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Red Cabbage Health Benefits, Anthocyanins, and Indicator Fun

Linda Crampton is a teacher with an honors degree in biology. She enjoys exploring nutrition as well as the culture and history of food.

Cabbage of any colour is healthy, but red cabbage has the advantage of containing anthocyanins.

Cabbage of any colour is healthy, but red cabbage has the advantage of containing anthocyanins.

Anthocyanin Pigments in Red Cabbage

Cabbage of any colour is a healthy and nutritious addition to the diet. Red cabbage has an extra benefit compared to its green relatives due to the presence of red, purple, or blue pigments called anthocyanins. Scientists are discovering that anthocyanins in plants may have many health benefits, including helping to prevent cancer, improving heart and blood vessel health, improving brain function, vision, and diabetes, reducing inflammation, and boosting the immune system. Anthocyanins also have the interesting ability to change colour at different pH values, which makes them useful in science experiments.

Anthocyanins are present in other vegetables (such as purple potatoes, purple corn, and red onions), fruits (such as strawberries, blueberries, red and purple grapes, and blood oranges) and grains (such as red and purple rice). Hundreds of different anthocyanins have been discovered. Scientists still have a lot to learn about the effects of these chemicals inside our body. The discoveries made so far have convinced nutritionists that we should all be eating a wide variety of anthocyanin-containing foods for their potential health benefits.

Some ornamental cabbages have leaves with curly edges. They are edible, but they don't taste as good as cabbage varieties grown for food,

Some ornamental cabbages have leaves with curly edges. They are edible, but they don't taste as good as cabbage varieties grown for food,

Cabbages of all colours and varieties have the scientific name Brassica oleracea. Cauliflower, broccoli, and Brussels sprouts have the same scientific name. The vegetables are different varieties of the same species.

Colour and pH

Red cabbages may actually be purple or even bluish instead of red, since anthocyanins change colour as the pH changes. The pH scale ranges from 0 to 14 and indicates how acidic or basic a substance is. The scale works as follows.

  • A neutral substance, which is neither acidic nor basic, has a pH of 7.
  • An acidic substance has a pH of less than 7.
  • The lower the pH, the more acidic the substance.
  • A basic or alkaline substance has a pH of greater than 7.
  • The higher the pH, the more basic (or alkaline) the substance.

The pH of the liquid in soil controls the colour of the red cabbages that are growing in the soil. Anthocyanins inside red cabbage are red in an acidic solution, purple in a neutral solution, and blue in a basic solution. A little vinegar added to the container in which red cabbage is cooking will keep the cabbage red, since vinegar contains acetic acid.

Potential Benefits of Anthocyanins

Thirty-six different anthocyanins have been found in red cabbage. Lab experiments have shown several potentially useful effects of these chemicals. In test tube reactions, they are antioxidants. One experiment showed that red cabbage anthocyanins protected nerve cells from damage in lab dishes and might have a useful role to play in the treatment of Alzheimer’s disease. This is a hopeful discovery, but it needs to be confirmed by other scientists. In addition, it’s not known if anthocyanins have the same effect inside the brain as they do in lab equipment. Clinical trials in humans are required.

In a lab cell culture, red cabbage anthocyanins prevented colon cancer cells from multiplying. This may also be good news, but once again the results need to be confirmed. Scientists don’t yet know if eating the anthocyanins will cause the same effect in our bodies.

Red cabbage juice has also been found to reduce inflammation, possibly due to protein components in the juice as well as the anthocyanins. In addition, some of the anthocyanins in the cabbage may have benefits similar to those in other vegetables and in fruits. Tests on humans are needed.

If the chemicals are found to be beneficial, the quantity of cabbage needed for obtaining a specific benefit and the required frequency of ingestion need to be determined. Even without benefits from its pigments, however, red cabbage is a nutritious food, as described below. It's a great idea to include it in the diet.

Nutrients in Red Cabbage

Raw red cabbage is rich in nutrients. It's an excellent source of vitamin C and of vitamin A in the form of beta-carotene, which our bodies convert into vitamin A. The cabbage is also a great source of vitamin K and a good source of vitamin B6, riboflavin, folate, and thiamin. In addition, it contains a useful amount of certain minerals, including manganese, potassium, calcium, magnesium, and iron. The vegetable contains fibre and a small quantity of natural sugars. It's almost fat free.

Since water-soluble vitamins leach into the water when cabbage is boiled, red cabbage should be eaten raw. If it's boiled, the boiling water should be drunk. Water-soluble vitamins include vitamin C and the vitamin B complex. (Vitamin C is damaged by heat, however.) Steaming is a gentler way to cook cabbage. A small amount of a healthy oil should be eaten with the cabbage to enhance the absorption of the fat-soluble vitamins in the small intestine. Vitamins A and K are soluble in fat.

Indoles and Isothiocyanates

Cabbage belongs to the family of flowering plants known as the Brassicaceae, which is sometimes known as the family Cruciferae. The members of this family have molecules called glucosinolates and an enzyme called myrosinase in their cells. When a vegetable is cut or chewed, the two chemicals come into contact. The myrosinase reacts with the glucosinolates to produce indoles and isothiocyanates. These chemicals may help to fight cancer.

Red and green cabbages produce an isothiocyanate called sulforaphane. Sulforaphane has been found to inhibit the growth of cancer cells in lab dishes and slow the growth of tumours in mice.

Surveys of large numbers of people have found that those who regularly eat vegetables from the Brassicaceae family, such as any type of cabbage, cauliflower, broccoli, kale, and Brussels sprouts, have a lower risk of developing some types of cancer than those who don't eat many of these vegetables. Correlation isn't causation, but in this case it's certainly interesting.

Cabbage is known for the unpleasant odour that it produces while it's being cooked. The chemical responsible for this smell is dimethyl sulphide.

Other Potential Benefits of Cabbage

Cabbage may have additional benefits. Drinking cabbage juice has traditionally been used to help treat peptic ulcers. In one clinical trial, a beverage containing a cabbage and broccoli mixture was found to lower the level of LDL cholesterol in the blood of people with an elevated level of the chemical. LDL cholesterol has essential functions in our body but is considered to be unhealthy for our arteries when it's at a high concentration.

The clinical trial didn't examine whether the cabbage component, the broccoli component, or both of them acting together was responsible for the cholesterol-lowering effect. Like cabbage, broccoli is considered to be a nutritious and healthy vegetable, so it's a good idea to include it in the diet.

Red cabbage in vinegar (left) and a sodium bicarbonate solution (right)

Red cabbage in vinegar (left) and a sodium bicarbonate solution (right)

Red Cabbage in Science Experiments

Red cabbage juice is popular in school chemistry experiments due to its anthocyanins that change colour at different pH values. The juice is an indicator. In chemistry, an indicator is a chemical that has one colour when it’s added to an acidic substance and a different colour when it’s added to a basic substance. The indicator can therefore be used to “indicate” whether a substance is acidic or basic.

The starting colour of the red cabbage juice depends on the pH of the water used to extract the anthocyanins. The juice indicates the approximate pH of a substance instead of simply whether it's acidic or basic. The juice is red or pink in an acidic solution, purplish or violet in a neutral solution, and blue, green or yellow in a basic solution, depending on the pH.

Red cabbage juice colours at different pH values. From left to right, the pH numbers are 1, 3, 5, 7, 8, 9, 10, 11, and 13. The juice looks violet at pH 7, despite its appearance in this photo.

Red cabbage juice colours at different pH values. From left to right, the pH numbers are 1, 3, 5, 7, 8, 9, 10, 11, and 13. The juice looks violet at pH 7, despite its appearance in this photo.

How to Make an Acid-Base Indicator From Red Cabbage

There are three methods to obtain the juice from a cabbage. The only parts of the preparation that offer any risk for children are the use of a knife to cut the cabbage, the use of a blender, and the use of boiling water in methods one and two. The third method described requires warm but not boiling water.

The best water to use for pigment extraction is distilled water. This is sold in drug stores and supermarkets. Distilled water is neutral, whereas tap water may be slightly acidic or slightly basic.

  1. Boil chopped red cabbage leaves in a small amount of water for five to ten minutes. Remove the cabbage leaves once they’ve released anthocyanin pigments into the water.
  2. Pour boiling water on chopped red cabbage leaves in a container and allow the leaves to soak for at least ten minutes. Remove the leaves once the water has a rich colour.
  3. Place red cabbage leaves in a blender. Add warm water, blend, and then filter out the cabbage leaves with a strainer. A good ratio to use is one large cabbage leaf per two cups of water.
Interesting colour and shapes inside a red cabbage

Interesting colour and shapes inside a red cabbage

Testing Solutions to Identify Acids and Bases

It’s fun and easy to use a red cabbage indicator in school or home science experiments. A small amount of cabbage juice can be added to test solutions to see what colour they turn. The solids could be added to distilled water and stirred to make a test solution. Adding a drop of indicator to a small piece of solid without dissolving it in water will work for some specimens. An alternate procedure for testing substances is to add the test solutions to containers of cabbage juice.

Some examples of acids and bases that could be tested are listed below. Children enjoy choosing their own liquids to test, too.

  • Acidic: lemon juice, vinegar, cream of tartar
  • Neutral: Distilled water
  • Basic or Alkaline: antacid tablet, baking soda, milk of magnesia

Red cabbage juice is safe and so are the test solutions above, although lemon juice and vinegar will irritate the eyes if they enter them. A child shouldn't perform this experiment unsupervised, however, in case they choose dangerous liquids to test. Muriatic (hydrochloric) acid is acidic and bleach and household ammonia are basic, for example, but they are all potentially dangerous unless they are highly diluted.

Safety goggles, protective gloves, and good ventilation are useful for handling some chemicals. If these are necessary for a child, however, they could be an indication that a substance shouldn't be used in an experiment.

Making Indicator Paper

Red cabbage juice can be used to make indicator paper strips resembling those used in school science labs. All that's needed is concentrated red cabbage juice and filter paper strips. A coffee filter works well for creating the strips.

The strips need to placed in the cabbage juice until they have absorbed the pigment and then hung up by a clothes pin to dry. (Red cabbage juice can stain clothing as well as paper, so it's a good idea for a child to wear a protective apron when experimenting with the juice.) The indicator paper should be dried indoors so that it isn't bleached by sunlight.

Once the indicator strips are ready, drops of test solution can be placed on the strips and the colour change observed. The video below describes another way to create and use indicator paper made from red cabbage.

A Versatile Vegetable

Red cabbage is an interesting and versatile vegetable. It's both nutritious and healthy. Researchers and nutritionists agree that we should eat cabbage and its relatives frequently, in both raw and lightly cooked forms. In general, the darker the cabbage, the more nutrients it contains.

The red version of cabbage is also useful because of its ability to change colour. This colour change is interesting to see during food preparation in a kitchen. It's also a fun and educational feature for children. As I know from experience, both younger and older students enjoying experimenting with red cabbage juice and observing its effects.

References

This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

© 2011 Linda Crampton

Comments

Linda Crampton (author) from British Columbia, Canada on July 07, 2015:

Thank you very much for the comment, vote and congratulations, Kristen!

Kristen Howe from Northeast Ohio on July 07, 2015:

Alicia, this was a great hub from you on red cabbage. I haven't had it in a long time. Voted up for useful! Congrats on Editor's Choice too!

Linda Crampton (author) from British Columbia, Canada on June 25, 2015:

Thank you, Kamiti. It's nice to meet you!

Harrison on June 25, 2015:

Great content. I didn't know red cabbages have so many health benefits!

Linda Crampton (author) from British Columbia, Canada on November 29, 2013:

Thank you very much for the comment, ANIL.

ANIL on November 29, 2013:

Nice you provide needful information to readers, thanking you

Linda Crampton (author) from British Columbia, Canada on April 03, 2013:

Thanks for the comment, Nancy!

Nancy on April 03, 2013:

Thank you very much for all the information on the red cabbage.

Linda Crampton (author) from British Columbia, Canada on June 25, 2012:

Thank you very much for the comment, Nare. I appreciate your visit!

Nare Gevorgyan on June 25, 2012:

Very interesting and well explained hub! Before reading this I was thinking that it might even be poisonous :D Thanks for the great info :)

Linda Crampton (author) from British Columbia, Canada on March 04, 2012:

Thank you for the comment and the share, Peggy. Yes, I like red cabbage, and it's good to know that it's healthy, too. Making German red cabbage sounds like a great idea - I think I'd love the taste!

Peggy Woods from Houston, Texas on March 03, 2012:

I always loved eating my mother's German red cabbage recipe. This reminded me of it. Thanks! Will have to make it sometime soon. Most scientists agree that the more color a vegetable or fruit has...the higher in benefits, and this just goes along with that theory. Informative hub! Will share.

Linda Crampton (author) from British Columbia, Canada on August 22, 2011:

Thanks a lot, Prasetio. Red cabbage is certainly an interesting vegetable.

prasetio30 from malang-indonesia on August 22, 2011:

I had never knew about red cabbage. This was useful information. I learn much from you. I love vegetables and I enjoy your review. Vote up!

Prasetio

Linda Crampton (author) from British Columbia, Canada on August 14, 2011:

Thank you, b. Malin. I'm glad to hear of another person who likes red cabbage!

b. Malin on August 14, 2011:

I am one of the Nuts who does like Red Cabbage and with such Great Health Benefits...I'm glad I like it. Thanks Alicia once again for such an Interesting Read!

Linda Crampton (author) from British Columbia, Canada on August 12, 2011:

Thank you very much, kashmir56. Red cabbage is my favorite type of cabbage too!

Thomas Silvia from Massachusetts on August 12, 2011:

Very interesting and useful information, i love cabbage and red cabbage is my favorite,and the nutritional benefits and health benefits are a plus for eating more cabbage .

Vote up and very useful !!!

Linda Crampton (author) from British Columbia, Canada on August 12, 2011:

Hi, Nell. Thanks for commenting. Children love watching the color of red cabbage juice change at different pH's, but it's interesting that the chemicals in red cabbage that are responsible for the color change may also be responsible for health benefits!

Nell Rose from England on August 12, 2011:

Hi, this was interesting, and really detailed, I never knew about all the chemical changes and colours, I am not going to say all the long words again! but seriously fascinating subject, rated up! cheers nell

Linda Crampton (author) from British Columbia, Canada on August 12, 2011:

Hi, Movie Master. Yes, it really seems like a good idea to eat red cabbage regularly, because it does contain lots of nutrients and it's strongly suspected to have other health benefits too. Thanks for the comment.

Movie Master from United Kingdom on August 12, 2011:

I have never had much to do with red cabbage, but had some in a restaurant at the weekend and thought how delicous it was.

Many thanks for the info, it seems there are lots of health benefits to eating it too, so I for one am going to be eating more of it, thanks for sharing.

Linda Crampton (author) from British Columbia, Canada on August 10, 2011:

Thank you, Reena J. I hope that you enjoy eating red cabbage.

Reena J on August 10, 2011:

Really this is useful hub. Thanks for bringing the health values of the red cabbage and to be frank i was avoiding this veg and will add up it regularly from now...

Linda Crampton (author) from British Columbia, Canada on August 10, 2011:

Hi, writer20. I hope your husband will like red cabbage. It's such a nutritious and healthy vegetable. Thanks for the comment about my cat's photo!

Linda Crampton (author) from British Columbia, Canada on August 10, 2011:

Thank you very much for the votes, cathylynn99!

cathylynn99 from northeastern US on August 10, 2011:

voted up, useful, interesting

writer20 on August 10, 2011:

Thank you for the info. on red cabbage.

I do like it but unsure about my husband, so I'll have to twist his arm a little to encourage him to try this.

Love the picture of your kitty.