A scientist from the University of Liverpool claims that increasing the amount of fruit, vegetables and nuts in one’s diet may reduce the degeneration of sight caused by an eye disease.

People who suffer from age-related macular degeneration (AMD) can experience a gradual loss of eyesight. The disease is the leading cause of blindness in the United States among people who are 60 and older, according to the National Institute of Health.

However, in an effort to raise awareness about the health benefits from whole food nutrition, professor Ian Grierson has produced a cookbook called Fruit for Vision, which encourages AMD patients to incorporate more fruits and vegetables into meals.

"Eye problems such as AMD, cataract and even glaucoma can all be affected by what we eat. But a relatively minor change in diet—adding a little more fruit into our meals—can make a profound difference and can keep eye diseases like AMD at bay for up to 20 percent longer," Grierson said.

Researchers involved in the study analyzed Medicare data on 625 elderly individuals. They found that those with poor vision who visited an ophthalmologist at least once for an examination were 64 percent less likely to develop dementia, compared to those who did not seek medical care for vision problems.

Proper vision is a requirement for many of the activities that previously have been found to lower the risk of Alzheimer’s disease. These include reading, playing board games, other mentally stimulating activities, social networking, as well as physical activity such as walking and routine exercising. A visual disorder may interfere with normal mobility and may also hinder a person’s ability to participate in such activities.

The types of vision treatment that were helpful in lowering the risk of dementia were surgery to correct cataracts and treatments for glaucoma, retinal disorders and other eye-related problems.

The Alzheimer’s Association says several nutritional supplements are believed to enhance memory and slow the progression of the disease. They include coenzyme-Q10, gingko biloba, coral calcium, huperzine A and omega-3 fatty acids.

Researchers at the University of Hong Kong analyzed the eye tissue of laboratory rats that were fed green tea. They found that the eye structures absorbed powerful antioxidants in the beverage called catechins.

The effects of green tea catechins in reducing harmful oxidative stress in the eye lasted for up to 20 hours, according to the report in the Journal of Agricultural and Food Chemistry.

"Our results indicate that green tea consumption could benefit the eye against oxidative stress," the report concluded.

The study’s authors say that the catechins in green tea are among a number of antioxidants thought capable of protecting the eye. Those include vitamin C, vitamin E, lutein and zeaxanthin. Until now, however, nobody knew if the catechins in green tea actually passed from the stomach and gastrointestinal tract into the tissues of the eye.

Green tea is also believed to be beneficial for reducing the risk of other illnesses including certain cancers, high cholesterol, cardiovascular disease, rheumatoid arthritis, depression and infection.

The association recommends 10 milligrams of lutein per day, which is readily available in leafy greens like spinach, kale and turnip greens. Zeaxanthin, zinc, vitamins C and E and essential fatty acids, all of which have a positive impact on vision, can also be found in these vegetables.

The most common conditions that cause loss of vision—cataracts and macular degeneration—cannot be reversed with nutrition, but further deterioration can be slowed by regularly eating leafy greens and maintaining healthy habits like wearing sunglasses and avoiding saturated fats.

This is particularly applicable to adults, for whom vision deteriorates far more rapidly than children. According to the Centers for Disease Control and Prevention (CDC), 3.4 million American adults aged 40 years or older suffer from vision loss or blindness.

While vegetables are indispensible to vision care, it can also be supported with the use of antioxidant supplements, which can help keep a high level of beneficial nutrients in the body if proper diet is not practiced regularly, or even as an alternative to regular consumption of leafy vegetables.

Researchers with Hadassah-Hebrew University Medical Center in Jerusalem say their finding is an exciting step toward the future use of cell replacement therapies to treat devastating degenerative eye diseases that cause millions of people worldwide to lose their sight.

"Although there are a variety of therapeutic approaches under development to delay the degenerative process, the grim reality is that many patients eventually lose their sight. Cell therapy to replenish the degenerating retinal cells may potentially halt disease progression," said the study’s lead author, Dr. Benjamin Reubinoff.

A 2001 study released by the National Eye Institute suggested that high doses of antioxidants such as vitamins C and E, beta-carotene and the mineral zinc reduced the risk of vision loss from advanced age-related macular degeneration (AMD) in some cases.

In addition, nutritional supplements containing the essential fatty acids omega-3 and omega-6 have been shown to help restore and maintain tear formation and eye lubrication.

Researchers involved with this study found that individuals who took low-dose aspirin reduced their chances of developing vision-impacting AMD by 18 percent.

Aspirin is known to have anti-inflammatory and antioxidant effects and can reduce the risk of blood vessel blockage. Scientists involved with the study say low-dose aspirin was also found to be more beneficial in non-vitamin users.

Cholesterol-lowering statin drugs, on the other hand, were not found to have a protective effect against AMD.

It’s known that the two conditions have some common risk factors including smoking, high blood pressure and inflammation, and a recent study has shown that people who have early-stage AMD have an increased risk of developing heart disease as well.

AMD affects millions of Americans and is the leading cause of vision loss in the U.S.

According to WebMD, previous studies have suggested that high doses of antioxidants vitamin C, vitamin E and beta-carotene, along with zinc may reduce the risk of vision loss from AMD.

In addition, nutritional supplements containing the essential fatty acids omega-3 and omega-6 have been shown to help restore and maintain tear formation and eye lubrication.

In an experiment using cells from animal models, Enrico Rizzarelli and his cohorts found that carnosine limited the cloudiness caused by a chemical thought to lead to cataracts called guanidine.

While cells that were injected with the cataract agent became completely foggy, as one’s vision would be distorted, the effects were roughly half as severe as those treated with the supplement, the scientists say.

A carnosine component called beta-alinine may also help fitness levels in senior citizens, according to a study from the University of Oklahoma.

The number of elderly people in the study who improved their fitness levels over the course of 90 days was three-fold higher in the supplement group compared to a control population.

"This could have importance in the prevention of falls, and the maintenance of health and independent living in elderly men and women," noted lead author Dr. Jeffrey Stout.

A new study has found that visual impairment is less common among those diagnosed with diabetes after 1970, according to Reuters. The results also took into account age, blood pressure and other factors that can affect sight in diabetics.

The University of Wisconsin-Madison study followed nearly 1,000 type-1 diabetics between 1980 and 2007 to determine complications.

They say better blood sugar control and improved treatment of diabetes-related eye disorders are preventing more cases of visual impairment than in previous years.

"I think the implication is that the translation of findings from clinical trials over the past 20 years…into clinical care has resulted in reduction of vision loss," said study author Dr. Ronald Klein.

Reuters points out that experts recommend that people with diabetes have an eye exam at least once per year to detect diabetic retinopathy and other eye disorders early, so that progression can be prevented or delayed.

Obesity and family history are among the risk factors for developing diabetes.

Health experts say proper nutrition and maintaining a healthy weight are natural ways to reduce your risk of getting the disease.

In addition, supplements containing chromium, magnesium and vanadium can be used to manage diabetes, according to WebMD.

The three-year study monitored 286 glaucoma patients in Hong Kong, finding that 30 percent of participants suffered from silent cerebral infarctions (SCI), or minor strokes. Among them, the likelihood of losing vision was 61 percent higher than those who did not experience SCIs.

Dexter Leung, assistant professor of ophthalmology at the Chinese University of Hong Kong told a news conference that "These (minor) strokes in the brain are likely to affect the eye."

That’s because SCIs disturb blood supply to the brain, which can lead to damage to centers that control vision. SCIs often go unnoticed, meaning they also go untreated.

Experts agree that the best way to avoid these cerebral events is to control risk factors like diabetes and hypertension that contribute to SCIs. Healthy diet and exercise can be an effective means of managing these conditions. Additionally, Omega-3 fatty acids, vitamin E and calcium can help regulate high blood pressure, while cinnamon, fenugreek and bitter melon could be beneficial to diabetes patients.