Vitamin E and Eye
Vitamin E is a fat-soluble vitamin that is found in many foods including vegetable oils, meat, poultry, eggs, fruits, vegetables, and wheat germ oil. Vitamin E exists in many different forms including 4 tocopherols and 4 tocotrienols.
Research studies discovered that people who consumed foods high in vitamin E or took vitamin E dietary supplements, had lower incidence of cardiovascular diseases, cancer, dementia, and other diseases. Vitamin E boosts skin, nail and hair health, maintain healthy cholesterol levels, balances hormones and reduce PMS symptoms as well.
Like Vitamin C, Vitamin E is a powerful antioxidant that exist in the lens of the eye, playing an important role in protecting the eye. It is essential in maintaining healthy eye performance. Vitamin E protects retinal cells from free radicals that slowly damage and break down healthy eye tissue.
Studies has suggested that high intake of Vitamin E was associated with lower risk of cataracts and Age-related Macular Degeneration (AMD).
- In a large long-term study, scientist discovered that people who have taken supplements containing Vitamin E for more than 10 years had 60% lower risk of developing cataracts.
- In another study with more than 35,000 female health professionals, women whose diet had high level of lutein and Vitamin E had a lower relative risk of cataracts.
- The Roche European American Cataract Trial, conducted in 2002, found that a supplement of vitamins C and E and beta-carotene leads to a slight decrease in the progression of cataracts in less than three years.
- A meta-analysis from 2015 reported that for studies which reported serum tocopherol, higher serum concentration was associated with a 23% reduction in relative risk of age-related cataracts (ARC).
- The Age-Related Eye Disease Study (or AREDS), sponsored by the National Eye Institute, found that a high dose of vitamin C, vitamin E, beta-carotene and zinc reduces by 25% the likelihood of AMD among people at high risk of developing advanced stages of the disease.
Dietary Sources of Vitamin E
Vitamin E is found naturally in foods. Nuts, seeds, and vegetable oils are among the best sources of alpha-tocopherol, and significant amounts are available in green leafy vegetables.
Zinc and Eye
Zinc is an essential mineral that is involved in hundreds of biochemical reactions in the body. Zinc is required as a cofactor by more than 100 enzymes in different parts of the body including the eyes, skin, muscles, bones and kidneys. It plays a vital role in bringing vitamin A from the liver to the retina in order to produce melanin, a protective pigment in the eyes. Zinc is found in high concentration in the eye, mostly in the retina and choroid, the vascular tissue layer lying under the retina.
In the AREDS study sponsored by National Eye Institute, it was revealed that Zinc along with other antioxidants, vitamin C, vitamin E, and beta-carotene, significantly reduced the risk of progression of age-related macular degeneration (AMD) by about 25% and lowered the risk of vision loss by about 19%. When Zinc was taken alone, it lowered the risk of developing advanced AMD by about 21% and reduced the risk of vison loss by about 11%.
In the AREDS 2 study, researchers lowered the amount of Zinc to 25mg and found that it provided similar benefits to lower the risk of progression of advanced AMD as 80mg. On the other hand, physicians and nutritionists expressed concerns of 80mg Zinc, which significantly exceeds that Recommended Daily Intake (RDI) of 11 mg for Adults and is twice the amount of the safe upper limit of 40 mg for adults. People with high intake of zinc may experience digestive issues such as vomiting, cramping, nausea, diarrhea and headaches. Many physicians and nutritionists recommended to take AREDS 2 formulations with 25mg zinc per day.
In one study performed in Africa, it was discovered that Zinc deficiency may be associated with the high prevalence of cataract development. The incidence of cataract development is more common in tropical countries due to the prolonged exposure to sunlight, and zinc can protect the lens of the eye from oxidative damage.
Dietary Source of Zinc
Zinc is found in a wide variety of foods. Oysters contain most zinc per serving while beans, nuts, certain types of seafood are good sources of Zinc.