Fats and Fatty Acids

Fats

Table of Contents

A molecule of dietary fat typically consists of several fatty acids (containing long chains of carbon and hydrogen atoms), bonded to a glycerol. They are typically found as triglycerides (three fatty acids attached to one glycerol backbone). Fats may be classified as saturated or unsaturated depending on the chemical structure of the fatty acids involved.

Saturated Fats

Saturated fats have all of the carbon atoms in their fatty acid chains bonded to hydrogen atoms, whereas unsaturated fats have some of these carbon atoms double-bonded, so their molecules have relatively fewer hydrogen atoms than a saturated fatty acid of the same length.

They have been a staple in many world cultures for millennia. These fats are most often solid at room temperature. Foods like butter, palm and coconut oils, cheese, and red meat have high amounts of saturated fat.

Saturated fats raise your LDL (bad) cholesterol level. High LDL cholesterol puts you at risk for heart attack, stroke, and other major health problems. You should avoid or limit foods that are high in saturated fats.

Keep saturated fats to less than 6% of your total daily calories.
Foods with a lot of saturated fats are animal products, such as butter, cheese, whole milk, ice cream, cream, and fatty meats.
Some vegetable oils, such as coconut, palm, and palm kernel oil, also contain saturated fats. These fats are solid at room temperature.
A diet high in saturated fat increases cholesterol buildup in your arteries (blood vessels). Cholesterol is a soft, waxy substance that can cause clogged, or blocked, arteries.

Facts about saturated fats https://medlineplus.gov/ency/patientinstructions/000838.htm

https://medlineplus.gov/ency/patientinstructions/000104.htm

Unsaturated Fats

Unsaturated fats may be further classified as monounsaturated (one double-bond) or polyunsaturated (many double-bonds). Furthermore, depending on the location of the double-bond in the fatty acid chain, unsaturated fatty acids are classified as omega-3 or omega-6 fatty acids.

Unsaturated fats are considered the ‘healthy’ fats and they’re important to include as part of a healthy diet. These fats help reduce the risk of high blood cholesterol levels and have other health benefits.

Unsaturated fats are liquid at room temperature. Healthy unsaturated fats come in two main forms, polyunsaturated and monounsaturated. These differ in their chemical structure and they have slightly different health benefits as a result.

Monounsaturated Fats

are belonh to the healthy fats, along with polyunsaturated fat. Monounsaturated fats are liquid at room temperature, but start to harden when chilled. Monounsaturated fats are found in plant foods, such as nuts, avocados, and vegetable oils. They can help lower your LDL (bad) cholesterol level. Cholesterol is a soft, waxy substance that can cause clogged, or blocked, arteries (blood vessels). Keeping your LDL level low reduces your risk for heart disease and stroke.

Polyunsaturated fats

Two main types of polyunsaturated fats are omega-3 fats and omega-6 fats, which act slightly differently to provide health benefits. Omega-3 and omega-6 fats are essential in the diet as they can’t be made in the body. Polyunsaturated fat is found in plant and animal foods, such as salmon, vegetable oils, and some nuts and seeds. Monounsaturated fats help develop and maintain your cells. Our bodies can not make essential fatty acids, so you can only get them from food.

Dietary fats: https://medlineplus.gov/ency/patientinstructions/000104.htm

Monounsaturated fats: https://medlineplus.gov/ency/patientinstructions/000785.htm

Polyunsaturated fats: https://medlineplus.gov/ency/patientinstructions/000747.htm

Trans Fats

Trans fats are a type of unsaturated fat with trans-isomer bonds; these are rare in nature and in foods from natural sources; they are typically created in an industrial process called (partial) hydrogenation. There are nine kilocalories in each gram of fat. Fatty acids such as conjugated linoleic acid, catalpic acid, eleostearic acid and punicic acid, in addition to providing energy, represent potent immune modulatory molecules. Trans fats are to be avoided

Trans fats are very rare in nature, and have been shown to be highly detrimental to human health, but have properties useful in the food processing industry, such as rancidity resistance.

Essential Fatty Acids

Most fatty acids are non-essential, meaning the body can produce them as needed, generally from other fatty acids and always by expending energy to do so. However, in humans, at least two fatty acids are essential and must be included in the diet. An appropriate balance of essential fatty acids—omega-3 and omega-6 fatty acids—seems also important for health, although definitive experimental demonstration has been elusive. Both of these “omega” long-chain polyunsaturated fatty acids are substrates for a class of eicosanoids known as prostaglandins, which have roles throughout the human body.

Omega 3 Essential Fatty Acids

The omega-3 eicosapentaenoic acid (EPA), which can be made in the human body from the omega-3 essential fatty acid. or taken in through marine food sources, serves as a building block for series 3 prostaglandins.

The potential health benefits of consuming omega-3s are the focus of a great deal of scientific research. By far, the majority of research has focused on EPA and DHA from foods (e.g., fish) and/or dietary supplements (e.g., fish oil) as opposed to ALA from plant-based foods. Several different omega-3s exist, but the majority of scientific research focuses on three: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA contains 18 carbon atoms, whereas EPA and DHA are considered “long-chain” (LC) omega-3s because EPA contains 20 carbons and DHA contains 22.

Many observational studies link higher intakes of fish and other seafood with improved health outcomes. However, it is difficult to ascertain whether the benefits are due to the omega-3 content of the seafood (which varies among species), other components in the seafood, the substitution of seafood for other less healthful foods, other healthful behaviors, or a combination of these factors. Data from randomized clinical trials are needed to shed light on these questions.

See; Omega-3 Fatty Acids – Fact Sheet for Health Professionals:

https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/#h7

Omega 6 Essential Fatty Acids

The omega-6 dihomo-gamma-linolenic acid (DGLA) serves as a building block for series 1 prostaglandins (e.g. anti-inflammatory PGE1), whereas arachidonic acid (AA) serves as a building block for series 2 prostaglandins (e.g. pro-inflammatory PGE 2). Both DGLA and AA can be made from the omega-6 linoleic acid (LA) in the human body, or can be taken in directly through food.

While omega 6 fatty acids are necessary for normal immune function and clotting, too much omega 6 fatty acid may promote abnormal clotting and an overactive immune system. It is believed that our ancestors evolved on a diet where these two omega fatty acids were approximately equal. However, modern diets usually have up to 20 times more omega 6 fatty acids than omega 3 fatty acids. Many of the chronic degenerative diseases we experience today are believed to have their origins in an imbalance of omega 3 and omega 6 fatty acids in our diet.

Among plant oils, the balance between omega-3, omega-6 and omega 9 fatty acids must dictate which oil is chosen. Oils which predominate in omega-3 component would be most likely to promote health, only perilla and flax seed (vegetable) oil predominate in omega-3 fatty acid. Most would actually contribute to the imbalance of omega-6 fatty acids because they contain more omega-6 than omega-3. Any amount of omega-9 is beneficial, but in balancing these fatty acids, the omega-3 component is the most important.

Health effects of omega-3,6,9 fatty acids: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3167467/

Other Fatty Acids

Omega 7 Fatty Acids

Omega-7 fatty acids are a class of unsaturated fatty acids in which the site of unsaturation is seven carbon atoms from the end of the carbon chain. The two most common omega-7 fatty acids in nature are palmitoleic acid and vaccenic acid. They are widely used in cosmetics due to their moisturizing properties. Diets rich in omega-7 fatty acids have been shown to have beneficial health effects, such as increasing levels of HDL cholesterol and lowering levels of LDL cholesterol.

Rich sources include macadamia nut oil and flax seed oil in the form of palmitoleic acid, while dairy products are the primary sources of vaccenic acid and rumenic acid.^[2] A lesser but useful source of palmitoleic acid is avocado fruit (25,000ppm)

Source: https://en.wikipedia.org/wiki/Human_nutrition

Omega 9 Fatty Acids

Omega-9 fatty acids (ω−9 fatty acids or n−9 fatty acids) are a family of unsaturated fatty acids which have in common a final carbon–carbon double bond in the omega−9 position; that is, the ninth bond from the methyl end of the fatty acid. Unlike omega-3 fatty acids and omega-6 fatty acid, omega−9 fatty acids are not classed as essential fatty acids (EFA). This is both because they can be created by the human body from unsaturated fat, and are therefore not essential in the diet, and because the lack of an omega−6 double bond keeps them from participating in the reactions that form the eicosanoids.

The main omega-9 fatty acid in the brain is oleic acid, but there are also large quantities of long-chain derivatives, especially in the myelin sheath. The nutritional value of oleic acid in a balanced diet has been the subject of a number of studies, with particular emphasis on the cardiovascular system. But this fatty acid is also important for the brain.

There may be several explanations for why the oleic acid concentration in cerebral structures is not altered according to the oleic acid content of the diet. The nervous system may selectively bind oleic acid, perhaps by specific, active transport mechanisms across the blood brain barrier. Or it may be able to synthesise all of the oleic acid that it needs, regardless of the dietary intake

https://en.wikipedia.org/wiki/Omega-9_fatty_acid

https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/omega-9-fatty-acid