Why can’t you eat kale stems?

Kale has become an increasingly popular leafy green in recent years, prized for its nutritional benefits. Both the leaves and stems of kale contain fiber, vitamins, minerals, and antioxidants. However, while kale leaves are commonly eaten raw or cooked, the stems are often discarded.

The tough, woody texture of kale stems

The central reason kale stems are not eaten is their tough, fibrous texture. As kale plants mature, the stems become thick, hard and woody. This makes the raw stems extremely difficult to chew and digest. The mature stems are composed of tough cellulose fibers that require thorough cooking to soften.

Younger, immature kale stems have a more tender texture. Baby kale stems are edible raw in salads or lightly sautéed. But as the kale plant matures, the stems become too hard and stringy to enjoy raw.

Unpleasant, bitter flavor

In addition to their rough texture, kale stems have an unpalatable bitter and pungent flavor. This is especially noticeable in mature kale plants. The bitterness is caused by a high concentration of phytochemicals, including glucosinolates. These compounds are responsible for many of kale’s health benefits but impart a sharp, unpleasant taste.

Cooking helps mellow some of the bitterness in kale stems. However, the unpleasant taste often lingers, which is why most people avoid eating the stems.

Low nutritional value

Kale stems contain fewer vitamins, minerals, and antioxidants compared to the leafy greens. Although the stems provide some fiber and small amounts of nutrients, they are not considered the most nutritious part of the plant.

A cup of chopped kale stems contains:

• 1 gram of protein
• 5 grams of carbohydrate
• 2 grams of fiber
• 54 mg of calcium
• 31 mg of magnesium
• 167 mg of potassium
• Small amounts of vitamins A, C, and K

By comparison, a cup of chopped kale leaves contains:

• 2 grams of protein
• 6 grams of carbohydrate
• 2 grams of fiber
• 93 mg of calcium
• 23 mg of magnesium
• 299 mg of potassium
• Large amounts of vitamins A, C, and K

While kale stems provide some nutrients, the leaves contain significantly higher concentrations of beneficial compounds like vitamins, minerals, and antioxidants.

Ways to use kale stems

Although kale stems are not ideal for eating raw or cooked, they don’t have to be thrown out. Here are some ways to make use of these nutritious parts of the plant:

• Chop and add to soups, stews, and stocks. The long cooking time will soften the tough fibers.
• Juice the stems along with kale leaves and fruits/veggies to make green juice.
• Dehydrate and grind into powder to add to smoothies, baked goods, etc.
• Pickle or ferment the stems to make them more palatable.
• Use as a nutrient-rich addition to broth for cooking grains like rice or quinoa.
• Compost the stems to create nutrient-rich fertilizer for your garden.

Key points

Here are the key takeaways on why kale stems are not typically eaten:

Reason	Explanation
Tough, woody texture	Mature kale stems are too fibrous to chew and digest when raw.
Bitter, unpleasant taste	Stems have a bitter, pungent flavor caused by phytochemicals.
Lower nutritional value	Stems contain fewer vitamins, minerals, and antioxidants than leaves.

While kale stems are not ideal for eating on their own, they can be incorporated into recipes or used in ways that enhance their nutrition. So don’t throw those stems out – find creative ways to make the most of this nutritious part of the kale plant!

Nutritional content of kale stems vs. leaves

Let’s take a more in-depth look at how the nutritional content of kale stems compares to the leaves:

Vitamin K

Kale is one of the best plant-based sources of vitamin K. This vitamin is important for blood clotting and bone health.

Kale stems contain about 13 micrograms of vitamin K per cup, while the leaves contain over 10 times more – 147 micrograms per cup.

Vitamin C

Vitamin C is a powerful antioxidant that supports immune function and collagen production. Kale leaves are high in vitamin C, providing about 80 milligrams per cup. The stems contain only about 10 milligrams per cup.

Vitamin A

Kale is an excellent source of provitamin A carotenoids like beta carotene. These antioxidants support eye and skin health. Kale leaves contain over 10,000 international units of vitamin A activity per cup. The stems provide only 700 international units.

Calcium

Calcium is essential for bone strength. Kale leaves contain 90 milligrams of calcium per cup, while the stems have about 55 milligrams.

Potassium

This important mineral supports heart health and muscle function. Kale leaves provide about 300 milligrams of potassium per cup. The stems contain only 170 milligrams per cup.

So while kale stems do contain some valuable nutrients, the leaves pack a substantially more concentrated nutritional punch. The combined nutrients, antioxidants, and phytochemicals in kale leaves offer greater health benefits compared to the stems alone.

Challenges with eating raw kale stems

Eating raw kale stems comes with some digestive challenges. Here’s why it can be difficult to enjoy kale stems in their raw form:

Tough to chew

The fibrous, stringy texture of raw kale stems makes them extremely difficult to chew. For many people, chewing only a few bites of raw stem can lead to jaw fatigue.

GI irritation

The rough texture and fibrous nature of kale stems can be irritating to the sensitive lining of the gastrointestinal tract when eaten raw. For some, this may result in nausea, stomach pain, bloating, or diarrhea.

Poor nutrient absorption

Since raw kale stems are so difficult to fully chew and break down, this decreases the bioavailability of the nutrients they contain. Nutrients are not as easily released and absorbed during digestion.

Phytochemical concentration

Some of the indigestible phytochemicals like glucosinolates are present in higher concentrations in raw versus cooked kale stems. This can accentuate the bitter taste and GI discomfort.

For most people, raw mature kale stems are too tough and fibrous to provide an enjoyable or comfortable eating experience. Cooking the stems helps soften the fibers. But even cooked, kale stems may still retain a slightly unpleasant bitter taste and fibrous nature.

How to choose the most tender kale stems

If you do wish to consume kale stems, choose young, tender stems for the best texture and flavor:

• Baby kale – Stems will be thin, soft, and fleshy.
• Young leaves near the top of mature bunches – Upper stems tend to be more tender.
• Smaller leaves – Large leaves at the base have the toughest stems.
• Younger plants – Stems get woodier as the plant matures.
• Smaller/thinner stems – Mature kale with smaller stems tends to be more tender.

The most tender kale stems can be chopped and enjoyed raw in salads or slaws. Slightly more mature stems can be cooked briefly by sautéing or boiling to soften.

Remove any oversized, hollow stems that are too fibrous even after cooking. Any remaining bitterness can be balanced by adding acidic, sweet, or salty ingredients to recipes.

Health benefits of consuming kale stems

While kale stems may not be as nutritious or palatable as the leaves, they do still offer some potential health benefits:

Dietary fiber

The indigestible fiber in kale stems can help promote gastrointestinal health. Fiber supports regular bowel movements, gut microbiota, and satiety.

Anti-inflammatory effects

Compounds like glucosinolates and polyphenols in kale stems have anti-inflammatory properties that may help reduce chronic inflammation.

Antioxidant activity

Kale stems contain antioxidant carotenoids, vitamin C, and polyphenols that help counter oxidative stress and damage from free radicals.

Nutrients

Kale stems provide small amounts of vitamins, minerals, and phytonutrients to support health. This includes nutrients like vitamin K, potassium, magnesium, and calcium.

The fiber and phytochemicals in kale stems may also contribute to other emerging health benefits, like reduced cancer risk and improved heart health. But more research is needed on kale stems specifically.

Maximizing nutrition from kale stems

Here are some tips to help maximize the nutritional value you get from kale stems:

• Chop or shred – Cutting helps release nutrients during cooking or digestion.
• Juice – Can boost absorption of nutrients.
• Ferment – Fermentation increases bioavailability of certain compounds.
• Blend – Breaks down fiber to make nutrients more accessible.
• Cook thoroughly – Softens fiber and helps deactivate antinutrients.
• Eat with fat – Fat aids assimilation of fat-soluble vitamins like K.

Combining kale stems with more nutritious ingredients can also help offset any limitations. Add stems to recipes along with kale leaves, other veggies, herbs, spices, healthy fats, etc.

Delicious ways to use kale stems

While most people avoid eating big piles of plain kale stems, you can make them more enjoyable to eat by incorporating them into various recipes. Here are some tasty ways to use up your kale stems:

Blended into smoothies

Mask the texture by blending chopped stems into fruit or veggie smoothies.

Mixed into stir fries

Quick stir-frying helps soften the stems so they aren’t as noticeable.

Added to soups and stews

Slow cooking tenderizes the stems so they blend right in.

Roasted as chips

Roasting chopped stems brings out sweetness to balance bitterness.

Pickled

Lacto-fermentation adds beneficial bacteria and makes stems more palatable.

Juiced

Stems add fiber and nutrients when juiced along with leaves, fruits, etc.

Dehydrated

Dehydrate and grind stems into a powder to add to baked goods.

So while kale stems may be tough and bitter on their own, they can be incorporated into recipes in ways that make them a beneficial and tasty addition to your diet.

Conclusion

Kale stems are often discarded due to their tough, fibrous texture and bitter taste. They contain fewer nutrients than kale leaves and can be difficult to properly chew and digest when eaten raw. However, the stems still provide some fiber, vitamins, minerals, and beneficial plant compounds.

Choose young, tender stems and chop, cook, ferment, or juice them to make them more palatable. To maximize nutrition, be sure to also include some of the vitamin-rich leaves. With some creativity in the kitchen, kale stems can be a nutritious part of a balanced diet rather than simply being thrown out.