What is palm oil? What are its uses, health benefits and risks?
In this article
Palm oil is obtained from the fruit of the oil palm (Elaeis guineensis) and is the world’s most-produced vegetable oil. Two exaggerated claims circulate about it: one declares it a direct cause of cancer; the other says “it is a vegetable oil, so it is harmless”. Both are wrong. The reality is more nuanced—and this article begins by correcting, with sources, eight misconceptions repeated in Turkish-language sources on this topic.
From an oncology perspective there are three separate questions, and they are constantly confused. First: formed during refining, glycidyl esters —there really is a substance classified by the International Agency for Research on Cancer (IARC) here, but that substance is not palm oil itself: it is a residue left by processing. Second: in 2021, Naturepublished a study showing that palmitic acid accelerated metastasis in mice—widely discussed and mostly misreported. Third: the relationship between saturated fat and cancer risk—for which evidence-assessing organizations give a much more cautious answer than commonly assumed.
Two framing statements at the outset: No authority has classified palm oil itself as carcinogenic—neither IARC nor the World Cancer Research Fund. In the World Cancer Research Fund’s comprehensive 2018 report, saturated fat was not rated a “convincing” or “probable” cause of any cancer , and palm oil is not mentioned in the document at all. In contrast, the refining residue glycidol is classified by IARC as Group 2A (probably carcinogenic to humans)—and its highest levels have been found in palm oil and palm fats. The remainder of this article distinguishes these two things.
Eight corrections first
| The circulating statement | The facts |
|---|---|
| “Palmitic acid accounts for, within saturated fat, %44” | The denominator is wrong. %44 of total fatty acids is its share. Simple arithmetic: if total saturated fat is ~%50 and palmitic acid is %44 of the total, palmitic acid represents approximately %88 of the saturated fraction. The sentence therefore makes palm oil’s predominant fatty acid look like a secondary component. |
| “Palm kernel: %83 saturated, %15,5 polyunsaturated, %2,3 monounsaturated" | Two values have been swapped. According to Codex Alimentarius, palm kernel oil contains monounsaturated fat (oleic acid) at %12–19, polyunsaturated fat (linoleic acid) at only %1–3,5. Its predominant fatty acid is lauric acid: %45–55. |
| “A tree produces 3–4 tonnes of fruit per year” | Trees and hectares have been confused. This figure is close to the annual oil yield per hectare (2,9–4,2 tonnes/hectare). A single bunch weighs 20–25 kg; for a tree to yield 3–4 tonnes of fruit, it would need 120–200 bunches annually. The annual number of bunches per tree could not be verified; therefore, no per-tree figure is given in the text. |
| “In palm oil, triacylglycerol has been shown to increase cardiovascular risk” | Meaningless. Triacylglycerol is the chemical form of all dietary fats—olive oil is also approximately %100 triacylglycerol. The health-related variable is not its being a triglyceride but its fatty acid composition. |
| “In breastfeeding mothers taking palm oil, breast milk increased 2,5-fold" | Could not be verified—removed from the text. No study containing a beta-carotene dose of 90 mg and the figures 2,5 / 1,6-fold could be found. Published studies in this field measure not milk volume but breast milk carotenoid and retinol concentrations . |
| “RSPO = sustainable palm oil formation" | RSPO = Roundtable on Sustainable Palm Oil —“Sustainable Palm Oil Roundtable”. Founded in 2004, it is a multistakeholder certification organization with more than 6.200 member organizations today. |
| “All products containing the following names contain palm oil” (SLS, stearic acid, glyceryl, palmitate…) | Overinclusive. Only names containing the root “palm” or Elaeis guineensis indicate palm oil definitively . Sodium lauryl/laureth sulfate, stearic acid, glyceryl esters and palmitates may come from palm, but also from coconut, animal fat or petrochemicals . A detailed table follows below. |
| EFSA’s 2016 report is cited, with nothing thereafter | Incomplete and outdated. After 2016, two important developments occurred: The EU introduced a legal maximum for glycidyl esters in 2018 (Regulation 2018/290), and EFSA on 10 January 2018 increased the tolerable daily intake for 3-MCPD from 0,8 to 2,0 µg/kg. The industry also reduced glycidyl ester levels in palm oils between 2010–2015 by approximately %50. |
Two different oils from one fruit
Palm fruit provides two distinctly different oils, and confusing them is a common mistake. From the fleshy outer portion of the fruit (mesocarp) palm oilis obtained, while its kernel yields palm kernel oil .
Figure 1 · The same fruit, two different oils
Bar lengths are proportional to the actual percentages. Color reflects the World Health Organization’s saturated fat recommendation (below %10 of energy)—it is not a cancer-related claim.
| Fatty acid | Palm oil (mesocarp) | Palm kernel oil |
|---|---|---|
| Lauric acid (C12:0) | trace | %45–55 |
| Myristic acid (C14:0) | %0,5–2,0 | %14–18 |
| Palmitic acid (C16:0) | %39,3–47,5 | %6,5–10 |
| Stearic acid (C18:0) | %3,5–6,0 | %1–3 |
| Oleic acid (C18:1) | %36–44 | %12–19 |
| Linoleic acid (C18:2) | %9–12 | %1–3,5 |
The chain-length issue. Lauric acid has 12 carbon atoms, and because medium-chain fatty acids are defined by carbon count (6–12 carbons), by classification it is medium-chain. Palm oil, however, is predominantly C16 and C18, meaning long-chain. However, whether lauric acid actually behaves like medium-chain triglycerides in the body—entering portal circulation or chylomicrons—could not be verified for this article. Therefore, only the structural classification is presented here, without a metabolic claim.
Yield: palm oil’s real advantage
The reason palm oil has become widespread is neither its taste nor its health properties but its yield per unit of land —and this is the paradox at the heart of the environmental debate.
| Crop | Yield (tonnes/hectare/year) | Relative to palm |
|---|---|---|
| Palm | 2,9 (4,17 in some sources) | — |
| Sunflower | ~0,7 (0,56) | approximately 4 times lower |
| Rapeseed (canola) | ~0,7 | approximately 4 times lower |
| Soybean | 0,39 | approximately 7–10 times lower |
| Coconut | 0,27 | approximately 10 times lower |
| Peanut | 0,14–0,16 | approximately 15–25 times lower |
The result: in 2017, palm oil used only %8,6 of the land planted with vegetable oil crops while providing %36 of the global vegetable oil supply. Thus, boycotting palm oil and replacing it with another vegetable oil requires more agricultural land—the least-discussed aspect of the environmental debate.
Glycidyl esters: the real cancer debate lies here
The scientific core of the cancer debate about palm oil is not the oil itself but a residue formed during refining. The subject cannot be explained without making this distinction.
Figure 2 · Where does the carcinogen come from? From heat, not palm oil
Glycidyl esters are not natural components of the oil. They form at approximately 200 °C during the deodorization stage of refining. This is a factory process—not frying in a home kitchen.
| Glycidyl esters (glycidol) | 3-MCPD | |
|---|---|---|
| IARC classification | Group 2A —probably carcinogenic to humans (Volume 77, 2000) | Group 2B —possibly carcinogenic to humans (Volume 101, 2013) |
| Human data | None | None |
| Animal data | Sufficient evidence | Sufficient evidence |
| Has a safe level been established? | No —a threshold cannot be established because it is both genotoxic and carcinogenic | Yes: 2,0 µg/kg/day (increased on 10 January 2018 from 0,8) |
| Which oil has the highest levels? | Palm oils and palm fats (EFSA, 3 May 2016) | |
“A safe level cannot be established” does not mean “every amount is dangerous”, as is often assumed. Regulators do not establish thresholds for a genotoxic carcinogen because, theoretically, the possibility of a single molecule causing DNA damage cannot be regarded as zero. This is a risk-management principle, not a measured risk. In practice, exposure is reduced as far as possible—and that is precisely what happened: between 2010–2015 the industry reduced levels in palm oils by approximately half, while the EU introduced a legal maximum in 2018.
| Product | Maximum level |
|---|---|
| Vegetable oils and fats supplied to the final consumer or used as food ingredients | 1000 µg/kg |
| Infant formula and foods for special medical purposes (powder) | Until 30.6.2019: 75 µg/kg, from 1.7.2019: 50 µg/kg |
| Infant formula and foods for special medical purposes (liquid) | Until 30.6.2019: 10,0 µg/kg, from 1.7.2019: 6,0 µg/kg |
That the limit for infant products is approximately 20 times stricter than for adult products is no coincidence: EFSA reported in 2016 that exposure among exclusively formula-fed infants was approximately ten times the low-concern level.
A framing error in the original text needs correction. The sentence “When you heat palm oil above 200 degrees, various molecules are released” moves the problem into the home kitchen. But the process EFSA describes is industrial refining —refining vegetable oils at high temperatures. Pan-frying at home is a different matter involving different chemicals, such as aldehydes and polycyclic aromatic hydrocarbons; moreover, this problem is not specific to palm oil but applies to all oils . Confusing the two gives consumers a false sense of control: reducing glycidyl esters is a matter of the manufacturer’s process and regulatory limits, not your frying pan.
Palmitic acid and metastasis: the widely discussed, widely misreported study of 2021
In November 2021, Naturepublished a study showing that palm oil’s predominant fatty acid, palmitic acid, accelerated metastasis in mice . Headlines circulated saying “palm oil spreads cancer”. What the study showed—and, more importantly, what it did not show—must be distinguished.
Figure 3 · Palmitic acid’s “metastatic memory”—in mice
Pascual et al., Nature 2021. The entire diagram concerns a mouse model. Its meaning for humans was not examined in this study.
What did the study’s own authors say? This part received almost no news coverage.
The lead researcher, Salvador Aznar-Benitah, said in the institution’s announcement: “To determine what kind of diet patients with metastatic cancer could consume to slow the metastatic process, I think it is still too early." What follows is equally important: “Based on our results, one might think that a diet low in palmitic acid could slow the metastatic process, but much more work is needed to establish this."
The team is therefore not even pursuing the dietary direction: “We are not focusing on this research direction; instead, we are focusing on new potential therapeutic targets that we can inhibit.” In other words, the study’s own authors see its practical implication as drug development targeting CD36, rather than dietary change .
Three rules for reading this study correctly:
(1) The study concerns not cancer formation but the spread of an existing tumor . The conclusion “palm oil causes cancer” does not follow from these data. (2) The findings are in mice. This study provides no data showing an association in humans between palmitic acid intake and metastasis . (3) The effect is specific to palmitic acid—the predominant fatty acid in olive oil, oleic acid, did not produce the same effect. This third point is the study’s strongest and least-reported aspect: the issue is not “fat” but which fatty acid it is.
So does saturated fat cause cancer?
Here, evidence-assessing organizations give an answer cautious enough to trouble both supporters and opponents of palm oil.
| Organization | What does it say? |
|---|---|
| World Cancer Research Fund (WCRF/AICR), comprehensive 2018 report | Saturated fat and total fat are not rated “convincing” or “probable” causes of any cancer. The only relevant entry concerns prediagnosis intake in breast cancer survivors: “limited evidence” —WCRF’s weakest grade, which does not form a basis for recommendations. Palm oil is not mentioned anywhere in the document. |
| World Health Organization, 2023 guideline | Reducing saturated fat intake to %10 of energy (strong recommendation), preferably lower still (conditional recommendation). The rationale is cardiovascular disease and all-cause mortality, not cancer —cancer outcomes were examined but did not drive the recommendation. |
| IARC | Palm oil itself is not a classified agent. What is classified is processing residues: glycidol (2A) and 3-MCPD (2B). |
The cardiovascular picture is clearer. Compared with vegetable oils low in saturated fat, palm oil raises LDL cholesterol —shown by a systematic review and meta-analysis of clinical trials. The numerical magnitude of the effect (in mg/dL) could not be verified for this article; therefore, only its direction is reported. Thus, the health rationale concerning palm oil is cardiovascular health, not cancer—and the solution there is not demonizing palm oil but keeping total saturated fat intake within WHO’s recommended limit.
Is the real issue palm oil or ultra-processed food?
Much of the palm oil debate is actually another issue in disguise. Palm oil is found in biscuits, cream, instant soup and chocolate—in other words, a common ingredient of ultra-processed foods. And cancer evidence for this product group is stronger than for a single ingredient.
| Participants | 104.980 people, median age 42,8 |
|---|---|
| Follow-up | 426.362 person-years, median 5 years |
| Cancer cases | 2.228 cases — 739 breast, 281 prostate, 153 colorectal |
| Overall cancer | For each increase in the dietary proportion of ultra-processed food of %10 , the hazard ratio was 1,12 (%95 CI 1,06–1,18; p for trend <0,001) |
| Breast cancer | 1,11 (1,02–1,22; p for trend =0,02) |
| Prostate and colorectal | Not statistically significant |
The authors did not claim causality, stating that the finding needed confirmation in other large observational studies and that research was needed to identify which aspect of processing—nutrient composition, additives, packaging material or newly formed contaminants—played a role.
We must be honest here: this study does not blame palm oil. BMJ does not mention palm oil by name or attribute the observed association to a single ingredient. The inference that “because palm oil is a marker of ultra-processed foods, this finding concerns palm oil” is ours, not a study finding. Moreover, in an observational cohort, ultra-processed food consumption accompanies smoking, inactivity, income level and overall diet quality—the authors tried to adjust for these, but residual confounding remains possible.
Vitamin E and tocotrienols: the promising-looking side without evidence
The argument most often used in defense of palm oil is its vitamin E content, especially tocotrienols. Let us examine the numbers.
| Palm oil, total tocopherol + tocotrienol | 150–1500 mg/kg (ppm) |
|---|---|
| Palm kernel oil | undetectable – 260 mg/kg |
| Carotenes (alpha-carotene, beta-carotene, lycopene) | Present in red (unrefined) palm oil; absent from refined palm oil |
The original text’s value “350–450 ppm” lies within this range but was presented as though it represented the entire range. A numerical percentage of vitamin E lost during refining could not be verified for this article.
But there is a large gap between “contains vitamin E” and “protects against cancer”—and the data filling that gap point in a frightening direction.
The SELECT study, in men aged 50 and older, more than 35.000 of them, tested whether vitamin E and selenium prevent prostate cancer. The result reported in 2011: among men taking vitamin E alone, prostate cancer showed a %17 relative increase. In absolute numbers: after seven years, in the placebo group, 1.000 men had 65 prostate cancer cases; in the vitamin E group, 76 were observed—meaning per 1.000 men, 11 additional cases. The National Cancer Institute’s position is clear: “No clinical trials show that taking vitamin E or selenium reduces the risk of prostate cancer or any other cancer or heart disease.”
For tocotrienols specifically, the situation is: there is interesting laboratory and mechanistic literature, but clinical evidence showing that tocotrienol supplementation prevents cancer in humans could not be found for this article. Thus, palm oil’s tocotrienol content is not a proven anticancer benefit. We discussed in detail why antioxidant supplements produce counterintuitive results in our selenium evidence review and our vitamin D article ; our prostate cancer article also covers the change in recommendations after SELECT.
The other side of the coin: red palm oil and vitamin A deficiency
The almost never discussed side of the palm oil debate: unrefined red palm oil works against vitamin A deficiency.
| Number of studies | 9 randomized controlled trials; 1.127 participants in the serum retinol analysis |
|---|---|
| Risk of vitamin A deficiency | Relative risk 0,55 (%95 CI 0,37–0,82; p=0,003) |
| Serum retinol | Increased in children (p<0,00001) and adults (p=0,002) |
| Beta-carotene | Increased (p=0,01) |
The authors’ conclusion: red palm oil may effectively prevent or alleviate vitamin A deficiency. A World Health Organization program or position document specifically recommending red palm oil could not be verified for this article.
Reading these two findings together reveals a striking symmetry. Glycidyl esters are a problem of refined palm oil in that form—a product of refining. Carotenes and vitamin A benefits, however, characterize unrefined red palm oil and are lost during refining. Thus, two products from the same plant have opposite profiles depending on processing level . This is why “Is palm oil healthy?” has no single answer: which palm oil?
Reading labels: which names really indicate palm oil?
Online lists saying “if you see these names, palm oil is present” are campaign material that turns “may be present” into “is present”. Correct reading has three layers.
| Level | Names | What does it mean? |
|---|---|---|
| Definite | Palm oil, palm kernel oil, palmate / sodium palmate, palm stearin, palmolein, Elaeis guineensis | If the root “palm” or the plant’s Latin name appears, it is palm-derived |
| Uncertain — lauric source | Sodium lauryl sulfate (SLS), sodium laureth sulfate (SLES), sodium kernelate | Produced from lauric acid. Lauric acid is abundant in both palm kernel oil (%45–55) and coconut oil ; SLS may also be petroleum-derived. Indicates a lauric raw material, not palm. |
| Generic chemical name | Stearic acid, glyceryl esters (glyceryl stearate, etc.), palmitate, palmitic acid, “vegetable oil” | Stearic acid occurs in animal tallow, cocoa butter and many vegetable oils; glycerol may come from any fat or synthesis; despite its name, palmitate is also found in animal fats and cocoa butter. Does not alone prove a palm source. |
Practical implication: Determining definitively from a label whether a product contains palm oil is often impossible unless “palm” appears. In the EU, the source of vegetable oils must be specified, as “vegetable oil (palm)”; this is the most reliable way to identify it on a label. The current requirement of Turkish labeling legislation on this point could not be verified for this article.
Environment: where boycotts backfire
| 2000–2011 deforestation | In major exporting countries, palm oil was responsible for an annual average of 270.000 hectares of forest conversion (Vijay et al., PLOS ONE) |
|---|---|
| Proportion of plantations converted from forest | Southeast Asia %45 (Indonesia %54, Malaysia %39); South America %31; Africa %7; Central America %2 |
| Trend | In Indonesia, during 2008–2009, palm-related deforestation approached %40, then fell below %15 |
| Production | Indonesia and Malaysia together account for more than %80of global production. 2023–24: Indonesia 44 million tonnes (%57), Malaysia 19,7 million tonnes |
| Growth | Between 1970–2020, production rose from ~2 million tonnes to ~80 million tonnes, and planted area from 3 million hectares to approximately 30 million hectares |
| RSPO-certified share | In 2025, 16,2 million tonnes of certified sustainable palm oil were sold—of the global supply, approximately %20 |
And here lies a counterintuitive fact. Because palm oil yields roughly four times as much per hectare as sunflower and seven to ten times as much as soybean, abandoning palm oil for another vegetable oil requires more land —potentially meaning more deforestation. For this reason, many environmental organizations advocate not a boycott but a transition to certified production . The problem is not the plant itself but where and how it is grown.
A note for Türkiye
Palm oil is also widely used in Türkiye’s prepared-food industry. However, this article makes no numerical claims specific to Türkiye: import volume, usage rates in foods, current labeling requirements and inspection data on glycidyl ester levels in products sold in Türkiye could not be verified for this article.
What consumers can do is simple and independent of legislation: reduce the proportion of ultra-processed products in their diet. This recommendation is not specific to palm oil—but because palm oil is among this product group’s most common ingredients, it is also the most effective way to reduce it. For an overview of our country’s cancer burden, see Türkiye cancer statistics; for a broader perspective on nutrition and cancer, see AACR Cancer Progress Report 2026 in our articles.
DROZDOGAN Academy commentary
Palm oil is a good example of how nutrition debates unfold: both sides take a true fact and put it in the wrong place. Opponents say “IARC called it carcinogenic”—yes, but not palm oil: the refining residue. Supporters say “it contains vitamin E and tocotrienols”—yes, but there is no evidence that this prevents cancer in humans, and the large vitamin E supplementation trial showed harm.
⚡ Why it matters
Because patients and loved ones want to do something through diet after a cancer diagnosis—and this wish is especially vulnerable to manipulation. “Cut out this oil and your cancer will slow down” is an example derived from Nature 2021 mouse data and turned into human advice. The authors explicitly rejected this. What patients should be told is not to ban a single ingredient but to consider the entire diet.
✅ The strong side
Two things are genuinely robust in this field. First, regulatory intervention works: EFSA identified the issue in 2016, the industry halved glycidyl ester levels between 2010–2015, and the EU set a legal limit in 2018, with a limit for infant products 20 times stricter than for adults. This is a textbook example of chemical risk management. Second, the benefit of red palm oil in vitamin A deficiency: a meta-analysis of nine randomized trials found a relative risk of 0,55—this is the strongest positive evidence about palm oil, yet it is hardly discussed.
⚠️ The weak side
On cancer, the available data lag behind the claims. For glycidol, there is no human epidemiology —IARC’s Group 2A decision rests entirely on animal data and genotoxicity. Nature 2021 was a mouse study about metastasis, not cancer formation. The ultra-processed food cohort is observational and its median follow-up was only 5 years —short for cancer. And the World Cancer Research Fund does not consider saturated fat a convincing or probable cause of any cancer. Thus, there is no evidence pyramid supporting “palm oil causes cancer”.
🩺 What to tell the patient
(1) Palm oil has not been declared carcinogenic; what is classified is a refining residue, whose levels have been substantially reduced over the last decade. (2) There is no evidence-based rationale for a person diagnosed with cancer to “cut out” palm oil; even the mouse study’s authors declined to give dietary advice. (3) The useful recommendation concerns products, not individual ingredients: reduce the proportion of ultra-processed food. (4) Vitamin E or tocotrienol supplements should not be taken—in SELECT, vitamin E caused prostate cancer to increase. (5) Avoiding very high temperatures and repeated reuse of oils is valid advice, although not specific to palm oil.
❓ Open questions
Does glycidyl ester exposure create a real cancer risk in humans? We do not have a single human epidemiological study today, and declining exposure levels will make this question increasingly hard to answer. Second: does palmitic acid’s effect in the mouse metastasis model occur in humans and, more importantly, can a drug targeting CD36 stop metastasis? The team itself is working in this direction. Third: in ultra-processed food’s association with cancer, which aspect matters—nutrient composition, additives, packaging or processing residues? BMJ authors themselves ask this question.
Conclusion: Palm oil is neither a “hidden carcinogen” nor an “innocent vegetable oil”. The scientific core of the cancer debate lies not in the oil itself but in the residue left by refining, and regulatory intervention has substantially reduced that residue over the last decade. The main health rationale is not cancer but cardiovascular health —palm oil raises LDL and total saturated fat intake should remain below %10 of energy. Perhaps most importantly, from the same plant, red palm oil has a proven benefit against vitamin A deficiency. Whether a food is good or bad often depends more on how much it is processed than on the food itself.
Frequently asked questions
- Does palm oil cause cancer?
- No authority has classified palm oil itself as carcinogenic. In the World Cancer Research Fund’s 2018 report, saturated fat is not a “convincing” or “probable” cause of any cancer, and palm oil is not mentioned. What is classified is the refining product, glycidyl esters —and that classification also rests on animal data, without human epidemiology.
- What is a glycidyl ester, and how does it form?
- It is a processing residue formed during the deodorization stage of vegetable oil refining at approximately 200 °C. Its highest levels occur in palm oil and palm fats. It is assumed to convert to glycidol during digestion; IARC classifies glycidol as Group 2A (probably carcinogenic). This is a factory-process issue, not home frying.
- Has this risk been reduced?
- Yes, substantially. The industry between 2010–2015 reduced glycidyl ester levels in palm oils by approximately %50. The EU introduced a legal maximum in 2018: 1000 µg/kg in vegetable oils supplied to final consumers, 50 µg/kg in powdered infant formula, and 6,0 µg/kg in liquid formula. The limit for infant products is approximately 20 times stricter.
- Are reports that “palm oil accelerates metastasis” correct?
- They originate from a real study (Nature, 2021), but three points are omitted: (1) The study was conducted in mice ; there are no human data. (2) What was examined was not cancer formation but an existing tumor’s spread . (3) The authors explicitly declined to give dietary advice, saying “much more work is needed to establish this”. Moreover, oleic acid, olive oil’s predominant fatty acid, did not have the same effect.
- I have cancer; should I stop consuming palm oil?
- There is no evidence-based rationale supporting this. The useful recommendation concerns products, not individual ingredients: reduce the proportion of ultra-processed food in your diet. This both reduces palm oil intake and rests on a broader evidence base. Discuss dietary changes with your treatment team; unnecessary restrictions during cancer have risks of their own.
- Palm oil or olive oil?
- Olive oil has a more favorable fatty acid profile: while approximately %50 of palm oil is saturated fat, olive oil contains much less saturated and much more monounsaturated fat. Compared with vegetable oils low in saturated fat, palm oil raises LDL cholesterol. However, this is a cardiovascular rationale, not a cancer rationale.
- Are palm kernel oil and palm oil the same?
- No, they are distinctly different. Palm oil comes from the fruit’s fleshy portion; its predominant fatty acid is palmitic acid (%39–47). Palm kernel oil comes from the kernel; its predominant fatty acid is lauric acid (%45–55) and its saturated fat content exceeds %80. Turkish-language sources often swap kernel oil’s monounsaturated and polyunsaturated values—kernel oil contains almost no polyunsaturated fat (%1–3,5).
- Is red palm oil different?
- Yes. Red palm oil is unrefined; it contains carotene and its benefit against vitamin A deficiency was shown in a meta-analysis of nine randomized trials (relative risk 0,55). Carotenes are lost during refining. Interestingly, glycidyl esters are a product of refining, whereas the vitamin A benefit belongs to the unrefined form— opposite profiles from the same plant, depending on processing level.
- Does palm oil’s vitamin E content provide protection?
- There is no human evidence showing this. Moreover, in SELECT, the largest vitamin E supplementation prevention study, prostate cancer among men taking vitamin E alone increased by %17 —over seven years, per 1.000 men, 11 additional cases. The National Cancer Institute states that no clinical trials show that taking vitamin E or selenium reduces the risk of any cancer. No human cancer-prevention evidence was found for tocotrienols either.
- How can I tell from a label whether a product contains palm oil?
- Only names containing the root “palm” (palm oil, palm kernel oil, palmolein, palm stearin, palmate) or Elaeis guineensis are definitive indicators. Sodium lauryl/laureth sulfate, stearic acid, glyceryl esters and palmitate may come from palm, but also from coconut, animal fat or petrochemicals —they are not proof on their own.
- Is boycotting palm oil right for the environment?
- It is controversial, for a counterintuitive reason. Palm yields approximately four times as much per hectare as sunflower and seven to ten times as much as soybean; in 2017 it used %8,6 of vegetable oil planted land to provide %36 of global supply. Replacing it with another oil requires more land . Many environmental organizations therefore advocate a transition to certified (RSPO) production rather than a boycott.
Glossary
- Mesocarp
- The fleshy outer portion of palm fruit. Palm oil is obtained from it.
- Palmitic acid (C16:0)
- A saturated fatty acid with 16 carbon atoms. Palm oil’s predominant component (%39–47 of total fatty acids).
- Lauric acid (C12:0)
- A saturated fatty acid with 12 carbon atoms. The predominant component of palm kernel oil and coconut oil. Classified as medium-chain by carbon count.
- Oleic acid (C18:1)
- A monounsaturated fatty acid; olive oil’s predominant component. Nature In the 2021 study, the metastatic effect of palmitic acid was not produced by it.
- Triacylglycerol (TAG)
- A molecule consisting of three fatty acids attached to glycerol. Almost all dietary fats have this form—it therefore does not distinguish one oil from another.
- Refining
- The process of lightening crude oil’s color and removing its odor and free fatty acids. The deodorization stage takes place at approximately 200 °C.
- Glycidyl ester
- A processing residue formed at high temperatures during refining. It is assumed to convert to glycidol during digestion.
- Glycidol
- IARC Group 2A—probably carcinogenic to humans. The classification rests on animal data; no human epidemiological data exist.
- 3-MCPD
- 3-monochloropropane-1,2-diol. IARC Group 2B. EFSA established the tolerable daily intake in 2018 at 2,0 µg/kg/day.
- Genotoxic
- Capable of directly damaging DNA. Regulators do not establish a safe threshold for substances that are both genotoxic and carcinogenic.
- CD36
- A cell-surface transporter protein that takes fatty acids into cells. Nature In the 2021 study, it was necessary for the palmitic acid effect.
- H3K4me3
- An epigenetic mark on a histone protein. Described as the molecular correlate of persistent “metastatic memory”.
- Ultra-processed food
- A product group made through industrial formulations, often containing ingredients unavailable at home. Palm oil is a common ingredient in this group.
- Tocotrienol
- A branch of the vitamin E family, relatively abundant in palm oil. A cancer-preventive effect in humans has not been demonstrated.
- RSPO
- Roundtable on Sustainable Palm Oil—Sustainable Palm Oil Roundtable. A multistakeholder certification organization founded in 2004.
- Hazard ratio (HR)
- The ratio of the rate of events developing in one group to another. A value of 1,12 means a %12 relative increase—the absolute risk increase may be much smaller.
Transparency note.
Verified: Fatty acid ranges and tocopherol/tocotrienol ranges for palm oil and palm kernel oil from Codex Alimentarius CXS 210; oil yields per hectare and palm oil using %8,6 of vegetable oil planted land to provide %36 of supply; EFSA’s assessment dated 3 May 2016 (highest glycidyl ester levels in palm oils, formation during refining at ~200 °C, assumed complete conversion of esters, no safe level established, exposure in exclusively formula-fed infants ~10 times the low-concern level); IARC classifications of glycidol as Group 2A (Volume 77, 2000) and 3-MCPD as Group 2B (Volume 101, 2013), with no human data for either; EFSA’s increase on 10 January 2018 of the 3-MCPD TDI to 2,0 µg/kg/day; maximum levels and effective dates in Regulation (EU) 2018/290; the industry’s reduction in glycidyl ester levels in 2010–2015 by ~%50; Pascual et al., Nature the 2021 study’s bibliographic details, its mouse model, use of oral carcinoma and melanoma, lack of effect from oleic and linoleic acids, the CD36 and Set1A/H3K4me3 mechanism, and Aznar-Benitah’s and Pascual’s exact statements in the institutional announcement; saturated fat not being a convincing/probable cause of any cancer and palm oil not appearing in the WCRF 2018 report; WHO’s 2023 saturated fat recommendation and its cardiovascular rationale; NutriNet-Santé (BMJ 2018) participant count, follow-up, case numbers and hazard ratios, with the authors not claiming causality; SELECT results reported by NCI (%17 relative increase, per 1.000 men, 65 versus 76 cases) and NCI’s statement on supplementation; Nutrients the 2017 red palm oil meta-analysis’s study count, participant count and relative risk; Vijay et al., PLOS ONE the study’s figure of 270.000 hectares/year and proportions of plantations converted from forest; Indonesia–Malaysia production shares; RSPO’s full name, founding year, member count and certified quantity sold in 2025.
Not verified: The numerical size of palm oil’s effect on LDL (only direction reported); annual bunches per tree and therefore fruit tonnage per tree; the percentage of vitamin E lost during refining; whether lauric acid behaves metabolically like medium-chain triglycerides; the study reporting 90 mg beta-carotene and 2,5/1,6-fold increases in breastfeeding mothers (removed from the text because it could not be found); IARC group number for high-temperature frying emissions (therefore not given); the quantitative contribution of trans-fat bans to increased palm oil consumption; any clinical evidence that tocotrienol supplements prevent cancer in humans; a World Health Organization program document recommending red palm oil; a registered clinical trial arising from Pascual 2021; Türkiye-specific import, usage, labeling legislation and inspection data —no claims are made on these topics.
Source of the critiques: The assessments that “palmitic acid’s percentage was attributed to the wrong denominator”, “the triacylglycerol sentence is meaningless”, “moving the glycidyl ester problem into the home kitchen is a framing error”, “linking the ultra-processed food finding to palm oil is our inference”, and “a boycott may require more land” belong to this article. In contrast, Codex composition ranges, EFSA and IARC decisions, Nature 2021 findings and the authors’ cautionary statements, WCRF grading and SELECT results are the sources’ own statements.
About the diagrams: The diagrams in this article are derived from verified statements in the text; they contain no new data. Dotted lines indicate an unestablished connection, not causality; dashed boxes indicate unverified areas.
Conflict of interest statement: We have no affiliation with any product, company or industry organization mentioned in this article.
References
- Codex Alimentarius. CXS 210 — Standard for Named Vegetable Oils, fatty acid composition and tocopherol/tocotrienol tables. fao.org
- European Food Safety Authority. "Process contaminants in vegetable oils and foods." 3 May 2016. EFSA Journal 2016;14(5):4426. efsa.europa.eu
- European Food Safety Authority. Update of the tolerable daily intake for 3-MCPD, 10 January 2018. efsa.europa.eu
- Commission Regulation (EU) 2018/290, 26 February 2018 — maximum levels for glycidyl fatty acid esters. eur-lex.europa.eu
- IARC Monographs. Glycidol, Volume 77 (2000) — Group 2A. 3-MCPD, Volume 101 (2013) — Group 2B.
- Pascual G, et al. "Dietary palmitic acid promotes a prometastatic memory via Schwann cells." Nature 2021;599:485–490. doi:10.1038/s41586-021-04075-0
- IRB Barcelona press release, 10 November 2021 (statements by Aznar-Benitah and Pascual).
- World Cancer Research Fund / AICR. Diet, Nutrition, Physical Activity and Cancer: a Global Perspective — Third Expert Report, 2018. wcrf.org
- World Health Organization. Guideline on saturated and trans-fat intake, 17 July 2023. who.int
- Fiolet T, et al. "Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort." BMJ 2018;360:k322.
- National Cancer Institute. SELECT study results—questions and answers. cancer.gov
- Dong S, Xia H, Wang F, Sun G. "The Effect of Red Palm Oil on Vitamin A Deficiency: A Meta-Analysis of Randomized Controlled Trials." Nutrients 2017;9(12):1281.
- Vijay V, et al. "The Impacts of Oil Palm on Recent Deforestation and Biodiversity Loss." PLOS ONE.
- Our World in Data. "Palm oil" — yield, production and deforestation data. ourworldindata.org
- Roundtable on Sustainable Palm Oil. Institutional information and 2026 impact report. rspo.org
- "Palm Oil Consumption Increases LDL Cholesterol Compared with Vegetable Oils Low in Saturated Fat: A Systematic Review and Meta-Analysis of Clinical Trials." Journal of Nutrition. (Full text unavailable; only direction is reported based on the title.)
Sources
2. Macit, S. ve Şanlıer, N. (2014). Palm Yağı ve Sağlık (Palm Oil and Health). Journal Tourism and Gastronomy Studies. 2(1): 13-20
3. Sundram, K., Sunbandhamurthi, R. and Tan, Y. (2003). Palm Fruit Chemistry and Nutrition. Asia Pasific J Clin Nutr. 12(3): 355-362.
4. Gloria Pascual, Alexandra Avgustinova et al.,Targeting metastasis-initiating cells through the fatty acid receptor CD36, Nature 541, 41-45 (January 2017).
5. Process contaminants in vegetable oils and food, https://www.efsa.europa.eu/en/press/news/160503a
6. Which Everyday Products Contain Palm Oil?
worldwildlife.org/
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