四六级阅读的每日一练：第9篇

　　Passage 1

　　The Look Younger Diet

　　Is the Fountain of Youth a myth? Not entirely, many experts in nutrition now believe, Age fast, or age slow its up to you. declares Dr. Kenneth Cooper, president and founder of the Aerobics Center in Dallas. Jeffrey Blumberg, associate director of the U. S. Department of Agricultures Human Nutrition Research Center on Aging at Tufts University in Boston, agrees, Research shows that many so-called age-related declines in physiological function seem to have less to do with aging than with environmental factors like diet and exercise.

　　Obesity is one of the leading causes of accelerated aging, according to Cooper, If you lose weight, stop smoking, and exercise, he says, you can slow the aging process and make dramatic changes in your looks in a relatively short period of time.

　　A 37-year-old sales director for a Boston computer-distribution company is a prime example. Over six feet tall, he had been considerably overweight most of his like. Then he began to worry that his appearance could be hurting his career. I got tired of people thinking I was the same age as my brother, whos nearly nine years older, he says, When youre fat, people in the business world assume youre out of control.

　　Determined to change, the sales director entered a hospital-based diet program and dropped over 70 pounds. I feel and look ten years younger. he says.

　　At 82, Clarice R. Mc Williams, a retired business owner in Dallas, has the appearance, skin tone and mental agility of someone many years younger. Most people think Im in my 60s. she boasts.

　　Mc Williams admits genes play some role in the way she looks, but believes diet is an important factor. It doesnt matter how good the genes are if you dont eat properly and take care of yourself, she says. If you want to look good, get plenty of rest, exercise every day, eat mostly raw fruits and vegetables and quit worrying.

　　Says Blumberg, Theres certainly a link between good nutrition, a positive 30

　　attitude and improved quality of life. People can have a say in whats going on with their bodies by selecting a healthful diet.

　　Skin. Nowhere do the signs of aging manifest themselves more clearly than in the condition of the skin. When your weight fluctuates, the skin stretches with each up cycle, but it may not completely shrink back to its original size in the down cycle. As a result, the skin may sag.

　　A severely deficient diet can lead to skin disorders, dramatically affecting ones appearance. By the same token, a well-balanced diet with ample supplies of nutrients is thought by many experts to produce a glowing, younger look.

　　Zinc and vitamin A are important for normal, healthy skin. Zinc helps the skin repair itself, and vitamin A aids in keeping skin supple, preventing dryness and helping shed dead cells. Good sources of zinc are beef, eggs and seafood, while many dark-green leafy vegetables are rich in beta carotene, which the body converts to vitamin A. Other foods containing ample amounts of beta carotene include carrots, cantaloupe, winter squash, sweet potatoes, sweet red peppers, apricots and mangoes.

　　Vitamin C helps improve the blood supply to the skin and aids in forming collagen , the fibrous protein that lies beneath the skins surface and gives it a smooth appearance. Good sources of vitamin C include citrus fruits and juices, Brussels sprouts, cauliflower, snow peas, red and green peppers, broccoli, white and sweet potatoes, tomatoes, watermelon, honeydew melon and cantaloupe.

　　Greens are excellent sources of skin-preserving nutrients and, generally, the darker the leaves, the more nutritious. Romaine lettuce, for example has about six times as much vitamin C and eight times as much beta carotene as iceberg

　　lettuce.

　　How food is prepared matters too. The longer vegetables cook, the greater the loss of vitamins and texture. Dont soak vegetables when washing them, since water-soluble vitamins such as C will be lost.

　　Blumberg also recommends drinking six to eight glasses of water or other fluids each day to help keep skin and other tissues hydrated. Thats especially important for older people, he says, who are at risk for dehydration because their thirst drive becomes blunted with age. Coffee, colas and tea arent the best sources, since they contain caffeine, a diuretic that induces water loss.

　　Hair. Healthy, shining hair is second only to vibrant skin for making one look younger. Yet many people unwittingly mistreat their hair by eating an unbalanced diet.

　　When a 33-year-old employee at a Texas corporation decided to lose weight quickly, she went on a fad diet, high in fiber and bulk, but low in protein. Over three months, she lost a lot of weight. She also lost a good deal of her hair.

　　Dermatologist David Alkek, a clinical professor at the University of Texas Southwest Medical Center at Dallas, sees too many cases like this womans. When diets dont contain enough amino acids, the building blocks of protein, theres dramatic increase in hair loss as the body breaks down its own protein.

　　Hair and skin cells are constantly reproducing and are, therefore, very sensitive to nutritional deficiencies, explains Dr. Alkek. Foods high in amino acids include meats, eggs, milk, grains and legumes. Just remember that the body cannot store protein. So foods high in protein must be ingested daily. Under Alkeks care, the woman began eating nutritionally balanced meals, and her hair was restored in about eight months.

　　Immune system. Vitamins E and C and beta carotene, known as antioxidants , are considered powerful disease-fighters, capable of slowing down or preventing a number of ailments typically associated with aging.

　　A growing body of evidence suggests that aging and decline in immune function may result in part from accumulated damage to cells caused by certain toxic compounds called free radicals . Antioxidants seem to counteract or impair the ability of these substances to attack healthy cells, thus avoiding at least some of the damage. Foods containing these nutrients are being linked by science rather than myth to the control and prevention of heart disease and cancer, stroke, cataracts and to the bodys ability to ward off infectious diseases.

　　Good general nutrition is essential to maintaining a healthy, youthful appearance. And the key to good general nutrition is balance. Proteins should make up roughly ten percent of your daily calorie intake; no more than 30 percent should come from fats; and the remaining calories should come mostly from complex carbohydrates.