The Science of Easter...and Chocolate

Bits ‘n’ Pieces
    Easter Sunday is, in the Christian calendar, the most important festival of the year, more theologically significant than even Christmas.  In the secular world it isn’t celebrated quite as fervently, but since Western history was dominated by Christianity, Easter Sunday is still a widely observed event.
    For Christians, it symbolises Jesus’ atonement for the sins of mankind and the rebirth of humanity through Godly salvation.  Outside Christianity it’s all about chocolate, eggs and rabbits.  That's a weird combination of stuff though.  Jesus wasn't a rabbit.  Rabbits don't lay eggs (as far as I'm aware, I'm not a Biologist) and chicks don't eat chocolate.  I am confusion. 
    So, I’ve decided to write a blog about Easter and its cultural paraphernalia, largely because the school term has finished and I finally have time on my hands, but also because it's interesting to look at the history and Science behind these traditions.  Oh, and I might as well do the Science of chocolate while I'm at it.   

Further confusion: in Rise of the Guardians, the Easter Bunny is Australian. What's the link there? Can I interest anyone in a Myxomatosis joke??

The Origins of Easter
    Let’s be clear about something first: Jesus of Nazareth absolutely existed and no self-respecting historian would claim otherwise.  Whether you believe Jesus to be a prophet, the Messiah or literally God himself is up to interpretaion.  What isn’t up to interpretation is whether he was real or not.  He was.  Get over it. 
    The influence of Christianity on Western culture over the past two millenia cannot be overstated either.  Even our dating system comes from the life of Jesus.  I mean, I just made reference to "two millenia".  Two millenia since what?  The birth of Jesus...duh.  
    We get our concept of a yearly date from a Romanian monk named Dionysius Exiguus who calculated Jesus’ birth as happening 753 years after the founding of Rome.  This year was obviously the most important in history so it was called year zero.   Anything before then was BC (Before Christ) while everything after became AD (from the Latin Anno Domini…year of the lord). 
    However, Exiguus screwed up.  The gospel of Matthew (Matt 2:1) records that Jesus was born “in the days of Herod the King”.  This is a reference to Herod the first, who died 749 years after the founding of Rome - making the date 4 B.C.  Furthermore, the gospel of Luke (Luke 2:1) tells us Jesus was born “when Quirinius was governor of Syria”.  Quirinius occupied this post from 6 - 4 BC, so if Jesus was born during the lives of both men, he must have been born six to four years before Christ.  Nice going Exiguus.
    The date of Jesus’ execution is a little easier to pin down though.  The gospel of John (John 2: 20) tells us Jesus first visited Jerusalem in the 46th year after the Temple started construction.  We know Herod began this project in 19 BC, so that places the date as 27 AD.  We are then told that three years passed before he was crucified (John 2:13, John 5:1, John 12:12), making the final year of his life 29 AD. 
    The gospel of Luke however refers to Jesus first visiting Jerusalem in “the fifteenth year of the reign of Tiberius Ceasar” (Luke 3:1) which was 29 AD - the year John records him dying.  Fortunately, the three synoptic gospels record the time between Jesus’ visit to Jerusalem and crucifixion as  one week (not three years) so all four gospels agree on the date of death, even if they disagree on the rest of his timeline.
    We are also told the crucifixion took place on “the day of preparation” (Matt 27:63) a reference to the Jewish week.  In Judaism, Saturday or Shabbat is considered the final day of the week (Sunday is the first) and it is a day of rest and religious contemplation.  The day before is the “day of preparation” for Shabbat, meaning the crucifixion took place on a Friday.  Jesus’ resurrection is reported to have happened two days after the crucifixion, making it Sunday morning.  The early Christians decided Sunday was therefore a more appropriate holy day and made Monday the start of their week instead. 
    And in case you’re curious, in 1988 the International Organization of Standardisation decided Monday was officially the first day of the week, going with Christian custom rather than Jewish.  What a fun meeting that must have been. 
    Jesus was in Jerusalem to celebrate passover which, in 29 AD, took place on Monday the 18th of April.  We know he celebrated this passover with his disciples, so the crucifixion must have occured the following Friday, making the date of his resurrection April 25th.  But Easter’s date moves every year!  This year it's happening on April 1st.  Next year it will be April 21st and last year it was April 16th.  Why is Easter, quite literally, a movable feast?

Oh, and Jesus wasn't white

Look to the Moon
    The Babylonians based their yearly caqlendar on the moon’s phases.  Of course they did, the moon's awesome.  Every twelve lunar cycles was a regeneration of the twelve signs of the Zodiac so the year was split into twelve “moonths” or “months”.  The Babylonians passed this calendar to both Greek and Jewish culture, which is why the number twelve is such a prominent number in their writing.
    The Egyptians however marked their year after the four seasons giving us a 365 day repetition.  They obviously didn't know about the solar system, but their calendar was inadvertantly based on Earth’s orbit of the Sun. 
    This gave us two rival calendars being used in 1st century Judea; the lunar and the solar, but they do not sync-up.  The moon’s phases do not coincide with Earth’s orbit around the Sun, so dates in both calendars are different which can lead to obvious confusion.
    The Jewish calendar has the feast of Passover fixed on the 15th day of the month of Nisan, based on the Moon-calendar.  The Chrisitian church was originally comprised of Jewish and Greek people, so their date for Easter was fixed in a similar way.  But from the perspective of the Romans (who adopted the Egyptian Sun-calendar) the date of Easter moved back and forth in line with the moon's phase. 
    Since the Roman empire eventually conquered most of the Western world, it was their Sun-calendar which won out and we mark a year as the time taken for a solar orbit.  By contrast, Christmas, a festival introduced centuries later, has a fixed point in the solar year (December 25th) but oscillates back and forth from the perspective of the Jewish calendar.
    The name “Easter” arose later, in 7th Century Germany, from the name of the Goddess Eoster.  Eoster was a deity associated with spring and fertility whose feast was celebrated in April and thus, the Jesus-resurrection festival became known as the Easter festivel.  The name Eoster seems to come from an even older German word Austro which means “shine”.  This is most likely where we get the word “East” because it's the place where the Sun begins to shine every morning, a symbol of new life.
    Oh, and during the 12th Century, the word “Good” also meant “Holy” so the Friday of Jesus’ crucifixion, originally called Holy Friday, came to be called Good Friday.  Just in case you were wondering why it was a "good" thing Jesus was brutally tortured and executed in public.

Historically, his name wasn't Jesus either...it was Joshua

So where do eggs and rabbits come in?
    Easter eggs are, surprisingly, one of the oldest Christian traditions, possibly as old as communion itself.  Eggs have always been a symbol of new life, particularly around the Spring season when plants start to grow again.  The early Christians began painting Spring-eggs red to symbolise the blood of Jesus and as time marched on the decorations became more elaborate, so egg-painting became a staple part of Easter fun.  The rabbit connection however, gets a bit weird. 
    Rabbits are notoriously hard to tell their sexes apart.  Males and females both have extremely small genitals which are hidden and look similar, even on close inspection.  For centuries, people believed rabbits were simultaneously male and female meaning they could, theoretically, have sex with themselves and induce “virgin birth.” 

There.  That’s a fact you now know.  

    You might have reasonably assumed rabbits and hares were pagan fertility symbols because they breed a lot in Spring but it turns out that's not true.  Rabbits were believed to engage in virgin birth rather than sex, so they became associated with the Virgin Mary and thus Christian religious festivals.  During the sixth Century, Chinese artwork also featured a lot of three-rabbit images (nobody knows why) but it was adopted by the Romans and when they converted to Christianity, brought rabbits along as well. 
    The whole thing is a result of obscure Chinese artwork and sexual ignorance, but a lot of medieval churches and paintings across Europe feature rabbit symbolism (some examples pictured below) and at some point, the rabbit became tied specifically to Easter.
    That seems to have begun in 17th century Germany where The Easter Hare served a similar function to Santa Claus - punishing naughty children and rewarding good ones the night before Easter.  My guess is that Christmas already had an associated winter-spirit so the rabbit was picked as his spring-time equivalent.  And since colourful eggs were a big part of Easter tradition already, it made sense for these to be the Easter Hare's gifts.  Today this has become the Easter egg-hunt and, of course, the chocolate egg. 

Right, now that we’ve done rabbit genitals, let's talk about chocolate.

What is chocolate?
    To get chocolate you start by picking fruit of the Theobroma cacao tree which tends to grow best in South America.  When you open the fruit you’ll find white seeds which you have to ferment with a fungus called aspergillus. 
    Once the cacao seeds have been digested, you remove the shells, grind them up and heat the whole thing.  A thick brown paste forms which, on cooling, separates into cocoa powder which is a brown solid and cocoa butter which is a white wax.
    People of the Inca and later Aztec empires would often use both ingredients as stock for various drinks, sometimes mixed with chilli powder, giving an early form of what we would now call hot chocolate.  When the Spanish invaders landed, they took the recipe home and began adding sugar, honey and vanilla to soften the bitter taste of the drink. 
    Chocolate drinks became very popular throughout Western Europe over the next hundred years.  So popular in fact that in 1662 Pope Alexander VII sanctioned the consumption of chocolate drinks during lent saying that drinking chocolate did not count as breaking your fast.  Thus, chocolate became associated with Easter.
    It wasn’t until 1847 that the confectioner Joseph Fry perfected a way to solidify the chocolate drink into a bar.  By a careful process of churning and cooling slowly, Fry was able to prevent cocoa crystals forming (which made things brittle) and generated lumps of sweet brown matter with a similar consistency to soap. 
    Fry’s company soon designed three types of chocolate bar.  Milk chocolate which contained cocoa powder, cocoa butter and sugar; white chocolate which contained only cocoa butter and sugar; and dark chocolate which contained only the cocoa ingredients and no sugar. 
    Then, in 1873, Fry decided to capitalise on the significance of eggs during the Easter season and began making small chocolate eggs instead of bars.  Originally a solid piece of chocolate, this became the infamous Easter egg, which was eventually increased in size and made hollow in order to contain small toys or...more chocolate.  

The fact the little boy on the Fry's wrapper looks like an egg is probably a coincidence

    
    Chocolate has since become the most widely consumed confectionary product in the world and, like anything popular, this has led to innumerable myths and pseudofacts.  So, to finish, let’s take a brief moment to look at some of the more famous chocolate myths and seperate the powder from the butter.

Is chocolate really poisonous to dogs?
    Yes.  Chocolate contains a chemical called theobromine which is poisonous to most animals so it has to get broken down once it’s inside you.  Dogs break it down very slowly however, so theobromine can reach toxic levels for them very quickly.  A big dog eating a small bar should be fine, but a small dog eating a large bar is at serious risk. 
    Technically, theobromine is poisonous to humans as well, we’re just good at breaking it down before it does damage.  You’d have to eat around 40 kilograms of milk chocolate in 24 hours to reach toxic levels.  Bearing in mind a standard bar of chocolate weighs 40 grams, this is a thousand bars in a day.  You're probably safe.  Just don't feed it to your dog.

That's why I keep Oompa-Loompas as pets...easier to clean up when they die

Is chocolate addictive?
    Yes and no, depending on what you mean by addictive.  When we talk about addiction we usually mean a person doesn’t just like a particular substance, they feel unable to function properly without it.  Want becomes need.  The boundary gets a little hazy because you could argue that some people cannot function unless they get the thing they want i.e. they do need it.  The debate gets even more complicated because addiction has many causes, most of which are poorly understood. 
    For example, one suspected mechanism is that the body can start using the ingested chemical as a substitute for chemicals it normally produces itself.  Over time, the body stops producing its own supply and when you stop taking it artificially you suddenly find your body lacking in something.  Thus, your body is depleted and you get withdrawal symptoms like shakes, aches and hallucinations etc.  It’s suspected that opioid addiction works along these lines.
    This kind of addiction is usually termed "physical addiction" because it has a measurable impact on the body due to changes in biochemistry.  By contrast, there is the so called “psychological addiction” where the chemical doesn’t necessarily alter the biology, but you find yourself dependent on it nonetheless.
    What is speculated to happen is that certain chemicals cause a rise in dopamine - a neurotransmitter associated with happiness and ability to function.  To prevent your body getting overloaded with dopamine (which would lead to schizophrenia), the body increases production of enzymes to break dopamine down and keep it at a tolerable level. 
    The more you take the drug, the more efficient your body gets at producing the enzymes and you find the drug becomes less and less effective over time.  This is "building up a tolerance" to it.  As a result, you find yourself needing to use more and more to get the desired effects which (unbenknownst to you) leads to an increase in the amount of enzymes as well. 
    When you finally stop taking the drug your body is still producing the enzymes in large amounts, but you’ve stopped boosting your dopamine.  All your naturally-produced dopamine gets destroyed quickly and you get a loss in psychological comfort.  In other words cravings, insecurity and sometimes depression. 
    Chocolate can cause a very small surge in dopamine so it is definitely possible to become psychologically addicted to it.  There are certainly reports of people who become so dependent on chocolate they don’t feel comfortable without eating it...so would we say they are unable to function therefore?  
    Harsh critics might say these people need to just use willpower to quit whatever they have become dependent on.  While others might point out that addiction to chocolate can be just like addiction to any other chemical substance.  The terminology is ill-defined but the take-home message is that even when a particular food or drug is described as “non-addictive”, that only means it’s not phsyically addictive.  You can still become addicted to it.  So be careful folks.

I'm not going to make a joke about addiction, so instead here's a terrifying picture of the Easter bunny

Wasn’t there a study which proved chocolate helps you lose weight?
    No.  Although it certainly seemed like it when Johannes Bohannon made global headlines in 2015, claiming to have found a link between chocolate and weight loss.  As interesting as this news story was, things were not as they seemed.  Johannes Bohannon (known by his real name Dr John Bohannon of both Oxford and Harvard University) was actually carrying out a subtle experiment, not on chocolate but on the media.  He wanted to see how carefully newspapers, magazines and websites would check a Scientific study before reporting it, so he decided to perform a deliberately terrible experiment and see how many outlets would pick it up.
    The trick he used was to carry out his experiment on a small number of people (15) and look at dozens of changes to their body.  By measuring all sorts of things he was able to find a link purely by coincidence.  A technique called "p-value manipulation".
     Imagine I give three people a pill and ask them how they feel.  Let’s say by coincidence all three of them have good days at work.  I could claim “this pill makes you have a good day at work!”  Or if, by a different coincidence all three people happened to sneeze a lot, I could claim “this pill makes you sneeze”. 
    If you keep asking people for information you’ll find a pattern eventually.  And it just so happened that the 15 people in Bohannon’s study all lost a tiny bit of weight, so that was the outcome reported. 
    Bohannan also decided to break with scientific protocol and went straight to the media with his claim rather than getting other scientists to peer review the article first.  A lot of reporters seized on the story because it sounded amazing however, and the study exploded.
     Bohannon’s experiment teaches us several things.  First: when a Scientist is doing an experiment they should have a clear view of what result they’re measuring i.e. don’t keep looking for results until you find them (because you always will).  Second: just because the words “a study has shown…” are used in a report doesn’t mean that study was a good one.  And perhaps most importantly, when you hear a headline about a Scientific discovery, check to see what other Scientists think first.

Really?

Does Chocolate Cause Bad Skin?
    No.  This one’s a very popular factoid but it seems to be completely untrue.  Many studies have been conducted on the impact of chocolate on human skin and none have found a link.  If you have a sudden rash on your skin, there are lots of things which could be causing it, but it's not chocolate.  I do have my own idea how this myth arose though.
   One thing which is known to cause bad skin is stress.  When you’re under a lot of emotional pressure or just really emotionally tired, the body produces cortisol which has the side effect of giving you bad skin.  My hypothesis is that stress causes acne and people also tend to manage stress by eating high caloric foods e.g. chocolate.  Think of the running joke of people binge-eating chocolate when they’re sad or the stereotype of menstruating women chowing down on chocolate ice cream. 
    I propose that stress causes both overeating chocolate and bad skin, leading to a misattribution of cause and effect.  Any thoughts?

Is this racist?

And finally...is chocolate an aphrodisiac?
    No.  Chocolate contains small amounts of tryptophan which the body can turn into serotonin, a chemical often produced when people fall in love.  The claim therefore runs that consuming large amounts of chocolate causes amorous feelings.  But the amounts contained in a bar are vanishingly small; far less than in a leg of turkey or a glass of milk which are not usually associated with hanky-panky behaviour.  My guess is that chocolate simply tastes nice so people give it to loved ones on special occasions (eg Valentine’s day) when amorous feelings are already on the table. 
    Is it theoretically possible to consume so much chocolate it becomes a subsitute for romance and sexual thrill though?  Well, I guess technically yes, but you’d have to eat crate-loads of the stuff and as we’ve already seen, that will kill you before you fall in love.  If you want to feel all loved up you’re better off watching Titanic rather than dying.  And if you don’t like Titatnic then you’re probably dead inside already.

Rose, seen here recreating the Crucifixion

Happy Easter Folks!


Image Credits
Easter Egg: Leicestershirediabetes
Easter Bunny Boomerang: deviantart
Christian Bale as Jesus: fanpop
Robert Powell as Jesus: rejesus
Mary Painting: apollo-magazine
Three Hares: Chinesepuzzles
Fry's chocolate: flickr
Willywonka: denofgeek
Scary Easter Bunny: YouTube
Chocolate Cancer: Twitter
Chocolate Skin: nowloss
Titanic: grantland