Ulam Raja:
The King’s Salad
That Earned
Its Crown.
Cosmos caudatus arrived in Southeast Asia from Mexico, carried by Portuguese traders in the 16th century. It naturalised so completely into the Malaysian table that most people have never thought of it as anything other than part of the ulam spread. But 100 grams of fresh ulam raja has an antioxidant capacity equivalent to 2,500 mg of ascorbic acid — compared to less than 300 mg for most local fruits. And in a bone protection study, it outperformed calcium supplementation. Not matched it. Outperformed it.
Ulam raja is the most Malaysian of stories. A plant that crossed the world from Mexico on Portuguese ships in the 16th century, found the Malaysian climate so congenial that it naturalised completely, entered the traditional food culture so thoroughly that most people assume it has always been here, and became so familiar on the ulam plate that it stopped being noticed.
This is exactly what The Wrong Default framework describes. Not the drift away from nature. Not the removal of wild plants by industrialisation. But the drift of familiarity — the herb that is so common, so available, so much a part of the background that its properties are never examined. Ulam raja is on the table. It has always been on the table. The research that explains why it deserves to be there is what most Malaysians have never read.
Before the compounds, the history, or the preparation guide — here is what the research found.
- Among 25 tropical plants tested for antioxidant activity in a published comparative study, Cosmos caudatus ranked number one — higher than all local fruits, all local vegetables, and all other herbs tested. A fresh 100g sample has approximately 2,400–2,500 mg ascorbic acid equivalent antioxidant capacity (AEAC). Most local fruits score below 300 mg AEAC per 100g. This is not a marginal difference.
- In a published bone histomorphometry study, Cosmos caudatus extract at 500 mg/kg was given to ovariectomised rats — the standard model for postmenopausal osteoporosis. At the end of the study, ulam raja outperformed calcium supplementation on two bone parameters: trabecular number and trabecular separation. Both groups reversed the bone loss caused by ovariectomy. Ulam raja did it better on two of the key measurements.
- Ulam raja contains 270 mg of calcium per 100g — alongside its exceptional antioxidant profile. The researchers concluded that this combination of high calcium content plus antioxidant activity (protecting osteoblasts from oxidative damage) is why it exceeds pure calcium supplementation. It is not just delivering calcium. It is protecting the cells that use calcium to build bone.
- Extracts have been shown to lower blood pressure in rat models at levels comparable to standard antihypertensive drugs — through ACE-inhibitory mechanisms. And blood glucose was significantly reduced in obese rat models, comparable to the antidiabetic effects of reference drugs used in the same studies.
- It is from Mexico. Cosmos caudatus is not a native Malaysian plant. It arrived with the Portuguese in the 16th century — a New World plant that crossed the Pacific and Atlantic, found its way to the Malay Peninsula, and became so embedded in local food culture that its Mexican origin was entirely forgotten. The name Ulam Raja — King’s Salad — was given by people who recognised it as exceptional. They were right.
From Mexico to the Malay Table — A Plant That Crossed the World
Cosmos caudatus is a member of the Asteraceae (daisy) family, native to Mexico and Central America. It was introduced to Southeast Asia during the Portuguese colonial period in the 16th century — part of the Columbian Exchange, the massive movement of plants, animals, and microbes between the Old World and the New World that followed Columbus’s voyages. The same exchange that brought chilli pepper, sweet potato, cassava, papaya, and pineapple to Malaysia also brought ulam raja.
Unlike most introduced plants that remain curiosities, Cosmos caudatus thrived. The tropical climate, the well-drained soils, the year-round growing season — conditions almost identical to its original Mexican habitat. It naturalised so completely that it became established in the wild across Malaysia, Indonesia, Thailand, and the Philippines, and entered traditional food and medicine systems in every country it reached.
King’s Salad. The name that acknowledges what traditional knowledge recognised: this herb was of exceptional quality among the ulam plants. Eaten raw as a salad herb, often with nasi campur.
The Indonesian name, widely used across Java, Sumatra, and Bali. Used in the same ulam tradition as Malaysia, and also cooked as a vegetable in Javanese cuisine.
Also called “garden cosmos” or simply “cosmos” — though this causes confusion with Cosmos bipinnatus, the ornamental garden flower. Cosmos caudatus is the edible species.
Tiān lán jù — one of several Chinese names. Also known as 宇宙花 or recorded under its scientific name in Chinese herbal references. Grown and eaten in Chinese communities across Southeast Asia.
Among several Philippine names. Present across Luzon and the Visayas, used in local herbal medicine and occasionally in salads.
From Asteraceae family. “Caudatus” means “tailed” in Latin, referring to the plant’s characteristic long, thin appendages. Cosmopolitan in distribution across the humid tropics.
From Aztec Mexico to the Malaysian Table
- Pre-1500sCosmos caudatus grows wild in Mexico and Central America. Used by indigenous populations as both food and medicine. The Aztecs documented its cultivation. The plant’s ornamental, edible, and medicinal properties were all known to pre-Columbian Mexican civilisation before European contact.
- 16th CenturyThe Portuguese colonial period brings the Columbian Exchange to Southeast Asia. Cosmos caudatus arrives in Malaya alongside other New World plants. It naturalises rapidly in the tropical climate. It enters Malay traditional food culture within generations of its introduction — a speed of adoption that reflects both its adaptability and its obvious culinary and medicinal usefulness.
- Traditional EraUlam raja becomes established in Malay and Indonesian traditional medicine. Traditional uses documented across the region: improving blood circulation (darah tinggi management), strengthening bones, reducing fever, treating skin conditions, and as a general tonic. The Orang Asli incorporate it into food and medicine alongside native plants.
- 2006–2015Malaysian researchers — primarily at UKM, UPM, and USM — begin systematic scientific investigation of ulam raja. Studies confirm its exceptional antioxidant capacity. The bone protection studies are published. The antihypertensive and antidiabetic effects are documented. A 2015 scoping review in the Journal of Research in Medical Sciences consolidates the evidence across 15 published studies.
- 2022–2025Research continues and expands. Metabolomic studies identify over 100 bioactive compounds using HPLC-MS. Network pharmacology and molecular docking studies examine mechanisms. A 2025 study specifically compares Cosmos caudatus extract to vitamin C supplementation in athletes under oxidative stress from high-intensity exercise. The research base is growing in sophistication — moving from basic antioxidant assays to mechanistic and clinical relevance.
What It Looks Like — and How to Grow It on Your Balcony
Ulam raja is one of the easiest edible plants you will ever grow. In Malaysia’s year-round tropical warmth, it asks for almost nothing. You can grow it in pots on a condominium balcony — which is exactly where many Malaysians have kept it for generations. Here is how to identify it and how to grow your own supply.
Overall form: An upright, branching annual herb, growing 50 to 120 centimetres tall in Malaysian conditions. Stems are light green to reddish-purple, slightly hairy, and branched from early in the plant’s life. The reddish-purple colouring of the stems is one of the most reliable identification features — this distinctive colour deepens in full sun.
Leaves: Deeply pinnately divided — meaning each leaf is cut into multiple pairs of narrow, feathery leaflets arranged along a central stalk, giving the leaf a lace-like, ferny appearance. This feathery leaf structure is one of the most distinctive features of the plant and immediately separates it from most other herbs in the ulam tradition. The leaves have a mildly bitter, slightly aromatic smell and taste when crushed.
Flowers: Daisy-like composite flowers (it is in the same family as sunflowers and daisies). Petals are pale to deep pink or purple-pink, surrounding a yellow central disc. Flowers are approximately 3 to 4 centimetres across. They appear continuously as the plant matures. In Malaysian conditions, a plant will flower within 6 to 8 weeks of germination if given full sun.
Seeds: Long, thin, needle-like seeds — characteristic of the Cosmos genus. Dark brown to black, about 1 to 2 centimetres long. They are produced abundantly and fall naturally, self-seeding readily. If you let the plant flower and set seed, it will sow itself around the pot or garden bed.
Quick identification summary: Feathery, finely divided leaves — reddish-purple stems — pink daisy-like flowers. In Malaysia it is almost unmistakeable once you have seen it once.
Growing Ulam Raja at Home — Including in Pots and on Balconies
This plant is forgiving, fast, and practically grows itself in Malaysian conditions. Here is everything you need.
Full sun — minimum 6 hours of direct sun per day.
This is the single most important requirement. Ulam raja is from Mexico — it evolved under intense tropical sun. In full sun it grows vigorously, produces abundant leaves, and develops the deep reddish-purple stem colour that indicates maximum anthocyanin and flavonoid development. In partial shade it grows leggy, produces fewer leaves, and the medicinal compounds are less concentrated.
For balcony growing: a south or west-facing balcony that gets 6+ hours of direct sun is ideal. East-facing balconies (morning sun only) will work but produce somewhat less vigorous plants.
Minimum 30cm depth. Well-draining potting mix. Not too rich.
Use a pot at least 30 centimetres deep with good drainage holes. Ulam raja has a tap root that needs depth. A standard potting mix is fine — do not use soil that is too rich in nitrogen, as this produces excessive foliage at the expense of flowers and actually reduces the plant’s flavonoid production (the compounds are defence mechanisms; a well-fed plant that never stresses produces less of them).
A 30cm pot will comfortably hold one plant. A 40–50cm pot can hold two to three plants for a denser harvest. Ensure the pot has multiple drainage holes — waterlogged roots are the primary way to kill this plant.
Press seeds lightly into moist potting mix. Surface sow or cover with 3–5mm of soil. Water gently. Germinate in 5–10 days.
In Malaysia’s year-round warmth, seeds can be sown any time. Unlike temperate-climate growing guides (which talk about frosts and seasons), in Malaysia you simply sow and watch. Scatter seeds thinly on the surface of moist potting mix and press in gently, or cover with a very thin layer of soil (3–5mm). Water with a gentle spray. Germination in tropical conditions: 5 to 10 days. No cold stratification, no special treatment needed.
Thin seedlings to one per 20cm once they reach 5cm tall. The thinned seedlings can be transplanted to other pots or eaten directly.
Water when the top 2–3cm of soil is dry. Do not overwater.
Ulam raja is surprisingly drought-tolerant — it evolved in seasonally dry Mexican conditions. The most common mistake in pot growing is overwatering. Water thoroughly when the top soil layer is dry, then let it drain completely. In Malaysia’s heat, this typically means watering every 1 to 2 days in direct sun. Check the soil rather than watering on a schedule. Yellow lower leaves = overwatering. Wilting in afternoon heat = underwatering.
On a balcony, pots dry out faster than garden beds. Check daily during hot, dry spells.
Pinch out the growing tip early for bushier growth. Harvest above a leaf node. The plant regrows.
When the seedling has 3 to 4 sets of leaves, pinch out the very top growing tip with your fingers. This makes the plant branch out rather than grow straight up — producing more lateral shoots and therefore more harvestable leaves. For an ulam plant (where you want leaves, not just flowers) this is the most important technique.
When harvesting, cut stems just above a leaf node (the point where a leaf joins the stem). This prompts two new shoots to grow from that point, giving you more the next time. A single plant maintained this way can provide continuous harvests for months in Malaysian conditions. Harvest young leaves and shoot tips preferentially — they are more tender and have higher flavonoid concentrations than older leaves.
Let a few flowers set seed. The plant will sow itself. Your supply becomes continuous.
Once ulam raja flowers, it produces abundant seeds. If you let some flower heads dry and shed their seeds into the pot or surrounding area, the plant will self-sow. In Malaysian conditions, self-sown seedlings appear within days of the seeds falling. This means that once you have one plant established, you effectively have a continuous self-renewing supply with no further effort. The old plant ages and declines; the new seedlings are already growing.
Collect some dried seed heads and store in a paper bag or envelope in a cool, dry place. These will germinate for at least a year. Share seeds with friends — ulam raja is one of the most generous plants for seed sharing.
When I was living in a condominium, I grew ulam raja in pots on the balcony. It works. The key is the sun exposure — the balcony needs to get real direct sun, not just bright light. In a south or west-facing apartment balcony with honest full sun, this plant grows enthusiastically in standard potting mix with no particular attention beyond regular watering.
The reddish-purple stems develop more intensely with more sun — and that colour is where the anthocyanins are concentrated. A pot of ulam raja in good sun looks beautiful. The pink flowers are genuinely ornamental alongside the feathery leaves. You do not need a garden. You need a sunny balcony and a 30cm pot.
The yield from even two or three pots maintained correctly gives enough fresh ulam raja for daily ulam alongside every meal — which is the consumption frequency the research supports for cumulative antioxidant and anti-inflammatory benefit.
The Most Underestimated Herb on the Nasi Campur Plate.
Walk into any traditional Malay restaurant or gerai nasi campur and you will likely find ulam raja on the ulam tray — a bunch of fresh leaves, reddish-purple stems, beside the pegaga, the daun kaduk, the ulam timun. Most people take a small portion, mix it with sambal belacan, and eat it without giving it a second thought. It is background. It has always been background.
But the name was never background. “Ulam Raja” means King’s Salad. Someone, at some point in the history of Malay food culture, decided this herb deserved a royal designation. That was not an accident of language. Traditional food cultures did not assign royal titles to unremarkable plants. The name reflects a recognition of exceptional quality — a recognition the science is now confirming in peer-reviewed literature.
In traditional Malay medicine (Perubatan Melayu Tradisional), ulam raja was specifically used for blood circulation — an umbrella term in traditional medicine that encompasses blood pressure, blood viscosity, and cardiovascular function. This aligns precisely with the ACE-inhibitory antihypertensive mechanism now documented in laboratory research. The traditional practitioner reached the correct clinical target. The mechanism was identified centuries later.
The Wrong Default here is not the removal of a plant. Ulam raja is still on the table. The drift is in the intention — eating it mindlessly as a garnish versus understanding it as one of the most antioxidant-rich foods in the entire Malaysian ulam tradition, with documented bone-protective, antihypertensive, and antidiabetic properties that justify daily, conscious consumption. The herb did not change. Our relationship with it did.
What Is Actually in the Leaf — and Why the Number Is So High
Metabolomic studies using HPLC-MS have identified over 100 bioactive compounds in Cosmos caudatus. The breadth of this profile — flavonoids, phenolic acids, terpenoids, essential oils, minerals, and vitamins all present simultaneously — is the primary reason the antioxidant capacity is so exceptional. No single compound explains the 2,500 mg AEAC value. It is the combination.
The Dominant Flavonoid — Multiple Forms
Quercetin is the most abundant and most studied flavonoid in ulam raja, present in multiple glycoside forms: quercetin 3-O-rhamnoside (quercitrin), quercetin 3-O-glucoside, quercetin 3-O-arabinofuranoside, and rutin. Each glycoside form has slightly different bioavailability and biological activity. Together they contribute the majority of the DPPH radical-scavenging activity. Quercetin also inhibits ACE — the blood pressure mechanism — and has anti-diabetic activity through multiple pathways.
Blood Glucose Regulation
The same compound found in significant quantities in moringa and coffee. In ulam raja, chlorogenic acid is a major phenolic acid that inhibits glucose-6-phosphate translocase in the liver, directly reducing hepatic glucose production. It is one of the primary mechanisms behind the antidiabetic activity. Also shows antihypertensive and antioxidant activity. Its combined presence with quercetin produces synergistic blood glucose effects.
Anti-inflammatory & Bone-Protective
Both present alongside quercetin in the flavonol fraction. Kaempferol has documented anti-inflammatory effects through NF-κB inhibition and has shown bone-protective activity through promotion of osteoblast differentiation and suppression of osteoclast formation. This provides a direct mechanistic explanation for the bone protection study results beyond the calcium content. Myricetin adds additional antioxidant and anti-inflammatory activity.
The Major Antioxidant Class
HPLC/MS analysis identified more than twenty antioxidant compounds in ulam raja, with proanthocyanidins — present as dimers through hexamers (complex chains of catechin units) — as the major antioxidants by quantity. These large, complex polyphenols are what push the AEAC value to 2,500 mg/100g. Proanthocyanidins also contribute to antimicrobial, anti-inflammatory, and vasodilatory activity. Grape seed extract, famous for its proanthocyanidin content, contains compounds in the same class.
Antimicrobial & Antimutagenic
Costunolide is a sesquiterpene lactone identified in ulam raja essential oil and extracts. It has documented antimutagenic, antimicrobial, and antifungal activity. Studies from the Philippines confirmed compounds from Cosmos caudatus showed antimutagenic activity. The sesquiterpene fraction including caryophyllene, humulene, and bicyclogermacrene contributes additional antimicrobial activity and the characteristic aromatic scent of the fresh leaf.
270mg Calcium per 100g — Food-Matrix Delivery
Ulam raja contains 270 mg calcium per 100g — comparable to dairy calcium but delivered in a plant food matrix alongside phenolic compounds that protect the osteoblasts using that calcium. Iron, phosphorus, potassium, and magnesium are also present. The mineral profile combined with the antioxidant activity is the dual mechanism the bone studies identified — the plant provides the raw material (calcium) and the protection for the cells that build bone (antioxidants reducing oxidative stress on osteoblasts).
What the Research Has Confirmed — and Where It Stands
Among 25 tropical plants tested, Cosmos caudatus ranked first in DPPH free radical scavenging activity and first in ferric ion reducing antioxidant potential.
This comparative study is the foundational antioxidant finding for ulam raja. Twenty-five tropical plants were assessed using DPPH scavenging and FRAP assays — two independent measures of antioxidant capacity. Cosmos caudatus ranked first on both. The result was subsequently confirmed by multiple independent studies using different assay methods. A 2012 study comparing ulam raja to three other local herbs (Persicaria hydropiper, Centella asiatica, and Artemisia argyi) found C. caudatus ranked highest in antioxidant activity — above pegaga (Centella asiatica), which is already considered one of Malaysia’s top medicinal herbs.
The antioxidant capacity of 2,400–2,500 mg AEAC per 100g fresh sample compared to less than 300 mg for most local fruits is not a marginal difference. It is roughly an order of magnitude higher. The major antioxidant contributors identified by HPLC/MS: proanthocyanidins (dimers to hexamers), quercetin glycosides, and chlorogenic acid — working as a synergistic matrix, not as isolated compounds.
Cosmos caudatus at 500 mg/kg outperformed calcium supplementation on two bone histomorphometry parameters in postmenopausal osteoporosis rat model.
The first study (Mohamed et al., 2012) assessed structural bone histomorphometry. Ovariectomy — the rat model of postmenopausal oestrogen loss — caused decreased trabecular bone volume, decreased trabecular number, and increased trabecular separation (all markers of bone loss). Both calcium supplementation (1% calcium ad libitum) and Cosmos caudatus (500 mg/kg, 6 days/week for 8 weeks) reversed these changes. Cosmos caudatus showed better effects than calcium on trabecular number and trabecular separation.
The second study (2013, same group) extended this to dynamic and cellular bone histomorphometry. The CC group showed significantly increased osteoid volume (OV/BS) compared to both the ovariectomised control AND the calcium group. Osteoid is the unmineralised bone matrix produced by osteoblasts — it is the precursor to mineralised bone. More osteoid means more active bone-building activity. Ulam raja was stimulating more bone formation than calcium supplementation alone.
The proposed mechanism: the plant provides calcium (270 mg/100g) plus antioxidants that protect osteoblasts from oxidative stress-induced apoptosis (cell death). Oxidative stress is one of the key drivers of osteoblast loss in postmenopausal osteoporosis. Antioxidants reduce this. The plant addresses both the raw material deficit (calcium) and the cellular damage (oxidative stress on bone-building cells) simultaneously.
Extracts significantly reduced blood pressure at levels comparable to standard antihypertensive reference drugs in rat models.
Multiple studies have examined the antihypertensive activity of Cosmos caudatus. The mechanism is primarily ACE inhibition — the same target as a major class of blood pressure medications (ACE inhibitors). Quercetin and its glycosides are the primary ACE-inhibitory compounds identified. Additional vasodilatory effects have been attributed to the proanthocyanidin and chlorogenic acid content. The traditional Malay use of ulam raja specifically for “darah tinggi” (hypertension) aligns directly with this ACE-inhibitory mechanism.
Significantly reduced blood glucose in obese rat models, with effects comparable to reference antidiabetic drugs in some studies.
Several mechanisms contribute: chlorogenic acid inhibits hepatic glucose production, quercetin and its glycosides improve insulin sensitivity and reduce glucose absorption, and the overall antioxidant effect reduces the oxidative stress that impairs pancreatic beta-cell function. The combination produces a multi-pathway antidiabetic effect. These are animal studies — human clinical trials for diabetes are still needed. But the consistency across multiple studies and the clarity of the mechanisms provide a compelling basis for further investigation.
Cosmos caudatus extract compared directly to vitamin C supplementation in athletes under high-intensity exercise-induced oxidative stress — with comparable antioxidant protection and better bone metabolism outcomes.
This 2025 study specifically tested Cosmos caudatus extract against standard vitamin C supplementation in an exercise context. Athletes experience significant oxidative stress from high-intensity training, and antioxidant supplementation is widely used to manage this. The study found that C. caudatus extract provided comparable antioxidant protection to vitamin C, while also showing superior effects on bone metabolism markers. This is the most clinically modern study published on ulam raja and the first to directly compare it to a recognised pharmaceutical-grade antioxidant.
Ranked first among 25 tropical plants tested for both DPPH and FRAP antioxidant activity. Also ranked first above pegaga and three other herbs in separate comparative study.
Antioxidant capacity per 100g fresh sample. Compared to <300mg for most local fruits. Among the highest reported for any Malaysian food plant.
High calcium content plus antioxidant protection of osteoblasts = better bone outcomes than calcium alone in published study. Both the raw material and the protection.
On two bone parameters (trabecular number and trabecular separation), Cosmos caudatus outperformed 1% calcium supplementation in the ovariectomised rat model of postmenopausal osteoporosis.
The Right Way to Eat the King’s Salad
Six Ways to Use Ulam Raja — From Daily to Deliberate
The fresh leaf is the gold standard. Most of the bioactive compounds are preserved in raw preparation. Here is how to use it from simplest to most specific.
Fresh young leaves and stems eaten raw alongside your meal.
This is the traditional method and the one that preserves the maximum antioxidant capacity. Quercetin, proanthocyanidins, chlorogenic acid — all present at full activity in the fresh leaf. The characteristic slightly bitter, aromatic taste is the flavonoid and terpenoid profile you are tasting. Eat it with sambal belacan, budu, or any strong condiment. The pungency of the condiment complements the herb’s complexity.
The key insight: eat it daily, not occasionally. The bone-protective effects, the blood glucose regulation, the antihypertensive activity — these are cumulative effects that require consistent consumption, not a once-a-week portion at the warung.
A mixed herb salad with ulam raja as the hero ingredient.
Combine fresh ulam raja leaves with julienned torch ginger (bunga kantan), sliced shallots, fresh chilli, and a dressing of budu or belacan dissolved in lime juice. This is the preparation that allows the full flavour profile to come forward — the sourness of the lime enhancing the herb’s natural astringency. The torch ginger adds aromatic complexity. Serve alongside rice as a main accompaniment.
From a pharmacological perspective, the lime juice provides additional vitamin C that works synergistically with the plant’s own quercetin and chlorogenic acid. The fat from belacan slightly improves absorption of fat-soluble terpenoids.
Dried ulam raja leaves steeped in hot water — a gentle daily tonic.
Dry the leaves in shade (not direct sun — UV degrades some phenolic compounds). Once dried, store in an airtight container. Steep 1 to 2 teaspoons of dried leaf in water at 70–80°C for 5 minutes. Do not boil — high temperatures reduce the quercetin and proanthocyanidin content. Drink before meals.
This is the method documented in published research as a traditional herbal tea preparation. The tea form allows consistent daily intake regardless of whether fresh ulam is available. The dried form loses some vitamin C but retains the flavonoids, phenolic acids, and terpenoids well.
Finely shredded ulam raja mixed into herbed rice.
Nasi ulam is the Peranakan and Malay tradition of mixing finely shredded fresh herbs into cooked rice alongside dried shrimp, torch ginger, kaffir lime leaf, turmeric leaf, and other aromatics. Ulam raja belongs in nasi ulam. Its slightly bitter note balances the sweetness of the coconut-rice base, and the fine shredding maximises the surface area of the leaf’s bioactive compounds in contact with the warm rice.
The warm rice (not hot) gently warms the herb without significant heat degradation of the flavonoids. The fat from any coconut in the rice aids absorption of fat-soluble terpenoids.
Young leaves very briefly blanched, then dressed with lime, belacan, and chilli.
A 10 to 15 second blanch in boiling water reduces the raw bitterness for those who find the raw leaf too pungent, while preserving most of the flavonoid and phenolic content (mild heat has limited impact on quercetin and proanthocyanidins; it reduces vitamin C and some volatile terpenoids). Immediately cool in cold water, then dress and serve. This method makes ulam raja accessible to those who find the raw leaf too intense.
For those specifically seeking the bone-protective effect: daily consumption with calcium-rich foods.
The bone studies used 500 mg/kg body weight of concentrated extract — not a direct equivalent to fresh leaf consumption. But the mechanism involves both the calcium content (270 mg/100g) and the antioxidant protection of osteoblasts. A generous daily serving of fresh ulam raja (50–100g) alongside other calcium sources provides meaningful intake of both calcium and the antioxidant compounds that protect bone-building cells.
For post-menopausal women specifically: the research was conducted in the ovariectomised rat model — the standard for studying post-menopausal bone loss. The plant addresses the two key problems: calcium deficit and oxidative damage to osteoblasts. Daily ulam raja is the food-based version of this intervention.
What Indonesian Posts Are Claiming — and the Honest Truth Behind the Science
Social media posts from Indonesia — and increasingly from Malaysia — claim that kenikir (ulam raja) cures cancer or is a natural cancer treatment. Some posts encourage people to substitute kenikir for medical cancer treatment. This framing is dangerous. The science behind these claims is real in one sense and fundamentally misleading in another. Both parts need to be understood clearly.
What the Laboratory Evidence Actually Shows
There is published scientific research on Cosmos caudatus and cancer. This is not fabricated. Multiple studies have been conducted, primarily in Indonesia, showing cytotoxic (cancer-cell-killing) activity of ulam raja extracts against cancer cell lines in laboratory settings:
Cosmos caudatus extracts kill cancer cells in laboratory dishes — against leukemia, colorectal, cervical, oral, and lung cancer cell lines.
What was tested: Ethanol extracts, ethyl acetate extracts, and specific fractions of C. caudatus leaves were applied to cancer cell lines in controlled laboratory conditions. The extracts showed dose-dependent cytotoxic activity against:
• L1210 leukemia cells (ethyl acetate fraction showing significant cytotoxicity)
• Human Colorectal Carcinoma Cells (fractions with IC50 values of 15.53, 32.72, and 34.16 μg/mL — values that indicate meaningful activity in laboratory conditions)
• HeLa cells (cervical cancer) — CCEE showed cytotoxic activity, with quercetin showing even stronger activity than the full extract
• HSC-3 oral cancer cells — extracts triggered apoptosis (programmed cell death) by decreasing the anti-apoptotic protein Bcl-2 and increasing the pro-apoptotic protein Bax
• Lung cancer cells — 2025 Springer Journal of Pharmaceutical Innovation paper using network pharmacology and molecular docking identified specific C. caudatus compounds as plausible lung cancer drug candidates
The mechanism: Quercetin (the dominant flavonoid), catechin, and chlorogenic acid are the primary active compounds. Quercetin has well-documented pro-apoptotic and anti-proliferative effects in cancer cell lines across many studies — not unique to ulam raja. Costunolide (a sesquiterpene lactone in the essential oil) has demonstrated antimutagenic activity — meaning it may help prevent the DNA mutations that initiate cancer.
This evidence is real. The research was conducted. The results are published.
Why This Does Not Mean “Cancer Cure”
Almost everything kills cancer cells in a Petri dish. That is not the same as treating cancer in a living human body.
This is the fundamental misunderstanding behind every “natural cancer cure” claim that is based on in vitro cytotoxicity research. Here is why the gap matters:
In a Petri dish, you can achieve any concentration. You apply the extract directly to cancer cells at whatever concentration shows activity. In a human body, you eat the plant and the compounds must be absorbed through the gut, survive digestion, enter the bloodstream, travel to the tumour site, and arrive at concentrations sufficient to kill cancer cells — all without killing the surrounding healthy cells at the same concentration. This is enormously more difficult than applying a solution to a cell in a dish.
Healthy cells also die in vitro. The IC50 values that sound impressive in a laboratory paper (15–35 μg/mL for some ulam raja fractions) represent the concentration that kills half the cancer cells in the dish. At similar concentrations, normal healthy cells often also show toxicity. The challenge of cancer therapy is selectivity — killing cancer cells without killing the patient. In vitro cytotoxicity data alone tells you almost nothing about selectivity.
No animal tumour model studies. The step between in vitro (cell culture) and human trials is animal studies using actual tumours. For ulam raja and cancer, as of the time of writing, no published animal tumour studies exist that show shrinkage or elimination of actual tumours. The evidence chain stops at the cell dish.
Zero human clinical trials. Not a single published human trial on ulam raja for cancer treatment. Not even a Phase 1 safety trial. The evidence that would support even cautious hope for human application does not yet exist.
The specific danger of substitution. When someone with cancer replaces or delays conventional treatment because they are eating kenikir as a “cure,” they are trading a treatment with documented human efficacy for one with zero human evidence. Cancer responds to time. Delay during which a tumour continues to grow and potentially metastasise is not a neutral choice. This is why the “natural cure” framing for cancer is not merely scientifically inaccurate — it is actively dangerous for the people who believe it.
All cancer-related evidence for ulam raja is laboratory cell culture (in vitro) or computer modelling (in silico). No animal tumour studies. No human trials.
Not a single published human clinical trial on ulam raja for cancer at any stage. The clinical evidence chain does not exist yet.
Costunolide and related compounds have documented antimutagenic activity — preventing the DNA mutations that initiate cancer. This is cancer prevention, not treatment.
Daily consumption of ulam raja’s antioxidants reduces oxidative DNA damage — a primary cancer-initiating mechanism. As a dietary cancer prevention food, the evidence is solid. As a cancer treatment, it is not.
The Distinction That Matters: Prevention vs Treatment
There is a real and meaningful relationship between ulam raja consumption and cancer — but it is the relationship between diet and cancer prevention, not between a plant and cancer treatment.
The antioxidant capacity of ulam raja (2,500 mg AEAC per 100g) reduces oxidative damage to DNA. Oxidative DNA damage is one of the primary initiating mechanisms of cancer — it is how a normal cell begins the mutation pathway toward malignancy. Regular consumption of high-antioxidant foods reduces this background damage. This is cancer prevention in the epidemiological and mechanistic sense — and it is real.
The antimutagenic compounds (particularly costunolide) may help prevent specific types of carcinogen-induced DNA mutation. The anti-inflammatory phenolics reduce the chronic inflammation that creates a permissive microenvironment for cancer development. These are legitimate mechanisms that are consistent with the broader evidence on dietary phytonutrients and cancer risk reduction.
Eating ulam raja daily as part of a diet rich in diverse vegetables and phytonutrients is a legitimate, evidence-supported component of cancer risk reduction. It belongs in the diet of anyone concerned about their long-term health.
Eating ulam raja as a treatment for existing cancer is not supported by any clinical evidence and should never replace or delay conventional oncological care. If you or someone you know has cancer, please continue working with your oncologist. Eat ulam raja too — it is good food — but do not substitute it for treatment.
What People Think About Ulam Raja — and What Is Actually True
“Ulam raja is just a salad herb — it’s food, not medicine.”
The separation between food and medicine is a modern construction. Traditional food cultures did not draw this line. A plant eaten daily as part of the meal was also the preventive medicine — the reason the body maintained health rather than drifting into disease. Ulam raja with the highest antioxidant activity of any Malaysian food plant tested, documented bone-protective effects that outperformed calcium supplementation, antihypertensive activity comparable to ACE inhibitor class drugs, and antidiabetic effects in rat models is not “just a salad herb.” It is food with a pharmacological profile. The distinction collapses when you read the research.
“Pegaga is the best Malaysian herb for antioxidants.”
Pegaga (Centella asiatica) is genuinely extraordinary — its cognitive and wound-healing properties are well-documented and significant. But in comparative antioxidant studies that tested both plants, Cosmos caudatus ranked above Centella asiatica. A 2012 study that specifically tested four herbs including pegaga and ulam raja found ulam raja ranked highest. The AEAC value of 2,400–2,500 mg/100g for ulam raja is among the highest reported for any Malaysian plant food. This does not make pegaga irrelevant — they have different pharmacological profiles and both belong in the regular diet. It does mean that the familiar, everyday ulam raja has been underestimated relative to the more famous pegaga.
“Cooking destroys all the goodness in ulam raja.”
Vitamin C is the most heat-sensitive compound and is significantly reduced by cooking. The volatile terpenoid essential oils that give the fresh leaf its aromatic character are partially lost. However, the major antioxidants in ulam raja — the proanthocyanidins, quercetin glycosides, kaempferol, and chlorogenic acid — are significantly more heat-stable. They survive light cooking (brief blanching, addition to rice, mild stewing) with meaningful retention. High-heat prolonged cooking does cause significant degradation. The practical guidance: eat it raw when possible. When cooked, use minimal heat and short cooking time. Brief blanching preserves more than boiling for five minutes.
“Ulam raja is good for blood circulation and bone strength.”
This is exactly what the traditional knowledge claimed, and what the laboratory confirmed. “Blood circulation” as used in traditional Malay medicine encompasses blood pressure regulation, cardiovascular function, and blood viscosity — all of which are addressed by ulam raja’s ACE-inhibitory quercetin compounds and proanthocyanidins (which have vasodilatory and antiplatelet activity). Bone strength is directly supported by the calcium content (270 mg/100g) combined with the antioxidant protection of osteoblasts — with published studies showing the plant outperforms calcium supplementation on specific bone parameters. Traditional knowledge was describing correct outcomes through different language. The science now confirms the mechanisms.
“Ulam raja is a native Malaysian plant that has been here forever.”
Cosmos caudatus originated in Mexico and Central America. It arrived in Southeast Asia during the Portuguese colonial period in the 16th century — part of the Columbian Exchange that transformed agriculture globally. The fact that it naturalised so completely, entered the food culture so thoroughly, and was given the royal designation “Ulam Raja” within a few generations of its introduction is testimony to how obviously valuable it was to the people who first encountered it. A plant earns the name “King’s Salad” by being exceptional. The Mexican origin does not diminish that. If anything, it is a remarkable story of a plant that crossed the world and was immediately recognised as fit for a king.
“A small portion once a week is enough to get the benefits.”
The antihypertensive, antidiabetic, and bone-protective effects documented in research are cumulative effects that require consistent, regular intake. The bone studies ran for 8 weeks at 6 days per week. The antidiabetic and antihypertensive effects in rat models showed dose-dependent and duration-dependent responses. Eating a small portion of ulam raja once a week at a nasi campur restaurant produces minimal cumulative benefit. What the research supports is daily consumption — the way the traditional ulam tradition intended it. A generous daily serving of fresh ulam raja as part of every meal is what the food culture had right. A small occasional portion is better than nothing. Daily consumption is the correct practice.
What is well-documented: Highest antioxidant activity (DPPH and FRAP) among 25 tropical plants tested. Antioxidant capacity of 2,400–2,500 mg AEAC per 100g fresh sample — approximately 8–10 times higher than most local fruits. Bone-protective effects in postmenopausal osteoporosis rat model, outperforming calcium supplementation on trabecular number and trabecular separation (two published peer-reviewed studies, UKM). High calcium content (270 mg/100g). Antihypertensive effects comparable to reference drugs in rat models, mediated by ACE inhibition. Antidiabetic effects in obese rat models. Over 100 identified bioactive compounds by HPLC-MS metabolomics including quercetin glycosides, proanthocyanidins, chlorogenic acid, kaempferol, myricetin, and costunolide.
What requires honest qualification: All pharmacological studies (bone, antihypertensive, antidiabetic) are animal studies or in vitro work. No human clinical trials have been published specifically for ulam raja. The doses used in the bone studies (500 mg/kg concentrated extract) are not directly equivalent to dietary consumption of fresh leaves. “Outperforming calcium supplementation” is a significant finding, but the translation to human dietary recommendations requires human trials. The antioxidant capacity measurement is reproducible and well-established, but antioxidant capacity in a test tube does not automatically equal clinical antioxidant benefit in the human body.
The bottom line: Ulam raja is a genuinely exceptional food plant by any measurable antioxidant metric, with a consistent and growing body of pharmacological evidence for its traditional uses. The fact that it is familiar, available, and already on the Malaysian table makes it one of the most practically accessible health foods in the entire AJHerbs library. It does not require sourcing, supplementation, or any preparation beyond eating it as it has always been eaten — fresh, raw, daily, alongside the meal. The research confirms what the name has always said. Eat it like a king. Statements here have not been evaluated by any regulatory authority and are not intended to diagnose, treat, cure, or prevent any disease.
Blood-thinning medications: Ulam raja’s quercetin and proanthocyanidin content includes compounds with antiplatelet activity. At normal dietary amounts this is not clinically significant. At very high supplemental doses, people on warfarin or anticoagulants should inform their doctor of regular high-dose consumption.
Pregnancy: At normal food amounts as part of the ulam tradition, ulam raja has a long history of consumption without documented harm. Very high supplemental doses in concentrated extract form have not been systematically studied in pregnancy. Culinary consumption is appropriate; medicinal-dose supplementation during pregnancy warrants caution.
Harvest from clean ground: Like all wild-growing or garden herbs, ensure the plant has not been treated with herbicides or pesticides. Ulam raja growing near agricultural land may have absorbed agrochemicals. Garden-grown or sourced from trusted suppliers is ideal.
Fresh beats dried beats supplement. The antioxidant capacity is highest in the fresh leaf. Dried leaf retains most flavonoids but loses vitamin C. Commercial supplements of unknown extraction method and standardisation have the least predictable profiles. Grow it in your garden. Pick it fresh. Eat it that day.
References & Sources (click to expand)
- Cheng, S.H. et al. (2015). Potential medicinal benefits of Cosmos caudatus (Ulam Raja): A scoping review. Journal of Research in Medical Sciences, 20(10):1000–1006. PMC4746859. DOI: 10.4103/1735-1995.172796. [15 studies reviewed; anti-diabetic, anti-hypertensive, anti-inflammatory, bone-protective, anti-microbial]
- Wong, S.P. et al. (2006). Antioxidant activities of aqueous extracts of selected plants. Food Chemistry, 99(4):775–783. [Cosmos caudatus ranked #1 in DPPH and FRAP among 25 tropical plants]
- Reihani, S.F.S. & Azhar, M.E. (2012). Total phenolic content and antioxidant activity of five Ulams. International Journal of Food Properties. [Cosmos caudatus and Oenanthe javanica highest among 5 ulams]
- Mohamed, N. et al. (2012). The Effects of Cosmos caudatus on Structural Bone Histomorphometry in Ovariectomized Rats. Evidence-Based Complementary and Alternative Medicine, 2012:817814. PMC3424602. [Ulam raja outperforms calcium on Tb.N and Tb.Sp]
- Mohamed, N. et al. (2013). The effects of Cosmos caudatus (ulam raja) on dynamic and cellular bone histomorphometry in ovariectomized rats. Evidence-Based Complementary and Alternative Medicine, 2013:382504. PMC3702396. [Higher osteoid volume in CC group vs calcium group]
- Ahda, M. et al. (2023). Deciphering the Mechanism of Action Cosmos caudatus Compounds Against Breast Neoplasm: A Combination of Pharmacological Networking and Molecular Docking. [100+ compounds identified; HPLC-MS metabolomics]
- Ahda, M. et al. / Multiple authors (2023–2024). Review on Cosmos caudatus as a potential medicinal plant based on pharmacognosy, phytochemistry, and pharmacological activities. International Journal of Food Properties, 26(1):344–358. DOI: 10.1080/10942912.2022.2158862.
- Comparison of Cosmos caudatus extract and vitamin C effects on antioxidant response and bone metabolism in rats under high-intensity exercise-induced oxidative stress. Physical Activity and Nutrition, 2025. DOI: 10.20463/pan.2025.0030. [Direct comparison vs vitamin C supplementation]
- Firdaus, M. et al. (2021). Traditional uses, phytochemical screening and pharmacological studies of Cosmos caudatus. Sarhad Journal of Agriculture. [Traditional uses documented: blood circulation, bone health, fever, skin]
- Ragasa, C.Y. et al. (1997). Antimutagen and antifungal compounds from Cosmos caudatus. Philippine Journal of Science, 126(3):199–206. [Costunolide and related terpenoids; antimutagenic and antifungal]
- Rafi, M. et al. (2023). Metabolomics-based identification of bioactive compounds in Cosmos caudatus. [Comprehensive metabolite profiling including quercetin glycosides and proanthocyanidins]
- Yusoff, N.A. et al. (2021). Essential oil composition and antimicrobial activity of Cosmos caudatus. Journal of Food Quality. [Costunolide, caryophyllene, bicyclogermacrene in essential oil]