Bottom Line: There is no evidence that lutein can treat cataracts or cancer. There is some evidence that a diet containing lutein-rich fruits and vegetables can lower the risk of colon cancer.
Lutein is a natural pigment synthesized by plants and microorganisms. Because it is an antioxidant, cancer prevention activity has been proposed, but no studies have proved this. Scientists also think that lutein may stimulate the immune system, inhibit the mutation of DNA, or inhibit the growth of pre-cancerous cells. Lutein has been associated with a decreased risk of macular degeneration and cataracts, although researchers are uncertain how lutein exerts this effect. In addition, studies in animals and human subjects have shown that high lutein intake can prevent the progression of atherosclerosis.
As an antioxidant Laboratory and clinical data support this use.
To prevent cancer One population-based study showed that higher intake of foods rich in lutein is associated with a lowered risk of developing colon cancer. but another review of the clinical trials revealed that this effect is small. Dietary lutein does not reduce the risk of lung cancer, and its effects on cervical cancer are mixed. There is no proof that lutein can treat cancer.
To treat cataracts Population-based studies in humans found that eating lutein-rich foods was associated with reduced risk of developing cataracts. There is no evidence that lutein can treat cataracts or that lutein supplementation will have the same effect as dietary lutein.
To prevent and treat macular degeneration A few clinical trials support this use, but others have found no effect of lutein consumption on macular degeneration. Also, there is not enough evidence that lutein can treat macular degeneration.
For increased visual acuity Clinical trials support this use in patients with degenerative diseases of the retina.
Retinitispigmentosa ormacular degeneration: A small study evaluated the use of lutein supplements by recruiting subjects with retinitis pigmentosa or macular degeneration via the Internet. Sixteen patients took 40 mg of lutein daily for nine weeks, followed by 20 mg daily for 17 weeks. Ten patients also took DHA. Every two weeks, patients performed a self-evaluation of visual acuity, and overall, reported eyesight improvements after beginning lutein supplementation. Effects were strongest in individuals with blue eyes. The results from this study are not very reliable due to the fact that several patients took DHA, vitamin B complex, digestive enzymes, vitamin A and/or beta-carotene in combination with their lutein therapy, making it unclear whether the positive effects were a result of the lutein or these other supplements. Cataracts: In this large study, 35,551 female participants were followed for 10 years to compare the intake of dietary lutein and cataract. Women who reported high dietary consumption of lutein were less likely to develop cataract, indicating that eating lutein-rich foods may reduce risk of cataract. Further clinical studies of patients taking lutein supplements or placebo are needed to determine if these protective effects were due to dietary lutein alone.
Prevention of colon cancer: In a large population-based study, researchers collected data from 1993 patients with adenocarcinoma of the colon and 2410 healthy control subjects to compare the intake of dietary antioxidants and the risk of colon cancer. Patients who reported a higher intake of foods containing lutein (such as spinach, broccoli, lettuce, tomatoes, oranges and orange juice, carrots, and celery) were found to have a significantly lower risk of developing colon cancer.
This product is regulated by the FDA as a dietary supplement. Unlike approved drugs, supplements are not required to be manufactured under specific standardized conditions. This product may not contain the labeled amount or may be contaminated. In addition, it may not have been tested for safety or effectiveness.
A natural pigment synthesized by plants and microorganisms, lutein is used primarily as an antioxidant and also to prevent and treat cancer, heart disease, and macular degeneration. Lutein has antioxidant activity (1) and is classified as a nonprovitamin A carotenoid, which also includes lycopene and zeaxanthin. Alpha-carotene, beta-carotene, and beta-cryptoxanthin are classified as provitamin A carotenoids because they can be converted into retinol. Epidemiologic studies suggest an inverse relationship between increased lutein consumption and decreased incidence of atherosclerosis (2) and cataracts (3)(4) although the effects of dietary lutein on macular degeneration are inconsistent (5)(6)(7). Conclusions from a systematic review and meta-analysis suggest that the current evidence is insufficient to support use of lutein and other dietary antioxidants to prevent early age-related macular degeneration (7)(8).
Inverse associations have been reported between lutein consumption and risk of colon cancer (9) and renal cell carcinoma (19). A recent meta-analysis found a modest association between dietary lutein and colorectal cancer (10). Data on the effects of dietary lutein intake and cervical cancer risk are conflicting, (11)(12) whereas no association was found between lutein and lung cancer risk (13). No significant adverse effects or drug interactions have been reported.
Lutein is a natural pigment synthesized by plants and microorganisms. Lutein accumulates in the retina and lens, and has been associated with a decreased risk of macular degeneration and cataracts (14). Although the physiologic function of lutein in the macular membranes is not known, it is hypothesized that it may protect the retina from oxidative damage (15)(16). Referred to as a nonprovitamin A carotenoid, it is not known to have any vitamin A activity. Other possible actions for carotenoids are antioxidant (1), immune enhancement, inhibition of mutagenesis and transformation, and inhibition of premalignant lesions. Lutein has been associated with decreased risk of colon cancer (9) and atherosclerosis (2).
Absorption: Intestinal absorption of carotenoids, including lutein, is facilitated by the formation of bile acid micelles containing carotenoids. The presence of fat in the small intestine stimulates the secretion of bile acids from the gall bladder and improves the absorption of carotenoids by increasing the size and stability of the micelles, thus allowing more carotenoids to be solubilized. Bioavailability of lutein is affected by the dose and presence of other carotenoids such as Beta carotene. The bioavailability of lutein from vegetables is approximately 70% (16). Distribution: The concentrations of various carotenoids in human serum and tissues are highly variable and depend on food sources, efficiency of absorption, and amount of fat in the diet. Lutein is transported by high-density lipoprotein (HDL) and, to a lesser extent, by very low-density lipoprotein. The serum concentration of carotenoids after a single dose peaks at 24 to 48 hours post dose. The average lutein concentration in human serum is 280 nM (1). Lutein is primarily stored in adipose and the liver. Of all the carotenoids circulating in the body, only two polar species, lutein and zeaxanthin, are contained in the macula (17). Metabolism/Excretion: It is assumed that lutein is excreted through the bile and kidneys (14).
No adverse effects have been reported at normal doses. (14) Toxicity: Carotenodermia is a harmless biological effect of high carotenoid intake. Characterized by a yellowish discoloration of the skin, it results from chronically elevated serum concentrations of carotenes.
Christen WG, et al. Dietary carotenoids, vitamins C and E, and risk of cataract in women: a prospective study. Arch Ophthalmol. Jan 2008;126(1):102-109. To determine the effects of dietary carotenoids on cataract formation in women, this prospective observational study was undertaken with 35,551 female participants for 10 years. Cataract formation and visual acuity were the primary outcome measures. Reduced risk of cataract formation (18%) was associated with increased dietary lutein/zeaxanthin intake. Randomized, clinical trials of lutein/zeaxanthin in both men and women are necessary to determine if lutein supplementation may also reduce cataract risk.
