Pandemics and the Epidemic of Heart Disease
This paper argues that the heart disease epidemic of the early 20th century was primarily caused by infectious pandemics in 1889 and 1918 that "primed" affected birth cohorts for later mortality, a factor deemed more significant than smoking or diet.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Imagine your body is a bustling city. For a long time, this city was pretty quiet, but then, in the early 1900s, something strange happened: the city's main power grid—your heart—started crashing more and more often. It wasn't just a few glitches; it was a full-blown epidemic. People started asking, "Why now? What changed?"
Most people thought the culprit was the city's lifestyle: maybe too much greasy food (like lard and butter) or too many people lighting up cigarettes. But this paper suggests a different story entirely. It argues that the real trouble started with a massive, invisible invasion that hit the city decades earlier.
The Great "Priming" Event
The authors propose that the heart disease epidemic didn't start with bad habits, but with a massive infection that swept through the population in 1889. They call this the "Russian flu." Think of this virus like a mischievous hacker who didn't just crash the system once; it left a "backdoor" open in the city's defenses.
When people survived this 1889 pandemic, their bodies didn't just go back to normal. Instead, the infection "primed" them. Imagine the city's immune system got so worked up by the attack that it started building thick, hard walls (atherosclerosis) everywhere to protect itself. These walls were meant to keep bad things out, but over time, they clogged the pipes and strangled the heart.
The paper suggests that the 1889 pandemic was the spark that lit the fuse for the heart disease epidemic that would rage through the 20th century.
The Double Whammy
Here is where it gets even more dramatic. The authors found that some groups of people got hit twice.
Imagine a group of kids who were born between 1870 and 1894. They were young enough to catch the 1889 "Russian flu" (which might have been a coronavirus, similar to the one causing COVID-19 today). Then, when they were in their 20s and 30s, the infamous 1918 influenza pandemic hit.
These folks were "doubly injured." They had the backdoor left open by the first virus, and then the second virus slammed right through it. The paper shows that men born in this specific window had the highest heart disease death rates of anyone. It's like they were the only ones who had to fight two wars back-to-back, leaving their city defenses completely shattered.
In contrast, people born after 1895 mostly missed the 1889 virus. They only faced the 1918 pandemic. While they got sick, they didn't have that "primed" vulnerability from the first attack, so their heart disease rates didn't skyrocket as high.
What Wasn't the Villain?
The paper is very clear about what wasn't the main cause, even though people often blame them:
- Diet: The authors argue that diet likely played "little or no role." They point out that if bad food (like butter and smoked meats) was the cause, heart disease should have been high right at the start of the 1900s. Instead, it was low and then exploded later. Plus, they note that heart disease has been found in ancient mummies from places with totally different diets, suggesting the body's reaction to injury is the real issue, not just what you eat.
- Cigarettes: Smoking is a known danger, but the paper suggests it wasn't the main driver of this specific epidemic. In fact, as more people started smoking in later generations (born after 1900), heart disease rates actually went down. The authors suggest that while smoking might have made things worse for some, the "susceptibility" caused by the infections was a much bigger factor.
The Numbers Tell the Story
The data backs this up with some heavy hitters:
- Over 95 percent of the heart disease epidemic can be blamed on people born before 1895 (the ones who lived through the 1889 pandemic).
- For men born between 1870 and 1894, the heart disease death rates were the highest of any group.
- The epidemic officially "ended" around 1959, when the older generations who had been "primed" by the 1889 virus had mostly passed away.
The Big Takeaway
The paper suggests that heart disease isn't just a slow, inevitable aging process or a result of bad choices. Instead, it looks like a "transitory condition"—a temporary state caused by the body's reaction to massive infections.
The authors warn that this isn't just history. They point out that if a new pandemic hits (like the one we faced recently), it could leave a similar "echo." Just as the 1889 and 1918 viruses set off a chain reaction that lasted decades, a new widespread infection could "prime" a whole generation for heart trouble later in life.
So, the next time you hear about a heart disease epidemic, remember the story of the city that got hacked twice. It wasn't the pizza or the cigarettes that broke the grid first; it was the invisible invaders that left the doors wide open.
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