The Fat Debate
Fat is a macronutrient. There are three macronutrients: protein, fats and carbohydrates. Macronutrients are nutrients that provide calories or energy. Large amounts are required to sustain life, hence the term “macro,” according to the University of Illinois McKinley Health Center. The amount of energy provided by the macronutrients varies: fat has 9 calories per gram, more than twice the number of calories in carbs and protein, which each have 4 calories per gram. The primary function of fat is as an energy reserve, according to Iowa State University. The body stores fat, or adipose tissue, as a result of excess calorie consumption. During exercise, the body first uses calories from carbohydrates for energy. After about 20 minutes, it uses calories from stored fat to keep going, according to the National Institutes of Health (NIH).
Saturated fats are saturated with hydrogen molecules. Saturated fat comes from animal sources, such as red meats, poultry and full-or-reduced fat dairy products. Saturated fats are solid at room temperature. Other examples include cheese and butter. Oils that are solid at room temperature, like palm oil, palm kernel oil and coconut oil, also contain saturated fats. This means that baked goods can be high in saturated fats. Saturated fat is linked to high cholesterol levels and an increased risk of cardiovascular disease. Saturated fats also tend to contain a lot of calories. The American Heart Association (AHA) recommends getting only 5 to 6 percent of calories from saturated fat. This puts someone on a 2,000-calorie-a-day diet with 120 calories or 13 grams of saturated fats per day. The 2010 U.S. Dietary Guidelines allow for up to 10 percent of calories to come from saturated fat.
Trans Fats (also called trans fatty acids)
Trans fats are sometimes found naturally in meats or dairy, but usually in small amounts. More often, they are “produced by the food industry for the purpose to increase shelf life of the product.” This is done by adding hydrogen to liquid vegetable oils to make the oils more solid. These are called partially hydrogenated oils. They are often found in “convenient foods” like frozen pizzas. Other common sources of trans fats include baked goods, crackers, refrigerated dough, margarine and coffee creamer. Fast food restaurants often use them in deep fryers because partially hydrogenated oil does not have to be changed as often as regular oil. Trans fats are not recommended at all because of the link to heart diseases, they are often considered the worst type of fat. According to the AHA, they both lower your good cholesterol and increase your bad cholesterol.
Triglycerides are a potentially dangerous type of fat found in blood, according to the NIH. They are associated with coronary artery disease, especially in women. The body converts any calories it doesn't need to use right away into triglycerides, which are stored in the fat cells. They are supposed to provide energy between meals. If you eat more calories than you expend, however, the body does not burn triglycerides, and they accumulate. Most types of fat we eat become triglycerides. A blood test can reveal your triglyceride levels.
Healthy Triglyceride Levels:
Normal: Less than 150 milligrams per deciliter (mg/dL), or less than 1.7 millimoles per liter (mmol/L)
Borderline high: 150 to 199 mg/dL (1.8 to 2.2 mmol/L)
High: 200 to 499 mg/dL (2.3 to 5.6 mmol/L)
Very high: 500 mg/dL or above (5.7 mmol/L or above)
These fats get their name because they are not saturated with hydrogen molecules and because they have a single carbon bond in the fat molecule (called a double bond). “They are liquid at room temperature. Examples are canola, peanut or olive oil. Olives and avocados also contain monounsaturated fats. Monounsaturated fats are known to have a heart-protective role and have been linked to improved cholesterol levels, they may also help insulin levels and blood sugar control.
Like monounsaturated fats, polyunsaturated fats are not saturated with hydrogen molecules. They get their name from having more than one carbon bond (double bond) in the fat molecule, according to the AHA. They are liquid at room temperature. Polyunsaturated fats are found mostly in plant food sources, such as soybeans and soybean oil, sunflower oil, sunflower seeds, walnuts and flaxseeds. Polyunsatured fats have been shown to impact blood cholesterol levels leading to a decreased risk of cardiovascular disease. They also help with cell development and maintenance and add vitamin E to your diet. Polyunsatured fats provide essential fatty acids, including omega-6 and omega-3.
Omega-3 fatty acids are a polyunsaturated fat that can come from plant-based sources such as algae and chia seeds.
Omega-6 fatty acids are also polyunsaturated fats commonly found in plant-based oils.
Omega 3 : ALA, EPA & DHA
There are three main kinds of omega-3s: eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and the plant-based alpha-linolenic acid (ALA). ... The problem for vegans is that seeds and nuts only contain ALA, while the health benefits of omega-3 fatty acids have been almost entirely linked to EPA and DHA.The two main omega-3s we hear most about are the long-chain fatty acids EPA and DHA. There is a long standing scientific debate about the best source of DHA & EPA, Many scientists stating that These fats are found only in oily fish and seafood, with small amounts of DHA found in algae. However many scientists state that the fist actually get their source of omega 3 from algae and do not manufacture it themselves. Therefore we can also get enough from algae. There is also evidence that as vegans we convert ALA into DHA & EPA.
A tremendous body of research has been conducted on these important nutrients since it was first discovered in the 1950s that fish oil offered many health benefits and that these benefits were attributable to a type of polyunsaturated fat called omega-3. Despite the volumes of research on omega-3s, it is only in recent years (within the last 15 years or so) that the actions of EPA and DHA have come to be understood individually. Researchers now often investigate the actions of EPA and DHA individually rather than together, no longer simply under the generic label omega-3 as they are widely referred to.
We are now fortunate to understand how these fats work in combination and in isolation, how they are digested, absorbed and utilised in the body, so we are able to tailor different blends of EPA and DHA according to the health benefits we are seeking to achieve. At Igennus, we have long specialised in the role of the omega-3 fatty acid EPA in clinical nutrition, as a powerful tool in the patient’s ‘toolkit’ for helping to regulate inflammation by restoring several biological markers, known as the omega-6 to omega-3 ratio and AA to EPA ratio. Before we discuss the therapeutic role of EPA in nutritional medicine, here’s a very brief summary of the role of both EPA and DHA in health throughout life.
Our requirements for EPA and DHA change throughout life and so does the optimal amount of each fatty acid in our diet.
Children require DHA for growth and development, and the brain, CNS and retina rely heavily on the adequate supply of DHA during growth in the womb. Thus women should emphasise DHA in their diets when they become pregnant and continue to take this until they cease breastfeeding. Children continue to need DHA up until the age they start school, so if children under the age of five are taking an omega-3 supplement, it should contain DHA. The exception is for children with developmental problems – where pure EPA or high EPA omega-3 has been shown to be most effective for supporting cognitive function.
EPA levels are under constant demand and low EPA levels in adolescents and adults correlates strongly with development of mental health issues, including depression, dyslexia and dyspraxia, heart problems, joint and bone conditions, as well as neurodegenerative diseases such as MS and Parkinson’s.
After the age of five, the development of the brain and CNS starts to reduce and the body’s need for DHA reduces. This is a good time to increase EPA in the diet, as studies show that EPA can help with childhood behaviour and academic performance, as well as focus, attention and reducing aggression. Dry skin conditions, asthma and allergies are also common in children and good levels of EPA at this time can help reduce the inflammation associated with these issues.
Between the ages of five and 65, the majority of the body’s needs can be met by using EPA-rich oils and eating fish, marine products, organic greens and pastured animal products. EPA levels are under constant demand and low EPA levels in adolescents and adults correlates strongly with development of mental health issues, including depression, dyslexia and dyspraxia, heart problems, joint and bone conditions, as well as neurodegenerative diseases such as MS and Parkinson’s. EPA also protects our genes and cell cycle, as well as helping to keep our stress response regulated, so an adequate supply of EPA throughout adult life can help prevent a range of chronic illness.
In later life, cognitive function and brain deterioration may become a concern. Once again, maintaining high levels of EPA has been shown to lower the risk of developing and worsening cognitive decline and dementia. If, however, you know someone who already has a diagnosis of dementia or Alzheimer’s, their brain has already been damaged and needs structural support. At this point, DHA becomes important again and taking a high-EPA product that contains 250mg of DHA also is important to prevent further loss of brain tissue.
RDA of ALA for conversion without supplementation of DHA & EPA: Female 1.1g per day. Male 1.6g. Vegan Female 2.2g per day & Vegan Male 3.2g per day. Otherwise take algae supplements or include chia seeds in daily diet. You can test your omega 3 blood levels by taking the Omega - 3 Index Blood Test.
Women are more efficient at converting ALA into EPA and DHA because estrogens support the conversion enzymes. Human conversion of ALA into EPA ranges from 8% to 20%. Conversion of ALA to DHA ranges from 1% to 9%. For Example: One tablespoon of flaxseed oil per 100 pounds of bodyweight is the recommended daily dose of ALA in order to convert to RDA of EPA & DHA.
A Great Vegan Source: Is From a company called Norsan. The oil is derivated from the micro algae Schizochytrium sp. with a high level of omega-3 (EPA and DHA).
NORSAN Omega-3 Vegan (100 ml) consist of a pure omega-3 rich algae oil and a biological cold-pressed olive oil as an antioxidant. The recommended daily dose of one teaspoon (5ml) gives 2,000 mg omega-3 fatty acids, rich in both EPA and DHA. The preferred liquid form and the excellent taste allow the oil easy to be used in daily food plan, for example as dressing for salad or as ingredient in the smoothie. Most consumes, however, take the oil “pure” before or together with the breakfast. The recommended daily dose of one teaspoon (5ml) contains 2,000 mg (2g) omega-3.( Dha & Epa)
Omega-6 (n-6) polyunsaturated fatty acids (PUFA) (e.g., arachidonic acid (AA)) and omega-3 (n-3) PUFA (e.g., eicosapentaenoic acid (EPA)) are precursors to potent lipid mediator signalling molecules, termed “eicosanoids,” which have important roles in the regulation of inflammation. In general, eicosanoids derived from n-6 PUFA are proinflammatory while eicosanoids derived from n-3 PUFA are anti-inflammatory. Dietary changes over the past few decades in the intake of n-6 and n-3 PUFA show striking increases in the (n-6) to (n-3) ratio (~15 : 1), which are associated with greater metabolism of the n-6 PUFA compared with n-3 PUFA. Coinciding with this increase in the ratio of (n-6) : (n-3) PUFA are increases in chronic inflammatory diseases such as nonalcoholic fatty liver disease (NAFLD), cardiovascular disease, obesity, inflammatory bowel disease (IBD), rheumatoid arthritis, and Alzheimer’s disease (AD). By increasing the ratio of (n-3) : (n-6) PUFA in the Western diet, reductions may be achieved in the incidence of these chronic inflammatory diseases.
What are fat molecules?
The terms “oil”, “fat”, and “lipid” are often used interchangeably. Technically, a fat molecule is sub-category of lipids called a triglyceride, i.e. three chains of fatty acids attached to glycerol backbone: Fatty acid chains come in all kinds of shapes and sizes. In the image above, we’re looking from top to bottom at a saturated, monounsaturated, and polyunsaturated fatty acid chain, respectively. Fatty acid chains come in all kinds of shapes and sizes. In the image above, we’re looking from top to bottom at a saturated, monounsaturated, and polyunsaturated fatty acid chain, respectively.
Saturated means all the carbons in the chain have maximized the number of hydrogen atoms that can be bonded to it. These types of fats tend to be solid at room temperature because they can pack together tightly.
Unsaturated means that one (monounsaturated) or many (polyunsaturated) double bonds exist along the chain, which makes the chain “branch” in different directions and not pack as tightly together. These types of fats tend to be liquids at room temperature, which are commonly called oils.
In most naturally occurring unsaturated chains, the configuration of the chains at either side of the double bonds is in the cis form (i.e. same side), but some processed fats can also contain trans configurations, where the chain extends on the opposite side of the bond.
Why and how are trans-fats manufactured?
Trans-fats are relatively cheap to make and help give food a desirable shelf-life, texture, and taste. Fast food restaurants will commonly use trans-fats in their friers, for example, since trans-fats remain reasonably stable after multiple uses. The most common food ingredient that contains trans-fats is partially hydrogenated vegetable oil, which can be soybean, corn, safflower, canola, cottonseed, and/or peanut oil infused with hydrogen to saturate some, but not all, of the double bonds along the chain. This process will produce trans-fats in a 2:1 ratio to cis-fats because of the favorable energy state of a trans-fat.
Medium-chain triglycerides (MCTs)
Mct oil is often derived from coconut oil and consists of fatty acid chains that have between 6 and 12 carbons and short-chain fatty acids (5 or less carbons) and And long-chain fatty acids (LCFA), where those with more than 21 carbons are called very long chain fatty acids (VLCFA).
How are fats digested after we consume them?
Now that we’ve looked at all the varieties of fats that exist (i.e. from chain length, bond conformations, and hydrogen saturation levels), let’s address what makes them “healthy” or not. To start, it’s important to note that fats we consume are mixed with bile sales, cholesterol, and lecithin to form emulsified fat droplets that are “cut” with lipase enzymes and packed into “mixed micelles”, These mixed micelles then passively diffuse into cells lining the intestinal wall. From here, long-chain fatty acids, cholesterol, and fat-soluble vitamins are processed into chylomicrons that enter the lymphatic system (i.e. not the blood quite yet). Importantly, short- and medium-chain fatty acids skip the chylomicrons and enter the portal vein directly to be metabolized quickly for energy by the liver, where as the chylomicrons enter lacteal lymph vessels around the intestines, collect from lacteal vessels into the thoracic duct, and are eventually emptied into the blood stream via the subclavian vein.
What happens to the chylomicrons once they are dumped into the bloodstream?
The “nascent” chylomicrons that first enter the blood stream quickly mature into full chylomicrons and then circulate around the body to deliver triglycerides to cells around the body (notably fat and muscle cells). They then get processed by the liver once most of the triglycerides are gone. Interestingly, because unsaturated fats can’t be packaged as tightly as saturated fats, unsaturated fats tend to be more easily moved into cells and burned for energy.
How are cholesterol, HDL, and LDL involved?
As we discussed above, cholesterol is adsorbed along with vitamins and fatty acids into the cells lining the intestines and transported in chylomicrons around the lymph and blood. Since blood is water-based and fats aren’t soluble in water, spherical lipoproteins (such as chylomicrons) are needed to transport many lipids (such as cholesterol and triglycerides) around the body. Importantly, the size and density of the lipoproteins vary. The various states commonly found in our bodies have been given names (HDL stands for “high-density lipoprotein”, and LDL = “low-density lipoprotein”, IDL = “intermediate density lipoprotein”, VLDL = “very-low density lipoprotein”):
As you might expect, these lipoproteins have different functions in our bodies. In general HDL is used to “scavenge” lipids (notably cholesterol) from tissues back to the liver, and VLDL/IDL/LDL/ send lipids from the liver to other tissues.
And finally on the topic of lipoproteins, to make matters even more complicated there are a variety of sub-types: Many of which are divided into even further subclasses.