Kale is one of the most nutrient-dense foods available. Not only is kale high in fiber, but it also contains a large number of vitamins, minerals, and antioxidants.

These vitamins include A, C, B-6, and K. Kale is high in minerals like iron, calcium, copper, potassium, and magnesium. Kale also contains powerful antioxidants like quercetin.

For most people, kale is a safe and healthy food choice. However, in rare cases, kale can cause an allergic reaction.

In recent years, there has been a large rise in allergies reported in industrialized countries. A person can develop a food allergy to any food, especially if they eat that food often.

A food allergy occurs when your immune system thinks your food is an invader. If your body misidentifies the food in this way, it will release antibodies, which can result in an allergic reaction.

Kale is in the cruciferous vegetable family. Some can develop an allergy to cruciferous vegetables.

Kale can also cause bloating in people who have difficulty digesting FODMAPs. You may also experience gastrointestinal distress from cruciferous vegetables if you have a C. diff infection.

Kale is high in an antinutrient known as oxalic acid. An antinutrient is a plant compound that lowers your ability to absorb nutrients. Oxalic acid is associated with an increased chance of kidney stones. If you already have a problem with kidney stones, it may be a good idea to avoid kale.

People who eat kale often at are a higher risk of developing a kale allergy. Rarely, you can also be allergic to all cruciferous vegetables. This family of vegetables includes:

  • arugula
  • cabbage
  • broccoli
  • cauliflower
  • kale
  • Brussels sprouts
  • collard greens
  • radish
  • turnips

Cruciferous vegetables are also known by their plant family name Brassicaceae. Some cruciferous vegetables fall into the category of brassica oleracea.

Some individuals have been found to develop an allergy to brassica oleracea pollen, but this isn’t the same as a cruciferous vegetable allergy.

More research is needed to see how much of the population has a cruciferous vegetable allergy.

One review on the safety of cruciferous plants included a study that looked at rapeseed oil, which is a member of this vegetable group.

Researchers found that 7 of 1,478 people who were naturally exposed to rapeseed oil had an allergic reaction. When those who were exposed to rapeseed oil occupationally were tested, the number jumped to 14 out of 37.

A kale or a cruciferous vegetable allergy may result in a range of symptoms. These can include:


In severe cases of food allergies, anaphylaxis occurs. If you ever experience anaphylaxis, get emergency medical treatment.

    If you find yourself among the small population with an allergic reaction to cruciferous vegetables, you should avoid eating kale and other vegetables in this category.

    While kale is full of vitamins, minerals, and antioxidants, there are other healthy food options you can choose to make sure you’re getting proper nutrition.

    Here’s a breakdown of foods you can eat to obtain the beneficial properties found in kale:

    • vitamin A: beef liver, sweet potato, salmon, winter squash, mango, goat cheese, butter
    • vitamin C: bell pepper, pineapple, kiwi, citrus fruit
    • vitamin K: soybeans, pickles, edamame, pumpkin, pine nuts, blueberries
    • iron: pumpkin seeds, shellfish, legumes, quinoa, turkey, tofu
    • vitamin B-6: chickpeas, carrots, ricotta cheese, beef, eggs, bananas, avocado
    • calcium: beans, sardines, almonds, cheese, lentils, amaranth
    • copper: spirulina, oysters, lobster, dark chocolate
    • potassium: white beans, beets, potatoes, parsnips, oranges, yogurt
    • magnesium: dark chocolate, nuts, seeds, legumes, avocado, bananas
    • quercetin: capers, onions, cocoa, cranberries, apples

    If you think you may have a kale or cruciferous vegetable allergy, make an appointment to speak with a doctor. They may refer you to a specialist or conduct allergy testing.

    A common test for allergies is a skin prick test. A doctor will prick your skin and inject a small amount of the allergen in question. If an elevated bump with a red ring around it appears, you’re allergic to the substance.

    A doctor may also choose to place you on an elimination diet. During an elimination diet, you’ll remove the cruciferous vegetables from your diet for a period of time. Then you’ll reintroduce them one by one to see if you have symptoms.

    Kale has many amazing health benefits, but it may not be the right food choice for everyone. People with an allergy to cruciferous vegetables should avoid kale. If you have an allergic reaction, you should see a doctor for testing.

    Kale may cause digestive issues in some people and may also result in a higher risk of kidney stones.