Главная > Реферат >Остальные работы
Osteoprosis Essay, Research Paper
The topic I have chosen is Osteoporosis and how it is related to a deficiency of calcium. Throughout my human nutrition course the importance for proper nutrition and adequate dietary supplements has been constantly emphasized.
Nutrition is the science that deals with food and how the body utilizes it. All living things need food to live. Food supplies energy, which people need to perform certain actions and bodily functions. Food also provides substances that the body needs to build and repair its tissues and to regulate its organs and organ systems. (Sizer&Whitney)
Food provides certain chemical substances needed in order for a person to maintain good health. These chemical substances are called nutrients. Nutrients can perform three important functions. They provide materials for building, repairing, or maintaining body tissues. They help regulate body processes. They serve as fuel to provide energy. The body needs energy to maintain all its functions.
The foods we eat contain thousands of different chemicals. Our body, however, only needs only a few dozen of these chemicals in order to stay healthy. These are the nutrients that the body needs. Nutrients are divided into six main groups, they are (1) water, (2) carbohydrates, (3) fats, (4) proteins, (5) minerals, (6) vitamins. Water, carbohydrates, fats, and proteins are called macronutrients. Since macro means large, the body needs these four nutrients in large amounts. Minerals and vitamins are called micro nutrients (micro means small). The body needs only small amounts of these nutrients.
Water is the most important nutrient. The body needs water to carry out all of its life processes. Watery solutions help dissolve other nutrients and carry them to all of the tissues. The body also needs water to carry away waste products and to cool itself. Adults should drink about 2 1/2 quarts of water every day. (Encarta)
The carbohydrates, fats, and proteins are needed because they have nutrients, which provide energy. Carbohydrates include all sugars and starches. They are the main source of energy for living things. There are two types of carbohydrates, simple and complex. Simple carbohydrates include sugars and have a simple molecular structure. Complex carbohydrates include starches and have a larger and more complicated molecular structure.
Fats are a highly concentrated source of energy. There are three types of fatty acids. They are saturated, monounsaturated, and polyunsaturated. Fats aid in the absorption of calcium.
Proteins serve as one of the main building materials for the body. Skin, cartilage,
muscle, and hair are made up largely of proteins. Protein also contains enzymes, which speed up chemical reactions. Cells could not function without these enzymes. Proteins also serve as hormones (chemical messengers) and as antibodies (disease fighting chemicals). Proteins are large, complex molecules made up of smaller units called amino acids. The body must have a sufficient supply of twenty amino acids. It can produce eleven of them in sufficient amounts. The nine others are called essential amino acids. The body cannot make these amino acids. They must come from food. The best sources of protein are cheese, eggs, lean meat, fish, and milk. The proteins in these foods are called complete proteins. They are called this because they contain adequate amounts of all the essential amino acids. Cereal grains, legumes (plants of the pea family), vegetables, and nuts also supply proteins to the body. These proteins are called incomplete proteins because they do not have adequate amounts of one or more of the essential amino acids. (Nadakavukaren)
Although the vitamins and minerals are only needed in small amounts, they are still important to the body. Minerals are needed for growth, to maintain tissues, to regulate body functions, and maintenance of body structures. These minerals are not to be confused with rock minerals. Minerals are inorganic compounds. This means that living things do not create them. The required minerals are calcium, magnesium, phosphorus chlorine, potassium, sodium, and sulfur. Calcium, magnesium, and phosphorus are important for the bones and the teeth. Calcium, which is mostly found in milk products, is also necessary for blood clotting. Cereals and meats provide phosphorus. Whole grain cereals, nuts, and lettuce, are good sources of magnesium. People need only small amounts of minerals each day. Vitamins are needed in order for a person to have good health. Vitamins regulate chemical reactions by which the body converts food into energy and tissues. There are 13 vitamins. The main vitamins are A, B-1, B-2, B-12, C, D, E, and K. Vitamin A is necessary for healthy skin and development of the bones. This vitamin can be found in liver, green and yellow vegetables, and milk. Vitamin B-1 is necessary for changing starches and sugars into energy. It is found in meat and whole grain cereals. Vitamin B-2 is needed for complicated chemical reactions that take place during the body’s use of food. This is found in milk, cheese, fish, liver, and green vegetables. Vitamin B-12 is needed for forming red blood cells and for a healthy nervous system. B-12 is found in animal products such as liver. Vitamin C is needed for the maintenance of the ligaments, tendons, and other supportive tissues. Vitamin C is found in fruits and potatoes. Vitamin D is necessary for the body’s use of calcium. Vitamin D is found in milk and fish. Vitamin E helps maintain cell membranes. It is found in vegetable oils, whole grain cereals, meats, fruits, and vegetables. Vitamin K is necessary for blood clotting and is found in lettuce.
A balanced diet is the key to having good health. A balanced diet includes every kind of nutrient. The food we eat directly effects our health. A good diet will help prevent certain illnesses and help in the recovery from others. An improper diet increases the risk of various diseases. Nutrition experts recommend that the daily diet include a certain number of servings from each of the five food groups: (1) vegetables, (2) fruits, (3) breads, cereals, rice, and pasta, (4) milk, yogurt, and cheese, and (5) meat, poultry, fish, dried beans and peas, eggs, and nuts.
Improper nutrition can lead to a deficiency of calcium and a disease called osteoporosis. Osteoporosis means “porous bones.” Osteoporosis causes bones to become weak and brittle so brittle that even mild stresses, such as bending to pick up a newspaper, lifting a vacuum or coughing, can cause a fracture. Lower levels of calcium, phosphorous and other minerals in your bones cause them to weaken. The disease causes more than 1.5 million fractures every year in this country usually in the spine, hip or wrist. Half of all white women age 50 and older can expect to have a bone fracture due to osteoporosis sometime during their remaining years. About 8 million American women and 2 million men have osteoporosis. As many as 18 million more Americans may have low bone density. Osteoporosis is a bone condition characterized by a decrease in mass, resulting in bones that are more porous and more easily fractured than normal bones. Fractures of the wrist, spine, and hip are most common; however, all bones can be affected. White females are the most susceptible, but other risk factors include low calcium intake; inadequate physical activity; certain drugs, such as corticosteroids, and a family history of the disease.
Secondary osteoporosis may be caused by bone disuse as a result of paralysis or other conditions, including weightlessness in space; endocrine and nutritional disorders, including anorexia nervosa; specific disease processes; and certain drug therapies.
The good news about osteoporosis: It?s never too late for action. If you haven?t reached menopause, you can prevent osteoporosis from silently draining your bones of strength. And if you?re past menopause, you can detect the early signs of the disease and halt the bone drain before debilitating fractures rob you of your mobility and independence.
Ever wonder if you should be taking a calcium supplement? You may want to if you’re one of the 18 million Americans who’s at risk for osteoporosis, a condition in which bones slowly lose mass and deteriorate. That’s the conclusion of a new Mayo Clinic study, which found that calcium supplements, if taken regularly, do reduce bone loss to a moderate degree.
The study followed 177 women (age 61 to 70) ? with no history of osteoporosis ? for 4 years. They were given either 1,600 milligrams (mg) of calcium a day or a placebo. At the end, the women who took the supplements had slightly higher (about 1 percent) bone density levels in areas measured ?lumbar spine, femur (thigh bone) and total body bone mineral ? than women who took the inactive pills.
The women who took the supplements also had lower levels in the blood of chemical indicators for bone resorption. Bone resorption is the opposite of bone formation and can lead to bone loss. Therapies that reduce bone resorption can prevent or slow the development of osteoporosis.
“The calcium supplement definitely had an effect on bone loss,” says B. Lawrence Riggs, M.D., a Mayo Clinic endocrinologist and director of the study. “But the effect is much weaker than those produced by drug therapies for osteoporosis. Anyone with significant bone loss can’t depend on supplements alone for treatment. They will need other, more potent agents, such as estrogen, bisphosphonates (the best known of which is alendronate, trade name Fosamax) and calcitonin (a hormonal drug that reduces bone resorption).”
“But for healthy individuals, calcium supplements are something everyone at risk for osteoporosis should take,” says Dr. Riggs. “They are relatively cheap, they are well-tolerated, and they have no significant side effects.”
What is osteoporosis?
Osteoporosis is the weakening of bone that can occur as you get older. As bones get thinner with age, they become weaker. There is a much greater risk they will break if you fall or have a minor injury. Medical complications of these injuries can result in longer stays at the hospital, disability, and even death.
Osteoporosis is most common in white and Asian women, especially slender women, but it can occur in women of any race.
How does it occur?
Osteoporosis occurs as women get older. After menopause women produce much less of the sex hormone estrogen. Estrogen helps women’s bones stay strong. For example, it helps deposit calcium in the bones. Low levels of estrogen cause a weakening of the bones.
Women who smoke or are physically inactive are at a greater risk of developing osteoporosis as they grow older. Too little calcium in the diet or a family history of osteoporosis are other risk factors.
In addition to aging, other causes of osteoporosis are:
surgical removal of the ovaries, which reduces estrogen levels
intense exercise (such as marathon running), which reduces estrogen levels
long periods of bed rest during serious illness
too much aluminum hydroxide, a common antacid used to treat heartburn and ulcers.
What are the symptoms?
You may have no symptoms until a bone breaks. Broken bones are the most common problem for people with osteoporosis. Often it’s the hip, arm, or wrist that breaks.
The bones of the spine are also a common area of thinning. Often, over time, the bones of the spine (vertebrae) collapse on themselves, one at a time, causing loss of height, back pain, and a stooping posture.
How is it diagnosed?
Your health care provider may discover you have osteoporosis from an x-ray taken for some other problem. Otherwise, the diagnosis might be made from a review of your medical history and symptoms, a physical exam, x-rays, and blood tests. If you are in a high-risk category, your provider may order tests that measure the density of the bones in your forearm and spine.
How is it treated?
Treatment cannot eliminate osteoporosis, but medications can slow down the loss of bone and rebuild some bone.
The single most effective treatment for osteoporosis is estrogen (hormone replacement therapy). Women begin to produce less estrogen before menopause. Without this hormone to help bones stay strong, women are more likely to have osteoporosis. Starting to take estrogen pills around the time of menopause is the best way to slow calcium loss from the bones and keep the bones strong. The greatest loss of bone density occurs in the first years of menopause. For this reason many health care providers prescribe estrogen for women who are close to menopause.
There are pros and cons for taking estrogen. Estrogen helps slow the loss of bone and may decrease your risk of heart and blood vessel disease. However, estrogen taken alone, without the hormone progesterone, may increase the risk of uterine cancer. Also, your health care provider may not recommend that you take estrogen if you have a history of breast cancer, blood clots, or stroke. You and your health care provider need to discuss your particular situation.
Treatment also includes increasing the calcium your body gets, usually through diet and supplements. Calcium is helpful in the treatment of osteoporosis, especially if you are not taking estrogen, but it is not nearly as helpful as estrogen. Most adult women should have 1000 mg of calcium a day. Women who are pregnant or who are breast-feeding need 1200 to 1500 mg per day. Postmenopausal women who are not taking estrogen supplements need 1500 mg a day.
New treatments for osteoporosis are being studied. Examples of new medicines are:
Calcitonin, which helps prevent bone weakening but is not as effective as estrogen. The most convenient form of calcitonin is a nasal spray, which you use once a day.
Alendronate (Fosamax), which also helps prevent bone weakening and helps build some bone. It is taken in the form of pills once a day.
Raloxiphene (Evista), which is a new estrogenlike drug that keeps bone dense without increasing the risk of uterine cancer. It is taken as a pill once a day.
These medicines are most often prescribed for women who cannot take estrogen or who have already had a fracture due to osteoporosis.
Weight-bearing exercise, such as walking or stair climbing, also helps keep your bones strong. Doing this kind of physical activity every day may help stop further weakening of your bones. Swimming, although very healthy, is not a weight-bearing exercise. It can be part of your overall fitness program, but for women at risk for osteoporosis, exercise should include walking.
How long will the effects last?
The risk of a broken bone resulting from osteoporosis increases with age. Once menopause begins, most women, especially Caucasian and Asian women, need to take precautions for the rest of their lives to prevent osteoporosis.
How can I take care of myself?
Follow the treatment prescribed by your health care provider. In addition, you can:
Eat healthy foods, especially low-fat milk and dairy products, green leafy vegetables, citrus fruits, sardines, and shellfish.
Take a daily calcium supplement if your provider recommends it.
Do weight-bearing physical activity, such as walking, regularly. Be sure to exercise your upper body also.
What can I do to help prevent osteoporosis?
You can help prevent osteoporosis with:
hormone replacement therapy, or other medications recommended by your health care provider, at menopause
adequate calcium in your diet, both before and after age 35 (the age when a woman’s bone density is at its peak)
What can I do to reduce my risk of injury?
You can reduce the risk of injury and broken bones if you:
Avoid lifting heavy objects.
Avoid unusually vigorous physical activity; build your activity level gradually.
Wear proper footwear: low-heeled shoes with nonslippery soles for walking and suitable shoes for sports and recreation. Make sure the soles of your shoes don’t catch on carpeted surfaces.
Use support for walking, such as a cane, if you need it.
Maintain a safe, well-lit, and uncluttered home to help prevent falls.
Avoid throw rugs on your floors at home.
Avoid icy, wet, or slippery surfaces, especially in the bathroom. Use nonskid mats in the shower and bathtub.