We Are The Healthiest We've Ever Been
On average, humans are right now healthier than at any point in our past history
Note: with thanks to the Our World In Data team, who I’ve leaned on heavily for their excellent visualisations of human longevity in this piece. They are a registered charity, and if you have a few pounds/dollars to spare, I would recommend a donation. Data is both beautiful and vital.
There’s a common myth that you will find online. It’s often told by people hawking supplements, by health gurus, and in general from those who have something unproven to sell that they claim will make you healthier in some vague and obscure way. The myth goes like this: in this modern age, humans are unhealthy. We are fat, lazy, poisoned by pollutants, and every year we just get worse.
This is usually followed by “but buy MY product, it’ll fix all that” because of course it is.
The problem is, this idea is simply not true. While there are ways in which humanity is less healthy now than in previous generations, overall we are living in the healthiest age in humanity’s collective history. Not everything is sunshine and roses, but personally I’d rather be alive now than at any point in the past.
Measuring Health
There are many ways to conceptualize human wellbeing. One way is simply to count the number of diseases that we see in society - how many cases of diabetes, lung disease, heart disease, etc. If you look at these figures, it does seem like people are more likely to report having various comorbidities in recent years than they were in the 80s and 90s. Some of this is explained by widening diagnostic criteria - there are people who have what we’d call diabetes today who would’ve been classified as healthy in the 80s, for example - but some of it is a real rise in certain diseases that is likely due to lifestyle factors like weight gain and inactivity.
This is, however, a fairly limited way of looking at human health. Having heart disease is bad, but having heart disease in the 2020s is much less bad than having heart disease in the 1920s. It’s true that you are somewhat more likely to get certain diagnoses, particularly those associated with obesity, in recent years than your great-grandparents, but you are also far more likely to survive those diseases than your ancestors.
One very useful method of looking at overall human health is life expectancy. People often misunderstand life expectancy, in part because it’s an inherently misleading term. Life expectancy at birth does not calculate the expected years of life for someone born today - rather, it calculates how long we would expect a person born today to live if they were, on average, to experience exactly the same conditions as people alive right now. If we take the average lifespan of people dying today, look at the causes of death, and apply that to someone born this year, with no improvements or advances in medicine or health in the ensuing years, we get life expectancy*.
This makes life expectancy a useful measure of human health because it looks at both how long people live and what is killing them. So not just the diseases, but also how survivable those diseases are. And pretty much the entire world has seen dramatic increases in life expectancy over the last 100 years.
Even if we are getting sicker more often, those illnesses are, on the whole, not killing us at increasing rates. This is a simple but powerful way to show that the average person today is healthier than the average person at any point in the past.
In many ways, this also makes intuitive sense. You’re much more likely to get diabetes than previous generations, but with new treatments and better management diabetes is now a disease that has a smaller impact on healthy lifespan than it used to. And while chronic diseases are more common, infectious diseases - which were once the biggest killers of humanity - are now more of a footnote on the death toll. None of this is to say that diabetes and infections have stopped being problems, but it is true that they are much more survivable problems than they used to be.
There are two main arguments against using life expectancy as a measure of human health. The first is that we are looking here at life expectancy at birth, which tracks any death from age 0, and therefore this just shows benefits to infant mortality. Large portions of humanity used to die before the age of 5, and since we can now prevent most of the things that kill small children life expectancy at birth will rise drastically even if the average person isn’t really living longer.
The data show that this is simply inaccurate. Life expectancy at birth has increased, but so has life expectancy at every other age. A 40-year-old today will, on average, live longer than a 40-year-old in the 1960s. The same is true for people at literally any age you pick, although obviously the differences get smaller the older you go.
The second objection that you hear is that life expectancy isn’t a good measure of health specifically. You can imagine a situation where people live longer but are less healthy for that time, with advancements in medicine leaving us in poor health but clinging to life.
Again, this argument is just not correct. While we don’t have measures of human health going back as far as life expectancy - even the idea of measuring things like quality of life is a relatively modern concept - but the data we do have shows a steady increase over time. One way of measuring this is the number of years that people on average live with a disability. Eventually, old age disables almost everyone to some extent, so if you look at the average rate of years lived with and without a disability, you can look at how human health has improved over time.
As the graph from Our World In Data shows, this has also been improving for decades. This is based on a metric called Disability Adjusted Life Years, and represents the work of the Global Burden of Disease team at the Institute for Health Metrics and Evaluation. On average, we are living longer lives that are also healthier than at any point in the past for which we have adequate data to assess.
COVID-19
The elephant in the room is, of course, COVID-19. While most of these graphs show only improvement over time, there is a noticeable dip in 2020/21. This is because COVID-19 killed a lot of people, and any large number of deaths will reduce life expectancy temporarily.
Fortunately, due to vaccines and improved treatments, COVID-19 is no longer the risk it once was for human health. Our World In Data, who produce the excellent graphs I’m referencing, use public datasets that only go up to 2021. More recent research has, however, shown that life expectancy reductions caused by COVID-19 have somewhat reversed, and countries including the United States are back to levels of life expectancy that are similar to or in some cases slightly better than their pre-pandemic figures.
Stubborn Improvements
It’s at this point that a lot of people are thoroughly confused. On the one hand, there are increasing rates of several serious diseases, in particular heart disease and other metabolic conditions. On the other, by any reasonable metric of ‘health’ we have been improving across the world for many decades.
What’s going on?
In part, this is because of the fact that chronic diseases have become more survivable, as I mentioned earlier. But it’s also because many of the worst dangers to humanity have been substantially mitigated. Tuberculosis has become a disease that is almost entirely gone in high-income countries, although shamefully it still kills 100,000s of people worldwide each year. In the last century, the death and serious injury rates for road fatalities have dropped by more than 90%. Things like vaccination, sanitation, and basic public health initiatives have dropped the rate of everything from cholera to childhood drowning to record lows, and all the data seems to show that things are still improving.
The last 40 years has seen the rise of chronic diseases, but these diseases are in large part only possible because all of the other things that used to kill and disable us have been mostly defanged. Polio used to cause fairly regular disability, ironically made worse by improved sanitation, but is now almost eliminated from the globe due to the amazing power of vaccines.
It’s true that, by some measures, we are doing worse than we did before. Diabetes is up. Heart diseases rates are currently stable at a much higher rate than in previous decades. Cancer is overall decreasing, largely due to successes in smoking prevention and workplace health and safety initiatives, but rates are increasing in younger people.
That being said, the overall improvements we’ve made to human health far outweigh the issues we are now seeing with chronic disease. Don’t get me wrong - chronic diseases are a huge issue. I’ve done a lot of work in diabetes epidemiology, it’s a serious and ongoing problem. But these things are only problems because we’ve made such huge strides in other areas. Diabetes is strongly related to age - you don’t see high rates of Type 2 diabetes in populations where most of the adults die before age 60.
Telling people that we’re all getting sicker is a great way to scare them into buying supplements, but it’s not really true. You are, on average, the healthiest person in your family to have ever lived, and your children will almost certainly be healthier still. There are still many issues for us to solve, but overall we are the best-off humans to have ever lived.
*Note: This is highly simplified, please don’t hate me demographers.
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https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8688697/
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https://www.alz.org/alzheimers-dementia/facts-figures