Measuring Health

Various methods exist to gauge human health, one of which involves counting the prevalence of diseases such as diabetes, lung conditions, and heart ailments. Current statistics indicate a rise in reported cases of these conditions compared to the 1980s and 1990s. Part of this increase can be attributed to expanded diagnostic criteria—individuals today might be diagnosed with diabetes who would have previously been deemed healthy—but there is also a genuine uptick in some diseases, likely linked to lifestyle choices such as increased weight and decreased physical activity.

However, this perspective is somewhat narrow. While heart disease remains a serious issue, the survival rate for such conditions in the 2020s is significantly better than in the 1920s. You may face a higher likelihood of certain diagnoses than your great-grandparents did, yet modern medicine allows for far greater survival rates.

Surviving heart disease today is not merely about "leeches and hope." Photo by David Trinks on Unsplash.

A valuable tool for assessing human health is life expectancy. Many people misunderstand this term, thinking it refers to the number of years a newborn is expected to live. In reality, it reflects how long a person born today might live if they experienced the same conditions as current populations. Essentially, it considers both longevity and the causes of mortality.

This makes life expectancy a powerful indicator of health, as it accounts for both longevity and the survivability of diseases. Remarkably, life expectancy has dramatically increased worldwide over the last century.

The graph illustrates notable declines during events such as World War II and the catastrophic Chinese famine of 1960-61.

Even if illness rates are rising, the likelihood of those illnesses resulting in death is not increasing correspondingly. This evidence strongly suggests that the average person today enjoys better health than at any time in history.

Intuitively, this makes sense. Although diabetes is more prevalent now, advancements in treatment mean it has less impact on healthy living than in the past. Chronic diseases may be on the rise, but infectious diseases, which once claimed millions of lives, now contribute far less to mortality rates. While diabetes and infections still present challenges, they are much more manageable today than before.

Two significant counterarguments often arise regarding life expectancy as a health metric. First, critics point out that life expectancy at birth primarily reflects reductions in infant mortality. Historically, many children did not survive past age five, so modern advancements in child healthcare may inflate life expectancy figures, even if the average lifespan doesn't increase significantly.

However, this claim is inaccurate. Life expectancy at birth has risen alongside life expectancy at every age. A 40-year-old today can expect to live longer than a 40-year-old from the 1960s, and this trend holds true across all age groups, although the differences narrow for older individuals.

The second argument against life expectancy as a health measure is the notion that longer life does not equate to better health. One could envision a scenario where medical advances allow people to live longer but in poor health.

This perspective is misleading. While historical data on human health is limited, existing information indicates a consistent improvement over time. One method of assessing this is by examining years lived with disabilities. Eventually, aging impacts nearly everyone, but data on Disability Adjusted Life Years (DALYs) shows that people are living longer, healthier lives than ever before.

The data from Our World In Data highlights that, on average, we are enjoying longer, healthier lives than at any point for which we have reliable data.

COVID-19: A Temporary Setback

Unquestionably, COVID-19 has had a profound impact on global health. The data shows a noticeable decline in life expectancy during 2020 and 2021 due to the pandemic’s toll. However, advancements in vaccines and treatment options have significantly mitigated its earlier dangers. While the datasets used by Our World In Data extend only to 2021, more recent research indicates that life expectancy reductions caused by COVID-19 have largely reversed, with many countries, including the United States, returning to or surpassing pre-pandemic life expectancy levels.

Understanding the Paradox

Many individuals find themselves puzzled by the juxtaposition of rising chronic disease rates alongside overall improvements in health metrics. How can this be?

One aspect is the increased survivability of chronic diseases, as previously mentioned. Additionally, many historical threats to human life have been significantly reduced. Diseases like tuberculosis have nearly vanished in high-income countries, although they still claim hundreds of thousands of lives globally each year. Over the past century, road fatalities have decreased by over 90% due to safety measures. Vaccination, sanitation, and other public health initiatives have dramatically lowered rates of diseases such as cholera and childhood drowning, and all indicators suggest that progress continues.

Attempting to find an image of antibiotics proved challenging, but let’s assume this represents amoxicillin for the sake of optimism. Photo by Roberto Sorin on Unsplash.

While chronic diseases have risen over the last four decades, these conditions are only possible because we have largely neutralized many other threats that once caused significant harm. Polio, once a widespread cause of disability, is now nearly eradicated thanks to vaccines.

It is true that some metrics show we are faring worse than in the past. Diabetes rates are climbing, and heart disease remains stable but at higher levels than decades ago. Meanwhile, cancer rates are decreasing overall, primarily due to successful smoking prevention and improved workplace safety, though rates in younger populations are rising.

Nevertheless, the overall enhancements in human health far outweigh the challenges posed by chronic diseases. Chronic conditions are indeed a serious concern, and I have extensively studied diabetes epidemiology. However, these issues arise in part because we have made such significant progress in other areas. Diabetes is closely linked to age; populations with high adult mortality rates typically do not exhibit high rates of Type 2 diabetes.

Claiming that we are all becoming unhealthier is an effective strategy to market supplements, but it misrepresents reality. On average, you are the healthiest person in your family’s history, and your children are likely to be even healthier. While challenges remain, we are overall the most fortunate humans to have ever existed.