I can’t believe I haven’t written anything about chocolate yet – my drug of choice, my favourite indulgence since time immemorial, something worth living for. Its earliest documented use is around 1100 BC and it was rather not so sweet – the seeds of the cacao tree have an intense bitter taste, and must be fermented to develop the flavor. The majority of the Mesoamerican people made chocolate beverages, including the Aztecs, who made it into a beverage known as xocolātl, a Nahuatl word meaning “bitter water”. I think I would still love it.
After fermentation, the beans are dried, then cleaned, and then roasted, and the shell is removed to produce cacao nibs. The nibs are then ground to cocoa mass, pure chocolate in rough form. Because this cocoa mass usually is liquefied then molded with or without other ingredients, it is called chocolate liquor. The liquor also may be processed into two components: cocoa solids and cocoa butter. Unsweetened baking chocolate (bitter chocolate) contains primarily cocoa solids and cocoa butter in varying proportions. Much of the chocolate consumed today is in the form of sweet chocolate, combining cocoa solids, cocoa butter or other fat, and sugar. Milk chocolate is sweet chocolate that additionally contains milk powder or condensed milk. White chocolate contains cocoa butter, sugar, and milk but no cocoa solids.
And while this may sound like a recipe for the routine, alkaloids are anything but. The first plant alkaloid isolated (in 1804) was morphine from the flowering poppy. Other notable examples include cocaine (1860), nicotine (1828), caffeine (1820), strychnine (1818) and a host of pharmaceuticals including the anticancer drug Vincristine; the blood pressure medication, reserpine; and the antimalarial compound, quinine.
Theobromine is mostly known as a mild stimulant in humans; it contributes (along with caffeine and a few other compounds) to that famed lift that people get from eating chocolate.
But if one looks at LD50 values, it’s obvious that the alkaloid is far more threatening to other species. LD50 is an oral toxicity measurement; it refers to the dose that will kill 50 percent of a given population and is usually calculated in milligrams of poison per kilograms of body weight. Thetheobromine LD50 is about 1000 mg/kg in humans. But for cats it’s 200 mg/kg and for dogs it’s 300 mg/kg – in other words, dangerous at a far lower dose.
The different toxicities have to do with the way different species metabolize the alkaloid; humans process it much more efficiently than canines. And in small amounts, theobromine’s effects can make it medically useful. But even here, it shows complexity. It increases heart rate and at the same time it dilates blood vessels, acting to bring down blood pressure. It can also open up airways and is under study as a cough medication. It stimulates urine production and is considered a diuretic. It interacts with the central nervous system, although not as effectively as caffeine.This varies, of course, by animal size and shape and breed. Mind you theobromine is more concentrated in dark chocolates making them more dangerous than milk or “white” chocolate. The dark chocolate effects are so acute for canines, that the alkaloid has been tested with some success as a means of controlling coyote populations. Interestingly, rats and mice are much less affected; their theobromine LD50 is much more like that found in humans.
Now some sweet quotes:
“All you need is love. But a little chocolate now and then doesn’t hurt.” – Charles M. Schulz
“It’s not that chocolates are a substitute for love. Love is a substitute for chocolate. Chocolate is, let’s face it, far more reliable than a man.” – Miranda Ingram
“Strength is the ability to break a chocolate bar into four pieces with your bare hands – and then eat just one of those pieces.” – Judith Viorst
“Chocolate makes everyone smile-even bankers.” – Benneville Strohecker, chocolatier
“Chocolate: the poor mans’ champagne.” – Daniel Worona
“There are four basic food groups: milk chocolate, dark chocolate, white chocolate, and chocolate truffles.” – Anonymous
“Chocolate is nature’s way of making up for Mondays.” – Anonymous
“Biochemically, love is just like eating large amounts of chocolate.” John Milton, The Devil’s Advocate