healthy, but there are signs that this is reversing since 2016.
If you are looking for disease answers—the smart money will have to stay on heart disease, cancer, and stroke because of the sheer volume of millions of deaths from those diseases. (The influenza people will raise the spectre of another 1918—but they forget how poor and sick everyone was back then.) Our current epidemics of suicide, alcohol, and opioids are small numbers of deaths, but they deserve attention because the death counts went up, when they should have gone down.
Please consider opening the discussion to leading causes of death to be something other than disease. The new leading causes of death of the future will be how we treat each other and who gets included in our collective envelope of “us.” Funning the tape forward across many centuries, whether we end in fire or ice—the root cause will be our failure to remember our humanity.
Assistant Professor, Biostatistics, Eastern Washington University, and head of its Disease Ecology Lab
I have to preface that I am not a medical practitioner, but a disease ecologist, who studies the interactions between hosts, pathogens, and their environment. However, I do have decades of experience studying the patterns of infectious diseases around the world.
To answer your question, one of the biggest issues we will have is antimicrobial resistance, where we already have people dying of bacterial infections that could have been treated easily earlier. This will get worse unless we develop new antimicrobial compounds. Another ongoing risk that we face is pandemic flu, which will remain an issue until we develop a universal flu vaccine that will protect us from all influenza strains. There is always the risk of novel infectious diseases emerging, and switching their host to us, or getting out from their original locations, with recent examples such as Ebola, Zika virus, chikungunya, MERS and SARS as examples. We are not prepared for the next one.
Climate change and land cover land use change, such as urbanization increases these risk, particularly for diseases transmitted by ticks, mosquitoes and other insects. However, climate change will bring many other issues unrelated to infectious diseases, such as floodings, wildfires, food security, and simply extreme heat and weather. Heat exhaustion and asthma and other respiratory diseases might become much more prevalent. However, they might contribute to ongoing chronic diseases such as cardiovascular disease, so it might be difficult to separate them. Non-infectious chronic diseases will remain the main cause of mortality, even if the causes might shift.
Lecturer, Health Sciences, Boston University, whose research focuses on innovative infectious disease surveillance, screening and treatment programs, disease and vector control, and neglected tropical diseases
There is no one single disease that we will all be dying from in the future and what we are most at risk of will depend heavily on geography. While we have made great progress in controlling some of our biggest past killers, such as polio and the plague, there are so many emerging and remerging infectious diseases currently. Water, sanitation, and hygiene (WASH) has improved throughout the world, as well, which has helped us to reduce many preventable deaths from things like cholera and other diarrhea causing diseases, but many populations are still suffering. Neglected tropical diseases (NTDs) is a group of diseases that affect over 1 billion people – many of them infected with more than one. While a number of NTDs are not directly fatal, they cause terrible lifelong suffering and disability and the secondary effects can be fatal. As they are neglected, most people have never heard of them and little is currently being done to combat them on a global scale outside of specific devoted groups and programs.
Climate change has undoubtedly changed our risk factors, as well, and will continue to do so. Mosquitoes, ticks, and other vectors capable of transmitting lethal or debilitating diseases are spreading to new areas and affecting populations that have zero immunity and have never had to think about diseases like malaria, yellow fever, chikungunya, and countless others. Climate change is also resulting in increasing natural disasters that lead to events that facilitate disease spread such as flooding and displacement of populations. Many experts agree we are primed for another pandemic, such as the Spanish Flu of 1918, and it is simply a matter of time. We are seeing some viruses mutate with the potential to become more deadly. About 70% of emerging diseases now come from animals and this is likely to be the source of our next pandemic.
Finally, we cannot ignore the effect of chronic and non-communicable diseases in many different populations, particularly high-income countries but increasingly in other populations. Heart disease, stroke, and cancers are some of the top killers globally currently and have been for many years. The causes are varied and sometimes location dependent but poor diets and lack of exercise are certainly contributing to this and will continue to do so until there are radical changes in the way people eat and live. Unfortunately, as wealth grows in many parts of the world, these habits are increasing instead of decreasing.
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