Fats from animal and vegetable sources provide a valuable sources of energy in a diet. These fats also provide the building blocks for cell membranes as well as a variety of hormones and hormone-like substances. Fats as part of a meal slow down absorption so that we can go longer until our next meal without feeling hungry as fast. In addition to this, fats bring along with them many fat soluble vitamins such as vitamin A, D, E and K. However, for the majority of the past few decades, the general public has been told to reduce the amount of fats they ingest (especially saturated fats from animal sources) as part of a healthy balanced diet. So that got me thinking… ARE saturated fats really that bad for you?? What gives??
The theory that there is a direct relationship between the amount of saturated fat and cholesterol in someone’s diet can directly affect their incidence of heart disease is call the “lipid hypothesis”. While it IS true that some fats are bas for us. What ISN’T true is that we need to cut all fats from our diet to be lean and healthy. To understand the difference between the two, we need to learn about the chemistry of fats. Fats (or in chemistry lingo: lipids) are a class of organic substances that are not soluble in water (think of how oil and water don’t mix). These fatty acids are chains of carbon atoms with hydrogen atoms attached. Most of the fat in our bodies and in the food that we eat is in the form of triglycerides. Triglycerides are three (TRIglycerides)) fatty-acid chains attached to a glycerol (triGLYcerides) molecule.
Increased triglycerides in the blood have been positively linked to a higher incidence of heart disease, BUT these triglycerides don’t necessarily have to come from the fat in our diets. These triglycerides CAN be made in the liver from any excess sugars that have not been used up for energy. And where can these excess sugars come from? – Any food that contains carbohydrates – especially those containing refined sugar and white flour.
Fatty acids are classified by their amount of saturation. Saturated fatty acids are those that have hydrogen atoms bonded to all of the available carbon atoms. These fatty acids are very stable because all of the carbon atoms are attached to hydrogen atoms – i.e. the molecule is “saturated.” These fats normally don’t go rancid and are solid or semisolid at room temperature. Saturated fatty acids can be found in animal fats or can be made by your body from carbohydrates.
Monounsaturated fatty acids have one double bond which is made from two carbon atoms double-bonded to each other. Because of this, they have two less hydrogen atoms. Monounsaturated fats have a bend where the double bond is located so they don’t pack together as easily as saturated fatty acids do. Your body makes monounsaturated fatty acids from saturated fatty acids. Monounsaturated fats tend to be liquid at room temperature and like saturated fats, they are relatively stable and don’t go rancid easily. They often come from olive oil and nut oils.
Polyunsaturated fatty acids have two or more pairs of double bonds and therefore lack four or more hydrogen atoms. The two polyunsaturated fatty acids found most frequently in our foods are omega-6 and omega-3 fatty acids. (The omega number refers to the position of the first double bond in the chain. Your body can’t make these fatty acids which is why they are called “essential” fatty acids (because we need to get them from the foods we eat).
For a long time we have been told that polyunsaturated fats are good fats while saturated fats do nothing but cause heart disease and illness. But saturated fats play very important roles in our diets!!!! Saturated fats:
- Make up at least 50% of your cells’ membranes
- Help calcium become incorporated into your skeletal structure
- Lower Lp(a) – a substance in the blood that indicates proneness to heart disease
- Protect the liver from alcohol and other toxins
- Help maintain healthy skin (because they’re the preferred fat for building collagen)
- Help you breath easier (lungs are coated with a surfactant layer that is made up of saturated fatty acids)
- Enhance the immune system
- Are needed to ensure proper function of your brain (which is why eating saturated fats is extremely important while pregnant and nursing to ensure proper brain development for babies)
- Are needed for the proper utilization of essential fatty acids.
- Are the preferred foods for the heart (which is why the fat around the heart muscle is highly saturated – The heart draws on this reserve of fat in times of stress)
- Protect us against harmful microorganisms in the digestive tract
Can you say “Pass the cheese, please!!!”