Contents
What it is
Doraji is the root of a perennial in the bellflower family, known in English as balloon flower for the way its buds puff up before opening. It grows wild in Korea, China and Japan and flowers purple or white in summer. The root is pale and slender, with a grain that tears lengthwise into strips. It is markedly bitter, so after trimming it is rubbed with salt and rinsed, or soaked, before being dressed as a seasoned side dish or stir-fried. It is also eaten raw, grilled, steeped in sugar, or dried and simmered as a tea.
Scientific name Platycodon grandiflorus
There is a compositional reason balloon flower root (doraji, Platycodon grandiflorus) became Korea's standard cough remedy. The saponin platycodin D in the root stimulates secretion from the airway lining, lowering the viscosity of mucus.
That is how saponin-based expectorants work. Saying doraji is "good for coughs" is less about stopping the cough than about making phlegm easier to clear.
Key benefits
- Early research
It thins mucus and helps clear it
Platycodin raises bronchial secretion and reduces mucus viscosity. That expectorant activity comes from animal and cell studies; we could not find a trial testing it in people. Platycodon extract is indeed used in over-the-counter expectorants, but that fact is not itself clinical evidence.[1]
- Nutrition data
Among the highest-fibre vegetables there is
Over 8 g per 100 g — three to four times most vegetables. Most of it is insoluble fibre, so it acts mainly by adding stool bulk.
- Early research
Anti-inflammatory activity has been studied
Platycodin D suppresses inflammatory signalling pathways in cell and animal experiments. Clinical evidence in humans remains limited.[2]
- Nutrition data
Low in calories and filling
76 kcal per 100 g with enough fibre to demand real chewing. It works well as a way to add volume in seasoned side dishes.
How to eat it well
- Rubbing it in salt water removes much of the bitterness — but it removes saponins too, so do not overdo it.
- Doraji syrups are heavy in sugar. If you are using it for a cough, count that sugar.
- Dried root should be rehydrated before use in side dishes or soup.
- Simmering it with honey and pear, the traditional way, adds a coating effect on the throat.
- Eaten raw and seasoned, saponin losses are smallest.
How to read the grades
Each benefit carries a label showing how far research on people supports it. Grades differ between items even within the same ingredient.
- Nutrition data
- A fact verifiable from food composition databases or health authorities. This is a different kind of statement from a clinical effect.
- Strong evidence
- Consistently confirmed across randomised controlled trials or meta-analyses.
- Moderate evidence
- Human studies exist, but effect sizes are small or results are mixed.
- Early research
- Cell or animal work, or small preliminary studies.
- Not established
- Commonly claimed, but not confirmed in studies on people.
What to watch out for
- Saponins irritate the gastric lining, so large amounts on an empty stomach can cause nausea.
- Haemolytic activity has been reported rarely, so long-term use of high-dose extracts is not advised.
- Avoid it with coughing up blood or severe cough, where it may be irritating.
- Commercial doraji syrups are often very high in sugar — check the label if you have diabetes.
- Evidence is lacking for high medicinal doses during pregnancy.
Nutrition
Approximate values per 100 g edible portion.
- Calories
- 76 kcal4%
- Carbohydrates
- 17.4 g6%
- Fiber
- 8.2 g29%
- Protein
- 2.4 g5%
- Potassium
- 330 mg7%
- Calcium
- 24 mg2%
- Iron
- 1.2 mg7%
Percentages are of the US FDA Daily Value for adults and children 4 and over. National reference intakes differ by sex and age.
Calculate this alongside other ingredients →
Key nutrients
Sources
The databases and health authorities this article's nutrition figures and health statements draw on.
- 1Distribution, Biotransformation, Pharmacological Effects, Metabolic Mechanism and Safety Evaluation of Platycodin D: A Comprehensive ReviewResearch literatureLi Q, et al. Curr Drug Metab 2022PMID 35114917
- 2Anti-inflammatory effects of Platycodin D on dextran sulfate sodium (DSS) induced colitis and E. coli Lipopolysaccharide (LPS) induced inflammationAnimal or lab studyGuo R, et al. Int Immunopharmacol 2021PMID 33611056
- 3MFDS Food Composition Database · 식품안전나라Food composition database
- 4USDA FoodData CentralFood composition database
- 5PubMedResearch literature
