Regular Curly Kale vs Lacinato (Black Kale)

There are many different types of kale, with regular curly kale and lacinato being among the most popular types. Curly kale has bright-green leaves that are sometimes curled so tightly it can difficult to clean them. Lacinato kale has longer, flatter leaves with a bumpy surface that is thought to resemble dinosaur skin. Lacinato's leaves are typically much darker than those of curly kale, which is why it is also known as black kale.

With a long tradition in Italian cuisine, particularly that of Tuscany, lacinato also goes by its Italian name, cavolo nero ('black kale'), and it is also frequently referred to as Tuscan kale.

But how does lacinato compare to curly kale in terms of taste, texture, culinary uses, preparation, nutrition facts, health benefits, and availability? Below, we take a look at some of the key differences between these two popular kale types to help you decide which one is better for the dish you are planning to prepare.

Taste and Texture

Mature curly kale has a peppery flavor with a pleasantly bitter edge. Lacinato kale tastes less bitter, and its flavor can be described as earthy, yet delicate, with a hint of nutty sweetness. A light frost makes both types taste sweeter, which is why late fall is the perfect time to cook with kale. In terms of texture, lacinato is generally more tender than regular curly kale.

Culinary Uses

With only subtle differences in taste and texture, curly kale and lacinato can usually be used interchangeably in cooked dishes like soups, stews, casseroles, stir fries, risottos and omelettes. The only significant difference when cooking with lacinato vs curly kale is that lacinato kale may cook a bit faster because of its tender leaves.

Kale can also be eaten raw, whether it's curly kale or lacinato. However, because of its tender leaves, lacinato kale requires less "massaging" for use in raw preparations. And, in case you were wondering, massaging kale with olive oil is a popular technique used by chefs to make this fibrous green leafy vegetable softer and easier to eat in salads and other raw preparations.

Preparation

While kale stems are perfectly edible, many people like to remove the hard stems, along with the hard mid-ribs, before using the leaves. The benefit of removing the stems and ribs is that your dishes will cook faster and more evenly, and you will find fewer stringy, fibrous bits in your kale smoothies.

To de-stem curly kale, simply pull the leaves off the stems – or use a kale trimmer, a handy little tool designed specifically for removing kale leaves from the stems! To remove the stems and mid-ribs from lacinato kale, lay a lacinato leaf on a cutting board and use a paring knife to cut along each side of the mid rib. Repeat until all the stems and mid-ribs have been removed.

Nutrition Facts

Low in calories and packed with a wide range of nutrients, it is not surprising that regular kale has been heralded as a superfood. But lacinato kale by no means pales in comparison with its better known cousin! In fact, lacinato kale has been shown to be an even better source of some key nutrients than curly kale.

For example, lacinato has been reported to contain almost five times the amount of beta-carotene found in curly kale on a dry weight basis. All common kale varieties are also known for being rich in vitamin K, but research suggests that lacinato kale is the ultimate winner, providing significantly more vitamin K than either regular curly kale or red kale. (1)

Health Benefits

Not only are curly kale and lacinato kale rich in nutrients, they also provide health-protecting phytochemicals. Like other Brassica vegetables, they contain glucosinolates which can be converted into isothiocyanates by myrosinase, an enzyme that is released when a Brassica vegetable like kale or broccoli is crushed, chopped or chewed.

Isothiocyanates have been extensively researched for their potential anti-cancer effects, and a growing body of evidence suggests that they can induce apoptosis (self-destruction of cancerous cells), fight inflammation, and modulate proteins that are involved in cell division (2).

Goitrogenic Properties

When we think of glucosinolates, we usually think of the wonderful health benefits their breakdown products may confer. But turns out, some breakdown products of glucosinolates have also been linked to adverse health effects.

Some glucosinolates found in Brassica vegetables can be converted into goitrogenic compounds that can disrupt the production of thyroid hormones by interfering with iodine uptake. This in turn can promote the growth of thyroid tissue and can eventually lead to goiter and other health problems.

The good news is that the kale varieties that belong to the Brassica oleracae species, which includes both regular curly kale and lacinato kale, contain very little of the type of glucosinolates than can be converted into goitrogenic compounds, and a study published in the journal Nutrition Reviews concluded that the consumption of typical serving sizes of B. oleracae kale is unlikely to impair thyroid function (3).

Russian/Siberian kale of the species Brassica napus, by contrast, was found to provide enough goitrogenic compounds to potentially decrease iodine uptake by the thyroid (3).

Availability

Regular curly kale is readily available both fresh and frozen at grocery stores, but also lacinato kale is relatively easy to find in fall and winter when it is in season. Farmers' markets are a good place to look for lacinato kale, but also many grocery stores, especially those focused on natural and organic foods, sell lacinato.

Just keep in mind that this Italian heirloom variety goes by many names, so if you have trouble finding "lacinato", look for Tuscan kale, dinosaur kale, palm tree kale, cavolo nero or black kale.

References

1. M. Kim et al (2017). Glucosinolates, Carotenoids, and Vitamins E and K Variation from Selected Kale and Collard Cultivars. Journal of Food Quality, Vol. 2017.
2. B. Mokhtari et al (2018). The role of Sulforaphane in cancer chemoprevention and health benefits: a mini-review. Journal of Cell Communication and Signaling, 12(1):91-101.
3. P. Felker et al (2017). Concentrations of thiocyanate and goitrin in human plasma, their precursor concentrations in brassica vegetables, and associated potential risk for hypothyroidism. Nutrition Reviews, 74(4): 248-258.