The Skinny on Fats Part I
Animal fats or vegetable fats? Saturated fats, unsaturated fats, polyunsaturated fats… hydrogenated fats…trans fats…essential fatty acids…omega 3, 6, 9 fats…but, what about the fat on my thighs???
Are you confused? It’s no wonder. We are often given snippets of information on dietary fats and only within the context of another subject. There is no doubt that dietary fats have an effect on our health, but which fats and what exactly is the effect? In this and subsequent articles, I will attempt to impart a more complete understanding of dietary fats; what they are, where they are found, and how they effect the body. With this information it is my intention that you, the consumer of the American food industry, will make more informed decisions, be less persuaded by marketing hype, and thereby be able to take greater control of your health.
Fats are a class of organic substances that do not dissolve in water. Chemically, they are made up of fatty acid molecules and are classified by the amount of hydrogen atoms the particular molecule contains. Saturated fatty acids have as many hydrogen atoms on the molecule as they can hold. Monounsaturated fatty acids have one less hydrogen atom. Polyunsaturated fatty acids have two or more “missing†hydrogen atoms. All fats and oils are a combination of saturated, monounsaturated and polyunsaturated fatty acids. This translates into thickness of the fat or oil. The thicker the fat/oil, the greater the percent of saturated fatty acids it contains. Also, the thicker it is, the more easily it becomes solid at lower temperatures and the more stable it is at higher temperatures. The more stable it is, the less easily it goes rancid. Animal fats and tropical oils are made up mostly of saturated fatty acids. They are solid at room temperature and do not go rancid even when heated for cooking.
The body also makes saturated fatty acids from carbohydrates. Monounsaturated fatty acids are found in olive oil, avocados and nut oils. These tend to be liquid at room temperature and do not go rancid easily and so can be used in cooking. The body can make monounsaturated fatty acids from saturated fatty acids. Polyunsaturated fatty acids are found mostly in vegetable oils from the northern climates. These remain liquid even when refrigerated. They are highly reactive and so will go rancid easily. They should never be used in cooking. The most common polyunsaturated fatty acids found in our foods are linoleic acid, also called omega-6, and linolenic acid, also called omega-3. Our bodies cannot make omega-3 or omega-6 fatty acids, so these are considered “essential fatty acidsâ€, or EFAs, and must be obtained from the diet.
Fatty acids are not only classified by their degree of saturation, but also by the length of their molecular chain. Short-chain fatty acids have four to six carbon atoms and are always found in saturated fats, mostly butterfat from cows or goats. These fats contribute to the health of the immune system by protecting the body from viruses, yeasts and bacteria in the gut. They do not need to be digested and are directly absorbed for quick energy. This is why they are less likely to cause weight gain than olive oil or vegetable oils. Medium-chain fatty acids have eight to twelve carbon atoms and are found in butterfat and tropical oils. They carry the same immune-enhancing properties as the short-chain fats and are also directly absorbed for quick energy. Long-chain fatty acids have 14 to 18 carbon atoms and are found in saturated, monounsaturated or polyunsaturated form.
The two EFAs, omega-3 and omega-6, are long-chain. Another long-chain fatty acid is gamma-linolenic acid, also known as GLA. It is found in evening primrose oil, black currant seed oil and borage oil. A healthy body can make GLA out of omega-6 linoleic acid. GLA is used in the production of prostaglandins, which are localized tissue hormones that regulate many cellular processes. Very-long-chain fatty acids have 20 to 24 carbon atoms and are always highly polyunsaturated. Some people can make these from EFAs, but some people genetically lack the enzymes to do so, especially those whose ancestors ate a lot of fish. These people must obtain their very-long-chain fatty acids from organ meats, egg yolks, butter and fish oils. There are some extremely important oils in this category with 20 and 22 carbon atoms. They are DGLA, AA, EPA and DHA. They are all used in the production of prostaglandins. Additionally, AA and DHA play important roles in the development and healthy function of the nervous system.
With this basic information on what fats are, the next article will further define fats and address the affects the different fats have on the body.
- Dr. Janice Piro
Are you confused? It’s no wonder. We are often given snippets of information on dietary fats and only within the context of another subject. There is no doubt that dietary fats have an effect on our health, but which fats and what exactly is the effect? In this and subsequent articles, I will attempt to impart a more complete understanding of dietary fats; what they are, where they are found, and how they effect the body. With this information it is my intention that you, the consumer of the American food industry, will make more informed decisions, be less persuaded by marketing hype, and thereby be able to take greater control of your health.
Fats are a class of organic substances that do not dissolve in water. Chemically, they are made up of fatty acid molecules and are classified by the amount of hydrogen atoms the particular molecule contains. Saturated fatty acids have as many hydrogen atoms on the molecule as they can hold. Monounsaturated fatty acids have one less hydrogen atom. Polyunsaturated fatty acids have two or more “missing†hydrogen atoms. All fats and oils are a combination of saturated, monounsaturated and polyunsaturated fatty acids. This translates into thickness of the fat or oil. The thicker the fat/oil, the greater the percent of saturated fatty acids it contains. Also, the thicker it is, the more easily it becomes solid at lower temperatures and the more stable it is at higher temperatures. The more stable it is, the less easily it goes rancid. Animal fats and tropical oils are made up mostly of saturated fatty acids. They are solid at room temperature and do not go rancid even when heated for cooking.
The body also makes saturated fatty acids from carbohydrates. Monounsaturated fatty acids are found in olive oil, avocados and nut oils. These tend to be liquid at room temperature and do not go rancid easily and so can be used in cooking. The body can make monounsaturated fatty acids from saturated fatty acids. Polyunsaturated fatty acids are found mostly in vegetable oils from the northern climates. These remain liquid even when refrigerated. They are highly reactive and so will go rancid easily. They should never be used in cooking. The most common polyunsaturated fatty acids found in our foods are linoleic acid, also called omega-6, and linolenic acid, also called omega-3. Our bodies cannot make omega-3 or omega-6 fatty acids, so these are considered “essential fatty acidsâ€, or EFAs, and must be obtained from the diet.
Fatty acids are not only classified by their degree of saturation, but also by the length of their molecular chain. Short-chain fatty acids have four to six carbon atoms and are always found in saturated fats, mostly butterfat from cows or goats. These fats contribute to the health of the immune system by protecting the body from viruses, yeasts and bacteria in the gut. They do not need to be digested and are directly absorbed for quick energy. This is why they are less likely to cause weight gain than olive oil or vegetable oils. Medium-chain fatty acids have eight to twelve carbon atoms and are found in butterfat and tropical oils. They carry the same immune-enhancing properties as the short-chain fats and are also directly absorbed for quick energy. Long-chain fatty acids have 14 to 18 carbon atoms and are found in saturated, monounsaturated or polyunsaturated form.
The two EFAs, omega-3 and omega-6, are long-chain. Another long-chain fatty acid is gamma-linolenic acid, also known as GLA. It is found in evening primrose oil, black currant seed oil and borage oil. A healthy body can make GLA out of omega-6 linoleic acid. GLA is used in the production of prostaglandins, which are localized tissue hormones that regulate many cellular processes. Very-long-chain fatty acids have 20 to 24 carbon atoms and are always highly polyunsaturated. Some people can make these from EFAs, but some people genetically lack the enzymes to do so, especially those whose ancestors ate a lot of fish. These people must obtain their very-long-chain fatty acids from organ meats, egg yolks, butter and fish oils. There are some extremely important oils in this category with 20 and 22 carbon atoms. They are DGLA, AA, EPA and DHA. They are all used in the production of prostaglandins. Additionally, AA and DHA play important roles in the development and healthy function of the nervous system.
With this basic information on what fats are, the next article will further define fats and address the affects the different fats have on the body.
- Dr. Janice Piro