I like to think it's not too much of a stretch. You see, rainforest plants provide the chemical basis for a quarter of Western medications, yet only a small number of the total rainforest plant species have been tested by science to see what other wonder ingredients they have on offer.

Chocolate comes from the rainforests, growing in a small band of tropical climate zone either side of the equator.  And the best news is that research reveals exactly what we want to hear: chocolate is good for you.

Actually, more specifically, cacao is good for you. Cacao (pronounced ka-cow) is where chocolate comes from. Cacao comes from the rainforest tree Theobroma cacao, which means food of the Gods (no argument here.) The tree produces flowers, a small percentage of those flowers turn into fruit pods, and inside each pod are beans covered in white flesh. Crack open the beans and you'll find the cacao nibs – small, hard and bitter fragments that give us cacao.

Raw cacao and cocoa are different. Cacao comes from cold-pressing unroasted nibs, while cocoa powder is the refined, processed product that has been heat-treated, thereby changing the vitamins and enzymes. One is a whole food and one is not.

This is an important difference. So before you run off to buy a truckload of high-fat, high-sugar, relatively inexpensive chocolate from the supermarket shelf, think again. After many years of researching (and eating) chocolate for my novel The Chocolate Promise, I've come to think of chocolate products as either confectionery or real food – there's not much in between. I can eat shameful quantities of a certain type of milk chocolate in a day (because it's confectionery) and much less of high-quality dark chocolate (because it's actually real food, and therefore filling, nourishing and satisfying).

So what makes this real food so great? Raw cacao is bursting with phenolic phytochemicals (that is, antioxidants), and minerals and vitamins (magnesium, iron and potassium to name a few). Some say it has the highest antioxidant of any food in the world. And many go so far as to call it a superfood. Backing this up, researchers at Cornell University (US) found that cacao surpassed the antioxidant levels of both red wine and green tea. Antioxidants are the marvellous little scavengers that work to beat off cancer cells and heart disease.

Cacao also assists the body to produce more of its feel-good hormones in the brain, namely serotonin and dopamine – it therefore has antidepressant qualities. It also contains phenethylamines, which help us to release endorphins, our "happy high" hormone. And since the time of the Aztecs – clever people who worshipped cacao as the food of the gods – it's been a known aphrodisiac. Theobromine is a stimulant to the central nervous system and the heart. (But be warned, while we enjoy the effects of theobromine, it also makes chocolate toxic to dogs.)

In fact, there are more than 700 known components of chocolate and more not yet known. And the science says that cacao is good.

Having said that, not all chocolates are created equal and you need to know what you're buying in order to benefit. Firstly, the price of the chocolate will give you a fair indication of quality. Next, look for the ingredients. You can make sweetened chocolate from just a few ingredients. I've handmade raw chocolate just from cacao, cacao butter, agave syrup and sea salt. That's pretty much as authentic as you're going to get. But if the ingredients are listing lots more than that, take note. Vanilla is used as a masking flavour to cover the (naturally occurring) variations between batches, while vanillin is a synthetic flavour.

And for goodness' sake, don't eat compound chocolate! It uses cocoa powder (of questionable value), "vegetable oil" (which could mean anything) and a lot of sugar. I wouldn't count on this for any medicinal qualities whatsoever.

The percentage of cacao mass will give you some indication of quality as well. The higher the number then, potentially, the more health benefits (and less sugar) you'll receive. I can enjoy up to 90 per cent, though 70 to 80 per cent is my preferred range. If you're new to dark chocolate, try starting around 40 per cent and working up.

Eat enough of the good stuff and your palette will change. Like all things, the more you educate yourself, the more you'll learn to appreciate the immense varieties and value of chocolates out there. Better yet, you'll be experiencing and receiving just a fraction of the amazing medicines the rainforest has to offer us, delivered in a silky smooth, universally loved and endorphin-boosting treat. And in my dreams, maybe one day we'll all be lucky enough to go the doctor and receive a script for chocolate.

* During the writing of her latest novel The Chocolate Promise, Josephine Moon researched the healing properties of chocolate extensively. The Chocolate Promise is published by Allen & Unwin, $29.99. She will speak at a Books at Breakfast event at the National Library on Tuesday,  March 31. For more information, see http://www.nla.gov.au/node/7855.