Eye Nutrition News
Leafy Greens, Every Day, May Keep Glaucoma Away
January 2016 New research indicates that leafy greens may be even healthier than we thought. While veggies like spinach, kale and collard greens may not be able to cure glaucoma, eating them regularly may help protect you against ever developing the most common form of the disease, known as primary open angle glaucoma (POAG).
Researchers at Brigham and Women's Hospital and Harvard Medical School followed more than 100,000 men and women who were enrolled in two major medical studies for a period of more than 28 years. Everyone in these studies was 40 years or older, and none had glaucoma at the start of the study.
The patients received eye exams every two years, and throughout the course of the studies, 1,483 people developed POAG. When the researchers looked at the diets of the study participants, they noted a strong similarity among those who did not develop glaucoma these people ate more leafy greens. In fact, greater intake of green leafy vegetables was associated with a 20 percent to 30 percent lower risk of POAG.
The association was even stronger for POAG with early paracentral visual field loss, a common subtype of POAG. The research revealed that people who ate a lot of leafy greens had a 40 percent to 50 percent lower risk of acquiring this form of the disease.
The reason these super foods offer such great protection is related to the dietary nitrate they contain. It's thought that glaucoma impairs blood flow to the optic nerve. Nitric oxide helps regulate this flow. Since leafy greens contain high levels of nitrates, the precursor to nitric oxide, consuming them likely keeps things running more smoothly.
A significant amount of other new research is currently aimed at developing therapeutics that treat glaucoma by way of nitric oxide. In fact, the FDA is reviewing at least one new medication that donates nitric oxide. But thanks to this latest report, far fewer people will need it if they load up on leafy greens before any glaucomatous damage is done.
So just how much roughage do you need to eat to protect yourself from glaucoma? In this study, those who consumed the most leafy greens averaged about 1.5 servings per day, which equates to about one and a half cups.
The study was published in JAMA Ophthalmology this month A.H.
Diets Rich in Lutein and Zeaxanthin Associated with Reduced Risk of Advanced Macular Degeneration, Study Finds
October 2015 Eating a diet rich in the carotenoids lutein and zeaxanthin is associated with a long-term reduced risk of developing advanced age-related macular degeneration (AMD), according to a new study.
Data for the study was gathered from two long-term studies the Nurses' Health Study and the Health Professionals Follow-up Study that followed 100,000 subjects (63,443 women and 38,603 men) ages 50 and older for more than two decades. None of the participants had diagnosed macular degeneration, diabetes, cardiovascular disease or cancer at the beginning of the study periods.
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Blood levels of lutein and zeaxanthin were estimated based on diet and food intake questionnaires administered throughout the study period and the bioavailability of the carotenoids in the foods eaten. Associations between these scores and development of AMD were then determined.
At the end of the study period, there were 1,361 cases of intermediate AMD and 1,118 cases of advanced AMD (visual acuity of 20/30 or worse) among the study participants. Comparing the incidence of macular degeneration among participants with lutein and zeaxanthin scores in the top 20 percent versus those with scores in the bottom 20 percent, the researchers "found a risk reduction for advanced AMD of about 40 percent in both women and men" among those whose diets contained the most carotenoids. Also, predicted plasma scores for other carotenoids including β-cryptoxanthin, alpha-carotene and beta-carotene were associated with a 25 to 30 percent lower risk of advanced AMD when comparing these same subgroups.
No associations between predicted plasma scores of lutein, zeaxanthin or other carotenoids with intermediate AMD were identified.
The study authors concluded the results of the study "further strengthen the evidence base for a protective role of lutein and zeaxanthin" (against macular degeneration). They also said, "Because other carotenoids may also have a protective role, a public health strategy for increasing the consumption of a wide variety of fruits and vegetables rich in carotenoids could be most beneficial and compatible with current dietary guidelines."
The study, published online this month by the American Medical Association journal JAMA Ophthalmology, was conducted by scientists affiliated with the following institutions: Department of Nutrition, Harvard T. H. Chan School of Public Health (Boston, Massachusetts); Warren Alpert Medical School, Brown University (Providence, Rhode Island); Department of Epidemiology, Brown School of Public Health (Providence, Rhode Island); Brigham and Women's Hospital, Harvard Medical School (Boston); and University of Utah School of Medicine (Salt Lake City).
Poor Eating Habits Are Causing Nutrient
Deficiencies in Children (and What To Do About It)
August 2015 Due to poor eating habits, American children of all ages (and especially adolescents) are missing key nutrients. That's the conclusion of Purdue University nutrition researcher Heather Eicher-Miller, PhD, during her presentation at a meeting of the Institute of Food Technologists last month.
We get it: fries are yummy! But good eye health requires more than a fast food diet.
It can be particularly challenging for adolescents to meet their nutritional needs because of accelerated physical growth during this stage of life and because teens make more independent food choices that often lack key nutrients, according to Dr. Eicher-Miller.
She and her Purdue colleagues conducted a review of research on nutritional gaps in children over the last 10 years. They found kids in the U.S. frequently were deficient in vitamins A, D, E and K (found in green vegetables), calcium and magnesium.
- Ages 9 to 13: Girls showed nutrient gaps in vitamins A, D, E and K, and in magnesium and potassium; boys were deficient in vitamins D and E.
- Ages 14 to 18: Girls lacked adequate levels of vitamins A, C, D and E, as well as zinc, potassium, magnesium and calcium; boys were deficient in A, C, D, E, calcium and magnesium.
Gaps in these important nutrients can have implications throughout the body, may affect attentiveness and academic performance, and may also affect long-term eye and vision health.
To make sure your children are getting the nutrition they need for healthy bodies, good vision and optimal performance both in and outside the classroom, encourage these healthy eating habits:
- Avoid or cut back on sugary soft drinks and energy drinks. Drink more water instead. For flavor, add a slice of lemon, lime or orange.
- Fruits and veggies are your friends. Snack on these instead of high-calorie, low-nutrient junk food.
- Don't add salt to your food. If you feel the need for a salty snack, try a small handful of nuts.
- Eat breakfast every day. (Eggs are a great source of nutrients and vitamins, including lutein and other eye-healthy nutrients.)
- Avoid fried foods. Try more healthful alternatives, including grilled lean meats and sushi.
- Take a balanced multivitamin supplement daily with breakfast or lunch.
Also, get plenty of sleep to help your body recharge, recover and be ready for a new day!
Cooked Eggs Improve Absorption of Eye-Healthy
Nutrients in Raw Vegetables
June 2015 Do you eat enough raw veggies? Most people don't. But not only should you add more salad to your diet, you should also consider eating eggs with it.
In a study by Purdue University researchers, 16 young men ate three versions of a salad containing tomatoes, carrots, romaine lettuce, baby spinach and Chinese wolfberries (also called goji berries). One version had no egg; the second version had one and a half scrambled whole eggs; and the third had three scrambled whole eggs.
Eating the cooked eggs increased the absorption from three- to nine-fold of the carotenoids in the vegetables, including beta-carotene, alpha-carotene, lycopene, lutein and zeaxanthin. (The egg yolks also contain lutein and zeaxanthin.) Many carotenoids are considered eye health boosters.
Wayne Campbell, PhD, professor of nutrition science at Purdue, and his group would also like to investigate the effects of eating cooked eggs on the absorption of other fat-soluble nutrients, such as vitamins E and D. L.S.
Visionary Kitchen: A Cookbook That Promotes Eye Health
February 2015 Written by optometrist Sandra Young, OD, Visionary Kitchen is a cookbook with beautiful photography that will inspire you and your family to eat better for eye health.
You can order a copy of Visionary Kitchen on Amazon or at VisionaryKitchen.com.
The book contains more than 150 easy, delicious recipes that include ingredients containing lutein, omega-3 fatty acids, vitamin A, vitamin C, zinc and other nutrients thought to promote eye health and good vision. The recipes list the amounts of eye-healthy nutrients in each serving.
The recipes are low-glycemic and include gluten-free, vegan, vegetarian and dairy-free options.
Especially interesting is the section on snacks: It includes several great recipes for energy bites that you can eat when your tummy's growling and lunchtime is still a couple hours away. Plus, the mushroom lentil pate and the salmon black bean mash make excellent spreads for party appetizers.
Other great ideas are herb and spice blends you can make yourself, healthful smoothie drinks and creative breakfast recipes, such as broccoli-quinoa mini-quiches and omega-3 pancakes. L.S.
Vitamin B1 Deficiency Linked to Brain Damage and Vision Loss
November 2014 In extreme cases, normally due to alcoholism, anorexia or other disorders that lead to malnourishment, vitamin B1 (thiamine) deficiency can cause Wernicke encephalopathy.
Sunflower seeds, pork and macadamia nuts are among the foods that are high in vitamin B1.
This serious neurologic disorder is associated with eye problems like double vision and involuntary eye movement, and can even lead to irreversible brain damage and death, according to researchers at Loyola University Medical Center.
Wernicke encephalopathy is often undiagnosed. "Particularly in those who suffer from alcoholism or AIDS, the diagnosis is missed on clinical examination in 75 to 80 percent of cases," wrote the researchers.
Thiamine is an essential vitamin for a variety of organ functions, including the nervous system. The current recommended daily value for vitamin B1 is 1.4 mg. Foods rich in thiamine include lean pork, sunflower seeds, trout, edamame and macadamia nuts.
Alcohol Consumption Reduces Optical Quality of the Eye
August 2014 It has been proposed that the antioxidants found in red wine may be beneficial to eye health. But before you raise that wine glass, you should also consider the harmful effect that alcohol has on our vision in low light and at night.
Halos around lights at night. (Image: UGRdivulga)
Scientists at the University of Granada in Spain say they have proven that alcohol consumption increases the perception of halos around lights at night. So, for example, streetlamps and oncoming headlights appear larger and more dazzling, so pedestrians and traffic signs can become less visible, creating a dangerous situation.
The researchers evaluated retina image quality and night vision performance in 67 people who had consumed various quantities of wine. Their breath alcohol content was also measured. Those with a breath alcohol content level over the legal limit (.25mg/l in Spain) experienced significant deterioration in their vision, with more perception of halos and other nighttime visual problems.
One reason may be that the ethanol in alcoholic beverages disturbs the lipid layer of the eye's tear film, which can increase evaporation of the tear film's watery component. This tear evaporation can create vision problems.
A report of the study appeared in the Journal of Ophthalmology.
More Omega-3 Fatty Acids in the Blood Linked to
Less Risk of Macular Degeneration
February 2014 Higher circulating blood levels of EPA and DHA essential omega-3 fatty acids found in salmon and other oily fish were significantly associated with lower risk for neovascular age-related macular degeneration (wet AMD).
Eating more salmon and other oily fish and seafood high in omega-3 fatty acids (sardines, mackerel, tuna, anchovies, oysters) may reduce your risk of macular degeneration.
Researchers in France evaluated levels of EPA and DHA in the blood serum and red blood cell membranes of 290 patients with wet AMD in one eye and early AMD lesions in the other eye and 144 patients without AMD in either eye. Dietary intake of seafood was estimated by a food questionnaire completed by all participants.
Dietary oily fish and seafood intake were significantly lower in AMD patients compared with healthy patients without AMD. After adjusting for age, gender, family history of AMD and other factors, higher serum EPA levels were significantly associated with a lower risk for neovascular AMD.
Higher levels of EPA and combined EPA and DHA levels in red blood cell membranes also were significantly associated with a lower risk for wet AMD.
The study authors concluded that blood levels of EPA and DHA omega-3 fatty acids, particularly levels found in red blood cell membranes, may be a useful objective marker to identify people at risk for neovascular AMD and those who might benefit most from changing their diet to reduce risk of macular degeneration.
The study appeared online this month in Investigative Ophthalmology & Visual Science.
Antioxidants May Lower Risk of Cataracts in Women
January 2014 Ladies, it's time to eat more of your fruits and veggies.
Colorful fruits and vegetables are the best source of antioxidants for women to lower the risk of cataracts as they age, according to a new Swedish study by the Institute of Environmental Medicine at the Karolinska Institutet.
Coffee, tea, whole grains, red wine and many fruits and vegetables all contain high amounts of antioxidants, which may lower the risk of cataracts in women.
For the study, more than 30,000 Swedish women over age 49 were observed for about seven years for signs of developing cataracts and were given a dietary questionnaire.
The study found those with the highest total intake of antioxidants had about a 13 percent lower risk of developing cataracts than women with the lowest intake.
Instead of looking at single antioxidants, such as vitamins C and E, and plant flavonoids such as lycopene, the researchers used a measure of total antioxidant values in foods, which takes into account how the nutrients work together. Foods high in antioxidants include coffee, tea, oranges, whole grains and red wine.
Based on total antioxidant consumption, the researchers divided the women into five groups, ranging from the greatest antioxidant intake to the least. Among those who ate the most antioxidants, 745 cases of cataract were recorded, compared with 953 cases among women with the lowest antioxidant consumption. Women who ate more antioxidants also tended to be more educated and were less likely to smoke.
The findings are in line with previous research suggesting antioxidants may help protect against cataracts.
More than 20 million Americans aged 40 years and older have cataracts, which cause clouded vision and eventually blindness, in one or both eyes, according to the U.S. Centers for Disease Control and Prevention.
FDA Steps Up Attack on Unhealthy Trans Fat, and
Better Eye Health Could Result
November 2013 With the holidays fast approaching, it's a good time to take a hard look at your diet and decide what to avoid in 2014 and beyond. One of the first things that should go: trans fat.
Trans fat is an unhealthy fat that is formed when hydrogen is added to liquid oils, making them into solids, such as margarine and shortening ("partially hydrogenated oils"). This type of artificial trans fat is frequently used in processed foods, because it increases flavor and shelf life.
Some brands of microwave popcorn still contain significant amounts of trans fat. If the FDA bans trans fat, these and many other processed foods will not be sold in the United States unless their ingredients are changed.
But, like saturated fat, trans fat raises blood levels of LDL ("bad" cholesterol), which increases the risk of heart disease and other conditions, including eye problems. This is because trans fat interferes with the body's absorption of beneficial omega-3 fatty acids, which appear to help protect against dry eyes and macular degeneration and are important in normal visual development in infants, among their other health benefits.
Common foods that contain artificial trans fat include crackers, cookies, microwave popcorn and other snack foods, fried foods, frozen foods and some baked goods.
This month, the U.S. Food and Drug Administration announced that, based on available scientific evidence and the findings of expert scientific panels, it has made a preliminary determination that partially hydrogenated oils (PHOs) the primary source of trans fat in processed foods are not "generally recognized as safe" for use in food. The agency has opened a 60-day comment period to collect additional data before a final decision is made.
"While consumption of potentially harmful artificial trans fat has declined over the last two decades in the United States…further reduction in the amount of trans fat in the American diet could prevent an additional 20,000 heart attacks and 7,000 deaths from heart disease each year a critical step in the protection of Americans' health," said FDA Commissioner Margaret A. Hamburg, MD.
Also, according to the independent Institute of Medicine (IOM), trans fat provides no known health benefit and, because there may be no safe level of consumption of artificial trans fat, the IOM recommends that consumption of trans fat should be as low as possible while consuming a nutritionally adequate diet.
If the FDA does finalize its preliminary determination, partially hydrogenated oils would be considered "food additives" and could not be used in food unless authorized by regulation. The preliminary determination concerns only PHOs and does not affect trans fat that occurs naturally in small amounts in certain meat and dairy products, such as milk, butter and cheese. Research suggests naturally occurring trans fat is not as harmful as artificial trans fat.
So here's a painless dietary resolution for 2014: Out with margarine, in with butter (in moderation, of course)!
Genes May Hold Key to Eye Supplement Effectiveness
September 2013 Why are eye supplements effective at reducing the risk for eye diseases like macular degeneration (AMD) for some people but not others? The answer may be genetic, according to a new study.
Researchers in the UK studied the response of 310 twins with variants in eight genes to use of supplements containing the carotenoids lutein and zeaxanthin, which may be protective against AMD according to other research.
They found a number of the gene variants studied were associated with changes in the density of protective pigments in the macula after supplement use.
According to the study authors, this is the first study to show this gene-related variance in ocular response to lutein and zeaxanthin supplementation. The authors added that the findings "suggest an important link between macular pigment response and the biological processes of carotenoids transport and fatty acid metabolism."
A full report of the study was published online in July by Experimental Eye Research and will appear in a future print issue of the journal.
New Dry Eye Supplements Introduced
August 2013 OcuSoft has introduced two new dietary supplements for people with dry eyes: Retaine OM3 and Retaine Flax.
Both contain a blend of omega-3 and omega-6 fatty acids, which have been shown to reduce inflammation associated with dry eye syndrome.
The omega-3 fatty acids in Retaine OM3 (800 mg EPA and 400 mg DHA per serving) are derived from fish oil, while the omega-3s in Retaine Flax come from flaxseed oil for people who cannot tolerate fish oil or prefer a vegetarian supplement.
Both supplements are packaged in convenient blister packs to help users remember to take their recommended daily dose of the softgel capsules for maximum effectiveness in relieving dry eye symptoms.
Retaine supplements are available from eye doctors or online.
Links Found Between Antioxidant / Vitamin Levels and Lower Cataract Risk
July 2013 If you aren't taking eye vitamins, you might want to start. A new study reveals that important associations exist between the level of certain antioxidants and vitamins in your bloodstream and your risk of cataracts.
Could antioxidant and vitamin supplements reduce your risk for age-related cataract?
Researchers in China analyzed the pooled results of 13 nutritional studies that included 18,999 participants. Those with higher blood levels of lutein, zeaxanthin, alpha-carotene and vitamin E had a lower risk of developing cataracts as they aged.
Vitamin A and vitamin C were inversely associated with age-related cataract in Asian populations but not in Western populations, and beta-carotene and lycopene had no significant association with risk of cataract.
The researchers did not study the role of antioxidant or vitamin supplement intake in preventing cataract and recommended that this role be investigated with additional studies.
The study was published on the American Journal of Clinical Nutrition website in July.
Diet of Many Americans Insufficient To Support Eye Health, Review Finds
July 2013 If you're over age 50, it's likely your diet doesn't contain all the nutrients necessary for optimum eye health. That's the finding of a recent review of nutritional studies performed by researchers at Tufts University and Lesley University.
The pigment in red bell peppers is the source of most of the zeaxanthin used in nutritional supplements.
The review highlighted data from the most recent National Health and Nutrition Examination Survey, which indicates that most Americans fall below the optimal intake of the following nutrients that research shows can help protect eye health as people age: vitamins C and E, lutein, zeaxanthin, beta-carotene, zinc and omega-3 fatty acids.
The researchers concluded that to limit vision loss within the aging U.S. population, it's important to increase awareness among Americans, especially those aged 45 to 65, about the importance of nutrients and foods that could help prevent age-related eye disease.
These foods were identified as good sources of nutrients important for eye health:
- Vitamin C. Citrus fruits, berries, tomatoes and broccoli.
- Vitamin E. Vegetable oils, wheat germ, nuts and legumes.
- Lutein and zeaxanthin. Kale, spinach, broccoli, peas, corn, colored bell peppers.
- Beta-carotene. Carrots, pumpkin, sweet potato and spinach.
- Zinc. Oysters, beef and other meats, nuts.
- Omega-3 fatty acids. Salmon and other cold-water fish.
Eye vitamins and other supplements also can help meet required daily intakes of these nutrients. But anyone considering a program of dietary supplements should consult their eye doctor or other health-care provider beforehand, the study authors advised.
The review was published online in June, in the Journal of Clinical Interventions in Aging, and was supported by Bausch + Lomb.
[Page updated January 26, 2016]