Unsaturated Fatty Acids
An unsaturated fat is a type of fatty acid in which there is at least one double bond within the fatty acid chain. Unsaturated fats are classified as either monounsaturated or polyunsaturated or trans-fatty depending on the number and type of double bond that they contain.
Unsaturated fats contain fewer calories and contain somewhat less energy than saturated fats. They are also more vulnerable to lipid peroxidation or becoming rancid. The higher number of double-bonds that the fatty acid contains the more vulnerable. The rancidity of fats and oils is often managed with antioxidants.
The amount of unsaturated fat consumed should not exceed 30% of one's daily caloric intake (or 67 grams given a 2000 Calorie diet).
- Monounsaturated fats are good. Sources of monounsaturated fatty acids include:
- Olive oil is about 75% monounsaturated fat.
- Canola oil and cashews are about 58%.
- Nuts and seeds and their oils including cashews, pecans, almonds, peanuts, macadamia nut oil, grapeseed oil, groundnut oil (peanut oil), sesame oil, safflower oil, sunflower oil and avocado oil.
- Vegetables oils including canola, olive, peanut, safflower, sesame and sunflower.
- Other sources include: avocados, whole milk products, corn oil, popcorn, whole grain wheat, cereal and oatmeal.
- Polyunsaturated fats are both good and bad. Sources of polyunsaturated fatty acids include those foods that are high in omega-3 fatty acids, omega-6 fatty acids and omega-9 fatty acids. Ideally you want to choose foods high in omega-3 fatty acids and low in [[Omega-6 Fatty Acids}omega-6 fatty acids]]. Foods high in polyunsaturated fats include:
- fatty fish such as herring, mackerel, salmon, trout and smelt
- fish oils
- nuts and seeds such as cashews, pecans, almonds and peanuts.
- vegetable oils such as canola, corn, flaxseed, soybean and sunflower.
- meat products contain both [saturated fatty acids]] saturated and unsaturated fats.
- Trans Fatty Acids are best avoided.
- Examples of unsaturated fats include palmitoleic acid, oleic acid, myristoleic acid, linoleic acid, and arachidonic acid.
- As unsaturated fats have a lower melting point and are more fluid they are more beneficial in increasing the fluidity of cell membranes.
- Polyunsaturated fatty acids lowers cholesterol and LDL cholesterol levels and seem to be protective against cardiac arrhythmias and atherosclerosis.
- Insulin Resistance
Unsaturated chains have a lower melting point, hence increasing fluidity of the cell membranes.