Month: January 2016

10 Foods High in Vitamin E

Why You Need Vitamin E

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American Optometric Association

Lutein & Zeaxanthin

BroccoliLutein (LOO-teen) and zeaxanthin are important nutrients found in green leafy vegetables as well as other foods such as eggs. Many studies have shown that lutein and zeaxanthin reduce the risk of chronic eye diseases, including age-related macular degeneration (AMD) and cataracts.

AMD and cataract incidence are growing. Worldwide, more than 25 million people are affected by age-related macular degeneration and the formation of cataracts. AMD is the leading cause of blindness in people over age 55 in the Western world and the incidence is expected to triple by 2025.

Benefits to Eye Health

Lutein and zeaxanthin are carotenoids that filter harmful high-energy blue wavelengths of light and act as antioxidants in the eye, helping protect and maintain healthy cells. Of the 600 carotenoids found in nature, only two are deposited in high quantities in the retina (macula) of the eye: lutein and zeaxanthin. The quantity of lutein and zeaxanthin in the macular region of the retina can be measured as macular pigment optical density (MPOD). Recently, MPOD has become a useful biomarker for not only predicting disease but also visual function. Unfortunately, the human body does not synthesize the lutein and zeaxanthin it needs, which is the reason why green vegetables are essential to good nutrition. Daily intake of lutein and zeaxanthin through diet, nutritional supplements, or fortified foods and beverages is important for the maintenance of good eye health.

Lutein, Zeaxanthin and Cataracts

The primary function of the crystalline lens (or natural lens in the eye) is to collect and focus light on the retina. To properly provide this function throughout life, the lens must remain clear. Oxidation of the lens is a major cause of cataracts, which cloud the lens. As antioxidant nutrients neutralize free radicals (unstable molecules) associated with oxidative stress and retinal damage, lutein and zeaxanthin likely play a role in cataract prevention. In fact, a recent study demonstrated that higher dietary intakes of lutein and zeaxanthin and vitamin E was associated with a significantly decreased risk of cataract formation.

Lutein, Zeaxanthin and Age-Related Macular Degeneration

Much evidence supports the role of lutein and zeaxanthin in reducing the risk of AMD. In fact, The National Eye Institute presently is conducting a second large human clinical trial, Age-Related Eye Disease Study (AREDS2), to confirm whether supplements containing 10 mg a day of lutein and 2 mg of zeaxanthin per day affect the risk of developing AMD. Beyond reducing the risk of developing eye disease, separate studies have shown that lutein and zeaxanthin improve visual performance in AMD patients, cataract patients and individuals with good health.

Daily Intake*

Foods with lutein and zeaxanthin
Discover great recipes rich in Lutein

The USDA Nutrient Database offers comprehensive
information on raw and prepared foods.

Although there is no recommended daily intake for lutein and zeaxanthin, most recent studies show a health benefit for lutein supplementation at 10 mg/day and zeaxanthin  supplementation at 2 mg/day.

FOOD SOURCES

Most Western diets are low in lutein and zeaxanthin, which can be found in spinach, corn, broccoli and eggs. The following table lists foods known to be high in lutein and zeaxanthin. If you are not getting enough lutein and zeaxanthin through diet alone, consider adding supplements to your daily routine.

REFERENCES

*At this time, the AOA is unaware of any studies that have examined interactions between medications and lutein and zeaxanthin. The AOA also is not aware of any adverse health reports from interactions between medications and lutein and zeaxanthin. However, the AOA recommends consulting with a health care professional before beginning any supplementation regiment.

Eye and Vision Benefits

Lutein and Zeaxanthin:

By Gary Heitin, OD

Good nutrition is important to keep your eyes healthy and functioning their best throughout your lifetime. Two very important eye nutrients that may reduce your risk for macular degeneration andcataracts have names you may not be familiar with: lutein (LOO-teen) and zeaxanthin (zee-ah-ZAN-thin).

Lutein and zeaxanthin are two types of carotenoids (kuh-RAH-teh-noids), which are yellow to red pigments found widely in vegetables and other plants. Though lutein is considered a yellow pigment, in high concentrations it appears orange-red.

In nature, lutein and zeaxanthin appear to absorb excess light energy to prevent damage to plants from too much sunlight, especially from high-energy light rays called blue light.

Cooked spinach is one of the best natural food sources of lutein and zeaxanthin.
Cooked spinach is one of the best natural food sources of lutein and zeaxanthin.

In addition to being found in many green leafy plants and colorful fruits and vegetables, lutein and zeaxanthin are found in high concentrations in the macula of the human eye, giving the macula its yellowish color. In fact, the macula also is called the “macula lutea” (from the Latin macula, meaning “spot,” andlutea, meaning “yellow”).

Recent research has discovered a third carotenoid in the macula. Called meso-zeaxanthin, this pigment is not found in food sources and appears to be created in the retina from ingested lutein.

Lutein and zeaxanthin appear to have important antioxidant functions in the body. Along with other natural antioxidants, including vitamin C, beta carotene and vitamin E, these important pigments guard the body from damaging effects of free radicals, which are unstable molecules that can destroy cells and play a role in many diseases.

In addition to important eye and vision benefits, lutein may help protect against atherosclerosis (buildup of fatty deposits in arteries), the disease that leads to most heart attacks.

Eye Benefits of Lutein and Zeaxanthin

It is believed that lutein, zeaxanthin and meso-zeaxanthin in the macula block blue light from reaching the underlying structures in the retina, thereby reducing the risk of light-induced oxidative damage that could lead to macular degeneration (AMD)March 2014 — Nutritional supplements containing lutein and zeaxanthin, lipoic acid, and omega-3 fatty acids are effective in preventing the development of retinopathy among diabetic rats, according to a new study.

Researchers at the Kresge Eye Institute in Detroit investigated the effect of carotenoid-containing supplements on retinal oxidative stress and inflammation and the development of diabetic retinopathy. Diabetes was induced and confirmed in all rats in the study, and then some rats were given a diet that included the nutritional supplements while others were given the same food but without the supplements. After 11 months, the retinas of the rats were evaluated for changes in blood vessels, cellular damage and other retinal changes characteristic of diabetic retinopathy.

In rats that had not received the nutritional supplements, diabetes-induced damage to retinal blood vessels was three to four times greater than among rats who had received the added nutrients.

The study authors concluded that the nutritional supplements used in this study prevented diabetic retinopathy and preserved normal retinal functioning. They also said that, though human testing is required to confirm, these supplements “could represent an achievable and inexpensive adjunct therapy” to inhibit diabetic retinopathy in people with diabetes.

A full report of the study was published online in January by Nutrition & Metabolism.

A number of studies have found that lutein and zeaxanthin either help prevent AMD or may slow progression of the disease:

  • Research published in Nutrition & Metabolismfound that a nutritional supplement containing meso-zeaxanthin, lutein and zeaxanthin effectively increased the optical density of the macular pigment in eyes of the majority of human subjects. The macular pigment is believed to offer protection against the development of macular degeneration.
  • Studies published in American Journal of Epidemiology, Ophthalmology and Archives of Ophthalmology found higher levels of lutein and zeaxanthin in the diet are associated with a lower incidence of AMD.
  • Two studies published in Investigative Ophthalmology and Visual Science found that eyes with greater levels of macular pigments were less likely to have or develop macular degeneration.
  • In research published in Archives of Biochemistry and Biophysics, the study authors conclude that lutein, zeaxanthin and meso-zeaxanthin filter short-wavelength light and prevent or reduce the generation of free radicals in the retinal pigment epithelium and choroid. They also suggest that a mixture of these carotenoids is more effective than any one of the individual carotenoids at the same total concentration.
  • In a study published in the journal Optometry, participants with early AMD who consumed 8 mg per day of dietary zeaxanthin for one year improved their night driving and their visual acuity improved an average of 1.5 lines on an eye chart.

In May 2013, the much-anticipated results of the second large-scale Age-Related Eye Disease Study (AREDS2) sponsored by the National Eye Institute were published.

AREDS2 was a follow-up to the original 5-year AREDS study published in 2001, which found use of a daily antioxidant supplement containing beta-carotene, vitamin C, vitamin E, zinc and copper reduced the risk of progressive AMD by 25 percent among participants with early and intermediate macular degeneration.

The goal of AREDS2 was to evaluate the effect of other nutrients — including lutein and zeaxanthin — on the prevention of AMD and other age-related eye diseases. AREDS2 also investigated the effect of removing beta-carotene from the AREDS supplement, since supplementation of this vitamin A precursor has been associated with increased risk of certain cancers among smokers and previous smokers.

The AREDS2 results revealed study participants with early signs of macular degeneration who took a modification of the original AREDS nutritional supplement that contained 10 mg lutein and 2 mg zeaxanthin (and no beta-carotene) every day for the 5-year study period had a 10 to 25 percent reduced risk of AMD progression. Study participants whose diets contained the lowest amounts of foods containing natural lutein and zeaxanthin experienced the greatest AMD risk reduction from taking the daily nutritional supplement.

While AREDS2 and other studies provide evidence that lutein and zeaxanthin may play a role in preventing macular degeneration (or at least reducing the risk of progression of AMD), it’s less clear if these carotenoids help prevent cataracts.

Research published in Archives of Ophthalmology suggests women whose diets include high amounts of healthful foods containing lutein, zeaxanthin and other carotenoids have a lower risk of cataracts than women whose diets contain lower amounts of these nutrients.

In AREDS2, however, supplemental lutein and zeaxanthin had no effect on cataract risk or progression.

Foods Containing Lutein and Zeaxanthin

The best natural food sources of lutein and zeaxanthin are green leafy vegetables and other green or yellow vegetables. Among these, cooked kale and cooked spinach top the list, according to the U.S. Department of Agriculture (USDA).

Non-vegetarian sources of lutein and zeaxanthin include egg yolks. But if you have high cholesterol, you’re much better off getting most of these yellow nutrients from fruits and vegetables.

LUTEIN AND ZEAXANTHIN FOODS
Food Serving mg
Kale (cooked) 1 cup 23.7
Spinach (cooked) 1 cup 20.4
Collards (cooked) 1 cup 14.6
Turnip greens (cooked) 1 cup 12.2
Spinach (raw) 1 cup 3.7
Green Peas (canned) 1 cup 2.2
Corn (canned) 1 cup 2.2
Broccoli (cooked) 1 cup 1.7
Romaine lettuce (raw) 1 cup 1.3
Carrots (cooked) 1 cup 1.1
Green beans (cooked) 1 cup 0.8
Eggs 2 (large) 0.3
Source: USDA National Nutrient Database for Standard Reference, Release 22 (2009)

Lutein and Zeaxanthin Supplements

Because of the apparent eye and cardiovascular benefits of lutein and zeaxanthin, many nutritional companies have added these carotenoids to their multiple vitamin formulas. Others have introduced special eye vitamins that are predominantly lutein and zeaxanthin supplements.

There currently is no Recommended Dietary Allowance (RDA) or Recommended Daily Intake (RDI) for lutein or zeaxanthin, but some experts say you should ingest at least 6 milligrams (mg) of lutein per day for beneficial effects.

It remains unclear how much lutein and zeaxanthin is needed daily for adequate eye and vision protection. Also, it is unknown at this time whether supplements have the same effect as lutein and zeaxanthin obtained through food sources.

There are no known toxic side effects of taking too much lutein or zeaxanthin. In some cases, people who eat large amounts of carrots or yellow and green citrus fruits can develop a harmless yellowing of the skin called carotenemia. Though the appearance of the condition can be somewhat alarming and may be confused with jaundice, the yellow discoloration disappears by cutting back on consumption of these carotenoid-rich foods. (Carotenemia also can be associated with over-consumption of carotenoid-rich nutritional supplements.)

EYE NUTRIENT AWARENESS

Do You Know Which Nutrients Are Good for Your Eyes?

In a 2011 survey of Americans aged 45-65, more than half the respondents said they take nutritional supplements to protect joints, bones or heart health. But fewer than a fifth said they take eye health supplements.

In addition, 66 percent were unaware of the key role that lutein plays in eye health.

For more results of the Bausch + Lomb-sponsored survey, click here for a brief slide show.

Popular lutein and zeaxanthin supplements include:

  • EyePromise Zeaxanthin (Zeavision)
  • ICaps Eye Vitamin Lutein & Zeaxanthin Formula (Alcon)
  • Macula Complete (Biosyntrx)
  • MacularProtect Complete (ScienceBased Health)
  • MaxiVision Ocular Formula (MedOp)
  • OcuGuard Plus (TwinLab)
  • PreserVision (Bausch + Lomb)

The source of lutein in many lutein supplements is marigold flowers, while for zeaxanthin it is often red peppers. If you choose a lutein and zeaxanthin supplement, make sure it’s a high quality product from a reputable dietary supplement company.

Remember that taking dietary supplements does not replace a healthy diet. Eating a well-balanced diet that includes plenty of fruits and vegetables usually is the best way to get the important eye nutrients you need.

Also, remember that individuals sometimes react differently to certain supplements, which can have unintended effects such as adverse reactions with medications. Consult with your physician or eye doctor before trying any vision supplements.