Dietary Fats

In today’s post, I am going to write about types of fats, and how they affect our health.  Fats provide energy, insulation, and storage of fatty acids.  There are two types of fats: unsaturated and saturated fats.  A fat molecule is made up of two primary components: glycerol and fatty acids.  In a saturated fatty acid, there are only single bonds between neighboring carbons in the hydrocarbon chain.  Due to this tightly-packed structure, they are typically solid at room temperature with few exceptions.  Examples of foods that contain saturated fats include beef, pork, lamb, poultry (especially with skin), butter, lard, cheese, coconut oil, etc.

In contrast, when the hydrocarbon chain contains a double bond, the fatty acid is unsaturated.  This means that the fatty acids do not pack together as tightly as in the saturated ones leaving most unsaturated fats in a liquid state at room temperature.  Unsaturated fats may be cis (hydrogen atoms in the same plane) or trans (hydrogen atoms in two different planes).  In the food industry, oils are artificially hydrogenated to make them of a consistency desirable for many processed food products.  During this process, the double bonds of the cis-conformation may be converted to double-bonds of the trans-conformation.

Examples of artificially-hydrogenated trans fats include some types of peanut butter, margarine, types of oils typically used in deep-frying machines for repeated cooling/reheating in fast food industries.  Trans fats may promote formations of arterial plaques, and increased risk of heart disease as they increase the amount of LDL cholesterol in the blood, and lower the amount of HDL cholesterol in the blood.  While the saturated fats have been found to increase the amount of LDL cholesterol, they have not been shown to decrease the HDL cholesterol and cause the formation of arterial plaques as considerably as the trans fats.

Unsaturated fats can be naturally occurring like the fats found in nuts, avocados, olive oil, or they can be chemically-manipulated to become unsaturated.  

A special type of fatty acids is called essential fatty acid as they are not made by the human body on its own.  However, they are required for the biological processes, and responsible for the overall health.  That’s why they need to be consumed via the food we eat. Examples are omega-3 polyunsaturated fatty acids, and omega-6 polyunsaturated fatty acids, the names stemming from the position of the double bond in the hydrocarbon chain.  Salmon, tuna, and trout are great sources of omega-3 fatty acids.  Omega-6 fatty acids are found in various nuts, avocado, seeds, tofu, etc.  While these are known to be healthy foods, we need to pay attention to the ratio of omega-6 to omega-3 fatty acids that we ingest as numerous studies have shown that a high ratio of omega-6 to omega-3 fatty acids may contribute to inflammation and chronic disease.

To conclude, the take-away of my post is this: based on numerous scientific studies of dietary fats, we can enjoy moderate amounts of food that contain mostly naturally occurring, unsaturated fats like those contained in olive oil, nuts, avocados but avoid all trans fats.  We also need to limit the intake of red meats, butter, cheese, etc. that contain high amounts of saturated fats.

Disclaimer: I am not a healthcare professional, and while I am happy to support you to make clever decisions about your optimal health, please consult with your doctor, or a healthcare professional first.

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