November 16, 2015

345 Smoke Point Smokescreen [16 Nov 2015]

This week I want to expand on a point made in #330 “Healthy Cooking Oils” back in August. It was that in choosing a cooking oil, smoke point is not the only factor to consider, and indeed is not the most important one. Looking at only smoke point obscures (with a “smoke screen”?) the harm caused by heating many “cooking” oils at temperatures as low as 160C, well before they reach their smoke point.

The more important factor is oxidative stability which is a measure of the oil’s resistance to oxidation. As unsaturated fats are heated and exposed to light and oxygen the double bonds are destroyed creating peroxides. The peroxides further react to form aldehydes which can be toxic or carcinogenic, and can bond with glucose to form Advanced Glycolated Endproducts (AGEs). AGEs have been linked to leaky gut syndrome, atherosclerosis, and heart disease. Oxidative stability is determined by measuring the amount of aldehydes produced over time as an oil is heated. Generally the higher the % of polyunsaturates in an oil, the lower the oxidative stability; oils of 20% or higher polyunsaturates are too unstable for frying.

Based on their low oxidative stability, the following oils should never be used in frying (% polyunstaturated):
• Hemp seed oil (80)
• Safflower oil (76)
• Grapeseed oil (69)
• Flaxseed oil (68)
• Sunflower Seed oil (60)
• Corn Oil (48)
• Cotton Seed oil (42)
• Sesame Seed oil (40)
• Canola oil (21)
• Peanut oil (20)

The two oils with the highest oxidative stability (and smoke points) are coconut and red palm olein. This makes them the safest, healthiest and all round best oils for cooking. Choose brands that are organic, fair-trade, and ethically produced.

Just looking at smoke point alone, as in a recent Globe & Mail article by Leslie Beck, the following (unhealthy, unstable) oils were recommended for frying: safflower, grapeseed, sunflower, corn, sesame, canola and peanut. Smoke point can be a smoke screen!

For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.

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