How to choose dark chocolate: don't go by the cacao percentage alone
4 min read
In "Is dark chocolate really good for you?" we saw that what research actually tested was less chocolate itself than a component called cocoa flavanols.
QUIZTrue or false: an 86% cacao chocolate always contains more of cacao's beneficial compounds than a 70% one.Show answer
False. Not always.
The cacao percentage includes cacao fat (cocoa butter). In research, the amount of these compounds matched the non-fat cocoa solids more closely.
So when choosing dark chocolate in a store, should you just pick the highest number: 70%, 86%, 95%? Looking into it, there are several things the number alone doesn't tell you.
Contents
First, check that it's legally "chocolate"
In Japan, where I live, chocolate labeling is set by an industry fair competition code, and the product name on the back of the package says "chocolate," "semi-chocolate," "chocolate confectionery," and so on [1]. Other countries have their own legal definitions.
To be called "chocolate," a product needs at least a certain amount of cacao content. If cacao is what you're after, first check that the product is labeled as chocolate, not as a chocolate-flavored confection.
The cacao percentage includes fat
The "cacao" percentage is the total of cacao-derived ingredients such as cocoa mass, cocoa powder, and cocoa butter [1]. In other words, it includes cocoa butter, the fat of the cacao bean.
A study of chocolate and cocoa products sold in the United States found that flavanol content matched the amount of non-fat cocoa solids more closely than the cacao percentage [2]. Higher cacao percentages do tend to have more flavanols, but products with the same number can differ.
POINT
The cacao percentage is a useful guide. But it doesn't decide the flavanol content on its own.
Processing reduces flavanols
A study of cocoa powders found that the more a cocoa had been "alkalized" (Dutch-processed, to reduce acidity and darken the color), the fewer flavanols it had. Non-alkalized cocoa averaged about 35 mg per gram, while heavily alkalized cocoa had about 4 mg [3].
When choosing cocoa, pick pure, unsweetened cocoa powder, not a drink mix with sugar and milk added. Then, if the product description says whether it's alkalized, check that too.
Heavy metals vary by product
A study that tested 72 cacao products in the United States from 2014 to 2022 found that a certain share exceeded daily limits for lead or cadmium based on California's standards. Organic products didn't have less [4]. Similar results have been reported in testing by a consumer organization [5].
But these were tests of products sold in the US, and may not apply as-is to products on the shelves where you live. The practical measures are not eating a lot every day and not always sticking to the same product.
Guidelines for choosing
| What to look at | What to choose |
|---|---|
| Product name | Labeled as chocolate |
| Cacao percentage | 70% or more as a guide. But don't compare by the number alone |
| Cocoa | Unsweetened pure cocoa. Even better if you can tell whether it's alkalized |
| Size and packaging | Individually wrapped pieces that make small portions easy |
| How to eat it | A small amount, in place of other sweets. Don't always stick to one product |
How much to eat is in the "How much should you eat?" section of "Is dark chocolate really good for you?"
If you choose by these guidelines
References
1. Japan Chocolate Fair Trade Council. Fair Competition Code concerning the labeling of chocolate products (in Japanese).
2. Miller KB, Hurst WJ, Flannigan N, et al. (2009). Survey of commercially available chocolate- and cocoa-containing products in the United States. 2. Comparison of flavan-3-ol content with nonfat cocoa solids, total polyphenols, and percent cacao. Journal of Agricultural and Food Chemistry, 57(19), 9169–9180.
3. Miller KB, Hurst WJ, Payne MJ, et al. (2008). Impact of alkalization on the antioxidant and flavanol content of commercial cocoa powders. Journal of Agricultural and Food Chemistry, 56(18), 8527–8533.
4. Hands JM, Anderson ML, Cooperman T, Balsky JE, Frame LA. (2024). A multi-year heavy metal analysis of 72 dark chocolate and cocoa products in the USA. Frontiers in Nutrition, 11. doi:10.3389/fnut.2024.1366231
5. Consumer Reports (2022). Heavy metals in dark chocolate (testing report on 28 products; not a peer-reviewed paper).