Dietary consumption of quality fat is crucial for providing an optimal level of nutrition to the body which drives cellular metabolism, structure, detoxification, organ function, and system regulation.
Triglycerides provide the most concentrated source of energy for the body. They are composed of glycerol and 3 fatty acid molecules. The body and brain can efficiently use fat as the primary source of fuel in the form of ketones and free fatty acids instead of glucose derived from carbohydrates. Once broken down into its constituents, glycerol may be converted into glyceraldehyde 3-phosphate that may then be formed into either glucose to be used directly by the body or pyruvic acid for ATP production via the Krebs cycle. These catabolic reactions may also be reversed and triglycerides may be created via anabolism.
The fatty acids that are attached to the glycerol backbone may be classified as either saturated, monounsaturated, or polyunsaturated which will dictate what functions they fulfill in the body as well as their inherent chemical stability. The saturation level of fat is determined by the number of carbon bonds occupied by a hydrogen atom. If 2 hydrogen atoms are missing then a double bond between two carbon atoms ensues (monounsaturated) creating a kink in the chain of molecules. Polyunsaturated fats have two or more pairs of double bonded carbon atoms creating more than one kink in the molecular chain. Saturated fat’s carbon atoms are completely filled with hydrogen atoms making them the most solid and stable fat. The more unsaturated (polyunsaturated) a fat becomes the more unstable it is. These types of fat will be liquid at room temperature and be more susceptible to becoming rancid. Animal fats are highest in concentration (40-60%) of saturated fats. Saturated fats exist in the body because they are stable and resist oxidation. However, the body needs all types of fat. Examples of polyunsaturated fats that are essential (can only be obtained via diet) to the human body are linoleic (omega-6) and linolenic (omega-3). The current government dietary recommendations are to receive up to 30% of calories from polyunsaturated fats whereas some sources (Fallon, 2003) believe a better value of polyunsaturated fats is ~4% with the majority of the total fat coming from quality saturated and monounsaturated fats. Of this 4% of polyunsaturated fats, Ms. Fallon recommends ~1.5% from omega 3 and ~2.5% from omega 6. Typically, the American diet is particularly lacking in omega-3 linolenic acid which is important for cellular respiration, metabolizing sulphur amino acids, and balancing prostaglandins.
Fats can be further classified according to the number of carbon atoms. Short chain (4-6 carbon atoms) are always saturated, have anti-microbial properties, and assist with immune function. Examples include butyric acid (butterfat) and capric acid (goat butterfat). Bile salts are not needed for their metabolism as they are directly absorbed into the bloodstream providing energy. These types of fats are less likely to cause weight gain. Medium chain (8-12 carbon atoms) have similar properties to short chain and include tropical oils. Long chain fatty acids (14-18 carbon atoms) can be saturated, monounsaturated, or polyunsaturated. Examples include stearic acid (beef), oleic acid (olive oil), palmitoleic acid (animal fats including antimicrobial properties), and gamma-linolenic acid (GLA) (comprises prostaglandins and hormones). Very long chain fatty acids (20-24 carbon atoms) tend to be highly unstable yet are still a necessity for the human body. Some individuals have the ability to synthesize these better than others. If one’s ancestors ate a lot of fish they typically do not have the ability to make these types of fatty acids on their own requiring increased dietary intake (meats, yolks, butter, fish oil). The most important ones are dihomo-gamma-linoleic acid (DGLA), arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic (DHA). These all have important roles with regards to optimal nervous system function.
Fat is absolutely essential for the human body to thrive. In particular, we need saturated fats and cholesterol which are primarily obtained through animal fats. In addition to providing energy, fat and cholesterol are necessary for the following in our system:
- Comprise hormones
- Cholesterol is involved in the synthesis and regulation of adrenal and steroid hormones (estrogen, progesterone, testosterone, adrenaline, cortisol, DHEA, vitamin D, pregnenolone)
- Make up cell membranes (phospholipids)
- Protect the liver from alcohol
- Essential for developing children. Breast milk has 50% fat, mostly saturated.
- Enhances immune function
- Supplies the heart with energy
- Balances the microbiota in our gut
- Vital nutrients come from fat and cholesterol and are regulated by them.
- Convert carotene to true vitamin A (retinol)
- Assist with absorption of calcium and play a role in bone metabolism
- Examples of fat derived nutrients include coenzyme Q10, taurine, EPA, conjugated linoleic acid, linolenic acid, glutathione, L-carnitine, vitamin A, E, D, K, anti-homocysteine vitamins B6, 12, folic acid, lipoic acid, magnesium, zinc, and sulphur
- Needed for proper use of dietary protein.
Cholesterol is derived from fat and is absolutely essential for proper cellular, organ, and system regulation. 90% of dietary cholesterol we consume is reabsorbed by the gut so it can be used again. Every cell can manufacture its own supply but this process is not efficient and puts stress on the liver. Reduction of cholesterol consumption signals crisis and famine to the body facilitating the liver enzyme HMG-CoA reductase to produce cholesterol from carbohydrates which can strain the liver under chronic demand. Therefore, it is best to consume cholesterol vs. rely on liver production via carbohydrates. It is of significance that statin pharmaceuticals inhibit HMG-CoA reductase at the cost of depleting the nutrient CoQ10 (important for heart function) and overburdening the liver. Such demand on the liver may ensue damage which will render the liver not able to produce C-reactive protein, a marker of inflammation. Therefore, in cases where the use of statins is associated with a reduction in C-reactive protein may actually be due to the statins’ negative impact on liver function vs a true inflammatory reduction.
Our medical culture is fixated on LDL (low-density lipoproteins) and HDL (high-density lipoproteins) ratios. Typically, it is recommended to have an LDL level lower than 130 mg/dL and HDL higher than 46 mg/dL with total levels no more than 200. Levels of HDL/LDL reflect transport mechanisms for cholesterol and not actual cholesterol levels. LDL takes cholesterol away from the liver to the extremities, organs, and makes hormones. HDL cholesterol removes excess cholesterol from the body tissues to the liver for elimination. Cholesterol travels to areas of inflammatory damage to patch up lesions. A high level is an indicator that an inflammatory process may be occurring that the body is attempting to compensate for. Some sources (Gedgaudas, 2011) suggest that HDL levels greater than 70-75 may indicate underlying inflammatory and autoimmune issues and that an activated inflammatory peroxidase system can increase HDL levels. Very low levels of LDL may indicate low inflammation but also an inability to compensate from inflammatory reactions. This is another reason why statin drugs may not be of benefit as they will restrict the body’s natural repair systems using cholesterol. Furthermore, low levels of cholesterol are associated with increased risk of cancer, hormonal imbalance, depression, sexual dysfunction, memory loss, Parkinson’s Disease, and stroke.
Our society demonizes cholesterol and yet, as just described, it is crucial for system function. The real problem is consumption of oxidized cholesterol through highly processed foods and rancid polyunsaturated oils. Increased polyunsaturated fat intake is associated with cancer, heart disease, and immune dysfunction. Polyunsaturated fats are typically oxidized and rancid when consumed due to high temperature and chemical processing creating free-radicals. When consumed, the body incorporates these altered fats into cell membranes with negative effects on cellular metabolism. Such chemicals can damage nuclear material and body tissues including the facilitation of atherosclerosis.
Between endothelial arterial cells are spaces that allow nutrients to pass and flow through. Lipoproteins can lodge in there, block flow, and cause an inflammatory response. Statins do not effect lipoproteins, only diet can. (Choi et al., 2010) (Gedgaudas, 2011). 80% of arterial plaque is not cholesterol or saturated fat but oxidized rancid unsaturated fats. More importantly, chronic systemic inflammation in the body can oxidize cholesterol leading to arterial plaque build-up.
Modern processing methods destroy practically all the nutritional value of food in addition to creating increased stress on the body to metabolize them. Hydrogenation turns liquid fats into solid fats at room temperature usually using cheap and already spoiled oils such as soy, corn, cottonseed, and canola. This process uses high pressure, hexane gas, metal (usually nickel oxide), and bleach. Consumption of hydrogenated oils blocks the utilization of beneficial fatty acids. They are also associated with cancer. Homogenization involves using high pressure to strain the fat particles of cream through tiny pores creating very small particles making them more susceptible to becoming rancid and oxidizing.
One must be cautious with fat consumption today because of the ease that fat soluble and water soluble poisons can accumulate in our standard sources of animal fat and water fraction of milk and meats. This includes antibiotics and growth hormones that are typically injected into most of our meat sources. It is therefore recommended to consume animal sources of fat that have been raised on organic pastures (grass fed) without the use of pharmaceutical treatments. It is also suggested to store high quality monounsaturated and polyunsaturated oils in cool dark places to minimize oxidation. A good quality oil is typically cold pressed and minimally processed.
In conclusion, the idea that “fat, particularly saturated animal fat, and cholesterol are bad for us” is simply not true. As described above, it is essential for humans to consume fat and cholesterol for proper cellular and thus system regulation. What is important is we choose the correct types, of good quality, and in balanced ratios. Bring on the butter and throw out the margarine!
References
Choi, C. U., Seo, H. S., Lee, E. M., Shin, S. Y., Choi, U.-J., Na, J. O., … Oh, D. J. (2010). Statins do not decrease small, dense low-density lipoprotein. Texas Heart Institute Journal / from the Texas Heart Institute of St. Luke’s Episcopal Hospital, Texas Children’s Hospital, 37, 421–428.
Fallon, S. (2003). Nourishing Traditions.
Gedgaudas, N. (2011). Primal Body Primal Mind.