@GossiTheDog in my own living memory I remember being told "eat carrots, they are good for eyesight" - whilst there are benefits to eyesight and general health from eating them, it originated as WW2 propaganda that British pilots could see well at night from being served them in military canteens (when the reality was we had radar)

People in Britain did not stop fighting WW2 in their heads until around 1987, and even then lingering suspicion about "The Continent" fed into Brexit vote as much as the Russian propaganda..