Tuesday, September 20, 2011

Lets Put This Life Expectancy Crap To Rest

Ok, one of the most common criticisms of the paleo diet is that paleolithic man (of 15,000 years ago) lived to only 18 years of age.  This point is so ignorant that it requires a quick education.  What critics really mean is the average life expectancy was 18 years.  Let's be clear what "life expectancy" means.  What this statistic describes is the average length of life a baby would expect to have after they were born.  This average takes into account men who lived to 70, babies who died at birth, men who fell off cliffs at a young age, mothers who died during child birth and even young children who starved due running out of baby formula (there weren't as many Walmarts back then).  

Sure their average life expectancy was short relative to today.  Paleolithic man had an average life expectancy of about 18 years vs. about 78 years in the US today.   There is little forensic evidence showing they died from chronic diseases vs. what people mostly die of today.  As recent as 1786 the average life expectancy in the US was only 24 years.  In a matter of about 15,000 years life expectancy went up a mere 6 years.  Not so impressive.  Consider that the increase from 1786 to today has increased 54 years.....that is very impressive.

You may ask why there has been such a jump in life expectancy in roughly 200 years verse a very small change in the previous 15,000.  Two advances deserve much of the credit, proper sanitation and modern medicine.  We can now prevent many early childhood deaths, better prevent plagues, and treat infections.  

This is a simple concept to comprehend and seems like it should be common sense.  It's not for many.  So the next time you hear someone drop the life expectancy bomb on your food choices, throw a little knowledge back at them.  Then ask them why our kids are expected to have shorter lives than us despite all the "great" nutrition advice being doled out in popular magazines like Time and US News.



Jan said...

I loathe that argument - even my 16-year-old can shred it to pieces in about 30 seconds, and has when listening to criticism about our diet from his friends. Friends who, oddly enough, are heavier and have bad skin and short attention spans and lots of cavities.

N Matheson said...

I wouldn't worry about it Paleolithic man had a mean life expectancy of 35-40 This is worked out by wear on teeth and joints, some archaeologists think that age estimates should be revised upwards. 20th century HGs have many older people in their societies and live lifestyles broadly analogous to Paleolithic man.