REPORTING POINT 02-01
AEROMEDICAL NEWS
“Live healthy...live well”
HEALTH NEWS
by Larry Kline
SWAPA Voice Mailbox 511/email: skyguy737@cox.net
MORE GOOD REASONS TO EXERCISE - a Duke University study found that intense exercise is very effective in reducing feelings of depression, tension, anger, and confusion. Also, intense exercising may be one of the best ways to combat or manage stress. Australian researchers compared people who did 30 minutes of aerobic exercise three times a week to those who practiced progressive-relaxation techniques. Those who exercised responded better to acute stress and had lower blood pressure. Men’s Fitness 2/00.
CARBOHYDRATE PRIMER - the three calorie-providing components of foods are carbohydrates, protein, and fat. Carbohydrates (the word means carbon dioxide combined with water) include all the sugars, starches, and fiber we eat. Carbs (except for fiber) are transformed by the body into blood sugar (mostly glucose), the body’s basic fuel.
Carbohydrates are the main energy source for the body. Carbohydrates supply 4 calories per gram, the same as protein, while fat supplies 9 calories per gram. Fiber supplies no calories because it isn’t absorbed by the body.
Since most carbohydrates are broken down into glucose, why does it matter which carbohydrates you consume? How is the energy in a teaspoonful of sugar any different from the equivalent amount of carbs in lima beans or whole-wheat bread?
Most carbohydrates come from plant-based foods - fruits, vegetables, grains, and legumes (beans, peas, and lentils). Dairy products are the only animal-derived foods with lots of carbs.
There are three general types of carbohydrates:
Simple carbohydrates are sugars - glucose (blood sugar - the sugar produced when you digest carbohydrates) and fructose from fruits and some vegetables, lactose from milk, sucrose from cane or beet sugar, and others. Table sugar is pure sucrose (a “double sugar” made from one unit of glucose and one unit of fructose. All other sweeteners contain either sucrose, fructose, glucose, or some combination of those sugars).
All sweeteners-except blackstrap molasses, which contains calcium, iron, and other nutrients-essentially supply nothing but nutritionally empty calories. (Concentrated fruit juices do contain some vitamins and minerals, but the tiny amount used in juice-sweetened cookies and other products has no significant nutritional value.) Honey and syrups are more concentrated than granulated sugar, so they pack more calories per teaspoon. Syrups are also stickier than granulated sugars and thus potentially worse for the teeth. Pure fructose does have a somewhat lower glycemic index than sucrose or glucose, meaning it raises the blood-sugar level more gradually. This difference is modest and has little practical significance. More important, foods are rarely sweetened with pure fructose. The most common sources of that fructose, concentrated fruit juice, honey, and high-fructose corn syrup, typically contain nearly the same proportions of glucose and fructose as sucrose does.
Sugar now accounts for 16% of all calories consumed by Americans - 20 years ago it supplied 11%. Soda alone supplies about one-third of this added sugar.
Complex carbohydrates, which are chains of simple sugars, consist primarily of starches as well as the fiber that occurs in all plant foods. Starch is the storage form of carbohydrates in plants. Foods rich in complex carbs include grains and grain products (such as bread and pasta), beans, potatoes, corn, and some other vegetables.
Most foods high in sugar (especially sucrose and other added sugars) supply “empty calories”. By contrast, the calories in foods rich in complex carbs usually bring many nutritional extras with them, depending on the food. Dairy products and fruit contain sugars, but are important parts of a healthy diet because of the other nutrients they contain.
Some foods rich in complex carbs are better than others. White bread and french fries contain complex carbs, but there are better choices. Whole grains (such as oats, whole wheat, brown rice) are more nutritious than refined grains, since they retain the bran and the germ, which are rich in vitamins, minerals, fiber, and beneficial phytochemicals. Whole grains are digested more slowly, and thus have a more modest effect on blood sugar than refined carbs or sugars. The same is true of vegetables and beans. The fiber in these foods has many health benefits. In particular, soluble fiber (found in oats, barley, and beans) may help lower LDL (bad) cholesterol, triglycerides, and blood pressure. In fact, people whose diet is rich in whole grains and other high-fiber foods tend to have lower risk of heart disease, diabetes, and some cancers.
Dietary fiber - a term used to distinguish the fiber in food from the natural and synthetic fibers (silk, cotton, wool, nylon) used in fabrics. Like the complex carbohydrates, dietary fiber (cellulose, pectin, beta-glucans, gum) is a polysaccharide. Some kinds of fiber are derived from fructose, glucose, and galactose. Dietary fiber is not like other carbohydrates. The bonds that hold its sugar units together cannot be broken by human digestive enzymes. Although the bacteria living naturally in your intestines do convert very small amounts of dietary fiber to fatty acids, dietary fiber is not considered a source of energy.
The USDA’s food pyramid recommends 6 to 11 daily servings of grains, 2 to 4 servings of fruit, 3 to 5 servings of vegetables, and 2 to 3 servings of dairy products (along with small amounts of meat, poultry, and fish). Servings are small; just one slice of bread or a medium piece of fruit, half a cup of cooked rice, pasta, beans, or vegetables, or 3/4 cup of juice. A large apple or banana, a cup of broccoli, or a medium-size salad each counts as two servings.
Such a semi-vegetarian diet will derive more than half its calories from carbs. Be choosy about the kinds of carbs you pick. Try to consume as many whole grains as you can, limit your intake of highly refined, low-fiber grain products such as white bread. It is much better to get simple carbs (sugars) from fruit, milk, and juice than from cake, cookies or soda. Also, many of these processed foods contain trans-fatty acids (in the form of hydrogenated oils), which increases LDL cholesterol and acts like saturated fat in the body.
CARBOHYDRATE MYTHS:
Myth: Carbohydrates, especially sugars, are the leading cause of obesity.
Fact: Eating more calories than you burn causes weight gain. It doesn’t matter where those calories come from, as far as weight gain is concerned. Many obese people get into trouble with excessive amounts of fat, not sugar or starch. Many sweet desserts (cakes, cookies, ice cream) actually get most of their calories from fat, not sugar. There is no evidence that eating carbs stimulates appetite or leads to more or easier fat storage and weight gain.
Myth: Only refined sugar causes cavities.
Fact: Refined sugar remains the leading dietary cause of tooth decay, but sugars such as fructose in fruit and lactose in milk also promote decay, as do some foods high in fermentable carbohydrates, such as bread and rice. The most important factor: how sticky the food is, since the longer the food remains on the teeth, the more damage is done.
Myth: Sugar in fruit is good, sugar in candy is bad.
Fact: The sugar in most fruit is primarily fructose, which has few advantages over sucrose (see above).
Carbohydrates and energy: the body runs on glucose, the molecules the cells burn for energy. Proteins, fats, and alcohol also provide energy in the form of calories. Protein also can provide glucose, but it takes longer for the body to acquire it. All the digestible carbohydrates provided by food turn into glucose or sugars quickly converted into glucose. The glucose is then carried into the cells with the help of insulin, the hormone secreted by the pancreas.
Inside the cells, the glucose is burned to produce heat and adenosine triphosphate, or ATP. The transformation of glucose into energy occurs in one of two ways: with oxygen or without it. Glucose is converted into energy with oxygen in the mitochondria - tiny bodies in the jelly-like substance inside every cell. This conversion yields energy (ATP, heat) plus water and carbon dioxide - a waste product.
Red blood cells do not have mitochondria, so they change glucose into energy without oxygen. This process yields energy and lactic acid.
Glucose is also converted to energy in muscle cells. When it comes to producing energy from glucose, muscle cells can operate with or without oxygen. Muscles have mitochondria, so they can process glucose with oxygen. But if that level of oxygen in the muscle cell falls very low, the cells can change glucose into energy without oxygen (anaerobically). This stage is reached when you exercise to the point where you are breathless. When the muscles exercise anaerobically, lactic acid is produced as a byproduct, which can cause muscle soreness.
Finally, besides providing energy, carbohydrates protect muscles. When the body needs energy, it uses carbohydrates first. If none are available, the body with start using a protein source - your own muscles - for an energy source. University of California Berkeley Wellness Letter 8/00, Consumer Reports of Health 8/99, Nutrition for Dummies
MILK AND CEREAL FOR A HEALTHY COLON - according to a study published in the American Journal of Clinical Nutrition, dairy products may reduce the risk of colon cancer. When test subjects, who consumed 1,000 mgs of calcium per day from dairy products stopped doing so for one week, there was a significant rise in cytotoxicity, a risk marker for colon cancer. Study leaders speculate that calcium and phosphate probably eliminate bile acids, which increases the toxicity of waste material. It is recommended that people consume at least 1,000 mgs of calcium per day from dairy products - about 8 ounces of nonfat yogurt plus 16 ounces of skim milk. Men’s Health 9/98.
NURSING AFTER INTENSE EXERCISE - for 60 to 90 minutes after intense exercise, the composition of breast milk changes. There is an increase in lactic acid, which causes a sour taste that may be unpleasant to the baby. There is also a decrease in immunoglobulin IgA - a substance important in the immune response. Hope Health Letter 12/98.
