When it came to fats and oils, the choice was simple for our hunter gatherer ancestors. All dietary fats were consumed directly from the food source and were based on their geographic availablity. They ate the whole carcass of wild animals, including all of the organs and visceral fat, and foraged for fatty, high oil plants. These foods balanced the fatty acids in their diet. Today, as technology engineers oils from vegetable seeds, like mustard seed, cottonseed, and rapeseed (canola) oil, not only is the yield unnatural, it is also unsafe for consumption.
All animal fats, such as lard, tallow, duck and chicken fat, can withstand very high temperatures without oxidizing,1 and have prolonged shelf lives. However, navigating the bottled oil aisle at any grocery store can overwhelm even the most advanced label reader to decipher which oils are safe and optimal for health. A thorough explanation of the fatty acid composition of vegetables oils, as well as identifying the six vegetable oils (flaxseed, walnut, olive, macadamia, coconut, and avocado) that are best suited for the Paleo Diet can be found HERE. Yet, many of us still struggle with which cooking oil to select and how to heat it without compromising the nutritious benefits.
When heating any oil, it is important to keep them below their smoke point, (before oil burns to the point of smoking). Oils heated above their stability point begin to decompose, releasing free radicals along with toxic fumes. Oils are often refined to raise their smoke point. The refining process (heating, neutralization, filtering, and processing with chemicals and bleaching agents) removes the oils from their pure state.2 Thus, despite their lower smoke point, unrefined virgin oils are preferential.
If we look to hunter-gather-societies, we see they did not regularly use flaxseed oil. It was originally included in The Paleo Diet as a tool to balance out increased omega-6/omega-3 fatty acid ratio due to the excessive intake of omega-6 vegetable oils, especially linoleic acid, in the average western diet. Flaxseed oil is exceptionally high in alpha-linolenic acid (ALA), which is the parent fatty acid to Omega-3 fatty acids. Omega-3 fatty acids are extremely sensitive to heat, oxygen, and light,3 so refrigerate and never heat, but instead use in a salad dressing or as a finishing oil over cool vegetables.
Walnut oil possesses many antioxidants, including ellagic acid, which research suggests is antiatherogenic and supports osteoblastic activity.4 It’s a great source of omega-3 fatty acids 5 and although the refined version is often labeled safe for high-heat cooking, it is best not to heat it to high temperatures. Not only will the omega-3s be damaged, but the oil will also develop a bitter taste. The unrefined version can be heated to 320°F,6 so sauté vegetables in walnut oil at low-to-medium heat, or drizzle on any salad.
Extra-Virgin Olive Oil
Olive oil contains at least 30 phenolic compounds.7 Phenols have been shown to reduce the amount of oxidative stress on the body8 and protect the polyunsaturated fat in the olive oil from oxidizing. Olive oil is a great source of healthy monounsaturated fats, which help control cholesterol levels and have been linked with heart health. There are many varieties of olive oils, sourced from all over the world. Each has its own unique flavor and color that can be experimented with to highlight whatever dish you are cooking. And, while extra virgin olive oil has a smoke point of 325°F,9 it is fairly resistant to oxidation, even when used for high-heat deep-frying.10, 11
Macadamia Nut Oil
Macadamia nut oil is higher in monounsaturated fats than olive oil12 and provides the lowest level of omega-6 fats of any nut.13 It is high in phytochemicals, (qualene, tocotrienols and tocopherols), which protect against oxidation, making it suitable for room temperature storage for up to two years.14 Macadamia nut oil has been shown to improve the biomarkers of oxidative stress, inflammation, and reduce the risk factors for coronary artery disease.15
With a smoke point of 413°F, 16 macadamia oil can be used for almost any dish whether you’re grilling, sautéing or stir-frying. It can even be used a binder for homemade Paleo mayonnaise.
Coconut oil is more than 90% saturated fat; specifically it is high in medium chain triglyceride (MCT). MCTs do not require bile acids for digestion, which makes them easy to digest and available immediately as a fuel source.17 Coconut oil is also rich in lauric acid, a fatty acid found in mother’s milk that has anti-fungal, anti-bacterial and anti-viral properties.18 Unrefined coconut oil, which has not been bleached or filtered to remove impurities or natural flavors, has a smoke point of 320°F.19
Coconut oil, which is solid at room temperature, can be used as a replacement in any recipe that calls for butter, such as for coating a whole chicken before roasting. It also works well with Caribbean or Asian recipes, especially to those who aren’t quite accustomed to the flavor. We use it regularly to sauté vegetables, like kale or onions, as well as to grease the pan for cooking eggs.
Avocados, thought classified as a fruit, are high in oil content. Cold pressing of avocados retains a high concentrations of vitamin E 20 and chlorophyll (40-60mg/kg), which gives the oil a green tint. 21 Research shows consuming avocado oil enhances carotenoid absorption from vegetables,22 and can decrease your risk of coronary artery disease.23 Similar to olive oil, avocado oil has a higher Omega 6:3 ratio (13.1:1).24 Avocado oil can withstand the heat. Virgin (unrefined) avocado oil has a smoke point of 40025 and can be used in any high heat cooking, dressing or as a finishing oil.
 Sherwin, E. R. Oxidation and antioxidants in fat and oil processing. Journal of the American Oil Chemists’ Society 55.11 (1978): 809-814.
 Available at: http://www.business2community.com/health-wellness/the-danger-of-cooking-with-healthy-oils-past-their-smoke-point-0418150. Accessed on October 28, 2014.
 Choo, W. S., E. J. Birch, and J. P. Dufour. Physicochemical and stability characteristics of flaxseed oils during pan-heating. Journal of the American Oil Chemists’ Society 84.8 (2007): 735-740.
 Papoutsi, Z., et al. Walnut extract (Juglans regia L.) and its component ellagic acid exhibit anti-inflammatory activity in human aorta endothelial cells and osteoblastic activity in the cell line KS483. British journal of nutrition 99.04 (2008): 715-722.
 Available at: http://www.hsph.harvard.edu/nutritionsource/omega-3/. Accessed on October 28, 2014.
Available at: http://www.goodeatsfanpage.com/collectedinfo/oilsmokepoints.htm. Accessed on October 28, 2014
 Tuck, Kellie L., and Peter J. Hayball. Major phenolic compounds in olive oil: metabolism and health effects. The Journal of nutritional biochemistry 13.11 (2002): 636-644.
 Kim, Hwa-Young, Ok-Hee Kim, and Mi-Kyung Sung. Effects of phenol-depleted and phenol-rich diets on blood markers of oxidative stress, and urinary excretion of quercetin and kaempferol in healthy volunteers. Journal of the American College of Nutrition 22.3 (2003): 217-223.
Available at: http://culinaryarts.about.com/od/culinaryreference/a/smokepoints.htm. Accessed on October 28, 2014.
 Casal, Susana, et al. Olive oil stability under deep-frying conditions. Food and Chemical Toxicology 48.10 (2010): 2972-2979.
 Sutherland, Wayne HF, et al. Effect of meals rich in heated olive and safflower oils on oxidation of postprandial serum in healthy men. Atherosclerosis 160.1 (2002): 195-203.
 Ako, H, Okuda D, and Gray D. Healthful new oil from macadamia nuts. Nutrition (Burbank, Los Angeles County, Calif.) 11.3 (1995): 286.
 Avaialable at: http://blog.lluniversity.com/nuts-and-oils-why-coconut-and-macadamia-nut-are-king/. Accessed on October 28, 2014.
 Wall, Marisa M. Functional lipid characteristics, oxidative stability, and antioxidant activity of macadamia nut (Macadamia integrifolia). Food chemistry 121.4 (2010): 1103-1108.
 Garg, Manohar L, et al. Macadamia nut consumption modulates favourably risk factors for coronary artery disease in hypercholesterolemic subjects. Lipids 42.6 (2007): 583-587.
 Available at: http://www.naturalnews.com/029202_olive_oil_smoke_point.html. Accessed on October 14, 2014.
 Prior, IA, et al. “Cholesterol, coconuts, and diet on Polynesian atolls: a natural experiment: the Pukapuka and Tokelau island studies.” The American journal of clinical nutrition 34.8 (1981): 1552-1561.
 Isaacs, CE, et al. “Antiviral and antibacterial lipids in human milk and infant formula feeds.” Archives of Disease in Childhood 65.8 (1990): 861-864.
 Available at: http://www.livestrong.com/article/446041-is-coconut-oil-good-for-frying-on-high-temperature-cooking/. Accessed on October 28, 2014.
 Eyres L, Sherpa N and Hendriks G. Avocado oil: a new edible oil from Australasia. Lipid Technol 2001;Vol 13, no 4:84-88.
 Swisher, Horton E. Avocado oil. J Am Oil Chem 65 (1988): 1705.
 Unlu, Nuray Z., et al. “Carotenoid absorption from salad and salsa by humans is enhanced by the addition of avocado or avocado oil.” The Journal of nutrition 135.3 (2005): 431-436.
 Watts GF, Lewis B, Brunt JNH, Lewis ES, Coltart DJ, Smith LDR, Mann JI and Swan AV. Effects on coronary artery disease of lipid-lowering diet, or diet plus cholestyramine, in the St Thomas’ Atherosclerosis Regression Study (STARS). Lancet 1992;339:563-569.
 Available at: https://theconsciouslife.com/omega-3-6-9-ratio-cooking-oils.htm. Accessed on October 28. 2014.
 Available at: http://www.vegkitchen.com/tips/avocado-oil-expeller-pressed-naturally-refined/attachment/smoke-point-chart/. Accessed on October 28, 2014.