Eighty percent of what we perceive and know about the world depends on our eyes. Like a camera, the eye has a single lens that focuses on objects and projects an image onto the retina, the light-sensitive region at the back of the eyeball. A normal, clear lens allows light to pass through unobstructed. But for a number of reasons, the lens, cornea, iris, or eye muscle may develop problems that can cause vision impairment.
A recent Gallup poll indicated that 75 percent of Americans value their eyesight above all other senses. Yet 85 percent admitted that they are not as careful in caring for their eyes as they should be. Virtually all eye injuries and half of the 50,000 cases of blindness that occur annually could be prevented, according to experts, with simple common-sense precautions.
Cataracts are the leading cause of impaired vision and blindness in the United States. Approximately four million Americans have some degree of vision-impairing cataract, and at least 40,000 people in the United States become blind each year as a result.
A cataract is any clouding of the normally clear and transparent lens of the eye. When a cataract forms, the lens becomes so opaque that light cannot easily be transmitted to the retina. If only a small part of the lens is involved, sight is not greatly impaired. If a large portion of the lens becomes cloudy, however, sight can be partially or completely impaired, and the cataract must be removed.
Many factors contribute to the progression of cataracts, including other eye disorders, injury, systemic diseases (such as diabetes mellitus), toxins, hereditary diseases, and ultraviolet and near-ultraviolet light or radiation exposure. Cataracts usually occur in elderly persons, although people of any age can develop them.
Prevention and treatment. Cataracts develop slowly and often don’t reach the point where they interfere with a person’s vision. The most important ways of preventing cataracts are to consume nutritional foods and supplements that maintain the integrity of the lens and prevent it from being damaged by chemical toxins and the sun’s ultraviolet rays. The U.S. Food and Drug Administration is now considering adopting national regulations that will require all new sunglasses to block 99 percent of ultraviolet B radiation.
Vitamin and mineral therapies. Several studies have shown a link between deficiencies of vitamins A, E, and C and the development of cataracts. Preliminary research suggests that vitamin C can prevent changes in proteins in the eye associated with cataracts. In one study reported in the July 1992 issue of Environmental Nutrition, people who took several vitamin supplements, including vitamin C, had four times less risk of developing cataracts than those who took no supplements. Research on vitamin C’s role in preventing cataracts is still inconclusive.Many holistic physicians believe that cataracts are caused by free-radical damage to some of the sulphur-containing proteins in the lens. The lens is dependent on adequate levels of superoxide dimutase, catalase, and glutathione—protective nutrients that can be damaged by free radicals. Glutathione levels can be increased by taking cysteine, glutamine, or glycine supplements, which have proven beneficial in cataract treatment.
Zinc supplements may also help treat cataracts. Zinc is a well-known antioxidant believed to be essential for normal lens functioning. In addition, beta-carotene may act as a filter, protecting the lens against light-induced damage. People with cataracts also have 15 percent of the selenium levels of those who do not have cataracts, which suggests that taking selenium supplements may also retard the progression of cataracts.
According to the May 1994 issue of The John Hopkins Medical Letter, more than three million Americans are visually impaired because of glaucoma. Several types of glaucoma have been identified, including chronic open-angle glaucoma, congenital glaucoma, acute angle-closure glaucoma, and secondary glaucoma, which is caused by secondary conditions such as hemorrhages, tumors, and inflammations. People with glaucoma usually experience hazy vision, eye and head pains, nausea, and rapid loss of vision. Glaucoma can occur in people of all ages, but is more likely to develop in people over the age of thirty-five who are very nearsighted or diabetic.
Glaucoma occurs when extra fluid builds up inside the eye, either from genetic factors or as part of the aging process. Normally a clear, transparent liquid called aqueous humor flows continually through the structures of the inner eye. If this flow becomes blocked, liquid pressure can build up against the optic nerves, which impairs their ability to transmit visual images to the brain.
Prevention. If diagnosed promptly, eye pressure can be stabilized and future glaucoma can be prevented. An important aspect of holistic treatment is testing patients to determine what type of glaucoma they have, and whether they are taking prescription medications for other disorders that may increase their risk of glaucoma. According to Alternative Medicine: The Definitive Guide, (Future Medicine, 1993) more than ninety medications, including antihypertensives, steroids, and antidepressants, can lead to glaucoma if used over a prolonged period of time.
Vitamin and mineral therapies. Vitamin C supplements and foods containing bioflavonoid compounds may help prevent glaucoma by protecting the optic nerves from free radical damage. However, vitamin, mineral, or botanical treatments have not been shown to be effective in treating acute forms of glaucoma, and eye damage caused by glaucoma usually cannot be reversed.
Nutritional therapies. Blueberry extract, bilberry, ginkgo biloba extract, and zinc sulfate have been shown in several preliminary clinical trials to be effective in retarding severe visual loss due to macular degeneration. Antioxidants such as vitamin C, selenium, and vitamin E may also be beneficial. However, consult an eye specialist before taking any supplements.
Adapted from The Alternative Health & Medicine Encyclopedia (1998) by James E. Marti, with permission of Visible Ink Press, a division of Gale Research.
Vitamin A for the brain
Next time you crunch on a carrot, consider this: it’s not just beneficial for your eyesight, it may also help you remember where you left your glasses.
Vitamin A, long noted for its role in vision and proper development of the nervous system, may also play a role in brain cell activity linked to learning and memory, according to a study by the Salk Institute for Biological Studies in La Jolla, California.
The study, published in the journal Neuron, linked the vitamin to learning through its activity in the hippocampus, the brain region responsible for learning and memory.
Vitamin A deficiencies common worldwide
If you ate broccoli or carrots for lunch, you consumed a healthy dose of a vitamin that is sorely lacking in diets of most people in developing countries.
Vitamin A is essential for eyes, bones, skin, and cell growth, yet according to the World Health Organization more than 225 million children in developing countries are vitamin A deficient.
For nearly ten years, the U.S. Agency for International Development (USAID) has given vitamin A supplements to malnourished children. Now, USAID is fortifying countries’ local foods with the vitamin, much like the fortified cereals in the United States. All cooking oil shipped to Kosovo is now fortified with vitamin A, and Uganda’s sugar may be the next recipient of the supplement. South Africans may add the vitamin to a popular grain, and the Philippines is considering wheat fortification, according to news sources.
A recent study supported by USAID revealed the benefits of vitamin A and beta-carotene on women’s health. The study, in the February issue of the British Medical Journal, found a reduced risk of maternal death in Nepal with the use of vitamin A or beta-carotene dietary supplements. Women in rural villages were randomly assigned to receive weekly supplements of the A vitamins for a period of three and a half years. Among 44,646 women, risk of death was lowered by 44 percent. During that time, 20,119 women became pregnant once and 2,070 twice, with a total of 110 maternal deaths.
Children ages 1–3400 RE
Children ages 4–6500 RE
Children ages 7–10700 RE
Males 11 and older1,000 RE
Females 11 and older800 RE
Pregnant Women 800 RE
Breast-feeding women 1,300 RE
Adapting to aging
Better nutrition may lengthen life
Anna Mary Robertson Moses, also known as Grandma Moses, took up painting at the age of seventy-six. Norman Maclean published his first work of fiction, the award-winning A River Runs Through It, at the age of seventy-five. Kurt Alder, the renowned conductor of the San Francisco Opera, was busy with music until he died in his mid-eighties, and even fathered a child in his seventies.
Most of us know elderly persons who are quite remarkable in their own way—either staying fit by competing in athletics or keeping their minds agile through absorbing activities such as reading, writing, hobbies, or art. The last years of one’s life, presumably, should be enjoyable, as they are usually years of leisure and reflection.
No matter how healthy the lifestyle, however, as people become older certain basic biological changes occur. People lose their hair or their hair grays, their skin wrinkles, they lose muscle tone and physical stamina, their lungs decrease in size, and their heart and immune systems become less efficient.
Causes of aging
One genetic theory suggests that the human body has a biological aging clock in which each cell is genetically programmed to live a fixed life span. The greater the maximum life span potential for a species, the greater the number of divisions a cell will undergo before its growth finally stops and the cell dies.
Another theory, called the “error catastrophe” hypothesis, suggests that aging occurs as a result of accumulated genetic and cellular damage. The longer people live, the more their bodies are exposed to radiation and cancer-causing chemicals. Eventually some essential cellular functions deteriorate due to mutations, which inactivate the genes. Human cells possess a variety of enzymes that can repair damage to vital cellular structures. If one or more of these enzymes become defective, it’s possible that essential cellular functions will begin to fail.
A third theory proposes that decline in immune system functioning is key to the aging process. Weakening of the immune system increases susceptibility to many diseases, including cancer and atherosclerosis. As the body ages, the immune system at some point cannot recognize and eliminate damaged or foreign cells efficiently.
Aging has also been attributed indirectly to the atrophy of the thymus gland. As people grow older, their thymus gland shrinks in size and produces less thymosin, a hormone that may help regulate the biological aging clock. Another theory argues that aging is linked to cellular damage caused by free radicals—toxic molecules that can damage arterial walls and other healthy cells. Free radicals are normally neutralized or destroyed by protective enzymes in cells. Yet cellular damage caused by free radicals may accumulate over time and contribute to the aging process.
A sixth theory suggests that aging may be related to dietary habits. Roy Walford, M.D., author of the book The Anti-Aging Plan: Strategies and Recipes for Extending Your Healthy Years, (Four Walls, Eight Windows, 1995) has shown that the aging process in mammals is always somewhat related to caloric intake: The more calories they eat, the faster they age; the fewer calories they consume, the slower they age. Walford has successively increased the life span of laboratory animals by reducing their caloric intake by 25 percent.
Finally, aging may be related to specific nutritional deficiencies, especially zinc. More than 100 enzymes in human cells require zinc to function properly. A mild zinc deficiency may not produce any obvious clinical symptoms, but a gradual depletion of zinc in the cells of older people could accelerate the aging process or increase their susceptibility to disease.
The most reasonable assumption about aging is that it’s caused by both internal and external factors—including genetics—that interact in a complex way, and that those factors will affect each person differently.
To slow the general decline of bodily functions that occurs with aging, Dr. Sheldon Hendler, M.D., author of The Doctors’ Vitamin and Mineral Encyclopedia (Fireside, 1991), suggests reducing fat intake to less than 30 percent and preferably 20 percent of total calories. He also recommends limiting red meat and animal protein intake, because they are harder for the kidneys of the elderly to absorb, and increasing the consumption of plant protein.
Nutrition authors James Balch, M.D., and Phyllis Balch suggest that the elderly restrict intake of sugar and refined carbohydrates. They recommend increasing the amount of fruits, vegetables, and fiber as substitutes for sugary foods. High-fiber foods are protein-rich and help ease constipation, another common complaint of older people.
According to the American Heart Association, eating less fat and salt and more fresh fruits, vegetables, and whole grains can reduce risk of heart disease, cancer, and obesity. Ongoing research at the USDA Human Nutrition Research Center on Aging at Tufts University has found that cutting back on fat and stocking up on key nutrients can help increase life span.
Vitamin and mineral therapies
Although the role of vitamins and minerals in delaying the aging process is still debated by scientists, one public health organization, the Alliance for Aging Research, recommends vitamin supplements to reduce the risk of life-threatening medical disorders such as heart disease and cancer. According to the Tufts University Diet & Nutrition Letter, the Washington, D.C., health advocacy group now officially advises people to take large doses of vitamin C, E, and beta-carotene to supplement the amount of these substances received from foods.
The alliance’s recommendations were developed after convening a panel of respected scientists from research and academic institutions around the country. The panel reviewed more than 200 studies of antioxidants conducted over the past twenty years, which together suggest that much larger amounts than the U.S. Recommended Dietary Allowances (RDAs) are necessary to combat free radical damage to the cells inside various tissues.
Nutritionist Elizabeth Somer, author of Nutrition for Women (Henry Holt, 1995), believes that the current RDAs for many vitamins and minerals are too low for people older than sixty-five. She argues that because it’s often difficult for the elderly to purchase or prepare their own foods, they should consider supplements that provide about 125 percent of the RDAs. (See “Optimal Dietary Allowances.”)
Adapted from The Alternative Health & Medicine Encyclopedia (1998) by James E. Marti, with permission of Visible Ink Press, a division of Gale Research.
Beta-carotene: Breast cancer fighter after menopause?
A diet high in the antioxidant beta-carotene may help postmenopausal women sidestep breast cancer, according to a study in the January issue of Epidemiology.
The study showed the relationship between beta-carotene, the plant form of vitamin A, and a reduced breast cancer risk was strongest in women whose diets incorporated the vitamin for at least twenty years before diagnosis or screening. But as little as a year and a half of a diet high in beta-carotene before diagnosis showed a reduction in cancer.
Researchers speculate that the relationship may be indirect, noting that “beta-carotene may be only a marker for other protective compounds in fruits and vegetables, including other micronutrients, phytochemicals, or fiber.”
The study involved 273 women with breast cancer and 371 without. The Swedish women, ages forty to seventy, were surveyed about their diets throughout their lives.
Antioxidant supplements don’t beat diet for heart health
Popeye was right—eat your spinach. Even if spinach won’t give you the muscles that Olive Oyl loves, the veggie’s antioxidant qualities may help reduce your risk of heart disease.
In fact, eating spinach may be better than popping a vitamin supplement. In an article published in February in the American Heart Association journal Circulation, lead author Diane Tribble writes that recent studies show that the popular antioxidants C, E, and beta-carotene—the plant form of vitamin A—may not be as effective heart helpers when taken in supplement form. The three vitamins, all found in green leafy vegetables such as spinach and collard greens, are known to fight free radicals in our bodies.
Clinical studies show that free radicals, or oxidants, may be involved in the development of coronary heart disease. Antioxidant-rich foods may lower heart disease risk, but it’s unclear whether supplements are as effective. Foods rich in antioxidants are also lower in saturated fat and cholesterol and high in fiber, characteristics that may lend an additional hand in fighting heart disease and stroke.
The effectiveness of antioxidant supplements has shown varying results in clinical trials. The American Heart Association continues to recommend that people consume a balanced diet with emphasis on antioxidant-rich fruits, vegetables, and whole grains. Popeye is paying attention—are you?Go to the source: foods rich in vitamins C, E, and beta-carotene
Study refutes connection between fat and breast cancer
A long-term study shows no association between the amount or type of dietary fat and breast cancer risk, contradicting earlier findings that a high-fat diet increases the risk of developing the disease.
The fourteen-year Harvard study, published in the March 10 Journal of the American Medical Association, involved nearly 90,000 nurses, ages thirty to fifty-five, who were all cancer-free at the start of the study in 1980. Every four years, the women completed detailed surveys about their diets.
Nearly 3,000 women, or approximately 3 percent, developed breast cancer during the study, a rate significantly lower than the national average of approximately 11 percent. The researchers saw no correlation between increased intake of animal fat, polyunsaturated fat (vegetable fat), saturated fat or trans-unsaturated fat (partially hydrogenated oil, as used in margarine).
“Nutrition supplement: vitamins, minerals, and more” is a bimonthly supplement written by Sarah Kelch and excerpted from other alternative health publications. Edited by Erika Lenz. Design by Bren Frisch. “Nutrition supplement” is intended as an educational service, not a source of medical advice or a guide for self-medication. Please consult a qualified health-care professional for treatment of any serious health problems.
Try some cherry with that burger
Cherry pies, cherry cobbler, cherry jam . . . how about cherry hamburgers? Just wait—they may be the next to join the list of all-American cherry favorites.
Cherry hamburgers, created by Ray Pleva, a Michigan butcher and cherry grower, are already on school lunch menus in at least sixteen states, right up there with chicken tenders and pizza.
Why cherries? Researchers at Michigan State University (MSU) found that adding cherries to beef retards spoilage and reduces the formation of carcinogenic compounds, or HAAs (heterocyclic aromatic amines). HAAs are formed naturally during cooking, but cherry tissue seems to inhibit the reaction that leads to HAA formation. In their study, researchers found a 78.50 percent reduction of HAA formation with the cherries, as opposed to 69 percent without them. Cherry hamburgers are lower in fat, juicier, and more tender than pure beef burgers, previous studies show.
To the discriminating burger connoisseur, the cherry flavor is not noticeable, says J. Ian Gray, professor of food science at MSU. But ordering a cherry pie with your fast-food burger doesn’t count.