Chocolate

Why the chocolate is an aphrodisiac food?
The book says that: "The Aztecs and Mayans were the first to recognize the potency of chocolate, celebrating the harvest of the cacao bean with festivals of wild orgies. The Aztec ruler, Motezuma, reportedly drank 50 cups of chocolate each day to better serve his harem of 600 women. The belief in chocolate carried on through the Mayan empire where payment for a night at the brothel cost one handful of cacao beans. Seventeenth-century church officials deemed to partake of chocolate. Casanova, the infamous 18th-century lover, believed in the power of chocolate. And if sales are any indication of our faith in chocolate, then we do too: sales in 1990s average 600,000 tons of cacao beans consumed each year. Obviously a tried-and-true staple for lovers, chocolate now has backing from the scientific community. Besides the jolt of caffeine served up in a piece of chocolate, this savory candy also contains PEA, or phenylethylamine, the very same molecule that courses through the veins of one who is in love. Combine our internal stores of this natural amphetamine with chocolate, and one only heightens that giddy sensation known as love."
Hhmmmppp??.How they know all this things? hmmmmm?