A New Look at Eye Health
The eyes have it—zeathanthin and lutein, two carotenoids shown to protect the retina from macular degeneration. Nutritional therapies ranging from vitamins C and E to inositol, omega-3 fats, and sulfur-rich foods can minimize two other primary visual conditions, cataracts and glaucoma.
Lutein and Zeaxanthin Make Macular Pigment
The carotenoids lutein and zeaxanthin, found in foods such as kale and spinach and not synthesized by the body, protect against macular degeneration. A new two-part study by researchers at Florida International University in Miami found higher dietary intake of these carotenoids resulted in higher serum concentrations, which resulted in greater macular pigment, a retina protectant. Researchers first measured diet and serum carotenoids of 19 men and women between age 18 and 60. Using photometry, they determined the optical density of their macular pigments. There was a direct correlation between dietary intake of lutein and zeaxanthin and the density of the macular pigments.
Eye-opening Zeaxanthin
Seemingly from out of the dark came the carotenoid lutein, which offers the hope of preventing ocular diseases such as age-related macular degeneration (AMD) and cataracts, and may improve visual function. [1] However, placing the spotlight on lutein alone may be myopic. Its rose-colored cousin, zeaxanthin, is also richly concentrated in the eye and, unlike lutein, is more elusive in the diet. [2]
Lutein and Zeaxanthin Monograph
Alternative Medicine Review 2005 (Jun); 10 (2): 128–135 ~ FULL TEXT
Lutein and Zeaxanthin belong to the zanthophyll family of carotenoids and are the two major components of the macular pigment of the retina. The macula lutea, or "yellow spot" in the retina is responsible for central vision and visual acuity. Lutein and Zeaxanthin are the only carotenoids found in both the macula and lens of the human eye, and have dual functions in both tissues- to act as powerful antioxidants and to filter high-energy blue light. In addition to playing pivotal roles in ocular health, Lutein and Zeaxanthin are important nutrients in the prevention of cardiovascular disease, stroke, and lung cancer.
Cancer Prevention by Carotenoids
Mutat Res 1998 Jun 18; 402 (1–2): 159–163
Epidemiological investigations have shown that cancer risk is inversely related to the consumption of green and yellow vegetables and fruits. Since beta-carotene is present in abundance in these vegetables and fruits, it has been investigated extensively as a possible cancer- preventive agent. However, various carotenoids have also anti- carcinogenic activity. For example, lutein, zeaxanthin, lycopene, phytoene, fucoxanthin, peridinin and astaxanthin seem to be promising.
Dietary Prevention of Age-related Macular Degeneration
J Am Optom Assoc 1999; 70 (1) Jan: 39–47
Large-scale clinical trials will be necessary to demonstrate that specific agents can reduce the incidence of ARMD. Nevertheless, specific dietary components-- particularly, the carotenoids found in dark green, leafy vegetables--have shown great promise. While lifestyle modifications such as smoking cessation, reduction of alcohol consumption, and the wearing of sunglasses may reduce the risk of ARMD, it is likely that consumption of specific dietary components can reduce the risk further.
Lutein and Zeaxanthin Concentrations in Plasma After Dietary Supplementation with Egg Yolk
Am J Clin Nutr 1999; 70 (2) Aug: 247–251
Egg yolk is a highly bioavailable source of lutein and zeaxanthin. The benefit of introducing these carotenoids into the diet with egg yolk is counterbalanced by
potential LDL-cholesterol elevation from the added dietary cholesterol.
Decrease in Serum Levels of Vitamin A and Zeaxanthin in Patients with Colorectal Polyp
Eur J Gastroenterol Hepatol 1999; 11 (3) Mar: 305–308
There are close and inverse correlations between the serum level of carotenoids and colorectal polyps with different histological grades. The low mean carotenoid levels in patients with adenocarcinoma in the polyp indicate that deficiency of carotenoids may be an important factor in the development of colorectal cancer.
Diabetes Mellitus and Serum Carotenoids: Findings From the
Third National Health and Nutrition Examination Survey
Am J Epidemiol 1999 Jan 15; 149(2): 168-176
If confirmed, these data suggest new opportunities for research that include exploring a possible role for carotenoids in the pathogenesis of insulin resistance and diabetes.
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Since 2-01-1998
Updated 10-24-2007
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