First of all, chocolate isn't always chocolate. What I mean is, raw chocolate isn't the same as dark chocolate and isn't the same as milk chocolate so before we can talk about 'chocolate' let's define the types.
Chocolate comes from the Theobroma Cacao Tree (also known as the cacao tree). The word Theobroma actually translates to 'food of the gods'.
The seeds of the cacao tree on their own are intensely bitter (ever had raw cacao seeds misunderstanding they weren't what you thought chocolate was?) and so we ferment them to sweeten them up a bit.
So we ferment them, then we dry and roast them and remove the shell - from this we have the cacao nibs we love so much - deeply intense chocolate - yummmm:) (I love dark chocolate.)
We then can take the nibs and grind them and make cacao powder which is also termed cocoa mass. When we add liquid to this - it is called chocolate liquor (no, chocolate liquor doesn't mean we add Vodka as my friend Tim used to insist).
From the chocolate liquor comes cocoa butter and cocoa solids. Cocoa butter is often misunderstood as cocoa solids + actual butter, that isn't the case.
Now in recent years, we have become increasingly interested in the alkaloids, acids and compounds in chocolate as we have found that when we eat chocolate we often feel happy :) As my friend's 6 year old Jana says "I want my 'happy choco' now".
The alkaloids in cocoa solids are theobromine and phenethylamine.
Phenethylamine is a neuromodulator or neurotransmitter and has been proven to elevate mood in certain concentrations however since orally it needs to be metabolized, the effects of eating chocolate are usually low.
Theobromine is in the same class of chemical compounds as caffeine and is proven to be useful as a diuretic (it increases urine output - coffee does too!), a vasodilator (it widens the blood vessels) and is a heart stimulant.
This is the compound that is difficult to digest for some animals and dangerous for dogs and cats (more dogs as they tend to eat it more - cats don't have a sweets receptor). Dogs can get theobromine poisoning from as little as 2 ounces of chocolate.
While the amount in normal chocolate usage is usually safe (except for with some animals and those with sensitivity to the theobromine), today we are so focused on raw that I've had clients come to me with what I would see as cacao poisoning. I had one client last year eat two packages of nibs while hiking and started vomiting uncontrollably and came to me after the ER visit (where they treated her for food poisoning from the cacao) to help her balance.
The reason I'm telling you this is we need to be conscious about our intake of pure cacao and recognize everyone's system is different. Natural doesn't always mean safe and since every body is different, be conscious and careful when eating the cocoa nibs or raw seeds.
That said, there are proven health benefits, most of which are linked to the theobromine and phenethylamine levels, such as increased heart and brain activity(1) and the ability to lower cholesterol(2) when eaten in moderation.
I hope you enjoyed this information on chocolate and wish you good health and a happy heart.
1 - http://jn.nutrition.org/content/139/1/120.abstract?sid=8776dd95-b0a2-4299-835f-98ed2561a48c
2 - http://jn.nutrition.org/content/138/4/725.abstract?sid=8776dd95-b0a2-4299-835f-98ed2561a48c