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Is kale hard on digestive system?

Kale has become an increasingly popular leafy green in recent years, prized for its rich nutritional content. However, some people find that eating kale can cause digestive issues like bloating, gas, and abdominal discomfort. This article explores whether kale is hard on the digestive system and provides tips for preparing kale to make it easier to digest.

What Makes Kale Hard to Digest?

There are a few components of kale that can make it difficult for some people to digest:

  • Fiber – Raw kale contains 2-3g of fiber per cup. This insoluble fiber adds bulk to stool but can cause gas and bloating when consumed in large amounts.
  • Raffinose – Kale contains raffinose sugars that humans lack the enzymes to digest. These sugars ferment in the colon causing gas.
  • Isothiocyanates – Isothiocyanates are sulfur-containing compounds that give kale its bitter flavor. They may irritate the digestive tract in sensitive individuals.
  • Oxalates – Kale is high in oxalates, which can bind to calcium and cause kidney stones in some people.

Who Is Most Affected by Kale’s Effects on Digestion?

While kale can cause digestive problems for some people, others are able to eat it with no issues. Here are the people most likely to experience indigestion from kale:

  • Individuals with irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD)
  • People with gastrointestinal reflux disease (GERD)
  • Those with digestive enzyme deficiencies
  • People with undiagnosed food intolerances or allergies
  • Individuals who lack gut bacteria that help break down raffinose sugars

If you have a sensitive stomach or frequent digestive issues, it’s a good idea to introduce kale slowly and be mindful of how it affects you.

Tips for Improving Kale’s Digestibility

There are several preparation methods that can help reduce digestive discomfort from kale:

  • Chop or massage – Cutting, shredding, or massaging kale breaks down cell walls, releasing sulfur compounds while making isothiocyanates less concentrated.
  • Cook – Cooking kale denatures isothiocyanates and softens fiber. Methods like steaming, braising, or blanching can help.
  • Ferment – Lactic acid fermentation through dishes like sauerkraut can make kale more digestible.
  • Sprout – Sprouting kale reduces fiber content and neutralizes isothiocyanates and raffinose.
  • Limit portion – Eating small amounts of kale minimizes its gassy effects.

Nutrients in Kale That Aid Digestion

Despite its potential digestive drawbacks, kale supplies nutrients that support a healthy gut:

Nutrient Daily Value in 1 Cup Raw Kale Digestive Benefits
Fiber 2-3 grams Promotes regularity and healthy gut microbiome
Vitamin A 134% DV Maintains intestinal barrier integrity
Vitamin C 134% DV Reduces inflammation and diarrhea
Vitamin K 871% DV Supports gut lining healing
Manganese 26% DV Aids nutrient absorption

When prepared properly and eaten in moderation, the nutrients in kale can counteract some of the potential negatives it poses for digestion.

Tips for Incorporating Kale

Here are some tips to help you incorporate kale into your diet in a digestive-friendly way:

  • Try massaged kale salads or smoothies made with peeled, de-stemmed kale leaves.
  • Add chopped kale to soups, stews, and cooked grains like rice or quinoa.
  • Saute kale in olive oil over low heat until just wilted.
  • Drink green juices with kale, cucumber, parsley, apple, and lemon.
  • Make chips by baking kale leaves dusted with olive oil and sea salt.
  • Start slow when adding kale, having 1-2 servings per week.

The Bottom Line

Kale is high in various compounds and fibers that may irritate the digestive tract and cause unpleasant symptoms like gas and bloating. Cooking kale thoroughly, massaging it, pairing it with other gut-friendly foods, and eating it in moderation can allow most people to consume it without issue.

Pay attention to how your body reacts when you eat kale. If it consistently causes significant discomfort, you may be sensitive and want to avoid it. But for most people, kale can be part of a healthy, fiber-rich diet that benefits digestion when consumed in appropriate portions.