Kohlrabi: Uses, Benefits and Side effects by Dr. Rajeev Singh 

Introduction

Kohlrabi is a vegetable with a swollen bulb-like stem at the base. Many people think that the kohlrabi vegetable is related to turnips because of their appearance, but it is a cabbage. It is scientifically known as Brassica oleracea var. Gongylodes of the Brassicaceae family.¹  

It is an annual herb that originated in Europe. Currently, it is grown in Germany, Hungary, China, Vietnam and eastern India. There are many kohlrabi varieties available in the market, such as White Vienna, Purple Vienna, Grand Duke, Gigante, Purple Danube and White Danube.2 It is sown in mid-August to early September and harvested from December to January. It requires a temperature of 15 to 20 degrees Celsius.³ 

The colour of the stem of the plant can be purple-red or green in colour with white flesh.¹ The root, the bulb, and the leaves are edible parts. Kohlrabi is also known as german turnip, cabbage turnip and stem turnip. In Hindi, it is called as gaanth gobi. It tastes like cabbage but slightly sweeter. Scroll down to read about the health benefits of kohlrabi!  

Nutritional Value of Kohlrabi:

According to the US Department of Agriculture, the food value of kohlrabi is as follows: ⁴ 

• Water: 91 g (per 100 gm)
• Energy: 27 kcal (per 100 gm)
• Protein: 1.7 g (per 100 gm)
• Total Lipid (Fat): 0.1 g (per 100 gm)
• Ash: 1 g (per 100 gm)
• Carbohydrate: 6.2 g (per 100 gm)
• Fibre, Total Dietary: 3.6 g (per 100 gm)
• Sugars, Total Including NLEA: 2.6 g (per 100 gm)
• Calcium: 24 mg (per 100 gm)
• Iron: 0.4 mg (per 100 gm)
• Magnesium: 19 mg (per 100 gm)
• Phosphorus: 46 mg (per 100 gm)
• Potassium: 350 mg (per 100 gm)
• Sodium: 20 mg (per 100 gm)
• Zinc: 0.03 mg (per 100 gm)
• Copper: 0.129 mg (per 100 gm)
• Manganese: 0.139 mg (per 100 gm)
• Selenium: 0.7 µg (per 100 gm)
• Vitamin C: 62 mg (per 100 gm)
• Thiamin: 0.05 mg (per 100 gm)
• Riboflavin: 0.02 mg (per 100 gm)
• Niacin: 0.4 mg (per 100 gm)
• Pantothenic Acid: 0.165 mg (per 100 gm)
• Vitamin B-6: 0.15 mg (per 100 gm)
• Folate: 16 µg (per 100 gm)
• Choline: 12.3 mg (per 100 gm)
• Vitamin A: 36 IU (per 100 gm)
• Vitamin E (Alpha-Tocopherol): 0.48 mg (per 100 gm)
• Vitamin K (Phylloquinone): 0.1 µg (per 100 gm)

nutritional value of kohlrabi (100 gms) 

Kohlrabi is believed to help build stronger bones since it contains a lot of calcium and magnesium. Kohlrabi, along with other calcium-rich foods and regular weight-bearing exercise, may help to increase bone density.

Dr. Siddharth Gupta, B.A.M.S, M.D (Ayu)

Properties of Kohlrabi:

Kohlrabi might have the following properties: ¹ 

• It may help alleviate the reaction of the body to any injury or irritation. 
• It may lower blood sugar levels.  

• It may lower weight gain. 
• Kohlrabi may be an antioxidant.  
• It may help in the regulation of the immune system. 
• It may lower the risk of developing heart disease. 
• It may protect the functioning of the nervous system. 

Potential Uses of Kohlrabi for Overall Health:

The existing studies show that kohlrabi might have the following potential uses for overall health: 

1. Potential Uses of Kohlrabi for Inflammation

The body’s different metabolic processes produce free radicals. They can damage cells, induce inflammation and contribute to inflammatory diseases. A study by Jung et al. in 2014 showed that the green and purple-red kohlrabi varieties have flavonoids and phenolics compounds that act as anti-inflammatory agents. The kohlrabi extracts also inhibit the production of compounds that are involved in inflammatory processes.¹ Therefore, kohlrabi might help with inflammation and inflammatory diseases, but you should always consult a doctor regarding kohlrabi’s nutritional benefits before self-medicating it. 

2. Potential Uses of Kohlrabi for Diabetes

In diabetes, blood sugar levels are high. It can happen because of insulin resistance. It means body cells are not responding to insulin and not absorbing blood sugar, resulting in high levels of sugar in the blood. A study by Jung et al. in 2014 showed that extracts from the kohlrabi vegetable inhibit the insulin resistance associated with obesity and diabetes. Kohlrabi extracts can prevent diabetes, aid in diabetes treatment and reduce long-term diabetic complications.¹ The study shows that kohlrabi might be helpful in people with diabetes. However, you should consult a doctor and understand the kohlrabi benefits for diabetes prior to its intake.  

3. Potential Uses of Kohlrabi for Skin

Kohlrabi juice has potent antioxidants such as vitamin C, isothiocyanates, anthocyanins, and glucosinolates.¹ A study by Michalak in 2022 showed that the above-mentioned antioxidants present in kohlrabi could protect the cells from free radical damage and slow down the ageing process.⁵ Additionally, vitamin C promotes collagen production, which may protect the skin and reduce the visible signs of ageing, such as wrinkles, fine lines and pigmentations. However, you should not self-medicate. It is advised to consult a doctor regarding kohlrabi benefits for the skin before consuming. 

4. Potential Uses of Kohlrabi for Heart Health

The heart is a major organ that pumps blood to the arteries. A study by Kamal et al. in 2022 showed that kohlrabi has plant-derived chemicals named glucosinolates and isothiocyanates that lower the risk of developing heart disease. The study also shows that it can prevent atherosclerosis, hypertension, cardiomyopathy and heart failure.⁶ Although it may have a protective action against heart disease, more research is required to understand the benefits of eating kohlrabi on heart health. It is best to consult a doctor regarding kohlrabi vegetable benefits instead of using it for heart disease. 

5. Potential Uses of Kohlrabi for the Nervous System

The nervous system controls the body’s functioning by transmitting signals from the brain to the rest of the body. In some individuals, the functioning of the nervous system is reduced because of the neurodegenerative diseases that result from damage to the neurons and nervous system. A study by Kamal et al. in 2022 showed that kohlrabi has plant-derived chemicals named glucosinolates and isothiocyanates that lower the risk of developing neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases.6 However, you should never self-medicate with kohlrabi. It is best to consult a doctor regarding its health benefits before consuming it in case you have a neurodegenerative disease. 

6. Other Potential Uses of Kohlrabi

Other potential kohlrabi benefits are as follows: 

• Phytochemicals such as isothiocyanate and sulforaphane in kohlrabi might protect against colon and prostate cancer.¹ 
• It might reduce the chances of developing metabolic disorders such as obesity.¹ 
• It might help in the regulation of immune function.³ 
• It might help in dealing with age-related degeneration.³ 
• It may reduce the risk of developing cancer.² 

Although with the advancement in knowledge and technology, new research methods are employed to study the kohlrabi benefits, they are still insufficient and further studies are required.  

Both soluble and insoluble fibre types that don’t dissolve in water are abundant in kohlrabi. From what I know, as insoluble fibre can’t be broken down by your digestive system, it may help food to move to your stomach and intestines more quickly. It may add to the bulk of your faeces. A healthy digestive system is supported by insoluble fibre, which may encourage regular bowel motions.

Dr. Rajeev Singh, BAMS

How to Use Kohlrabi?

Kohlrabi can be used in the following ways: 

• You can cook, roast, saute and make pickled kohlrabi vegetables and use them as a savoury dish.¹ 
• It is used as a raw vegetable in sprouts or grated in salads.¹ 

You must consult a qualified doctor before taking any herbal supplements. Do not discontinue or replace an ongoing treatment of modern medicine with an ayurvedic/herbal preparation without consulting a qualified doctor.    

Side Effects of Kohlrabi:

Consuming kohlrabi in healthy amounts is considered safe. However, a study by Pasko et al. in 2022 on rats found that kohlrabi can have the following side effects: ⁷ 

• Reduction in white blood cells. 
• Interference with liver function. 
• It may affect thyroid function. 

Although there are insufficient studies on humans to understand the side effects of kohlrabi, it is best to consult a doctor if you notice any unusual symptoms.  

Precautions to Take with Kohlrabi:

General precautions must be taken while consuming kohlrabi. Here is a list of a few precautions to follow:   

• If you have any thyroid disorder, it is best to consult a doctor before consuming kohlrabi, as cruciferous vegetables adversely affect thyroid functions.⁷ 
• If you are pregnant or breastfeeding, take extra caution along with the doctor’s advice regarding the amount of kohlrabi you eat.  
• Care must be taken that elderly patients and children are monitored regarding the amount of kohlrabi they should eat.  
• If you have any medical condition, consult a doctor before taking kohlrabi. 

Interactions with Other Drugs:

There is not enough evidence on the interaction of the kohlrabi extracts with other drugs. Further studies are required. Therefore, you must consult your doctor if you are on any other medication before consuming kohlrabi.  

Frequently Asked Questions (FAQs)

References:

1. Jung HA, Karki S, Ehom N-Y, Yoon M-H, Kim EJ, Choi JS. Anti-Diabetic and Anti-Inflammatory Effects of Green and Red Kohlrabi Cultivars (Brassica oleracea var. gongylodes). Preventive Nutrition and Food Science. 2014 Dec 31;19(4):281–90. Available From: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4287320/  

2.  Pale-green kohlrabi, a versatile brassica vegetable – researchgate [Internet]. [cited 2022Dec20]. Available from: https://www.researchgate.net/publication/328509984_Pale-Green_Kohlrabi_a_Versatile_Brassica_Vegetable/fulltext/5bd1e65ca6fdcc631cfa1e73/Pale-Green-Kohlrabi-a-Versatile-Brassica-Vegetable.pdf   

3. Nie X, Chen H, Xiang L, Zhang Y, Liu D, Zhao Z. GC-TOF-MS-based non-targeted metabolomic analysis of differential metabolites in Chinese ultra-long-term industrially fermented kohlrabi and their associated metabolic pathways [Internet]. Metabolites. U.S. National Library of Medicine; 2022 [cited 2022Dec20]. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9610423/  
4. Michalak M. Plant-Derived Antioxidants: Significance in Skin Health and the Ageing Process. International Journal of Molecular Sciences. 2022 Jan 6;23(2):585. Available From: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8776015/   

5. Kamal RM, Abdull Razis AF, Mohd Sukri NS, Perimal EK, Ahmad H, Patrick R, et al. Beneficial health effects of glucosinolates-derived isothiocyanates on cardiovascular and Neurodegenerative Diseases [Internet]. Molecules (Basel, Switzerland). U.S. National Library of Medicine; 2022 [cited 2022Dec20]. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8838317/  

6. Paśko P, Okoń K, Prochownik E, Krośniak M, Francik R, Kryczyk-Kozioł J, et al. The impact of kohlrabi sprouts on various thyroid parameters in iodine deficiency- and sulfadimethoxine-induced hypothyroid rats [Internet]. Nutrients. U.S. National Library of Medicine; 2022 [cited 2022Dec20]. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9316894/   

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