This was shared by my sister Vivi*.
2000 BC - Here, eat this root.
1000 AD - That root is heathen. Say This prayer.
1850 AD - Prayers are superstition. Here, drink this potion.
1940 AD - That potion is no better than snake oil, Here, swallow this pill.
1985 AD - Pills are somewhat overrated. Here, take this antibiotic.
2003 AD - Antibiotics don't work anymore. Here, eat this root.