In 1820 the life expectancy in the world was 29 years. Nearly 50% of children died before reaching the age of 5.

In 1920 the life expectancy had nearly doubled to 54 years. That still meant about 25% of children died before the age of 5.

Today, global life expectancy is 73 years. 0-5 death rates are at 4% worldwide.

The change can be marked by 3 major events over that time period. 1. The industrial revolution made modern agriculture capable of feeding most everyone. 2. Germ theory and the idea of antiseptic healthcare. (And yet hospitals and other healthcare facilities are still the locations most associated with premature death due to infections) 3. The rise of antibiotics as treatment for bacterial infections and vaccines for prevention of viral infections.

None of these happened overnight and really happened across a wide span of time so are really difficult to point to on a chart and say "That was the moment this event happened".

But it isn't distributed evenly across the globe. The difference between the 0-5 mortality rate from best to worst is about 65 times. In western countries like the US the 0-5 death rate is about .2%. In Nigeria it is 11.4%.

Before you think "maybe not getting diseases we now give vaccines for is causing health problems" just imagine what it must be like where the average grandparent can expect to lose 1 grandchild to childhood disease before the age of 5. Which would you rather have, a dead grandkid or a 2% chance of having one with autism.

And while autism can't be definitively pinpointed to any single cause yet, there are some interesting correlations. As marijuana use increased over the years, autism increased in the same time frames. Every mother of a child with autism I have ever met has admitted to having used marijuana before they became pregnant. Women are born with every egg they will ever have and those eggs are exposed to every substance that enters the woman's body for her entire life. And the same goes for all sorts of other substances we don't have any clue how they affect those eggs in the ovaries that showed increased rates of use over the same time frame.

It is easy to pick apart the individual cases but a huge mistake to throw everything back to the way it used to be to prevent the small anomalies that as yet haven't been explained.