Speaker 1: Welcome to brain stuff from how stuff works. Hey, brain stuff,
Speaker 1: Lauren vogel Bomb here. Anyone else have the common childhood
Speaker 1: dream to be able to hit clay pigeons with a
Speaker 1: crossbow in the dark at three yards while riding on
Speaker 1: the back of a beautiful pegasus. Just me. Anyway, When
Speaker 1: I told my parents this, they told me, Lauren, if
Speaker 1: you want to have that kind of hyper acute night vision,
Speaker 1: you've got to eat your carrots. It's common wisdom eat
Speaker 1: a lot of carrots if you want eyes like a
Speaker 1: jet pilot. But do carrots really give you better eyesight?
Speaker 1: The short answer is, if you already have enough vitamin
Speaker 1: A in your diet, probably not. But if you don't,
Speaker 1: a big old sack of carrots might be exactly what
Speaker 1: you need. Carrots are packed full of a nutrient called
Speaker 1: beta carotene, which is a kind of natural dye for
Speaker 1: fruits and vegetables. Plans use beta carotene in their bodies,
Speaker 1: is a pigment that gives them a yellow or orange color.
Speaker 1: But when you eat foods containing this natural pigment, like
Speaker 1: sweet potatoes, spinach, or carrots, the beta carrot he can
Speaker 1: gets absorbed by your intestinal wall and converted into vitamin A.
Speaker 1: So here's the true part of the myth. If you
Speaker 1: want to maintain normal eye health, you've got to get
Speaker 1: enough vitamin A, and carrots are a perfectly good source.
Speaker 1: In regions where people don't get much vitamin A and
Speaker 1: their diets, vision problems are rampant. Without vitamin A, the
Speaker 1: photo receptors in your eyes start to deteriorate and your
Speaker 1: corneas can actually vanish. But if you don't have a
Speaker 1: vitamin A deficiency and your vision is already healthy, stuffing
Speaker 1: your face with carrots or any other source of the
Speaker 1: vitamin will not lead to superhuman eyeball powers. So where
Speaker 1: did we get the idea that carrots can do to
Speaker 1: your eyes what spinach does to Popeye's forearms. Believe it
Speaker 1: or not, this myth got a big boost from World
Speaker 1: War two propaganda. During World War Two, the United Kingdom
Speaker 1: underwent air raids conducted by access powers. The German luft
Speaker 1: Buffa would strike at British cities in the night. Over
Speaker 1: the years, the British Royal Air Force had some success
Speaker 1: pushing back the German air attacks. An explanation for their
Speaker 1: success is that from nineteen thirty nine onward. British pilots
Speaker 1: had access to a technology called onboard airborne interception radar
Speaker 1: to help them spot enemy planes for a great distance,
Speaker 1: but the UK Ministry of Food launched a propaganda campaign
Speaker 1: claiming that its fighter pilots could pick out enemy aircraft
Speaker 1: in the dark because they honed their eyes with carrots.
Speaker 1: Some sources have speculated that this story was designed to
Speaker 1: hide the existence of the Royal Air Forces on board
Speaker 1: radar system from the enemy. Another explanation might be simple economics.
Speaker 1: Germans set up blockades to use starvation and discomfort as weapons,
Speaker 1: which meant that many goods like sugar, had to be rationed.
Speaker 1: The UK government encouraged its citizens to turn to sugar substitutes.
Speaker 1: For example, carrots, which were plentiful even during the war,
Speaker 1: could be used as a sweetener in foods like carrot
Speaker 1: pudding and carrot fudge, or as a substitute for meat
Speaker 1: in the infamous Wolton pie. Carrots were so plentiful because
Speaker 1: they could be grown by citizens at home and around
Speaker 1: their communities in so called victory gardens. Food supplies were
Speaker 1: low due to those blockades, and canned fruits and vegetables
Speaker 1: largely went to feed the military. Citizens were encouraged to
Speaker 1: make up the difference. The slogan of the campaign was
Speaker 1: dig for Victory. Two million private gardens were constructed and
Speaker 1: some public ones as well. The dry moat surrounding the
Speaker 1: Tower of London was filled in with growing vegetables. Today's
Speaker 1: episode was written by Joe McCormick and produced by Tyler Clang.
Speaker 1: For more on this and lots of other sharp topics,
Speaker 1: visit our home planet, how Stuff Works dot com.