What are strengthening physical exercises?(Part 4)

Muscle groups and their corresponding functions

Upper body[1,2]

When you mention upper body, you are referring mainly to the arms. Thus, the muscles in this region will be discussed, and the most important ones are: (1) biceps brachii, (2) triceps, (3) brachioradialis, (4) extensor carpi radialis longus, and (5) deltoid muscle. The biceps is very much attached to the humerus, which is the bone of the upper arm. With that position, it rotates the forearm and flexes the forearm at the elbow. The triceps, on the other hand, is located at the back of the upper arm, and it assists in straightening the whole arm. The brachioradialis covers parts of the upper and lower arms, and it is mainly responsible for flexing the forearm at the elbow. In addition, it helps in the rotation of the forearm both outwardly and inwardly[1].

The extensor carpi radialis longus is located near the brachioradialis, and it is one of the five major muscles responsible for moving the hand at the wrist in different directions. When you clench your fist, this muscle becomes visible as it rises below your skin. The deltoid is the main muscle at your shoulder, and it controls all movements arising from the shoulder joint[1].

Strengthening exercises for the muscles in the upper body using body weight

Push-ups [2]                               

Lie flat with your face against the floor. With the use of your arms, raise your body from the floor until your arms are fully extended. When your arms are fully extended, ensure that your hands are parallel,while your arms are perpendicular, to the floor. From an elevated position, go down to your starting point. Complete two or three sets of five, having breaks in between sets to perform other physical exercises. Gradually, increase your daily goal to sets of 20 or so with the right form [2].

Reverse push-ups [2]

Stand with your back facing a table or chair. Place your hands on the table or chair with your extended legs moved forward in front of you. Slowly lower your body towards the table or chair and with your legs slightly flexed at the knees and your heels serving as your fulcrum. After lowering your body as far as you can, you can return to your starting position. Do 10 to 20 times. To increase the difficulty of this exercise, you can select another support which is lower than a chair or table. A good suggestion is a bench. Before starting this exercise, however, ensure that your support is in good condition and stable so that you will not be injured. This specific exercise is intended for the triceps which are located at the back of the upper arms [2].

Quadriceps[1,2]

The quadriceps are group of four muscles located at the front of the thigh. These muscles are: (1) vastus lateralis, (2) vastus medialis, (3) vastus intermedius, and (4) rectus femoris. Each of the vastus muscles is attached to the femur, which is the primary bone of the upper leg, and is attached down under in the patella or the kneecap. The rectus femoris is also attached to the patella; however, in the higher portion, it is attached to the hip bone—and not to the femur[1].

As suggested by their location, the quadriceps are very important in extending the lower legs at the knees. In addition, these are used for walking, running, and other physical activities; hence, they are prone to injuries, such as strains, tears, and ruptures [1].

(To be continued)

References:

  1. http://www.healthline.com/human-body-maps/abdomen-muscles#seoBlock
  2. Glover B, Shepherd J, Glover SF. Strengthening. In: The Runner’s Handbook. 2nd revised ed. New York: Penguin Books USA Inc.; 1996:578-597.

What are strengthening physical exercises?(Part 3)

Muscle groups and their corresponding functions

Calf muscles [1,2]

When you are talking about the calf muscles, you are actually referring to: (1) the gastrocnemius, and (2) the soleus muscles. Both of them are located at the back of your lower legs, and play important role when you walk, run, jump, and stand at the balls of your feet. These two muscles are attached to your heel bone by the so-called Achilles tendon.When you overwork your Achilles tendon, you will have inflammation on it, and this is called tendinitis[1].

Strengthening exercises for the calf muscles using body weight

Toe raises[2]

Face the wall and place one hand against it to support you. Slowly raise your whole body on your toes then slowly return your heel to the floor. Perform two or three sets of 10 to 20 toe raises. In between, you can have a 1-minute rest. As your legs get stronger, you can hold additional weights in your hands or place barbell over your shoulders behind the neck to increase the resistance[2].

Hamstrings[1,2]

The hamstrings are muscles that occupy the back portion of your thigh. One of these is calledthe biceps femoris which is a two-headed muscle. One of its heads is attached to the ischiumwhich is the lower and back part of the hip bone and the other one is attached to the femur which is the main bone of your upper leg. The other hamstring muscles are the semitendinosus and the semimembranosus. Lumping the three muscles togetherinto one, their main actions are to flex the knee and extend the hip. In addition to these main functions, however, the biceps femoris is involved in the internal and external rotation of the legs [1].

Strengthening exercises for the hamstrings using body weight

Hamstring curls[2]

Stand in front of a table or any other object whose height is at the level of your thigh and which could serve as your support. Place your hands on the supporting table and bend backward your one leg at the knee, maintaining that your thigh is still aligned with your upper body. Slowly raise your foot towards your buttocks as far as you can and slowly return to the starting point. Finish two or three sets of 20 with each leg[2].

Back muscles[1,2]

The three muscles at the back are the following: (1) multifidus, (2)longissimus, and (3) spinalis.The multifidus muscle stabilizes and supports the spinal column. Thus, it provides stiffness to it[1].The longissimus muscles, on the other hand, flex the head and neck on the same side, and they extend the vertebral column [3]. Finally, the spinalis muscle extends and laterally bends the neck and the trunk [1].

Strengthening exercises for the back muscles using body weight

Back extensions[2]

Lie flat on yourfront abdomen with your hands under your shoulders as if you are about to do push-ups. Slowly raise your chest up using solely your back muscles and slightly assisted by your arms. As your chest goes up, exhale and pause at the top of the exercise. Go down slowly and inhale as you do it. Complete two or three sets of 10 [2].

Alternate extensions[2]

Lie flat on your front abdomen with your arms extended in front of you. Rest your forehead on a folded towel on the floor. Raise one of your arms simultaneously with the opposite leg. Maintain it for three seconds and then slowly lower it down to the starting position. Complete ten repetitions for each.

(To be continued)

References:

  1. http://www.healthline.com/human-body-maps/abdomen-muscles#seoBlock
  2. Glover B, Shepherd J, Glover SF. Strengthening. In: The Runner’s Handbook. 2nd revised ed. New York: Penguin Books USA Inc.; 1996:578-597.

https://en.wikipedia.org/wiki/Longissimus

What are strengthening physical exercises?(Part 2)

Muscle groups and their corresponding functions

Abdominals[1,2]

The external oblique muscles serve as the cover of the sides of the abdomen. In addition, it helps in the rotation of the trunk and the spine. Serving as further support to the abdominal wall, theinternal oblique muscles are located beneath the external oblique muscles; thus, they also serve as cover of the abdomen at its sides[2].

The internal oblique muscles help in forced respiration, and aid in raising the pressure inside the abdominal cavity. They also rotate and turn the trunk with assistance from other muscles. More importantly, they serve to counteract the actions of the diaphragm[2], resulting in coordinated fashion of regulating the volume of the chest cavity.

The transverse abdominis is the muscle in the side and front of the abdomen. It lies underneath the internal oblique muscles; therefore, it follows that it is the deepest muscle in the front and side of the abdomen. Its main function is to compress the ribs and the abdominal organs. In addition, it stabilizes the thorax and the pelvis. It plays a great role when a pregnant woman delivers her child[3], by pushing the child through and out in the pelvic canal.

Probably unknown to you, there is a back portion of the abdomen, and one of the most prominent muscles in this region is the latissimus dorsi. It is responsible for extending, adducting, and rotating the arms[2]—aside from covering the abdomen at the back.

Strengthening exercises for the abdominals using the body weight

Crunches (Modified sit-ups)[1]

Lie flat on the floor in a supine position, with knees bent and your hands placed over your chest. Slowly raise your head and your shoulders around six inches off the floor. Remain as it is for two seconds then return to the starting point.Exhale as you sit up and inhale as you come down. Do two to three sets of 10 to 20 crunches daily. These exercises are intended and good for your rectus abdominis[1].

Reverse sit-ups[1]

Lie flat on the floor in a supine position, with knees bent and your feet flat on the floor. Place your arms at your side and with the palms down.Keeping your knees still bent, bring your legs up followed by lifting your pelvis towards the chest. Exhale as you gradually lift your pelvis. You can do two to three sets of 10. This exercise is intended for the transverse abdominis muscle[1].

Pelvic tilt[1]

Lie flat on the floor in supine position, with your knees bent and your feet flat on the floor. Simultaneously tighten your butt muscles and your abdominals while raising your pelvis fromthe floor. While raising your pelvis, press your lower back towards the floor. Hold contracted muscles for three to ten seconds while exhaling. You can do this for three to five times[1].

Calf muscles [1]

The gastrocnemius muscle is found at the back portion of the lower leg, andit runs overits entire length. It is connected at the back of the knee and to the heel.When this muscle contracts, your lower leg is pulled towards the upper leg, causing bending at your knees. More importantly, this muscle plays an active role when you walk[2].

The other component of the calf muscles is the soleus. It is located at the back of the lower leg, in close proximity with thegastrocnemius. It is primarily used to push the ground when you walk. In addition, it is very important in dancing and running. To prevent you from falling forward, the soleus will contract to pull your feet against the ground, maintaining your upright posture[2].

(To be continued)

References:

  1. Glover B, Shepherd J, Glover SF. Strengthening. In: The Runner’s Handbook. 2nd revised ed. New York: Penguin Books USA Inc.; 1996:578-597.
  2. http://www.healthline.com/human-body-maps/abdomen-muscles#seoBlock
  3. https://en.wikipedia.org/wiki/Transverse_abdominal_muscle

What are strengthening physical exercises?(Part 1)

Definition

Strengthening physical exercises are movements that you need to do repeatedly in order to develop and improve the strength of a group of muscles. The groups of muscles are abdominals, ankles, arch, back, buttocks, calf muscles, hamstrings, hips/groin, quadriceps, shins, and upper body[1]. As to which group(s) of muscles you would like to develop depends on your purpose. If you would like to be a good runner, then the groups of muscles that you need to strengthen are the calves, hamstrings, and buttocks. If you would like to firm up your abdomen, then you strengthen your abdominals. If you would like to have firm and sturdy shoulders and chest, then strengthen your muscles in your upper body.

Means of doing strengthening exercises

Using body weight[1]

In this method of strengthening exercises, you do not use any gym equipment and gadgets. You use your own body to do them. Examples are modified sit-ups, reverse sit-ups, pelvic tilt, ankle push, towel sweep[1], and many more. This means that you can do these exercises at home, without even going to the gym.

Using free weights [1]

In contrast to the exercises using your body weight, you may need to report to the gym if you will use the free weights. Generally, there are two kinds of free weights that you can use: (1) handheld dumbbells, or (2) the weight plates on barbells[1]. The need for gym in these exercises is not solely due to the availability of these equipment; more importantly, there are personnel in the gym who could guide you on how to properly use these equipment.

Using machines[1]

Using body weight and free weights will not totally strengthen all of your muscles. In addition, you will use some machines which are intended to strengthen other sets of muscles. Examples of these machines are the biceps curl machine, triceps machine, pull-down machine[1], and many others. When you visit the gym for the first time, you can look around and familiarize yourself with these machines. Each machine has its own use and purpose. Use it (them) if it (they) is (are) what you need. Thus, before using any machine in the gym, consult any fitness adviser around so that you could be guided accordingly.

Muscle groups and their corresponding functions

Abdominals[1,2]

The abdominalsare muscles located in the front section of your abdomen. Their function is to provide you with postural support, protect your internal organs located in the abdomen and pelvic area, and to allow you to perform some movements, such as rotating the spine, bending, breathing, and defecating. The most prominent muscles are the rectus abdominis, external oblique muscles, internal oblique musclesand the latissimus dorsi.The rectus abdominis runs downward from the sternumdown to the pelvic bone, and the external oblique muscles are located at its sides, running downward in oblique direction—hence, the word external oblique. Beneath the external oblique muscles are the internal oblique muscles. Covering the back is the latissimus dorsi muscle[2].POWERTEC

Figure 1.0.Diagrammatic illustration showing the major muscles in the front abdomen.

The rectus abdominis is activated when you do crunches because it is responsible for pulling the rib and the pelvis toward each other. In addition, it curves the back. In terms of bodily functions, it is very important during the delivery of your child, for bowel movements, and for coughing. When you have a bulging belly, the accumulated fat is lying over your rectus abdominis. Thus, when you do periodic physical exercises for the abdominals, the fats will be burned, and you will see the exposed rectus abdominis as a six-pack muscle[2].

References:

  1. Glover B, Shepherd J, Glover SF. Strengthening. In: The Runner’s Handbook. 2nd revised ed. New York: Penguin Books USA Inc.; 1996:578-597.
  2. http://www.healthline.com/human-body-maps/abdomen-muscles#seoBlock

Symptoms that could prevent you from doing physical exercises(1)

The Symptoms

Back pain

If you have been experiencing back pain for the last few months, accompanied by some urinary disturbances, such as more frequent urination and low abdominal discomfort, it is possible that you have been suffering from urinary tract infection (UTI). You need to consult a medical doctor, and, more often than not, he will request you to have examination of the urine, otherwise known as urinalysis. If it turns out that you haveUTI, then you will be prescribed with the most appropriate antibiotic(s).

If your back pain, however, is acute—that is, it happened so suddenly—then you need to consider compression of your spinal nerves. This consideration is most probable if you have a history of trauma or injury at the back. However, even if there was no trauma, you need to factor in spinal nerve(s) injury, and you need to consult a medical doctor who is either a general practitioner, neurologist, or rehabilitation medical doctor. If you have spinal nerve(s) injury, and you insisted on having your physical exercises, it is possible that you will injure yourself all the more, and you will aggravate your medical problem. Hence, prior to totally ruling out the possibility of spinal nerve(s) injury, you need to refrain from having physical exercises.

If it is confirmed that you have spinal nerve(s) injury, resulting from compression, the basic management is for you to have bed rest for at least seven days. It could be longer, depending on the severity of your medical problem. In addition, you will have sessions under the rehabilitation medicine department, wherein traction and physical therapy will be administered to you. You will be asked to report for physical therapy for around ten sessions—each session lasting for at least one hour. You will be taught how to perform the different physical therapies, and you will continue doing them at home.

Joint pain

If you have been experiencingjoint pain—whether acute or chronic—you need to refrain from having physical exercises. You need to consult a medical doctor first to find out what is your problem, and you will be prescribed with the necessary medications. If the pain is gone, then you can resume your physical exercises. If you insist to do your physical exercises, in spite of your joint pain, then you will aggravate your problem, and it will be harder to treat it.

Sudden weakness of one or more extremities

Sudden weakness of one or more extremities is a symptom that cannot be taken for granted. It could be a symptom of stroke (bleeding in the brain), especially if you have a history of hypertension and you have been taking medications for it—and worse, if you have not been taking medications in spite of knowing that you have hypertension. Immediately, consult a medical doctor so that your medical problem could be diagnosed at once. Refrain from doing your physical exercises because, if you do, you might aggravate your medical condition. Much worse, you will die from it.

Getting tired so easily

If you have been well and good, then suddenly in the last few days you have been experiencing easy fatigability or getting tired so easily, it is possible that your blood pressure has risen. Refrain from doing your physical exercises. Instead, consult a medical doctor, and have your blood pressure checked. If your blood pressure is higher than normal, then your medical doctor will surely prescribe you with the right medications. Take them regularly and faithfully! Once your blood pressure is controlled, you can return to the gym, and resume your workouts.

                                 (To be continued)

 

General guidelines on how to lose weight(2)

Limitation of fats in the diet

Operationalization

TDCR vs. TDCI

In the previous article [Powertec (136)], it was mentioned that your basis of subtracting the 500 calories should be from thetotal daily caloric intake(TDCI); however, in most instances, the computation of TDCI is so demanding and difficult for people, like you, who are on the go to keep up with the demands of daily living. In fact, you might need the help of a nutritionist-dietitian to compute for it.Thus, instead of TDCI, it is thetotal daily caloric requirement(TDCR)which is used.

Assuming that you opted to lose 1 pound per week, then you need to reduce your TDCR by 500 calories per day or 3,500 calories per week. Since you are moderately active, your TDCR should be 157 pounds x 15 giving a product of 2,355 calories; and since you are 38 years old, you need to subtract 100 from 2,355 giving a difference of 2,255[1]. If you have normal weight, the total number of calories that you need to take per day in order to maintain your normal weight is 2,255 calories; this is your TDCR; but since you are overweight, you need to reduce your TDCR by 500 calories per day [consult Powertec (136)for all the necessary tables].

Limitation of fat intake

To fast track your weight reduction, you limit your fat intake to 10% of the TDCR; hence, 10% of 2,255 is 225.5 or 226 calories which is equivalent to 25 grams of fat per day, derived from dividing 226 by 9. You need to take only 25 grams of fat per day which means limiting your fat intake to 10% of the TDCR. This is the smallest amount of fatintake allowable to you; if you take less than 10%, you will suffer from some vitamin deficiencies, especially linked to the fat-soluble vitamins [1].

If you used to take 80 grams of fat per day, but now you are taking only 25 grams per day, then you are reducing your food intake by 495 calories per day derived from multiplying 55 (the difference of 80 – 25) grams of fatby 9 calories. If you multiply 495 by 7 days, then you are losing approximately 3,500 calories per week which could reduce your weight by 1 pound per week. This means that even if you will not reduce your protein and carbohydrate intake, the reduction in fat intake is enough to effect reduction in your weight.

In the preceding example, you limited your fat intake to 10%. If you want to use 20% or 30%, then it is also acceptable; however, you now need to reduce also your protein and carbohydrate intake, enough to give a total of 500 calories of daily reduction in your TDCR.

When you have reached your ideal weight, you now shiftto consumingyour total TDCR which is 2,255 calories. You need to take foods whose total caloric contribution will be 2,255. You do not need to reduce it; otherwise, you become underweight.

Ways of reducing fat intake

  1. Avoid deep-fried and fried foods;
  2. Take fatty meats, lard, butter, cheese, cream, whole milk, egg yolk, vegetable oils, nuts, chocolates, avocados, olives, and margarine [1] in moderate amounts;
  3. When buying packed foods, read the “Nutrition Facts” and find out the saturated fat It should contain less than 10% of saturated fat; and
  4. When buying packed foods, select those not containing trans-fatty acid and hydrogenated fats.

Reference:

  1. Roth, Ruth A. Nutrition and Diet Therapy. Singapore: Delmar Learning, 2007.

General guidelines on how to lose weight(1)

Limitation of fats in the diet

One of the ways of facilitating your weight reduction is to focus on the limitation of fat intake. This is very effective because one gram of fats could give you 9 calories of energy whereas protein and carbohydrates could only give you 4 calories per gram. Thus, if you limit your intake of fats, your losing calories—and subsequently your weight—would be faster than when you solely restrict your protein or carbohydrate intake.

Steps

Determine how many calories you need to maintain your ideal weight. You can look at your ideal body weight in the ensuing Table 1[1]USDA Acceptance Weights for Adults

*The higher weights in the ranges generally apply to men, who tend to have more muscle and bone than women; the lower weights more often apply to women [1].

To find your calorie needs, multiply your ideal weight by 15 if you are moderately active or by 20 if you are very active[1].

From that total, subtract the following according to your age:

                              Age 25-34, subtract 0

                             Age 35-44, subtract 100

                             Age 45-54, subtract 200

                             Age 55-64, subtract 300

                              Age 65+, subtract 400[1]

To find your fat-gram allowance, multiply your daily calories by the percentage of fat desired (10%, 20%, or 30%); then divide by 9 calories/g[1].

Operationalization

Suppose you are male, 38 years old, with height of 5’ 4”,  with present weight of 170 pounds, and moderately active. Firstly, you want to find out if you are overweight, underweight, or with normal weight. So you look at Table 1, and you find out that the maximum weight that you should have is 157 pounds. Offhand, you are overweight by 13 pounds. Therefore, the program that you will need is weight reduction.

Ideally, you need to lose 1-2 pounds per week; thus, if you prefer to lose 1 pound per week, then you will need 13 weeks or approximately three months to normalize your weight. If you want to accelerate your weight reduction, you can target to lose 2 pounds per week, and you need around 6-7 weeks or 1 ½ months.

Before proceeding with the discussion, you need to understand two technical terms: (1) total daily caloric intake (TDCI), and total daily caloric requirement (TDCR). TDCI refers to the actual number of calories that you take each day, while TDCR refers to the number of calories that you should take each day to maintain your ideal weight [Please consult Powertec (20)].

Since you are overweight, it is safe to assume that your TDCI has been very much higher than your TDCR. You have been taking more calories than what you need, or more than what you can burn. Thus, the excess calories are stored and deposited in your body making you heavier than your ideal weight. Therefore, in your weight reduction, the basis of subtracting the number of calories that you need to slice off each day should be from the TDCI.

 

Reference:

  1. Roth, Ruth A. Nutrition and Diet Therapy. Singapore: Delmar Learning, 2007.

Role of cholesterol in the development of cardiovascular diseases(Part 2)

Anatomy of the blood vessel wall

You have three types of blood vessels: (1) arteries, (2) veins, and (3) capillaries. Your arteries carry the blood from your heart and deliver them to different parts of your body. You veins collect the blood from the different parts of your body and return it to the heart. Your capillaries, on the other hand, connect your network of arteries to your network of veins.In the development of hypertension and heart diseases, the type of blood vessels that are primarily involved are the arteries.Therefore, the center of discussion in the next few sections will be on them.

Your arteries can be likened to your water pipes at home. They are tubes wherein fluid passes through. In your water pipes, water passes through them; in your blood vessels, blood will pass through them. Your arteries are relatively thick tubes, and they are made this way because they need to withstand the high pressure generated by your blood and the regularpumping of your heart.

Tunica adventitia

The wall of your arteries are made up of three layers: (1) tunica adventitia, (2) tunica media, and (3) tunica intima, also known as the endothelium.The tunica adventitia is the outermost layer, the tunica media is the middle layer, and the tunica intima is the innermost layer. The tunica adventitia is responsible for attaching your arteries to the surrounding tissues, thereby preventing them from moving astray. In addition, it provides some strength for your arteries. The tunica media is mainly responsible for providing the strength of your arteries to contain your varying blood pressure. Meanwhile, the tunica intima provides the internal lining of your arteries.

Important role of the tunica intimaor endothelium

Since the tunica intima or endothelium is the innermost lining of your arteries, it is in intimate contact with the flow of your blood. As your blood flows in your arteries, your endothelium offers a frictional resistance to such flow; therefore, the endothelium receives the brunt of the flowing blood. In the parlance of medicine, this is called the shearing effect of the flowing blood. When your blood pressure is very much increased compared to the normal values, this shearing effect also increases, and your endothelium will be injured. The higher the blood pressure is, the higher and more serious the injury to your endothelium will be. This injury will be the beginning of developing the so-called atherosclerosis wherein fatty substances are attached to the lining of the endothelium, giving rise to inelastic arteries which will, in turn, lead to the development of hypertension and heart diseases.

Injury to the endothelium and high level of LDL-cholesterol

In the development of atherosclerosis (deposition of fatty substances in the endothelium), it has been established that the first stage in the process is the infliction of injury to the endothelium.This injury to the endotheliumare caused by increased blood pressure and the increased level of LDL-cholesterol[1]. Hence, if you have elevated blood pressure and you have elevation of the LDL-cholesterol, your hypertension will get worse as days go by, if you do not take medicines to control your high blood pressure and the elevated level of LDL-cholesterol.

The LDL-cholesterol has dual effects in the causation and worsening of atherosclerosis. Firstly, it decreases the production of nitric oxide which is responsible for the dilation of the arteries[1]. Thus, in the absence of nitric oxide, you are prone to have elevated blood pressure because of constriction of your arteries.Secondly, with increased level of LDL-cholesterol in the blood, these fatty substances, together with platelets, could attach themselves in the injured sites in the endothelium. This will make the arteries inelastic and obstructed—be it partial or total—leading to the development of hypertension and heart diseases.

Reference:

Davigon J, Ganz, Peter. Atherosclerosis: evolving vascular biology and clinical implications, role of endothelial dysfunction in atherosclerosis. Circulation. 2004;109: III-27-III-32. doi:10.1161/01.CIR. 0000131515.03336.f8.

Role of cholesterol in the development of cardiovascular diseases(Part 1)

Nature of cholesterol

Cholesterol is a form of fatty substance needed by your body for the maintenance of cell membranes,and production of bile acid and hormones[1]. With insufficient cholesterol, your cells will be adversely affected because the integrity of the cell membrane which encloses all its structures will be impaired. In addition, the quality of your bile acid which is one of the components of your bile and the different hormones that you need every minute of your life will deteriorate.

Cholesterol can be sourced from: (1) the foods and drinks that you take, and (2)the different chemical reactions taking place in your body. Because it is produced in your body, it has been postulated that probably you do not need the cholesterol coming from your foods and drinks! Hence, the cholesterol being produced in your body is enough to meet your needs[1]! However, it is not possible to totally remove all the cholesterol that is in your foods! It is impossible! Thus, if you want to control your dietary intake of it, you need to be choosy with your foods, selecting only those which are not rich in it (Consult Powertec 144). Examples of foods rich in cholesterol are meats, liver and other organ meats, dairy foods, egg yolks, and shellfish[2].

Transfer and elimination of cholesterol

When cholesterol is absorbed in your gastrointestinal tract, it travels in the bloodstream in the form of lipoproteins. It cannot travel as cholesterol; it has to be in the form of lipoproteins. There are two lipoproteins that carry cholesterol: (1) the low density lipoprotein (LDL) and the (2) high density lipoprotein (HDL). The LDLcarry the majority of cholesterol, around 75 to 85%, while the HDL carry approximately 15 to 25%[1]. Thus, they are called either LDL-cholesterol or HDL-cholesterol.

Aside from having different densities, the LDL-cholesterol and the HDL-cholesterol have different behavior when they are in the bloodstream. The LDL-cholesterol tends to bring the cholesterol away from the liver; that is, it brings its passengers to the far-flung structures of the body, such as in the blood vessels and peripheral tissues. Consequently, the cholesterol molecules are deposited in these organs. Specifically, when the cholesterol molecules are deposited in the inner lining of your medium to large blood vessels, these structures become inelastic, leading to the development of hypertension. When they are deposited in the small blood vessels of your heart, you will have heart disease and possible heart attack[3]. Since the LDL-cholesterol contributes to the development of cardiovascular diseases, such as hypertension and heart diseases, it is also known as the bad cholesterol.

The HDL-cholesterol, on the other hand, carries cholesterol molecules from the peripheral organs, such as the muscles and blood vessels, and brings them back to the liver—otherwise known as the reverse cholesterol transport—where they are taken up and incorporated as part of the bile. In a way, these cholesterol molecules were removed from the bloodstream, without inflicting any damage to the blood vessels and other organs of your body. Since the HDL-cholesterolhelped to remove cholesterol in the blood, it is also referred to as the good cholesterol.

Injury to the inner lining of blood vessels and cholesterol deposition

The innermost layer of your blood vessels is called the endothelium, and lately this structure has been receiving a lot of research attention because it has been becoming more clear that it is very much involved in the causation of atherosclerosis (deposition of fatty substances in the blood vessels) andhypertension. It has been postulated that the deposition of fatty substances is preceded by the injury of the endothelium.

(To be continued)

References:

  1. Sacher, Ronald A. and Richard A. McPherson. Widmann’s Clinical Interpretation of Laboratory Tests. F. A. Davis Company, Philadelphia, 2000.
  2. http://www.nhlbi.nih.gov/news/spotlight/fact-sheet/questions-and-answers-cholesterol-and-health-nhlbi-nutritionist-janet-de-jesus-ms-rd
  3. http://www.nhlbi.nih.gov/health/resources/heart/heart-cholesterol-hbc-what-html

Relationship between the intake of saturated fats and the development of cardiovascular problems

Nature of saturated fats

Saturated fats (SFs) are also known as saturated fatty acids. They are found in meats, coconut, palm oil, palm kernel oil, butter, egg yolks, milk, and milk products (except fat-free) [1] {Consult Powertec 63}.SFs come in different names, and examples are formic, acetic, propionic, butyric, valeric, caproic, caprylic (octanoic), capric (decanoic), lauric, myristic, palmitic, stearic, arachidic, behenic, and lignoceric[2]. Thus, if a food product that you are buying contains one or more of these, then you know that it contains SFs, and the best way to find out the SFsincorporatedin any grocery product is to look at the “Nutrition Facts” wherein the different substances contained in it are listed, including the quantity in terms of percent.

Relationship of saturated fats with cardiovascular diseases

It has been established from researches that if your diet is high in SFs, the level of your low-density lipoprotein(LDL) cholesterol is also high[3]. You should remember that LDL cholesterol is also known as the bad cholesterol, because it carries cholesterol away from yourliver and deposited them to far-away structures, such as the blood vessels. When LDL cholesterol is deposited in the internal lining of the blood vessels, atherosclerosis takes place, and the blood vessels become inelastic, leading to the development of hypertension.

Neutralizing the adverse effects of saturated fats

Substitution of saturated with polyunsaturated fats

One of the ways of counteracting the adverse health effects of SFsis to replace them with the polyunsaturated fats(PFs). If PFs are taken in instead of SFs, the LDL cholesterol decreases, and the ratio of total cholesterol with the high density lipoprotein (HDL) cholesterol, which is known as the good cholesterol, decreases, too [3],           implying that either the total cholesterol decreases, or the HDL cholesterol increases, or both scenario happen. When the LDL cholesterol decreases and the HDL cholesterol increases, the combination is a perfect recipe for the prevention of heart and blood vessel diseases.

PFs are abundantly found in safflower oil, soybean oil, sunflower oil, soybeans, tofu, and fish[1]{Consult Powertec 63}. In simpler terms, what you will do is to replace meat with fish, and replace animal-based cooking oil with the ones taken and derived from plants.

 

Avoidance of replacing saturated fats with carbohydrates

When carbohydrates are used to replace SFs, it was found out that the level of both the triglycerides (another form of fat) andLDL cholesterol are elevated in the blood while the HDL cholesterol decreases. These consequences are all the more pronounced if the carbohydratesare refined and added with sugar[3]. This is bad for the heart and the blood vessels. Thus, it should be avoided.

Dietary cholesterol should be avoided if significant saturated fats have been in the diet

Based on animal researches, it was determined that if the dietary cholesterol has been increased,   the tendency of saturated fat to increase the LDL cholesterol level in the blood is also increased. This means that working alone, saturated fats increase the LDL cholesterol level in the blood. If the intake of dietary cholesterol is increased, it will aggravate the LDL cholesterol-raising effect of saturated fats. Therefore, as much as possible, the simultaneous intake of significant amount of dietary cholesterol and saturated fats should be avoided [3].

Foods rich in cholesterol are the following: eggs, roast beef, leg lamb (lean), leg lamb (lean and fat), pork chop (lean), chicken leg (fried, meat and skin), crabmeat (canned), salmon (canned), shrimp (canned) [1]. You need to avoid taking these foods if you have been taking a lot of saturated fats.

References:

  1. Roth, Ruth A. Nutrition and Diet Therapy. Singapore: Delmar Learning, 2007.
  2. Murray, Robert K., Daryl K. Granner, Peter A. Mayes, and Victor W. Rodwell. Harper’s Biochemistry. Appleton and Lange: Stamford, Connecticut, 2000.

Siri-Tarino, P., et. al. (2010). Saturated fatty acids and risk of coronary heart disease: modulation by replacement nutrients. http://www.ncibi.nlm.nih.gov/pmc/articles/pmc2943062/