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The-Okanagan-Naturopath

Not all dietary oils are created equal

Good oils and bad oils

Dietary oils are fats found in foods that are liquid at room temperature.

They can be classified according to their molecular composition, the amount of omega-3 and 6 oils content and the degree of processing with pressure, heat and solvents, as to whether or not they are good or bad.

Humans consume some oils in the diet daily from different foods including fish, cereals and grains, beans and legumes, nuts and seeds and other vegetables.

The most common types of plant oil sources include avocado, canola, corn, flaxseed, grapeseed, hemp seed, olive, palm, peanut, pumpkin seed, rice, safflower, sesame, soybean, sunflower, walnut and others.

Oils are used for energy, cell membrane integrity, cellular communication, hormone production, mediators of inflammation in humans.

Twenty to 35 percent of dietary caloric intake should be from fats and oils. Saturated fat mainly from animal products should account for about 10 percent of this intake. The remaining caloric intake should be from fats and oils from plant products. It should be remembered that fats and oils produce more than twice the number of calories or energy than carbohydrates and proteins.

Fats and oils are made up of long chains of carbon atoms attached to hydrogen and the occasional oxygen molecule. They are further classified as being saturated and unsaturated. Saturated fats are completely filled up with hydrogen atoms and are described as being saturated. Unsaturated fats are not completely filled up with hydrogen atoms and are described as being unsaturated.

Unsaturated fats and oils are further described as mono-unsaturated or poly-unsaturated. A mono-unsaturated fat has only one site on the carbon chain that is not filled up with hydrogen. A poly-unsaturated fat or PUFA has more than one site on the carbon chain that is not filled up with hydrogen.

The degree of saturation dramatically changes the physical property of the fat. Saturated fats, mainly from animal products, tend to be solid at room temperature. Mono-unsaturated fats like coconut oil tend to be semi-solid at room temperature. Poly-unsaturated fats like vegetable oils found in the supermarket tend to be liquid at room temperature.

Essential fats are oils that are required by the humans in small amounts for proper and specific functions. They cannot be manufactured in the body and must be obtained from dietary sources. The two main types of essential fatty acids are omega-3 oils and omega-6 oils.

Most oils contain a mixture of different mono-unsaturated and poly-unsaturated oils in different amounts and ratios. Some oils are richer in omega-3 oils and some are richer in omega-6 oils.

Omega-3 oils are rich in alpha-linolenic acid or ALA. Omega-3 oils also contain varying degrees of docosahexaenoic acid or DHA and eicosapentaenoic acid or EPA. Both DHA and EPA have vital specific functions in the human body including brain and neurological development and eyesight especially for developing fetuses and babies.

The most common examples of omega-3 rich oils are fish, canola, chia, flaxseed, soybean and walnut oil.

Omega 6 oils are rich in linoleic acid or LA. LA cannot make DHA or EPA oils. Some LA is converted by the body to inflammatory Arachidonic acid or AA.

The most common examples omega-6 rich oils are almond, avocado, canola, corn, eggs, hempseed, olive, peanut, safflower, soybean and sunflower oil.

In modern times, the amount of vegetables oils, specifically omega-6 oils have increased dramatically. The ratio of omega 6 to omega 3 is between 10: and 20:1. In ancient times the ratio was between 1 and 3 to 1. Some nutritional experts believe that the increased consumption of omega-6 oils is fueling atherosclerosis and inflammation. The evidence for this remains controversial.

There are differing degrees of processing involved in making oils. Pressure, heat and solvents can be used in the extraction procedure to isolate oils from the plant. In general, the harder and more solid the plant material, the more pressure and heat is involved. The amount of pressure to extract oil from a softer plant like avocado, olive and soybean is less than the pressure required to extract oil from a harder source like flaxseed, peanut and sunflower.

Pressure and heat can disrupt the unsaturated sites on the oils leading to oxidation of the oil. Oxidation changes damage the molecular structure of the oil. Structural alterations of essential fats like omega-3 and 6’s changes their function and usefulness in the body.

Solvents such as benzene, ethanol and hexane may also used in oil extraction procedures to isolate the oil from other plant material. Some of the residues may persist in the final product.

In general, liquid oils are healthier than solid fats like butter. An oil richer in omega-3 is preferred over omega-6. An oil processed with less pressure, heat and solvents is also preferred. Cold pressed, virgin oil are also preferred.

The information provided in this article does not, and is not intended to, constitute medical advice. All information and content are for general information purposes only.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.



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About the Author

Doug Lobay is a practicing naturopathic physician in Kelowna, British Columbia.

He graduated with a bachelor of science degree from the University of British Columbia in 1987 and then attended Bastyr College of Natural Health Sciences in Seattle, Washington, where graduated with a doctorate in naturopathic medicine degree in 1991. While attending Bastyr College, he began to research the scientific basis of naturopathic medicine. 

He was surprised to find many of the current major medical journals abounded with scientific information on the use of diet, vitamins, nutritional supplements and herbal medicines.

Doug is a member of the College of Naturopathic Physicians of British Columbia and has practiced as naturopathic family physician for more than 30 years.  He maintains a busy practice in Kelowna where he sees a wide age range of patients with various ailments.

He focuses on dietary modification, allergy testing, nutritional assessments, supplement recommendation for optimal health, various physical therapy modalities, various intravenous therapies including chelation therapy.

An avid writer, he has written seven books on various aspects of naturopathic medicine that are available on Amazon and was also a long-time medical contributor to the Townsend Letter journal for doctors and patients, where many of his articles are available to view on-line. He has also given numerous lectures, talks and has taught various courses on natural medicine.

Doug enjoys research, writing and teaching others about the virtues of natural health and good nutrition. When not working, he enjoys cycling, hiking, hockey, skiing, swimming, tennis and playing guitar.

If you have any further questions or comments, you can contact Dr. Lobay at 250-860-7622 or [email protected].



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The views expressed are strictly those of the author and not necessarily those of Castanet. Castanet does not warrant the contents.

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