What are the advantages and disadvantages of using palm oil, and is it associated with an increased risk of developing diabetes?

Palm Oil: Advantages, Disadvantages, and Diabetes Risk

The evidence regarding palm oil's relationship with diabetes and cardiovascular disease remains controversial and inconclusive, but given its high saturated fat content and lack of proven benefits compared to other vegetable oils, I recommend prioritizing extra-virgin olive oil, canola oil, or soybean oil over palm oil for cooking and dietary fat choices. 1

Advantages of Palm Oil

Nutritional Composition

• Contains beneficial compounds beyond fatty acids, including tocopherols, tocotrienols (forms of vitamin E), carotenoids (beta-carotene/vitamin A), and sterols with antioxidant properties 2, 3
• Balanced fatty acid profile with approximately equal amounts of saturated and unsaturated fatty acids (50% saturated, with significant monounsaturated and polyunsaturated content) 1, 3
• Does not contain trans fats, making it a natural alternative to partially hydrogenated oils 2

Metabolic Effects (Context-Dependent)

• Similar lipid effects to olive oil in some studies: two trials showed that despite palm oil's higher saturated-to-monounsaturated fat ratio (1.1:1) compared to olive oil (0.22:1), there was no difference in serum lipid effects in healthy volunteers 1
• May reduce endogenous cholesterol synthesis despite raising blood cholesterol, possibly due to tocotrienols and the specific isomeric position of its fatty acids 3
• In moderate amounts, fresh (unoxidized) palm oil promotes efficient nutrient utilization and adequate hemoglobinization in experimental studies 3

Disadvantages of Palm Oil

High Saturated Fat Content

• Palm oil is an exception among vegetable oils due to its high saturated fatty acid content (approximately 50%), similar to coconut fat and cocoa butter 1
• Saturated fats increase total and LDL cholesterol concentrations, which are established risk factors for coronary heart disease 1
• The American Heart Association and American College of Cardiology recommend limiting coconut oil and by extension other tropical oils high in saturated fats in patients with hypertriglyceridemia 4

Oxidation Concerns

• Oxidized palm oil (from processing and cooking) poses significant health risks including adverse lipid profiles, reproductive toxicity, and toxicity to kidney, lung, liver, and heart 3
• Processing methods significantly affect metabolic impact, with increasing processing associated with more adverse effects on cholesterol metabolism 4
• High-temperature cooking can generate harmful compounds, including potentially adverse 18:2 trans fatty acid isomers through oil deodorization 1

Limited Evidence of Benefit

• Insufficient evidence supports strong promotion of tropical oils including palm oil for cardiometabolic health 1
• Countries with high tropical oil intake having low heart disease rates does not establish causation and may reflect confounding factors 1

Palm Oil and Diabetes Risk

The Controversial Evidence

• The association between palm oil and type 2 diabetes remains controversial with heterogeneity in studies, differences in selection criteria, wide age ranges, and poorly controlled confounding factors 1
• No strong association was found between general fat consumption and development of type 2 diabetes in a low-quality review of large-scale Western cohort studies 1
• Dairy fat consumption (also containing saturated fats) is not associated with type 2 diabetes in moderate and high-quality systematic reviews, suggesting saturated fat per se may not be the primary issue 1

Context Matters: The Carbohydrate Connection

• Circulating saturated fatty acids (particularly palmitate) are associated with increased diabetes risk, but these levels are more closely related to dietary carbohydrate intake than saturated fat intake 1
• When carbohydrate intake is lower, increased saturated fat consumption has no effect or actually decreases serum saturated fatty acid levels through reduced de novo lipogenesis and increased fat oxidation 1
• Palmitoleic acid (a marker of carbohydrate-driven fat synthesis) is strongly linked to diabetes development, independent of saturated fat intake 1

Comparative Risk

• In contrast, olive oil consumption is protective: daily 10g olive oil consumption is associated with reduced type 2 diabetes risk (RR: 0.91; 95% CI: 0.87-0.9), and the highest olive oil intake category showed 16% reduced diabetes risk 1
• Virgin olive and flaxseed oils considerably decrease the incidence of type 2 diabetes in cohort and RCT studies 1

Clinical Recommendations

For General Population

• Replace palm oil with unsaturated plant oils such as extra-virgin olive oil, canola oil, or soybean oil, which have established cardiometabolic benefits 1, 4
• Virgin oils are preferable due to low-temperature refining that preserves trace phenolic compounds with potential health benefits 1
• Limit total saturated fat intake to 7-10% of daily energy, regardless of source 1

For High-Risk Patients

• Patients with hypertriglyceridemia should be screened for consumption of foods high in saturated fats, including palm oil 4
• For persistent hypertriglyceridemia, replacing palm oil with unsaturated plant oils may be beneficial 4
• Elderly patients and those with dyslipidemia, previous cardiovascular events, or hypertension are at greater risk from saturated fatty acid-rich foods 5

Important Caveats

• Focus on overall dietary pattern rather than single nutrients: the Mediterranean diet high in unsaturated fats reduces risk of both cardiovascular disease and type 2 diabetes 1
• Avoid replacing saturated fats with refined carbohydrates, as this leads to atherogenic dyslipidemia and may increase diabetes risk 1
• If palm oil is consumed, use fresh (unoxidized) palm oil in moderate amounts and minimize high-temperature cooking 3
• Modern nutritional science demonstrates limitations of judging foods solely by nutrient content—long-term investigations of tropical oils are urgently needed 1, 4