What is the difference between cold-pressed (CP) oils and refined oils in terms of health benefits?

Cold-Pressed vs. Refined Oils: Health Benefits Comparison

Virgin oils (e.g., extra-virgin olive oil, virgin soybean oil) are preferable to refined oils due to their low-temperature refining process that better preserves trace phenolic compounds, which may provide additional cardiometabolic benefits beyond their fatty acid profiles. 1

Key Differences Between Cold-Pressed and Refined Oils

Processing Methods

• Cold-pressed oils are produced by pressing plant materials with minimal heat (typically below 40°C), preserving more bioactive compounds and nutrients 2, 3
• Refined oils undergo high-temperature processing that removes many beneficial compounds but increases shelf life and smoke point 4

Nutritional Content

• Cold-pressed oils retain higher levels of:
  • Phenolic compounds (including oleocanthal in olive oil with anti-inflammatory properties) 1
  • Phytosterols (663-15,123 μg/g depending on oil type) 5
  • Tocopherols and tocotrienols (vitamin E compounds) 2, 4
  • Carotenoids and other antioxidants 2, 6
  • Squalene (265-5,979 μg/g depending on oil type) 5

Health Benefits of Cold-Pressed vs. Refined Oils

Cardiovascular Benefits

• In the PREDIMED randomized trial, participants receiving extra-virgin olive oil experienced 30% lower risk of stroke, MI, or death compared to control 1
• The benefits of extra-virgin olive oil appear to extend beyond its fatty acid profile, suggesting phenolic compounds play an important role 1
• Daily consumption of 10g olive oil is associated with reduced risk of type 2 diabetes (RR: 0.91; 95% CI: 0.87-0.9) 1

Stability During Cooking

• Cold-pressed oils contain natural antioxidants that may protect against oxidation, but some bioactive compounds degrade at high temperatures 4
• Tocopherols (vitamin E compounds) are lost during high-temperature heating, with α-tocopherol being most thermolabile 4
• Phytosterols show high thermal stability even at cooking temperatures of 200°C 4

Specific Oil Recommendations

• Extra-virgin olive oil, virgin soybean oil, and canola oil have the best-established health benefits 1
• Cold-pressed rapeseed oil offers health benefits through preserved fatty acid profile and bioactive compounds that may regulate blood lipid profile and insulin sensitivity 6
• Different cold-pressed oils have unique phytochemical profiles:
  • Marrow seed oils are rich in phytosterols and cholecalciferol 5
  • Pseudo-cereal oils contain high levels of squalene and linolenic acid 5
  • Legume oils are good sources of phytosterols and oleic acid 5

Clinical Considerations and Caveats

• When recommending oils, consider both fatty acid composition and processing method 1
• Cold-pressed oils have shorter shelf life and may be more expensive than refined alternatives 3
• For cooking at high temperatures, be aware that some beneficial compounds in cold-pressed oils may degrade 4
• The quality of cold-pressed oils depends on the quality of raw materials and proper storage conditions 3
• For patients with allergies, be aware that less refined oils may contain more protein residues that could trigger allergic reactions 1

Practical Recommendations

• For unheated applications (salad dressings, dips, finishing): Choose cold-pressed oils to maximize health benefits 1, 2
• For moderate-heat cooking: Cold-pressed oils may still retain some benefits 4
• For high-heat cooking: Consider the balance between nutritional benefits and stability; some refined oils may be more appropriate for very high-temperature cooking 4
• Recommend replacing butter, lard, and highly processed fats with vegetable oils, preferably virgin or cold-pressed varieties when possible 1