How Did a Parisian Lemonade Craze Fight the Plague?

While the black plague ravaged the rest of France, Paris remained relatively untouched -- and they may have had their fondness for lemonade to thank. Learn why in this episode of BrainStuff.

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Episode Transcript

Speaker 1 (00:02):
Welcome to brain stuff from how Stuff Works. Hey there,
brain stuff, Lauren Vogel bomb here. In the seventeenth century,
a return of plague, also known as the Black Death,
killed about one million people in France. Oddly enough, the
residents of Paris were largely unaffected, despite having the same
rat problem as any other large city. The rodents carried

(00:23):
fleas that bore the plague. After the plague killed the rats,
the fleas often hopped onto human hosts. In this way,
the plague spread like wildfire, snuffing out life after life.
The Parisian's miraculous avoidance of the plague could have remained
one of history's mysteries, but author Tom Nielan squeezed a
potential explanation out of seemingly desperated events. A purveyor of

(00:44):
rare books, Neilon is not only a connoisseur of history,
but of the impact that condiments and food stuffs may
have had on antiquity. His new book of Food Fights
and Culture Wars follows these sometimes surprising influence food has
had throughout history. Neilan says health food were intimately connected
for the longest time. Early collections of recipes frequently mixed

(01:05):
medical and cookery receipts as recipes were called, so it's
easy to start to conflate them when you're studying the
period and old cookbooks. Even after they started to separate,
the Renaissance Book of Secrets kept elements of food and
home remedies together for centuries longer in the case of Paris,
and it's largely unscathed population. In the sixteen hundreds, the

(01:25):
timing of a lemonade trend and the timing of a
plague coincided, and Nilan wondered whether it was more than
a coincidence. Up until the sixteen hundreds, lemons had been
a rare and expensive fruit. All the lemon trees had
been cultivated throughout Europe and Asia in the preceding decades,
and a few recipes using lemon as an ingredient had emerged.
The citrus fruit was a little used in England and France,

(01:47):
both because of cost and the notion that eating raw
lemons was harmful. Then an increase in trade and a
fascination with lemonade popularized the tart fruit, so that by
the mid sixteen hundreds it was widely available. Nilan explained,
during the Renaissance, lemons had been bread and domesticated enough,
and trade had become organized enough that lemons were sufficiently
inexpensive in the mid seventeenth century to import in bulk.

(02:10):
Lemonade was all the fashion in a number of cities
in Italy at the time, especially Rome, and the fad
spread from there. The cookbook liquis ineur Francois, published in
sixteen fifty one and written by chef Francois Pierre Lavarenne,
is considered one of the founding texts of modern French cuisine.
It included a recipe that combined lemon juice, water and sugar.

(02:30):
This recipe also contributed to the popularity of lemonade in France.
And with all this lemonade came lots and lots of
lemon peels. Lemon peels were everywhere, in the garbage, in
the gutter, in the river, anywhere that you could find rats.
It was this fortuitous combination of rats and lemon peels
that may have stopped the spread of plague. Lemon peels
contain lemoning, a natural ingredient that kills flea larvae and

(02:54):
adult fleas. The more people that made lemonade and discarded
the lemon peels, the more the rats nibbled on the peel,
inadvertently ingesting, lemoning, and killing fleas and their eggs. Neil
And says the lemoning disrupted the spread of fleas from
the rats to people. Because the plague kills so quickly,
the fleas needed to move from rats to people back
to rats over and over again to keep it going

(03:15):
as their hosts expired. Lemoning, a flea killer that is
still broadly used in pet treatments, killed the fleas and
prevented the chain from getting going. At the time and
four centuries after the plague subsided, the survival of Parisians
was attributed to an airing out of goods blankets, bedsheets,
clothes that had been quarantined. At the time. It was
mistakenly believed that the illness traveled by air, when it

(03:37):
was really the rats and fleas traveling with the quarantined
goods that were at the root of the plague. If
not for Parisians love of lemonade, many more may have
met a tragic end. Today's episode was written by Laurie L.
Dove and produced by Tristan McNeil. For more on this
and lots of other lemony fresh topics, visit our home planet,

(03:59):
how stuff dot com