Reviewed on 6/11/2021
Other Name(s):

Berza, Brassica oleracea, Brassica oleracea var. acephala, Brassica oleracea var. viridis, Chou Cavalier, Collard Greens, Cow Cabbage, Dalmatian Cabbage, Morris Heading, Spring Heading Cabbage, Tall Kale, Tree Kale, Winter Greens.


Collard is a dark, leafy, vegetable that is commonly eaten as a food source. Collard leaves can also be eaten as a medicine.

Collard is taken by mouth as an antioxidant; for anemia, heart disease, constipation, diabetes, an eye disorder that causes damage to the optic nerve (glaucoma), high cholesterol, loss of vision (macular degeneration), and weight loss; and to prevent bladder cancer, breast cancer, prostate cancer, and scurvy.

How does it work?

Collard contains chemicals that are thought to help prevent cancer. Chemicals in collard might also have antioxidant activity.


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Uses & Effectiveness

Insufficient Evidence to Rate Effectiveness for...

  • Bladder cancer: There is some evidence that people who eat large amounts of collard and related vegetables have a lower risk of developing bladder cancer.
  • Breast cancer: Some early research suggests that eating collard and related vegetables is linked with a slight increase in the risk of breast cancer in premenopausal women. However, eating collard and related vegetables is not linked with a higher risk of breast cancer in postmenopausal women.
  • Prostate cancer: Some early research shows that eating larger amounts of collard and related vegetables is not linked with a lower risk of developing prostate cancer.
  • Anemia.
  • Heart disease.
  • Constipation.
  • Diabetes.
  • An eye disorder that causes damage to the optic nerve (glaucoma).
  • Hypercholesterolemia.
  • Loss of vision (macular degeneration).
  • Weight loss.
  • Scurvy.
  • Other conditions.
More evidence is needed to rate the effectiveness of collard for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

Side Effects

Collard is LIKELY SAFE when consumed in food amounts. It isn't known if collard is safe or what the possible side effects might be when taken in medicinal amounts.


Next to red peppers, you can get the most vitamin C from ________________. See Answer

Special Precautions & Warnings

Pregnancy and breast-feeding: There isn't enough information about the safety of eating collard in medicinal amounts during pregnancy or breast-feeding. Stay on the safe side and stick to usual food amounts.


The appropriate dose of collard depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for collard. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

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Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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