South African seed oils are safe for human consumption

Perspectives on the use of seed oils in the South African diet

“…These data may indicate that the conversion of essential fatty acids to longer-chain metabolites are more effective in this population than in others, 18 and that seed oils remain a key source of essential fatty acids in the various levels of the food chain. Furthermore, as correctly indicated by Opperman et al, 1 seed oils are excellent sources of vitamin E, which, among other functions, protect the fatty acids in membranes from oxidation. 19 Therefore, there is no evidence to support the premise that seed oils are toxic or unhealthy due to their fatty acid composition, as stated in The Real Meal Revolution, 2 but rather what is of importance is how we use these oils in food preparation and processing, a point on which there remains a need to educate the consumer.…”

“…This was carried out so as to derive benefit from this seed oil's favourable fatty acid composition [55% of MUFA (oleic acid), 25% linoleic acid, 10% α-linolenic acid and only 4% SFA]. 23 Therefore, canola is not genetically modified, and neither is the canola, olive or sunflower plants used for oil production in South Africa, as discussed by Opperman et al 1 The natural trans-fat content of seed oils is almost negligible. 1,3,24 However, during the refining of oils, and depending on the applied deodorisation conditions, trans-fatty acids can be formed, but generally, the total trans-fat content remains below 1%, 25 as also confirmed for several brands of South African olive, sunflower and canola oils by Opperman et al 1 The trans-fat content of oil may also increase when used for an excessive time at high frying temperatures, 26 but the formation of trans-fat during frying is highly dependent on the type of oil used, temperature, total frying time, and how often the oil is replaced or replenished.…”

“…[28][29][30] Opperman et al 1 made a valuable contribution by measuring oxidation products and the fatty acid composition of newly purchased South African canola, olive and sunflower oils. 1 However, a limitation of the study was that it did not include the effects that household storage conditions and food preparation, such as frying, may have had on these oils. Autoxidation of edible oils by heat, air 20 and light 31 is generally a problem, and is enhanced by the presence of free fatty acids, monoacylglycerol and diacylglycerols, metals such as iron, and thermally oxidised compounds.…”

“…They further concluded that oil crops are not genetically modified. 1 The chemical and health properties of any fat or oil in the diet depend on the individual fatty acid composition of that specific fat or oil. Each fat and oil is classified according to the main proportions of saturated fatty acids (SFAs), i.e.…”

Commentary: Iconoclastic Reflections on the ‘Safety’ of Polyunsaturated Fatty Acid-Rich Culinary Frying Oils: Some Cautions regarding the Laboratory Analysis and Dietary Ingestion of Lipid Oxidation Product Toxins

“…Moreover, HNE also acts as a toxic second messenger [43]. Therefore, the 'safety' of vegetable-based culinary oils, seed or otherwise [44], remains highly questionable, particularly when they have been thermally stressed at high frying temperatures.…”