Chocolate has been irresistible for ages: the Aztecs used it as currency, the Spaniards kept it a secret from neighboring countries for about a century, and the average American eats 9.5lbs of it in one year. It's safe to say we’re all obsessed with chocolate… and we may even be addicted to it.
So, if you’ve proclaimed chocolate as your drug of choice, you’re not alone. But what is it about chocolate that turns some people from dabblers into full-blown chocoholics?
Your brain thinks it’s a drug
It turns out that a substance called enkephalin may be responsible for turning chocolate from a pretty tasty treat into a legitimately impossible-to-resist indulgence. Researchers who fed chocolate to rats (fun!) found that enkephalin triggered opioid receptors -- yep, the ones that react to opiates like morphine -- in a part of the brain that increases the impulse to eat. The effect worked both ways: chocolate consumption spurred enkephalin production, and injections of enkephalin-like substances increased chocolate consumption, suggesting that it’s pretty easy to binge on the stuff. Once you start, your brain tells you to eat more. And more. And more.