MILK 'N HONEY HEALTH FOODS

NUTRITION 101: LESSON THREE

 

 FATS:

        As covered in lesson one, the three macronutrients of protein, carbohydrate and fat are the source of calories for the body’s production of energy.  Protein and carbohydrate have four calories per gram of potential energy.  Fat (also referred to as lipids) has nine calories per gram of potential energy.  The reason fat has more potential energy per gram is because it is more slowly oxidized than protein and carbohydrate.  Oxidation is a process where oxygen combines with the molecules of nutrients to produce bi-products that lead to the production of energy.  Protein and carbohydrate oxidize almost twice as fast as fat   Fat, on the other hand, produces oxidative bi-products at a slower pace and thus provides more total energy per gram.

       Since fats oxidize slower, they require more total oxygen per gram than protein and carbohydrate in order to break down into energy producing bi- products.  Lack of adequate oxygen being present during the oxidation (breakdown) of fats, results in inferior bi-products such as ketones which make the body more acid.  An acidic body is more susceptible to disease.  When the body becomes acidic, enzymes that control the body’s rate of metabolism become denatured which results in poor energy production.

        Just as proteins are made from smaller units called amino acids and carbohydrates are made from units called saccharides, fats are made from units of fatty acids which are chains of carbon atoms placed next to one another with hydrogen atoms connected to them.  At the beginning of the chain the first carbon atom has three connected hydrogen atoms.  At the end of the chain is what is called a carboxyl acid group. Thus fatty acids are a combination of fat and acid from where they get their name.  There are two kinds of fatty acids, saturated and unsaturated. 

 Types of fat:

        A saturated fatty acid is one that has all its carbon atoms arranged in a straight line one next to another with each carbon atom having one hydrogen atom above it and one hydrogen atom below it.  The carbon chain of saturated fatty acids can be anywhere from 4 to 24 carbon atoms long.  The longer the carbon chain the higher its melting point.  Triglycerides are an example of a fat largely made up of saturated fatty acids.  This fat is a chemical combination of three fatty acids held together by a liquid alcohol called glycerol.  Triglycerides are the major form of dietary and body fat.   

        An unsaturated fatty acid is a chain of carbon atoms where hydrogen atoms are not found above and below every carbon atom.  Where this is the case, the carbon atoms bound to each other without an accompanying complete set of hydrogen atoms is called a double bond. Such chains of carbon atoms are called unsaturated because they contain less than the two hydrogen atoms per carbon atom as found in saturated fat and therefore the carbons are said to not be fully saturated with hydrogen atoms.  

        Unsaturated fatty acids are further broken down into monounsaturated and polyunsaturated fatty acids.  A monounsaturated fatty acid is where there is but one double bond in the carbon chain.  Fats having monounsaturated fatty acids will tend to be liquid at room temperature but become solid as the temperature gets colder. Olive oil is an example of this type of fat.  Polyunsaturated fatty acids have two or more double bonds and fats with a lot of these fatty acids will remain liquid even at cold temperatures. Safflower oil is an example of this kind of fat.

 Essential fatty acids:

        There are two polyunsaturated fatty acids which are especially important to our health.  One is called linoleic (omega 6) and the other is linolenic (omega 3).  These fats are called essential fatty acids (EFA’s) and must be obtained from the diet, as your body does not make them.  When ingested, the EFA’s go through a number of conversions which lead to the production of what are called prostaglandins.  These prostaglandins are hormone like substances that play a role in much of what goes on in the body.

        At levels above 12 to 15% of total calories, EFA’s increase the rate of metabolic reactions and thus facilitate more rapid burning of fat.  EFA’s are very involved in the energy making process and must be present in order for oxygen to transfer from the lungs to the blood plasma.  EFA’s actually hold oxygen in cell membranes and thus create a barrier to viruses and bacteria which cannot live in the presence of oxygen.  These acids form a structural part of all cell membranes and play a role in the recovery from muscle fatigue.  Essential fatty acids lead to reduction in inflammation, play a role in the regulation of cholesterol and blood sugar, immune response, calcium metabolism, nerve function and the list goes on and on.

       A lack of these acids in the diet can lead to multiple health problems. These problems include dermatitis, eczema, reproductive inefficiency, menstrual irregularities, atrophy of the adrenal and thyroid glands, elevated cholesterol levels, arthritis, low energy, and neurological problems, to name just a few.

       The American diet is very high in omega 6 fatty acids because of our consumption of products containing oils high in these acids.  Sources of omega 6 are the common vegetable oils extracted from corn, sunflower and safflower. An additional source of omega 6 is found in the meat we eat from animals raised on grain rather than green vegetation.  While high in omega 6, the American diet is low in omega 3.  Typically, Americans have body tissue ratios of from 10:1 to 20:1 omega 6 over omega 3.  Such imbalances lead to a variety of health problems including excessive inflammation, hypertension and cancer. 

       The goal should be to get more of the omega 3 fatty acids into the diet and less of the omega 6.  A good source of omega 3 linolenic acid is flax seed oil.  Flax oil has a ratio of omega 3 to omega 6 of 4:1.  Therefore flax oil provides the much needed omega 3 without adding much additional omega 6.

        In the body, omega 3 EFA linolenic acid converts to the fatty acids EPA (eicosapentaenoate acid) and DHA (docosahexaenoic acid).  These converted fatty acids are important to all aspects of our health.  As we get older or become diabetic, our bodies do not efficiently convert linolenic acid to EPA and DHA.  Fortunately, you can obtain EPA and DHA direct from the diet by eating fish such as salmon, sardines, cod and herring. 

 Fatty acid configuration:

        The double bonds in unaltered unsaturated fatty acids are in a natural cis configuration where the hydrogen atoms are on the same side of the double bond.  Another pattern called the trans configuration is where hydrogen atoms are on the opposite sides of the double bound.  Trans-fats are not handled by the body as well as cis fats and tend to interfere with the action of cis fats.  Trans-fats are created by heating unsaturated oils and/or allowing them to rancidify by exposure to oxygen.  The more unsaturated an oil is, the greater at risk it is for the creation of trans-fats when exposed to heat.

       Many cooking oils are made from highly unsaturated oils and are exposed to high heat in the refining processing. This causes them to have trans-fats.  Additional trans-fats are created when cooking with such oils.   Hydrogenation is a process where unsaturated fatty acids are made more saturated. This process also creates trans-fats.  Spreads, such as margarine, are an example of hydrogenated oils. It’s best to buy cold pressed, unrefined oils and use them raw, like in salads dressings, and sparingly in cooking.  Olive oil is excellent for cooking as it is more stable due to having monounsaturated fatty acids which don’t break down as easily when heated.   Butter and coconut oil, being more of a saturated fat, are even more stable and won’t create trans-fats even at high temperatures.

 Digestion of fats:

        Dietary fats pass into the upper part of the small intestine called the duodenum.  These fats are first emulsified by bile released from the gall bladder.  They are further broken down in the small intestine by the enzyme lipase secreted from the pancreas. They are then taken up into the lymphatic system, pick up protein molecules, and are transported to the liver as high density lipoprotein (HDL).  The liver converts HDL to low density lipoprotein (LDL) and LDL’s are transported via the blood to various areas of the body.   Bile, which is made in the liver and stored in the gall bladder, is composed of cholesterol and its bi-products lecithin and bile salts.  If the stool tends to be very light in color it could indicate an insufficient flow of bile.  Insufficient bile will result in pure digestion of fats and can lead to deficiency in the absorption of essential fatty acids.  The amino acid taurine has been found to be helpful in increasing bile flow.  Getting plenty of fiber in the diet is also very important to maintaining good flow of bile.     

Phosphatides:

       Phosphatides are the major structural lipids of all organisms.  Unlike other fats which are only soluble in fat, phosphatides are soluble in both fat and water.  They have the ability to spread out in thin layers and are a chief component of body membranes.  Lecithin is the most well known of the phosphatides and is an important emulsifying agent in the body.

 Cholesterol:

       The best known fat is cholesterol which has the very important function of keeping the membranes of our cells functioning properly.  This function is so important that every cell in your body has the ability to synthesize cholesterol.  The liver, intestines, adrenal glands and sex glands also make cholesterol as necessary. All steroid hormones are made from cholesterol.  Vitamin D is, in part, synthesized from cholesterol. 

        The dark side of cholesterol is that the so-called bad LDL and VLDL (low and very low density lipo protein) cholesterol can oxidize and create free radical activity causing damage to the walls of the arterial system.  One way to guard against such oxidation is to insure that you are consuming a large variety of anti-oxidant nutrients on a daily basis.  HDL (high density lipo protein), the so-called good cholesterol helps to remove LDL cholesterol by collecting it and returning it to the liver. Aerobic and resistive exercise is the best way to raise HDL levels.

        You can lower LDL cholesterol levels in the body by moving bile through the colon and out the stool.  Bile is basically a cholesterol waste product and failure to remove it can result in excess cholesterol circulating in the arterial system, which may end up as deposits in the arteries. Consuming thirty to forty grams of water soluble fiber per day will insure the elimination of cholesterol waste.  Oat bran, rice bran, apple pectin, flax fiber and psyllium are all examples of fibers that will facilitate this process.

     Lesson Four: Vitamins