Lutein and Zeaxanthin
Monograph

This section is compiled by Frank M. Painter, D.C.
Send all comments or additions to:    Frankp@chiro.org

FROM:   Alternative Medicine Review 2005 (Jun);   10 (2):   128–135

---

Introduction

Lutein and zeaxanthin belong to the xanthophyll 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 .lter high-energy blue light. [1] Lutein is found in high amounts in human serum. [2] In the diet it is found in highest concentrations in dark green, leafy vegetables (spinach, kale, collard greens, and others), corn, and egg yolks. [3] Zeaxanthin is the major carotenoid found in corn, orange peppers, oranges, and tangerines (Table 1). [4] In addition to playing pivotal roles in ocular health, lutein and zeaxanthin are important nutrients for the prevention of cardiovascular disease, stroke, and lung cancer. They may also be protective in skin conditions attributed to excessive ultraviolet (UV) light exposure.

---

Clinical Indications

Ocular Conditions

Age-related Macular Degeneration In older Americans, age-related macular degeneration (AMD) is the leading cause of blindness. It is characterized by atrophy of the macular disk. The retinal pigmented epithelium and photoreceptors (particularly the rods and the blue-light sensitive cones) are the most affected. There are two types of AMD – early or dry and late or wet. Early AMD is characterized by soft drusen accumulation and pigmentary changes in the retinal epithelium and macula, while late-stage AMD involves neovascularization of the retina, an exudative mound, and intraretinal hemorrhage and scarring. [27-28]

Numerous observational studies have examined the correlation between lutein and zeaxanthin concentrations in the macula, dietary intake, and macular degeneration. In the multicenter Eye Disease Case-Control study, Seddon et al evaluated the relationship between dietary intake of carotenoids and the risk of neovascular AMD in 356 subjects. After adjusting for risk factors, they found a 57-percent decreased risk for AMD in individuals with the highest intake of lutein/zeaxanthin (6 mg daily), compared to those who consumed the lowest level (0.5 mg daily). [29]

Other studies have examined the relationship between lutein/zeaxanthin intake, serum lutein/ zeaxanthin, and macular pigment density (MPD). In 278 healthy volunteers higher levels of dietary lutein intake correlated with higher serum lutein and zeaxanthin and signi.cantly higher MPD. [30] Bernstein et al also demonstrated lutein supplementation of 4 mg daily resulted in signi.cantly higher MPD levels in AMD patients compared to control subjects not supplementing. [31] These observational studies seem to indicate maintenance of macular pigment density is crucial to maintaining visual acuity and decreasing the risk of developing AMD.

Since 2001, three double-blind, intervention studies have examined the effects of lutein supplementation on vision improvement in AMD patients. In a 12-month trial of 14 AMD patients, Richer demonstrated improvements of up to 92 percent in visual acuity tests after subjects consumed a diet containing .ve ounces of spinach (approximately 14 mg lutein) 4-7 times weekly. [32]

In 2004, Richer published the results of a follow- up study – the Lutein Antioxidant Supplementation Trial (LAST), a double-blind, randomized, placebo-controlled study. Ninety males with atrophic AMD were supplemented with either 10 mg lutein, 10 mg lutein plus a broad spectrum formula containing antioxidants/vitamins/minerals, or placebo for one year. The subjects were examined for MPD, photostress recovery, contrast sensitivity, and visual acuity at baseline, and every four months until the end of the study. The most signi.cant .nding was a 36-percent increase in MPD in the lutein group and a 43-percent increase in MPD in the lutein plus antioxidant group, compared to a slight decrease in MPD in the placebo group. Lutein supplementation also resulted in significant improvements in visual acuity, objective visual function parameters, photo-stress recovery, and contrast sensitivity. The LAST con.rms lutein plays an important role in ocular health and that AMD appears to respond favorably to lutein supplementation. [33] In an Italian study, 50 patients with AMD were given daily cocktails containing antioxidants and 15 mg purified lutein or placebo for 18 months. The study was published in Italian so details are not readily available, but the researchers demonstrated a two-fold increase in visual acuity in AMD patients compared to the placebo group. [34]

Cataracts

Cataracts are the leading cause of impaired vision in the United States, with a large percentage of the geriatric population exhibiting some signs of the lesion. Cataracts are developmental or degenerative opacities of the lens that result in a gradual, painless loss of vision. Oxidative insult appears to be a precipitating factor in cataracts, resulting in the development of insoluble, oxidized lens proteins. Higher levels of hydrogen peroxide have been found in cataractous lenses compared to normal lenses, indicating oxidative stress. [35-36]

Studies examining lutein and zeaxanthin levels in extracted cataractous lenses have found up to three-fold higher levels in the newer epithelial tissue of the lens than in the older inner cortex portion. The epithelial cortex layer comprises 50 percent of the tissue, yet it has been found to contain 74 percent of the total lens lutein and zeaxanthin, supporting the hypothesis that these nutrients are protective against the oxidative damage causing cataract formation. [37] The Nurses Health Study examined the effect of 12 years of carotenoid consumption on the risk of cataract formation in 77,466 female nurses, ages 45 and over. After controlling for other risk factors, nurses in the highest quintile for lutein and zeaxanthin consumption had a 22-percent decreased risk for cataract extraction, compared with those in the lowest quintile. [38] Numerous other observational studies have found that increased consumption of foods high in lutein/zeaxanthin is associated with a decreased risk for cataracts or cataract extraction in both men and women. These studies provide strong evidence for a protective role for lutein/zeaxanthin against development of cataracts. [39,40]

The only randomized, double-blind trial on carotenoid supplementation and age-related cataracts measured visual acuity, glare sensitivity, and serum carotenoid levels in 17 clinically diagnosed patients. Patients received 15 mg lutein three times weekly for two years and were compared to patients receiving 100 mg alpha-tocopherol or placebo for the same period. In patients receiving lutein, statistically signi .cant improvements in visual acuity and glare sensitivity and increased serum concentrations of lutein were observed, compared to the alpha-tocopherol and control patients. [41]

Return to the LUTEIN Page

Return to the ZEAXANTHIN Page