What Is Cardamom?
It is a perennial plant of the family of Zingiberaceae, which also includes ginger and turmeric .
The plant produces pods or capsules that contain 15 to 20 seeds each. These seeds are often ground to a fine powder before use in cooking or medicine .
There are two main types of commercially available cardamom:
- Green, large, or true cardamom (Elettaria cardamomum)
- Black, small, or winged cardamom (Amomum subulatum)
Because these two species grow at different elevations, regional cuisines and folk medicines tend to favor the species that is most common in their area. Southern Indian cuisine typically uses green cardamom and northern Indian and Nepalese cuisines favor the black. Both types have been used in traditional Unani and Ayurvedic medicines .
Cardamom contains a number of potentially active ingredients, the most important of which are :
Terpenes – a class of compounds known for many familiar aromas and associated with antioxidant health benefits.
- Limonene – also found in citrus fruit oils
- 1,8-cineole – also found in eucalyptus oil
- Linalool – known for its pleasant scent
- Linalyl acetate – a terpene derived from linalool
- Alpha-terpinyl acetate – also found in pine oil
Flavonoids and propanoids – two classes of compounds with antioxidant activities produced by plants.
- Eugenol – phenylpropanoid, also found in cloves, cinnamon, nutmeg, and basil
- Quercetin – flavonoid found in many other fruits and vegetables
The peculiar aroma of cardamom is due to alpha-terpinyl acetate and 1,8-cineole .
Mechanisms of Action
- Anti-inflammatory: Cardamom increases Th2 cytokine release and decreases Th1 cytokine release. Cardamom also decreases inflammatory markers COX-2, IL-6, NF-κB, and TNF-α, and the production of NO through iNOS [2, 3, 4].
- Antispasmodic: Cardamom reduces potassium-ion-induced contractions in intestinal, bronchial, and heart tissues. It also binds calcium ion receptors to stimulate tissue relaxation. The result is an antispasmodic property that can reduce gut distress, asthma symptoms, and blood pressure. Alternatively, it may achieve the same effects by blocking muscarinic acetylcholine (cholinergic) receptors [5, 6, 7].
- Anti-anxiety: Quercetin, a flavonoid found in cardamom, has an anti-anxiety effect in the brain by reducing corticotropin-releasing hormone (CRF) .
- Antioxidant: In addition to its free radical scavenging capacity, cardamom extract increased activities of some liver enzymes (SOD, GSH, GST)) and reduced activity of others (cytochrome p450, ALT, AST, and ALP). These changes are associated with increased antioxidant status, and detoxification of foreign compounds [9, 10, 3, 11].
- Anti-cancer: Cardamom oil prevents cancer-causing DNA damage. It also increases the activity of natural killer cells and causes cancer cell death through the activation of the ERK1/2 pathway and inhibition of HDAC2 [12, 13, 2].
Health Benefits of Cardamom
1) Cardamom Reduces Chronic Inflammation
A DB-RCT of 80 pre-diabetic women compared a cardamom supplement to a placebo over 8 weeks. The patients taking green cardamom had decreased markers of inflammation at the end of the trial (hs-CRP and the hs-CRP: IL-6 ratio) .
Rats with swollen paws (induced edema) had reduced inflammation when injected with green cardamom extract or with its essential oil at the site of the swelling. The extract/oil likely blocked the production of inflammatory molecules (including COX-2, IL-6, and TNF-α, as well as iNOS) [6, 3].
Similar suppression of inflammatory factors was observed with immune cells treated with a green cardamom extract in the laboratory. The extract suppressed Th1 and increased Th2 cytokines .
2) Cardamom Boosts Antioxidant Activity
In 20 hypertensive (high blood pressure) patients, a 3-month course of green cardamom powder supplements increased their antioxidant status by 90% .
Rats fed a high-fat diet supplemented with black cardamom had increased levels of important antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) in both their liver and heart .
3) Cardamom Lowers Cholesterol
A 19% overall decrease in total cholesterol, 25% decrease in LDL cholesterol, and 15% drop in triglycerides was observed in 20 hypertensive (elevated blood pressure) patients treated with green cardamom powder over a 3-month period .
In 80 pre-diabetic women (RCT), the group given green cardamom had lower total cholesterol and lower LDL cholesterol after 2 months .
Green cardamom powder supplements over 8 weeks also significantly decreased total cholesterol, LDL, but also HDL cholesterol levels in a randomized controlled trial (RCT) with 204 type 2 diabetes patients .
A study of rats with high cholesterol separated green cardamom oil from its powder and found the oil to be more effective at reducing cholesterol than powder alone .
4) Cardamom Improves Heart Health
Cardamom Prevents Blood Clots
Twenty patients with high blood pressure took green cardamom supplements for 12 weeks and this increased their ability to dissolve clots (fibrinolysis), reducing their risk of heart disease .
Clotting (platelet aggregation) in human blood samples was reduced by a green cardamom extract .
Cardamom Protects Against Heart Damage
Rats treated with green cardamom for 30 days suffered less heart damage after heart attack and maintained higher levels of antioxidants. This was due to the free radical scavenging and antioxidant activities of the cardamom .
Rats treated with black cardamom extract suffered less heart damage when infected with Enterovirus (Coxsackie virus), a contributing factor to some cases of chronic heart problems .
5) Cardamom Lowers Blood Pressure
Twenty patients with mildly elevated blood pressure (and not taking medication) were given a twice-daily dose of green cardamom powder for 12 weeks. By the end of the study, their blood pressure levels had dropped to within normal range .
Studies in cells and in mice confirm that green cardamom lowers blood pressure by two mechanisms: through the cholinergic pathway, and by controlling calcium ion channels .
Cardamom is also a diuretic. Rats fed a green cardamom extract had increased urine volume and excreted higher levels of sodium and potassium ions. Because diuretics help to relax blood vessel walls, which decreases blood pressure, they are often prescribed in combination with blood pressure drugs. This suggests cardamom may potentially be an even more effective therapeutic .
6) Cardamom May Help Weight Loss and Metabolic Syndrome
Rats fed a high-carb, high-fat diet develop metabolic syndrome. When this diet was supplemented with black cardamom (rich in 1,8-cineole), their metabolic syndrome symptoms got reversed: fat mass decreased, so did blood pressure and triglycerides, while heart and liver function improved. Green cardamom did not have the same effect .
In a similar study, obese rats fed a high-carb, high-fat diet with a green cardamom powder supplement showed an improvement in metabolic syndrome symptoms, including reduced belly fat .
More studies are required to determine which species of cardamom may have positive effects on metabolic syndrome and weight loss in humans.
7) Cardamom May Reduce Digestive Issues
Cardamom May Reduce Gut Discomfort
This spice improved symptoms of gut discomfort like diarrhea and stomach cramps related to spasms in the gut in animals, due to its antispasmodic action. Treatment of rabbit intestinal cells with green cardamom oil reduced movement. Cardamom likely achieves this by blocking muscarinic receptors (the cholinergic pathway) [6, 7].
Cardamom May Prevent Ulcers
Green cardamom extracts and essential oils prevented stomach lesions (ulcers) caused by alcohol or aspirin in rats. Ulcers caused by excess stomach acid did not improve with cardamom treatment. Moreover, one of the extracts was more effective than ranitidine, a drug used to treat ulcers .
Bacteria known to cause stomach ulcers (Helicobacter pylori) were only mildly inhibited in the presence of green cardamom extract in a laboratory .
8) Cardamom Is Antibacterial and Antifungal
Black cardamom extracts and its essential oils were able to slow or stop the growth of many bacterial and fungal species when tested in a laboratory. The essential oil was particularly effective, reducing the growth of the largest number of species tested (Bacillus pumilus, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Saccharomyces cerevisiae) .
Cardamom May Improve Oral Health
Both green and black cardamom extracts inhibited the growth of several species of cavity-causing harmful microorganisms commonly found in the human mouth (S.aureus, C. albicans, S. cerevisiae, and S. mutans) .
Cardamom has historically been chewed to freshen breath and even to help smokers quit (when used in nicotine gum), but more studies are needed to determine if its antibacterial properties improve cavities in humans [32, 33].
9) Cardamom May Improve Diabetes Symptoms
Rats with symptoms similar to diabetes were dosed with green cardamom and compared to a group given a common diabetes medication, pioglitazone. Both were effective in reducing blood cholesterol and fasting blood glucose levels, and preventing liver enlargement. However, only pioglitazone effectively lowered blood glucose after a meal .
However, in an RCT with 204 type 2 diabetes patients, green cardamom supplements (3g powder in their tea per day for 8 weeks) didn’t improve blood sugar levels .
A similar study of 80 pre-diabetic women measured no significant difference in blood sugar levels of those given green cardamom compared to those who received a placebo over 2 months but did show improved insulin sensitivity .
10) Cardamom May Improve Liver Function
Rats fed a high-fat diet had increased antioxidant enzymes and glutathione (GSH) in their liver tissues over a 90-day treatment with black cardamom. They retained better liver function as a result .
Improved liver function was among the improved metabolic syndrome symptoms observed in rats fed a high-carb, high-fat diet supplemented with black cardamom .
Rats given green cardamom extracts had higher antioxidant enzyme activities (SOD, GSH, and GST) in the liver that protected them from damage under stress .
11) Cardamom May Prevent Cancer
Cardamom Protects DNA
Green cardamom protected cells against DNA damage from free radicals, and reduced protein and fat damage (oxidation) .
Green cardamom essential oil prevented the binding of cancer-causing chemicals to DNA, reducing the risk of potentially cancer-causing DNA damage .
Cardamom Prevents Cancer Growth
Mice given oral doses of green cardamom had reduced incidence (number) and size of tumors of both skin and stomach cancers. These cancer-protective effects were observed when cardamom was given before and after tumors appeared [35, 10, 4].
Natural killer cells are part of the immune system’s response to seek out and kill cancer cells. The activity of these cells is enhanced by the presence of green cardamom when tested in cells .
Green cardamom also fights cancer by blocking NF-κB activation and decreasing COX-2 production (shown in mice) .
Cardamom Improves the Work of Detox Enzymes
Mice fed green cardamom essential oil had altered enzyme activities in the liver, with reduced CYP p450 and elevated glutathione S-transferase activity (GST). These enzyme levels are associated with detoxification of cancer-causing chemicals and mutagens .
12) Cardamom May Reduce Anxiety
Rats with symptoms similar to PTSD were given green cardamom extracts either before or after stressful sessions. In both treatments, anxiety-related behaviors improved compared to rats that did not receive the cardamom .
13) Cardamom May Reduce Pain
Green cardamom oil decreased pain in rats with swollen paws. This reduction was similar to another group of rats treated with aspirin .
14) Cardamom May Be a Sedative
Mice fed a green cardamom extract became sedated, similar to the effect of a prescription sedative (diazepam) .
More study is needed, but this sedative effect may be the source of claims that cardamom is good for patients with epilepsy .
15) Cardamom May Reduce Asthma Symptoms
Because of its anti-inflammatory properties, cardamom has long been a folk remedy for asthma.
When tested in rats and in rabbit throat cells, green cardamom extract had an anti-asthma effect, relaxing airway muscles through control of calcium ion channels .
However, cardamom does stimulate Th2 allergic responses, so it would be hard to say what the effects on asthma would be in humans or animals.
Cardamom is listed as a rare trigger of severe allergic reactions (anaphylaxis) .
Cardamom powder can cause contact dermatitis in some people .
This is likely because it stimulates Th2 cells responsible for allergic reactions. In rare cases, this dermatitis may even be systemic after ingestion of cardamom .
Limitations and Caveats
Many of the benefits are derived from animal studies. There are a couple of human studies, but even those have small amounts of test subjects.
Differences Between the Two Species of Cardamom
Most studies focus on only one of the two main kinds of cardamom, green and black. In a few studies where both were analyzed, the health benefits were sometimes very different between the two types .
Incomplete data makes it difficult to determine which type might be of best value for some health conditions where only one type has been thoroughly tested.
Table of evidence for health benefits described in this article:
(A “+” indicates evidence for a species of cardamom (green or black) and a particular health benefit. A “-” indicates that a species was tested and did not have evidence for the health benefit. A blank cell indicates that no study has been done at the time of writing. Where conflicting results were found, both “+/-” are indicated in the table.)
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Benefits May Depend on the Type of Extract
Not all studies use the same cardamom sources – examples used include powder from the seeds, crude extracts, alcohol-soluble extracts, water-soluble extracts, and the essential oil, among others. Some of these cardamom sources might have lost certain potentially active compounds, and in doing so, fail to identify potential health effects in their study data.
The composition of cardamom can additionally vary from harvest to harvest according to environmental factors.
There were a few reports in which patients with high cardamom intakes excreted red blood cells through their urine (hematuria). Patients taking anticoagulant or antiplatelet medications should be particularly mindful of their cardamom intake .
Because cardamom can lower cholesterol significantly on its own, patients prescribed medication to lower their cholesterol should be careful about combining those therapies with cardamom. The same is true for patients taking medication to lower blood pressure.
- Seed pods
- Whole seeds
- Powdered seeds (spice)
- Essential oil
Common sources of cardamom include the seed pods, spice powder (ground seeds), essential oil, and tea. Cardamom tea and its essential oil are likely to only contain a portion of the compounds responsible for its health effects, so spice powder may be the most complete form of supplementation for health .
Cardamom supplements often come bundled with other wellness herbs for various uses (mind health, colon health, etc.) or as part of chai or other tea blends.
Dosages reported in studies varied greatly depending on the type of cardamom extract or preparation. For cardamom powder, 3g daily seems sufficient for most health benefits and is within normal doses for dietary cardamom intake .
Of common supplement formulations (whey protein, guar gum, carrageenan), the best formulation for encapsulation while still preserving shelf stability was the 30% whey protein isolate .
Users of cardamom tea typically report improved regularity and digestion, but few other specific health benefits.
Essential oil users sometimes reported relief of muscle cramps when the oil was rubbed on the skin.
Customers who used cardamom capsule supplements sometimes saw improved cholesterol or heart health, but as a part of an improved diet and lifestyle.