Higher vitamin D levels associated with reduced risk of macular degeneration among women.

The results of a study reported in the April, 2011 issue of the American Medical Association journal Archives of Ophthalmology suggest that having a high level of vitamin D could be protective against the development of early age-related macular degeneration (AMD), a leading cause of vision loss in adults.

The Study involved 1,313 women participants in the Carotenoids in Age-Related Eye Disease Study (CAREDS), an ancillary study within the Women’s Health Initiative. Serum samples drawn between 1994 and 1998 were analyzed for 25-hydroxyvitamin D, which reflects vitamin D exposure from oral sources and sunlight. Dietary questionnaires administered upon enrollment were analyzed for vitamin D intake from food and supplements.

Although no significant association was found between vitamin D and early macular degeneration risk in the entire group, when subjects younger than 75 years of age were analyzed, a protective association emerged. “In women younger than 75, those who had 25-hydroxyvitamin D concentrations lower than 38 nanomoles per liter were more likely to have age-related macular degeneration than women with concentrations greater than 38 nanomoles per liter,” reported University of Buffalo School of Public Health and Health Professions assistant professor Amy E. Millen, PhD, who is the article’s lead author. “Blood concentrations above 38 nanomoles per liter were associated with at least a 44 percent decreased odds of having AMD.”

Intake of vitamin D from food and supplements was also found to be protective against early disease in participants under the age of 75. Those whose intake was among the top one-fifth of participants experienced a 59 percent lower risk of developing AMD compared to women whose intake was among the lowest fifth. Time spent in direct sunlight did not appear to be protective against the disease.

“The take-home message from this study is that having very low vitamin D status (25-hydroxyvitamin D blood concentrations lower than 38 nanomoles per liter) may be associated with increasing your odds of developing age-related macular degeneration,” Dr Millen concluded. “But based on these study findings, being at a higher vitamin D level than 38 nanomoles per liter does not appear to be more protective.”

“This is a promising study, but more still needs to be done,” she added. “We still don’t understand all of the effects of vitamin D on health.”

Age Related Macular Degeneration

Cindy Smith was driving down a country road in Kansas a couple of years ago when she noticed something odd. The telephone poles all had kinks in them.

“I thought, ‘Wow, what’s all that about?'” says Smith, a marketing consultant. “They all had distinctive bends in the middle.”

She pulled off the road and called a friend. “I knew something bad was happening,” she says. “It was nothing I could ignore.”

Her friend referred Smith to an eye specialists. Smith made an appointment and was diagnosed as having age-related macular degeneration.

AMD is a disease that causes significant vision loss in 1.75 million Americans. More than 10 million suffer from various forms of this potentially sight-stealing disease, more than glaucoma and cataracts combined, according to the American Macular Degeneration Foundation.

By 2020, as the population ages, that number is expected to double.

In addition, says Dr. Karl of the Retina Foundation of the Southwest, “more severe forms will be more of an issue.”

“People who are in their 70s and 80s are extremely active,” says Dr. Karl, head of the foundation’s Harrington Molecular Laboratory and an ophthalmologist with Texas Retina Associates. “If you had even a relatively small disturbance in vision, that could be extremely devastating in terms of what you’re used to doing.”

Some vision disturbances, such as difficulty reading small print, are inherent with aging. The lenses of our eyes change and can no longer focus close up, so we rely on reading glasses.

Macular degeneration goes beyond the normal aging process. It affects the center of the retina; specifically, the 0.1 percent that’s responsible for 99.9 percent of our fine vision, Csaky says.

“Unfortunately,” Csaky says, “the central part is what gives you quality of life, the ability to read, drive, play golf, to discern faces.”

He uses the analogy of a camera to explain the difference between normal eye aging and macular degeneration.

“The lens of the eye is like the lens of a camera,” he says. “Cataracts are when the lens of the camera gets cloudy and the picture gets fuzzy. The solution? Change your lens, which is what cataract surgery is.

“In macular degeneration, your film has gotten old. We can change lenses, put in a special lens, and still have a bad picture because the film is starting to decay.”

Macular degeneration has no cure, but those involved in studying and treating it point out glimmers of hope:

Though it may cause legal blindness, rendering some victims unable to drive or read, it won’t cause total blindness.

Most kinds never progress past the initial stage. Diagnosis is not “a death sentence for vision,” Csaky says.

Treatments can slow down and sometimes reverse the more severe cases of the condition.

Diagnostic tools can catch it in its early stages.

To check for it, “We dilate your eyes, use a lens and look for yellow spots (drusen) or pigmentation changes or bleeding,” says Dr. Yuguang He, associate professor of ophthalmology at the University of Texas Southwestern Medical Center and a specialist in age-related macular degeneration. “It’s not like it takes a blood test or X-ray to diagnose. We just look at it.”

The sooner it’s found, the better, he says. “There is a window in which we can do treatments.”

Most treatments are geared toward the more advanced form called wet macular degeneration. The early stage is called dry, which can progress to late-severe dry and sometimes lead to wet.

Progression from the dry form to wet can be rapid. Tyler went to a doctor when she first had symptoms, so he was able to diagnose the disease early. Thus, she’s been able to receive a relatively new and often successful treatment: a monthly shot directly into each of her eyes.

“It’s psychologically and emotionally very draining,” says Tyler, whose father has the dry variety of the disease.

The shot, explains Csaky, her doctor, inhibits a protein responsible for blood vessels growing and bleeding under the retina.

“We’re not curing the disease,” he says. “We’re inhibiting, with a drug, a protein that’s constantly being made, and with the injection it disappears for four to six weeks. The blood vessels are still there in a dormant state. If you don’t treat them, they start to grow back.”

It’s not comfortable, but patients tolerate it well, he says, though occasionally “we have a loved one faint who’s watching. We use a topical anesthetic and a very, very small needle.”

Although there is no surefire way to prevent the disease, studies have shown that eating fish two or more times per week helps reduce the risk, he says. “I take fish oil. I’m 54 years old and take it not only to prevent AMD but also to protect my heart, help my cholesterol. I tell patients, something good for your heart has to be good for your eyes.”

He also points out the Age-Related Eye Disease study of the National Eye Institution. Participants took large quantities of vitamins A and C, as well as zinc, copper and beta carotene. The regimen neither prevents the disease nor, in the study, did it have any effect on the dry form, but it “slowed the progression of the wet variety by 20 percent,” he says.

Tyler, who declined to give her age, manages her ailment as best she can, getting injections and participating in a study. She is constantly aware of her surroundings, on the lookout for any line in a grid that appears curvy or wavy. She checks the spindles on her staircase, “whatever’s around me,” for possible distortion.

“It was never even in my mind, as driven and focused as I am in my career, that I wouldn’t be responsive to it,” she says. “It’s your vision for heaven’s sake. How scary is that?

“You can work with it and make it a positive thing, or it can devastate you. You make these choices in life. What am I going to do about it? Is it going to define me, or am I going to help define it?”

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Age-related macular degeneration (AMD) is the No. 1 cause of irreversible vision loss among senior citizens, according to the Retina Foundation of the Southwest. Some risk factors:

Caucasians are more likely to contract AMD than other races.

“If you’re a Caucasian older than 65, there’s a 20 percent chance you’ll get it,” says Dr. Yuguang He, associate professor of ophthalmology at UT Southwestern Medical Center. “If you’re Chinese or Japanese, less than 5 percent. African-Americans have it much less than Caucasians.”

Yet, “as the Japanese adopted our diet, their incidence has gone up,” says Dr. Karl Csaky of the Retina Foundation of the Southwest and Texas Retina Associates.

Smoking increases incidence.

“Cigarette smokers are 20 times more likely to develop AMD than nonsmokers,” he says. “The chances are very, very high.”

If one eye is affected, the other eye will be, too.

It’s important to periodically cover up the eye that has it to see whether the other eye is seeing distortions, too.

Genetics play a factor.

“If your parents have it, there’s an increased risk you’ll get it, but it’s not a guarantee,” he says. “We’re still struggling with the practical implications of these genetic associations other than scaring people.”

Nutrition’s Potential to Save Sight

While 20/20 vision is a symbol of visual acuity, between now and the year 2020, more and more people will experience some extent of vision loss due to age-related macular degeneration (AMD) and other sight-robbing diseases.
Now, Agricultural Research Service (ARS)-funded scientists at the Laboratory for Nutrition and Vision Research are finding that healthy eating can reduce not only health care costs, but also the decline of quality of life due to these diseases. The laboratory, directed by Allen Taylor, is part of the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston, Mass.
One study indicated that regularly consuming a combination of protective nutrients and a low-glycemic-index, or “slow carb,” diet provided an AMD protective effect. A food’s glycemic index is an indicator of how fast the carbohydrate it contains will spike blood sugar levels. The macula is a 3-millimeter-wide yellow spot near the center of the retina responsible for the central field of vision.
For the study, the researchers analyzed dietary intake and other data from more than 4,000 men and women, aged 55 to 80, who had participated in the long-term Age-Related Eye Disease Study, or AREDS. Led by Chung-Jung Chiu, the researchers ranked intake of each of several nutrients consumed during the AREDS study, then calculated a compound score to gauge their combined dietary effect on the risk of AMD. The scoring system allowed them to evaluate associations between individual–and combined–dietary nutrients.
The nutrients that were found to be most protective in combination with the low-glycemic-index diet were vitamins C and E, zinc, lutein, zeaxanthin, and the omega-3 fatty acids known as DHA and EPA. The 2009 study was published in Ophthalmology.
Read more about this and other research related to improving health through nutrition in the July 2010 issue of Agricultural Research magazine, available online at: http://www.ars.usda.gov/is/AR/archive/Jul10/sight0710.htm.
ARS is the principal intramural scientific research agency of the U.S. Department of Agriculture (USDA).

Why Highly-prized Saffron Could Save Your Sight

It is one of the world’s most valuable spices. Patiently collected flower by flower, the deep red stamens of the saffron crocus can fetch up to Pounds 500 per pound, writes Anastasia Stephens.

But now there is more reason than ever to covet it. A study at Sydney University and the University of L’Aquila in Italy has found that when eaten, saffron may protect eyes from UV damage and slow the progress of diseases such as macular degeneration, a leading cause of blindness.

In macular degeneration, the cells in the retina at the back of the eye, which are responsible for clear vision, begin to die. But when patients with macular degeneration taking part in the study began eating a diet containing saffron, these cells began to recover. Professor Silvia Bisti, who led the research, says: ‘Saffron appears to affect genes that regulate the fatty-acid content of the cell membrane, and this makes the vision cells tougher and more resilient.’ The 25 participants in the study took saffron supplements or a placebo every day for three months. All those who took the saffron pill experienced improved vision, but the improvements disappeared when they stopped taking it.

Monique Simmonds, who investigates medicinal properties of plants at the Royal Botanic Gardens in Kew, explains: ‘The unique compounds found naturally in saffron that we believe may have medicinal value include crocin and safranal. They belong to a family called carotenoids, which includes betacarotene [a type of Vitamin A]. Carotenoids give plants such as carrots or red peppers their colour.

‘Studies show that these compounds play key roles in preserving eyesight, protecting against cancer and preventing Alzheimer’s.’ Added to pilau rice, risotto and dishes such as paella, saffron threads give a slightly bitter taste as well as a yellow colour. To replicate the Italian study, 20mg of neat saffron – about 16 threads – would need to be eaten daily.

A study of its anti-cancer properties at the National Institute of Paediatrics in New Mexico found that crocin and safranal actively prevent cancer cells from dividing. ‘Several studies have confirmed anti-tumour properties of saffron,’ says Fikrat Abdullaev, who conducted the study. ‘Research has found that saffron boosts immunity by helping white blood cells to mature, as well as increasing levels of enzymes that help the body break down toxins.’ Research published in the British Journal Of Gynaecology found that saffron eased symptoms of premenstrual syndrome. Fifty women with PMS received either 30mg of saffron twice a day or placebo capsules. Those taking the saffron reported marked improvements in symptoms such as depression, irritability and mood swings.

However, 1g of saffron is expensive – around Pounds 6. It is not yet available in supplement form and the quality of culinary saffron can vary hugely.

Good Fats Reduce the Risk of Macular Degeneration

A study was reported in the Archives of Ophthalmology that revealed a protective effect of omega-3 fatty acids and monounsaturated fats against age-related macular degeneration. Dr. Jennifer Tan and her colleagues determined that men and women who consume at least one serving of fish per week had a 31% lower risk of developing macular degeneration compared to those who consumed less. Eating nuts, olive oil, and other good fats helped even more.

A follow-up study reported in the same journal, showed that those individuals who had a high intake of trans fats were at a significantly higher risk of developing macular degeneration. In my Healthy for Life Program, I strongly promote decreasing your intake of bad fats (saturated fats), eliminating trans fats, and increasing your intake of the good fats (monounsaturated and omega-3 fats). All fats are not bad. It is the types of fats you consume that are the key.

Fish oil tablets are readily available, but many are contaminated with mercury. Insure you only take a pharmaceutical grade fish oil.

Greater intake of several nutrients combined with low-glycemic foods linked to reduced risk of macular degeneration

Researchers analyzed data from 4,003 participants in the Age-Related Eye Disease Study (AREDS). Information was collected on the subject’s intake of several nutrients related to eye health, including vitamin C, vitamin E, zinc, lutein/zeaxanthin, and the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Glycemic index was calculated for consumed food items. Photographs of the macula of the eye (taken upon enrollment) were graded for severity and type of macular degeneration.
Participants with a high overall intake of the associated nutrient group, as well as higher intakes of low-glycemic foods, had the lowest risk of early or advanced macular degeneration. When single nutrients were analyzed separately, vitamin E emerged as significantly protective against the disease..
The study is the first to analyze the combination of multiple nutrient groups and a low-glycemic diet on the risk of age-related macular degeneration.
Ophthalmology. May 2009. 116:5(939-946).