A comparison of eye-health nutrients, lutein (L)/zeaxanthin (Z) Intakes and L/Z rich food choices between college students living in Los Angeles and Taiwan.
Age-related macular degeneration (AMD) is a devastating deterioration happening on macula, the posterior area of retina, controlling the fine, detailed and sharp vision. AMD is the leading cause of blindness in older people in the Western World (Congdon et al., 2004; Munoz et al., 2000; Wang, Foran & Mitchell., 2000; Weih, VanNewkirk, McCarty & Taylor, 2000; klaver et al., 1998; Klein, Rowland & Harris, 1995). With the increasing life expectancy of most populations, the incidence and prevalence of AMD is inevitably increasing worldwide. The Age-related Eye Disease Study (AREDS) Research Group announces that approximately 8 million U.S. people older than 55 years old have the potential to develop advanced AMD within 5 years and will render a public health impact (Bressler et al., 2003). The Eye Disease Prevalence Research Group proclaims that it is currently affecting more than 1.75 million individuals in the United States and with the rapid increase of aging population in the U.S., 3 million of AMD cases are expected by 2020 (Friedman et al., 2004).
Most epidemiological researches support the belief that dietary intake plays a decisive role in the development of AMD (Seddon & Chen, 2004; AREDS, 2001; Snodderly, 1995). A growing body of evidence indicates that lutien and zeaxanthin (L/Z) are two most crucial carotenoids for macular health (Hammond, Wooten & Snodderly, 1998; Hammond & Wooten, 2005). L/Z is named as Macular Pigments (MP) (Snodderly, Auran & Delori, 1984) because they are 5 fold higher concentrations in the macular retina than in the peripheral retina and account for the yellow color of the macula.
AMD is varied with geographic distribution and ethnic groups (Klein, Peto, Bird & Vannewkirk, 2004). In Asia, the World Health Organization (WHO) estimates approximately 20 million Aisans are blind (Thylefors, Negrel, Pararajasegaram & Dadzie, 1995). Instead of AMD, the main causes of blindness in Asians are found to be cataract and undercorrected refractive errors in most studies (Wong, Loon & Saw, 2006). Compared with that AMD accounts for 70% of blind cases and 33% of low vision cases among European-descendents (Munoz et al., 2000), AMD appears to play a minor role in Chinese people for blindness (Xu et al., 2006; Wang, Xu & Jonas, 2006). Whereas in Shihpai Eye Study conducted in Taiwan, retinal diseases (AMD and other retinal or choroidal diseases) serve the leading cause of blindness for Taiwanese (Hsu, Cheng, Liu & Tsai, 2004). This might be a strong indication that westernized diet, physically inactive lifestyles, and increasing life expectancy (Department of Statistics Ministry of the Interior, Taipei, Taiwan, 2006) have brought different eye epidemics in Taiwan. Since MP is exclusive of dietary source (Malinow, Feeney-Burns, Peterson, Klein & Neuringer, 1980), it is noteworthy to probe L/Z dietary consumption in Taiwanese. Although AMD mostly occurs after 65 years old but relative damages are accumulated from younger ages. It is known that L/Z are two most important carotenoids for macular health. The purpose of this study is to examine the dietary L/Z intake and related food preference in college students living in Los Angeles (LA) and in Taiwan (TW).
The population study used a convenient, nonrandomized, biased sampling method due to the location, major, educational level and ethnicity of the surveyed subjects who participated. A total of 240 college students
were recruited in this study, 137 of them enrolled in California State University, Los Angeles (CSULA) and the other 93 were students studying in China Medical University (CMU) in Taichung, Taiwan. The CSULA subjects (LA) consisted of 101 females and 36 males and the CMU students (TW) consisted of 71 females and 22 males.
Each student was assigned to complete a 3-day dietary record and a dietary supplement survey form. The 3-day dietary record was designed to record daily dietary intake on two consecutive weekdays and one weekend day to retrieve more accurate dietary data because the dietary habit may fluctuate between weekdays and weekend days. Dietary supplement survey was added to investigate the use, the intake frequency, the dosage of dietary supplements containing lutein and zeaxanthin for these college students. A total of 137 LA had been trained by a nutritional science professor on how to accurately estimate the serving size of their daily dietary intake and most of them were nutrition majors or nursing majors. A study design and a detailed explanation for the method of this study were translated into Chinese for the TW. A total of 93 Taiwan nutrition students had all been trained in nutrition classes to obtain serving sizes of foods and dietary records.
The results of L/Z consumption from 3-day diet were calculated by Microsoft Excel 2003 and based on the USDA National Nutrient Database for Standard Reference, Release 18 (USDA, 2005). Tropical vegetables which were popular in Taiwan but not listed on the USDA database were categorized as "leafy greens" using the value of "Mustard greens". Food items which did not contain L/Z were all excluded. Cereal which had not been specified its brand was calculated using an average value of all ready-to-eat cereals: 167 mcg (L/Z)/serving. Furthermore, most records also did not specify what kind of bread they took. Therefore, an average value of 14 mcg (L/Z)/serving was used to compute the content of L/Z for bread.
All statistical analysis was performed by Statistical Package for Social Science (SPSS) 12.0 for Windows. Statistical tests set at p value <0.05 were deemed as "significantly different".
Human Characteristics: Independent-t-test was used to compare the differences of gender, age, weight, height, BMI between LA and TW. Mann-Whitney test was run for age, weight, BMI to correct the statistic outcome of Independent-t-test.
L/Z Intake: The intake of L/Z was compared between groups and between genders using Independent-t-test. All data were expressed as mean [+ or -] standard error of mean (SEM).
Top Ten Food Choices Containing L/Z: Top ten food choices which contained L/Z were determined based on their frequencies in different groups and in different genders as well. The results were expressed as frequency (%) and mean serving size [+ or -] standard deviation (SD)
L/Z Supplement Survey: The results of the usage of dietary supplements which contained L/Z were analyzed by descriptive statistics and expressed as frequency (%). The difference between LA and TW was compared by Independent-t-test.
LA's average age was of 24.5 [+ or -] 5.6 years (ranging from 18.9 to 30.1 years). The mean weight was 61.4 [+ or -] 15.8 kg (ranging from 45.6 to 77.2 kg) and the mean height was 1.64 [+ or -] 0.09 m (ranging from 1.55 to 1.73 m). The mean BMI was 22.7 [+ or -] 4.8 kg/[m.sup.2] (ranging from 17.9 to 27.5 kg/[m.sup.2]).
TW's average age was of 22.1 [+ or -] 1.3 years (ranging from 20.8 to 23.4 years) and the mean weight was 56.2 [+ or -] 10.0 kg (ranging from 46.2 to 66.2 kg). The mean height was 1.64 [+ or -] 0.08 m (ranging from 1.56 to 1.72 m). The mean BMI was 20.7 [+ or -] 2.5 kg/[m.sup.2] (ranging from 18.2 to 23.2 kg/[m.sup.2]).
There were no significant differences shown in age, height but significant differences were found in weight and BMIs between LA and TW. The results revealed that the weight of LA was approximately 5 kg heavier than those of TW and the BMIs of LA were 2 kg/[m.sup.2] more than those of TW.
The Intake of L/Z
Comparisons within LA: LA's mean intake of L/Z was 4149.4 [+ or -] 467.5 mcg/day. After adjusted for gender, the mean L/Z intake of 101 LA females was 4142.4 [+ or -] 548.9 mcg/day. The mean L/Z intake of 36 LA males was 4169.1 [+ or -] 903.9 mcg/day. LA males ate more L/Z than those of LA females but not significantly different.(Table 2) Comparisons within TW: TW's mean intake of L/Z was 4994.2 [+ or -] 533.4 mcg/day. After adjusted for gender, the mean L/Z intake of 71 TW females was 4920.4 [+ or -] 543.3 mcg/day. The mean L/Z intake of 22 TW males was 5232.4 [+ or -] 1445.8 mcg/day. TW males ate more L/Z than those of TW females but not significantly different. (Table 2)
Comparisons between LA and TW: The overall comparisons between LA and TW revealed that there was no significant difference found on L/Z intake between LA (4 mg) and TW (5 mg); however, the intake of L/Z of both groups were lower than the recommended intake of 6 mg of L/Z (Eye Disease Case-Control Study Group, 1994).
When compared by gender between different groups, there were no significant differences found on the consumption of L/Z.(Table 2)
Top Ten Food Choices containing L/Z and their Serving Size
Top ten food choices for LA: They were chosen out of 60 food items containing L/Z which were listed LA's on 3-day dietary records (N=137). Top tens for LA were bread, banana, apple, orange juice, lettuce, cereal, egg, tomato, orange, and broccoli. Orange and orange juice both appeared in the list of top tens (Table 3). Those two foods did not show up on the list of TW's top tens (Table 4).
Top ten food choices of LA adjusted for gender: After adjusted for gender, top ten food choices and the mean serving size for LA females and LA males are shown in Table 3. LA females' top ten food items were similar to LA's general top tens but in different order. Grape, however, was added into top tens for LA males.
Top ten food choices for TW: As for TW, the top ten food choices were chosen out from 38 food items which contained L/Z were listed on TW's 3-day dietary records (N=93). The top ten food items of TW were egg, leafy greens, cabbage, bread, mix vegetables, carrot, lettuce, tomato, apple and cucumber. (Table 4)
Top ten food choices of TW adjusted for gender: After adjusted for gender, top ten food choices and the mean serving size for TW females and TW males are shown in Table 4. Regardless of gender, egg was always the top one food item comprising L/Z for the TW. Broccoli and corn appeared on the list of TW females' top tens to replace cucumber which was one of top ten food items for all participants. Pakchoy showed up on the list of TW males' top tens instead of apple which was one of the general top tens for the TW.(Table 4)
Lutein and Zeaxanthin Supplement Survey
The total survey forms of dietary supplements collected were 178 copies including 85 of LA and 93 of TW. Among the totals of 178 copies, only 1.7% of them reported their supplements containing L/Z and another 3.4% announced that their supplements containing lutein only. After adjusted for groups, 2.4% of LA was taking something containing L/Z and the other 4.7% was taking supplements containing lutein only. 1.1 % of TW was taking some kind of supplements containing L/Z and 2.4% was taking supplements containing lutein only. When compared the dosage of L/Z or of lutein in students' dietary supplements and the interval when they took them between LA and TW, there were no significant differences found in any way.
Lutein and Zeaxanthin
Lutein is abundant in perifoveal region but zeaxanthin is particularly abundant in foveal area (Bone et al., 1997; Bone, Landrum, Hime, Cains & Zamor, 1993; Snodderly, Handelman & Adler, 1991). L/Z of about 40 to 50 carotenoids consumed in typical Western diet (Khachik, Beecher, Goli, Lusby & Daitch, 1992a; Khachik, Beecher, Goli & Lusby, 1992b), are two hydroxyl-carotenoids ([C.sub.40][H.sub.56][O.sub.2]) with antioxidant activity. Oxidative damage has been proposed to play an important role in the induction of AMD. The antioxidant property of L/Z has been inferred to be able to quench free radicals, to absorb blue light and the functions of L/Z have been postulated to effectively protect macula against AMD (Landrum, Bone & Kilburn, 1997a; Snodderly, 1995; Wyszechi & Stiles, 1982). Higher ocular L/Z in normal elderly population seemed to provide better lenticular transmission and higher retinal sensitivity than those with lower L/Z concentration (Hammond & Wooten, 2005; Hammond et al., 1998). The supplementation of L/Z from diet and dietary supplements have been found to increase macular pigment optical density (MPOD) 4 to 5% (Berendschot et al., 2000; Landrum et al., 1997; Ciulla et al, 2001; Bone, Landrum, Dixon, Chen & Llerena, 2000; Curran-Celantano et al., 2001; Koh et al. 2004). Futhermore, high lutein serum level may protect carotid intima from thickening and reduce the risk for coronary heart disease (Dwyer et al., 2001; Iribarren et al., 1997).
Previous researches revealed that approximately 78% of dietary L/Z is from vegetable sources, especially concentrated in leafy green vegetables, many fruits and colored vegetables such as squash, sweet peppers, sweet corn, spinach, collards, kale, guava and peas. Animal sources include milk, egg yolk, and even human breast milk (khachik et al., 1997). Average L/Z intake differs from 0.3 to 6 mg per day among different populations (Mares-Perlman et al., 2001; Landrum & Bone, 2001; Goldbohm, Brants, Hulshof & van den Brandt, 1998; Michaud et al., 1998). Most adults aged older than 40 years consumed 1 to 3 mg in NHANES III (Mares-Perlman et al., 2001). In the current study, both of LA females (4142.4 [+ or -] 548.9 mcg/day) and males (4169.1 [+ or -] 903.9 mcg/day) averagely consumed L/Z 4mg per day. Both of TW females (4920.4 [+ or -] 543.3 mcg/day) and males (5232.4 [+ or -] 1445.8 mcg/day) consumed one mg/day more than those of the LA but without statistical significance of the means (Table 2). There are reasons to explain why our surveyed subjects consumed more than those of average Americans. One was that the USDA has updated the L/Z database with more than thousands of food items in 2005 (USDA, 2005) and the new database was used to compute L/Z intakes in this study. The other may be owing to sampling bias since our subjects were all taking nutrition science courses.
White rice, the main grain for the TW did not contain any L/Z; therefore, it was excluded from the calculation of L/Z intake and hence, it was not included on the list of top tens in TW (Table 4). It's noteworthy that in this study, none of the highest L/Z rich food items, such as spinach (raw: 3659 mcg/serving; cooked: 20354 mcg/serving), collards (cooked: 14619 mcg/serving), or kale (cooked: 23720 mcg/serving) is shown on the list of the top ten food choices for either the LA or the TW (Table 3 and 4). This may indicate that the poor understanding and unfamiliarity of the general public regarding L/Z rich content foods. Dietitians and nutrition specialists need to educate the general public for the intakes of L/Z containing foods.
The intake of L/Z in LA and TW were statistically similar but the L/Z sources were quite different (Table 3 and 4). Egg was the top one food choice which contained rich L/Z in the TW. Even after the adjustments for gender, it was still the top one for both genders in the TW (Table 4). Approximately 80 % of TW took 0.2-1.0 egg per day, whereas 42% LA took egg and egg was merely the 7th food choice in the LA (0.3-1.1 egg/day) (Table 3). The egg preference in LA (42%) was about half that of TW (80%) (Table 3 and 4). Abundant studies identify that lutein bio-availability was better from eggs than from supplements or even from spinach (Chung, Rasmussen & Johnson, 2004). Lutein obtained from vegetable sources increases serum lutein level 20-40 nmol/L for each milligram of lutein ingested (Hammond et al., 1997a; Yeum et al., 1996). Lutein obtained from lutein ester or lutein supplements increases serum lutein concentration 40-75 nmol/L for each milligram of lutein ingested (van bet Hof, et al., 1999; Bowen, Herbst-Espinosa, Hussain & Stacewicz-Sapuntzakis, 2002). However, lutein obtained from egg yolk increases serum lutein level 110-350 nmol/L for each milligram of lutein ingested (Surai, MacPherson, Speake & Sparks, 2000; Handelman, Nightingale, Lichtenstein, Schaefer & Blumberg, 1999). One titbit is that although Taiwan is a banana paradise but banana seemed not to be consumed by Taiwan college students. (Table 4) On the contrary, banana was chosen on the top tens list for both genders in the LA.
Dietary intake of L/Z is significantly and positively related to serum L/Z (Hammond, Ciulla & Snodderly, 2002; Rock et al., 2002; Ciulla et al., 2001; Bone et al., 2000; Carroll, Corridan & Morrissey, 1999; Hammond et al., 1996; Brady, Mares-Perlman, Bowen & Stacewicz-Sapuntzakis, 1996). Instead of lutein is carried by low-density lipoprotein (LDL), zeaxanthin is transported by high-density lipoprotein (HDL) in serum. The serum level of L/Z is linked with processing of food materials, digestion of the food matrix, the formation of lipid micelles, uptake of the carotenoids by mucosal cell, competition of carotenoids by adipose tissue, transport of the carotenoids to the lymphatic or portal circulation (Whitehead, Mares & Danis, 2006; Erdman, Bierer & Gugger, 1993). The processing of foods were quite different in LA and in Taiwan, for example, LA preferred more raw vegetables and salads to cooked vegetables but TW liked to have stir-fry mixed vegetables. Therefore, the intake of L/Z may be similar but the L/Z bioavailability could be fairly varied.
Serum L/Z level is also found to vary with smoking, heavy drinking, ethnicity/race, gender, physical activity, fat-free mass, percentage of fat mass, waist-hip ratio, serum cholesterol, white blood cell count and level of C-reactive protein (Gruberet al., 2004). Especially, smoking is distinctly marked out to raise 2 to 3-fold risk of AMD and is the only risk factor to influence the 5-year incidence for AMD (Thornton et al., 2005; Miyazaki et al., 2003). In the current study, smoking was not included in demographic survey (Table 1). Accordingly, we could not adjust L/Z intake for smokers and nonsmokers to examine the possible variety between them. We suggest that smoking should be taken into account in the demographic investigation in our future study.
Patients with AMD are living in a fuzzy, color-washed-out world. In addition of visual impairment, the quality of life is severely lowered by AMD. AMD causes visional impairment especially in the daily activities such as recognition of families' faces, reading newspapers and labels on household items, watching TV and driving (McGwin, Chapman & Owsley, 2000; Wood, 2002; Owsley, McGwin, Sloane, Stalvey & Wells, 2001; Hassan, Lovie-Kitchin & Woods, 2002). Moreover, approximately one-third of AMD patient comorbid with some degree of depression (Brody et al., 2001; Casten, Rovner & Tasman, 2004; Dong et al., 2004). This also causes the increase of health care expenses due to physical limitation, more falls and disability of older people and the demand for residential nursing care (Klein, Moss, Klein, Lee & Cruickshanks, 2003).
Based on increasing understanding on the physiology of MP and pathology of macular degeneration, a growing body of evidence has demonstrated that supplementation with foods rich in L/Z or L/Z supplements increased MP density in most human studies (Berendschot et al., 2000; Hammond et al., 1997b; Landrum et al., 1997b). This has drawn people's attention to identify more effectively preventive strategies to avoid visual loss (Friedman et al., 2004), such as to eat more dark green leafy vegetables, wear UV protective lenses and a hat (Mozaffarieh, Sacu & Wedrich, 2003).
Lutein and zeaxanthin supplements
Supplement marketing has been increasing since 1997, an estimated amount of $ 18.8 billion were estimated in 2003 (US Nutrition Industry, 2004). More than half of Americans take dietary supplements every day (Millen, Dodd & Subar, 2004; Radimer et al., 2004) and those supplements often consist of 100% of the daily value of nutrients. The most recent published nationally representative data, the National Health and Nutrition Examination Survey (NHANES), 1999-2000, highlights the importance of assessment of dietary supplement use because of supplements' large contribution to nutrient intake (Radimer et al., 2004). Hall (2005) incoporates the viewpoints of dietetic professionals and encouraged that all dietetic practitioners to expand their insights, comprehension and attentions on the use of dietary supplements.
Receiving lutien supplementation improved visual acuity in AMD patients but not in those who took placebo in an earlier clinical trial (Richer et al., 2004). The AREDS Research Group also confirms that supplementation of zinc, [beta] carotene, Vitamin C and E effectively lower the progression of AMD by 25% (AREDS, 2001). However, L/Z was not included in this NIH-sponsored intervention. In the present study, we also assessed the intake of L/Z supplement. L/Z supplement was not as popular as supplemental multivitamin and multimineral and an estimation of half of Americans took multivitamin and multimineral supplements. Very few subjects (7.1% of LA and 3.3% of TW) in this study were taking dietary supplements which contained L/Z or lutein. The use of L/Z supplements did not differ between groups or genders in our study.
Reedy, Haines, and Campbell (2005) categorized supplement users into:
2) both multivitamin/multimineral and uses of certain vitamins and/or minerals
4) multivitamin/multimineral only
5) single uses of vitamins and/or minerals only
They identified that users of the fourth category probably regarded dietary supplements as nutrient insurance only and not necessary themselves having a healthy dietary pattern or lifestyle. Therefore, as the appeal made by Reedy et al. (2005), reiterating the benefits of natural foods to the general public in particular L/Z rich content foods for AMD disease prevention and health promotion is important in spite of people who are taking dietary supplements or not.
AREDS (Age-Related Eye Disease Study) Research Group, (2001). A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss: AREDS report no. 8. Archives Ophthalmology, 119, 1417-36.
Berendschot, T.T.J.M., Goldbohm, R.A., Klopping, W.A.A., van de Kraats, J., van Norel, J., van Norren, D. (2000). Influence of lutein supplementation on macular pigment, assessed with two objective technique. Investigative Ophthalmology & Visual Science, 41,3322-6.
Bone, R.A., Landrum, J.T., Dixon, Z., Chen, Y., Llerena, C.M. (2000). Lutein and zeaxanthin in the eyes, serum and diet of human subjects. Experimental Eve Rresearch, 71, 239-45.
Bone, R.A., Landrum, J.T., Friedes, L.M., Gomez, C.M., Kilburn, M.D., Menendez, E., et al. (1997). Distribution of lutein and zeaxanthin stereoisomers in the human retina. Experimental Eye Research, 64, 211-8.
Bone, R.A., Landrum, J.T., Hime, G.W., Cains, A., Zamor, J. (1993). Stereochemistry of the human macular carotenoids. Investigative Ophthalmology & Visual Science, 34, 2033-40.
Bowen, P. E., Herbst-Espinosa, S. M., Hussain, E. A. & Stacewicz-Sapuntzakis, M. (2002). Esterification does not impair lutein bioavailability in humans. The Journal of Nutrition, 132, 3668-73.
Brady, W.E., Mares-Perlman, J.A., Bowen, P., Stacewicz-Sapuntzakis, M. (1996). Human serum carotenoid concentrations are related to physiologic and lifestyle factors. The Journal of Nutrition, 126(1), 129-37.
Bressler, N.M., Bressler, S.B., Congdon, N.G. Ferris, F.L. 3rd, Friedman, D.S., Klein, R., et al. (2003). Potential public health impact of Age-Related Eye Disease Study results: AREDS Report no. 11. Archives Ophthalmology, 121, 1621-4.
Brody, B.L., Gamst, A.C., Williams, R.A., Smith, A.R., Lau, P.W., Dolnak, D., et al. (2001). Depression, visual acuity, comorbidity, and disability associated with age-related macular degeneration. Ophthalmology, 108, 1893-1900.
Carroll, Y.L., Corridan, B.M., Morrissey, P.A. (1999). Carotenoids in young and elderly healthy humans: dietary intakes, biochemical status and diet-plasma relationships. European Journal of Clinical Nutrition, 53, 644-53.
Casten, R.J., Rovner, B.W., Tasman, W. (2004). Age-related macular degeneration and depression: A review of recent research. Current Opinion in Ophthalmology, 15(3), 181-3.
Chung, H.Y., Rasmussen, H.M., Johnson, E.J. (2004). Lutein bioavailability is higher from lutein-enriched eggs than from supplements and spinach in men. The Journal of Nutrition, 134, 1887-93.
Ciulla, T.A., Curran-Celantano, J., Cooper, D.A., Hammond, B.R. Jr., Danis, R.P., Pratt, L.M.. et al. (2001). Macular pigment optical density in a midwestern sample. Ophthalmology, 108(4), 730-7.
Congdon, N., O'Colmain, B., Klaver, C.C., Klein, R., Munoz, B., Friedman, D.S., et al., Eye Diseases Prevalence Research Group, (2004).
Causes and prevalence of visual impairment among adults in the United States. Archives Ophthalmology, 122,477-85.
Curran-Celentano, J., Hammond, B.R. Jr., Ciulla, T.A., Cooper, D.A,, Pratt, L.M., Danis, R.B. (2001). Relation between dietary intake, serum concentrations, and retinal concentrations of lutein and zeaxanthin in adults in a Midwest population. The American Journal of Clinical Nutrition, 74(6), 796-802.
Department of Statistics Ministry of the Interior, Taipei, Taiwan, (2006). Retrieved Sep/08/2006 from http://www moi.gov.tw/stat/
Dong, L.M., Childs, A.L., Mangione, C.M., Bass, E.B., Bressler, N.M., Hawkins, B.S., et al., Submacular Surgery Trials Research Group, (2004). Health- and vision-related quality of life among patients with choroidal neovascularization secondary to age-related macular degeneration at enrollment in randomized trials of submacular surgery SST Report no. 4. American Journal of Ophthalmology, 138, 91-108.
Dwyer, J. H., Navab, M., Dwyer, K. M., Hassan, K., Sun, P., Shircore, A., et al. (2001 ). Oxygenated carotenoid lutein and the progression of early atherosclerosis: The Los Angeles atherosclerosis study. Circulation, 103, 2922-7.
Erdman, J.W. Jr., Bierer, T.L., Gugger, E.T., (1993). Absorption and transport of carotenoids. Annals of the New York Academy of Sciences, 691, 76-85.
Eye Disease Case-Control Study Group, (1994). Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. The Journal of American Medical Association. 272(18), 1413-20. Erratum in: JAMA 1995 Feb 22, 273(8), 622.
Friedman, D.S., O'Colmain, B.J., Munoz, B., Tomany, S.C., McCarty, C., de Jong, P.T., et al. Eye Diseases Prevalence Research Group, (2004). Prevalence of age-related macular degeneration in the United States. Archives Ophthalmology, 122, 564-72.
Goldbohm, R.A., Brants, H.A., Hulshof, K.F., van den Brandt, P.A. (1998). The contribution of various foods to intake of vitamin A and carotenoids in The Netherlands. International Journal for Vitamin and Nutrition Research, 68(6), 378-83.
Gruber, M., Chappell, R., Millen, A., LaRowe, T., Moeller, S.M., Iannaccone, A. (2004). Correlates of serum lutein + zeaxanthin: findings from the Third National Health and Nutrition Examination Survey. The Journal of Nutrition, 134, 2387-94.
Hall, R., 2005. Including dietary supplements in nutrition assessment. Journal of American Dietetic Association, 105( 11 ), 1757.
Hammond, B.R., Wooten, B.R. (2005). CFF Thresholds: Relation to macular pigment optical density. Ophthalmic and Physiological Optics, 25(4), 315-9.
Hammond, B.R. Jr., Ciulla, T.A., Snodderly, D.M. (2002). Macular pigment density is reduced in obese subjects. Investigative Ophthalmology & Visual Science, 43(1), 47-50.
Hammond, B.R. Jr., Wooten, B.R., Snodderly, D.M. (1998). Preservation of visual sensitivity of older individuals: association with macular pigment density. Investigative Ophthalmology & Visual Science, 39, 397-406.
Hammond, Br. Jr., Johnson, E.J., Russel, R.M., Krinsky, N.I., Yeum, K.J., Edwards, R.B., et al. (1997a). Dietary modification of human macular pigment density. Investigative Ophthalmology & Visual Science, 38, 1795-1801.
Hammond, Jr. B.R., Johnson, E.J., Russell, R.M.. Krinsky, N.I., Yeum, K.J., Edwards, R.B., et al. (1997b). Dietary modification of human macular pigment density. Investigative Ophthalmology & Visual Science, 38, 1795-1801.
Hammond, B.R. Jr., Curran-Celentano, J., Judd, S., Fuld, K., Krinsky, N.I., Wooten, B.R., et al. (1996). Sex differences in macular pigment optical density: relation to plasma carotenoid concentrations and dietary patterns. Vision Research, 36, 201-212.
Handelman, G. J., Nightingale, Z. D., Lichtenstein, A. H., Schaefer, E. J., Blumberg, J. B. (1999). Lutein and zeaxanthin concentrations in plasma after dietary supplementation with egg yolk. American Journal of Clinical Nutrition, 70, 247-251.
Hassan, S.E., Lovie-Kitchin, J.E., Woods. R.L. (2002).Vision and mobility performance of subjects with age-related macular degeneration. Optometry and Vision Science, 79, 697-707.
Hsu, W.M., Cheng, C.Y., Liu, J.H., Tsai, S.Y. (2004). Prevalence and causes of visual impairment in an elderly Chinese population in Taiwan: the Shihpai Eye Study. Ophthalmology, 111(1), 62-9.
Iribarren, C., Folsom, A. R., Jacobs, D. R., Gross, M. D., Belcher, J. D., Eckfeldt, J. H. (1997). Associations of serum vitamin levels, LDL susceptibility to oxidation, and autoantibodies against MDA-LDL with carotid atherosclerosis. Arteriosclerosis, Thrombosis, and Vascular Biology, 17, 1171-7.
Khachik, F., Spangler, C.J., Smith, J.C. Jr., Canfield, L.M., Steck, A., Pfander, H. (1997). Identification, quantification, and relative concentrations of carotenoids and their metabolites in human milk and serum. Analytical Chemistry, 69, 1873-81.
Khachik, F.. Beecher, G.R., Goli, M.B., Lusby, W.R., Daitch, C.E. (1992a). Seperation and quantification of carotenoids in human plasma. Methods in Enzymology, 213, 205-19.
Khachik, F., Beecher, G.R., Goli, M.B., Lusby, W.R. (1992b). Seperation and quantification of carotenoids in foods. Methods in Enzymology, 213, 347-59.
Klaver, C.C., Wolfs, R.C., Assink, J.J., van Duijn, C.M., Hofman, A., de Jong, P.T., (1998). Genetic risk of age-related maculopathy. Population-based familial aggregation study.
Archives Ophthalmology, 116(12), 1646-51 Klein, R., Peto, T., Bird, A., Vannewkirk, M.R. (2004). The epidemiology of age-related macular degeneration. American Journal of Ophthalmology, 137(3), 486-95.
Klein. B.E., Moss, S.E,. Klein, R., Lee, K.E., Cruickshanks, K.J. (2003). Associations of visual function with physical outcomes and limitations 5 years later in an older population. The Beaver Dam Eye Study. Ophthalmology, 110, 644-50.
Klein, R., Rowland, M.R., Harris, M.I. (1995). Racial/ethnic differences in age-related maculopathy. Third National Health and Nutrition Examination Survey. Ophthalmology, 102, 371-8
Koh, H.H., Murray, I.J., Nolan, D., Carden, D., Feather, J., Beatty, S. (2004). Plasma ad macular responses to lutein supplement in subjects with and without age-related maculopathy: a pilot study. Experimental Eve Research, 79, 21-27.
Krishnadas, R., Nirmalan, P.K., Ramakrishnan, R., Thulasiraj, R.D., Katz, J., Tielsch, J.M., et al. (2003). Pseudoexfoliation in a rural population of southern India: the Aravind comprehensive Eye Survey. American Journal of Ophthalmology, 135, 830-7.
Landrum, J.T., Bone, R.A. (2001). Lutein, zeaxanthin, and the macular pigment. Archives of Biochemistry and Biophysics, 385(1), 28-40.
Landrum, J.W., Bone, R.A., Kilburn, M.D. (1997a). The macular pigment : a possible role in protection from age-related macular degeneration. Advances in Pharmaceutical Sciences, 38, 537-56.
Landrum, J.T., Bone, R.A., Joa, H., Kilburn, M.D., Moore, L.L., Sprague, K.E. (1997b). A one year study of the macular pigment: the effect of 140 days of a lutein supplement. Experimental Eye Research, 65, 57-62.
Malinow, M.R., Feeney-Burns, L., Peterson, L.H., Klein, M.L., Neuringer, M. (1980). Diet-related macular anomalies in monkeys. Investigative Ophthalmology & Visual Science, 19, 857-63.
Mares-Perlman, J.A., Fisher, A.I., Klein, R., Palta, M., Block, G., Millen, A.E., et al. (2001). Lutein and zeaxanthin in the diet and serum and their relation to age-related maculopathy in the third national health and nutrition examination survey. American Journal of Epidemiology, 153(5), 424-32.
McGwin, G. Jr., Chapman, V., Owsley, C. (2000). Visual risk factors for driving difficulty among older drivers. Accident; Analysis and Prevention, 32, 735-44.
Michaud, D.S., Giovannucci, E.L., Ascherio, A., Rimm, E.B., Forman, M.R., Sampson, L., et al. (1998). Associations of plasma carotenoid concentrations and dietary intake of specific carotenoids in samples of two prospective cohort studies using a new carotenoid database. Cancer Epidemiology, Biomarkers & Prevention, 7(4), 283-90.
Millen, A.E., Dodd, K.W., Subar, A.F. (2004). Use of vitamin, mineral, nonvitamin, and nonmineral supplements in the United States: The 1987, 1992, and 2000 National Health Interview Survey Results. Journal of American Dietetic Association, 104, 942-50.
Miyazaki, M., Nakamura, H., Kubo, M., Kiyohara, Y., Oshima, Y., Ishibashi, T., et al. (2003). Risk factors for age related maculopathy in a Japanese population: the Hisayama study. The British Journal of Ophthalmology, 87, 469-72.
Mozaffarieh, M., Sacu, S., Wedrich, A. (2003). The role of the carotenoids, lutein and zeaxanthin, in protecting against age-related macular degeneration: a review based on controversial evidence, Nutrition Journal, 11(2), 20.
Munoz, B., West, S.K., Rubin, G.S., Schein, O.D., Quigley, H.A., Bressler, S.B., et al., SEE Project Team, (2000). Causes of blindness and visual impairment in a population of older Americans: the Salisbury Eye Evaluation Study. Archives Ophthalmology, 118, 819-25.
Owsley, C., McGwin, Jr. G., Sloane, M.E., Stalvey, B.T., Wells, J. (2001). Timed instrumental activities of daily living tasks: Relationship to visula function in older adults. Optometry and Vision Science, 78,350-60.
Radimer, K., Bindewaid, B., Hughes, J., Ervin, B., Swanson, C., Picciano, M.F. (2004). Dietary supplement use by US adults: data from the Naitonal Health and Nutrition Examination Survey, 1999-2000. American Journal of Epidemiology, 160(4), 339-49.
Reedy, J., Haines, P.S., Campbell, M.K. (2005). Differences in fruit and vegetable intake among categories of dietary supplement users. Journal of the American Dietetic Association, 105(11), 1749-56.
Richer, S., Stiles, W., Statkute, L., Pulido, J., Frankowski, J., Rudy, D., et al. (2004). Double masked, placebo-controlled, randomized trial of lutein and antioxidant supplementation in the intervention of atrophic age-related macular degeneration: the Veterans LAST study (Lutein Antioxidant Supplementation Trial). Optometry, 75, 216- 30.
Rock, C.L., Thornquist, M.D., Neuhouser, M.L., Kristal, A.R., Neumark-Sztainer, D., Cooper, D.A., et al. (2002). Diet and lifestyle correlates of lutein in the blood and diet. The Journal of Nutrition, 132, 525-30.
Seddon, J.M., Chen, C.A. (2004). The epidemiology of age-related macular degeneration. International Ophthalmology Clinics, 44, 17-39.
Snodderly, D.M. (1995). Evidence for protection against age-related macular degeneration by carotenoids and antioxidant vitamins. The American Journal of Clinical Nutrition, 62, 1448S-61S.
Snodderly, D.M., Handelman, G.J., Adler, A.J. (1991). Distribution of individual macular pigment carotenoids in the central retina of macaque and squirrel monkeys. Investigative Ophthalmology & Visual Science, 32, 268-79.
Snodderly, DM., Auran, J.D., Delori, F.C. (1984). The macular pigment. II. Spatial distribution in primate retinas. Investigative Ophthalmology & Visual Science, 25, 674-85.
Surai, P. F., MacPherson, A., Speake, B. K., Sparks, N. H. (2000). Designer egg evaluation in a controlled trial. European Journal of Clinical Nutrition, 54, 298-305.
Thornton, J., Edwards, R., Mitchell, P., Harrison, R.A., Buchan, I., Kelly, S.P. (2005). Smoking and age-related macular degeneration: a review of association. Eye, 19(9), 935-44.
Thylefors, B., Negrel, A.D., Pararajasegaram, R. Dadzie, K.Y., (1995). Global data on blindness. Bulletin of the World Health Organization, 73, 115-21.
USDA (U.S. Department of Agriculture), Agricultural Research Service. (2005). USDA national nutrient database for standard reference, release 18. Nutrient Data Laboratory Home Page, http://www.nal.usda.gov./fnic/foodcomp
US Nutrition Industry: Top 70 supplements 1997-2001, (2004). Nutrition Business Journal, htt ://storeyahoo.com/nbj/nbsupbusrep2.html
Van Het Hof, K. H., Brouwer, I. A., West, C. E., Haddeman, E., Steegers-Theunisson, R. P., van Dusseldorp, M., et al. (1999). Bioavailability of lutein from vegetables is 5 times higher than that of beta-carotene. The American Journal of Clinical Nutrition, 70, 261-8.
Wang, Y., Xu, L, Jonas, J.B., (2006). Prevalence and causes of visual field loss as determined by frequency doubling perimetry in urban and rural adult Chinese. American Journal of Ophthalmology, 141(6), 1078-86.
Wang, J.J., Foran, S., Mitchell, P. (2000). Age-specific prevalence and causes of bilateral and unilateral visual impairment in older Australians: the Blue Mountains Eye Study. Clinical Experimental Ophthalmology, 28, 268-273.
Weih, L.M., VanNewkirk, M.R., McCarty, C.A., Taylor, H.R. (2000). Age-specific causes of bilateral visual impairment. Archives Ophthalmology, 118, 264-69.
Whitehead, A.J., Mares, J.A., Danis, R.P. (2006). Macular pigment: a review of current knowledge. Archives of Ophthalmology, 124, 103845.
Wong, T.Y., Loon, S-C., Saw, S-M. (2006). The epidemiology of age related eye diseases in Asia. The British Journal of Ophthalmalogy, 90, 506-11.
Wood, J.M. (2002). Age and visual impairment decrease driving performance as measured on a closed-road circuit. Human Factors, 44, 482-94.
Xu, L., Wang, Y., Li, Y., Wang, Y., Cui, T., Li, J., et al. (2006). Causes of blindness and visual impairment in urban and rural areas in Beijing: the Beijing Eye Study. Ophthalmology, 113(7), 1141.-3.
Yeum, K. J., Booth, S. L., Sadowski, J. A., Liu, C., Tang, G., Krinsky, N. I., et al. (1996). Human plasma carotenoid response to the ingestion of controlled diets high in fruits and vegetables. American Journal of Clinical Nutrition, 64, 594-602.
LI HUI WANG & CHICK F. TAM
School of Kinesiology and Nutritional Science
California State University at Los Angeles
HSIN LING YANG
School of Nutrition and Institute of Nutrition, China Medical University
YIN CHANG CHEN
Keck School of Medicine, Department of Preventative Medicine
University of Southern California at Los Angeles
Department of Art California State University at Los Angeles
MIRIAM E. SCHWARTZ
Division of Geriatric Medicine, Department of Medicine, University of California at Los Angeles
Table 1. Subject Characteristics: Gender, Age, Weight, Height, and BMI LA ([section]) TW ([double dagger]) Sample Size 137 93 Gender (a) Female 101 72 Male 36 22 Age(y) *, (b) 24.5 [+ or -] 5.6 22.1 [+ or -] 1.3 Height(cm) *, (c) 1.64 [+ or -] 0.09 1.64 [+ or -] 0.08 Weight(kg) *, (d) 61.4 [+ or -] 15.8 56.2 [+ or -] 10.0 BMI *, ([+ or -]), (e) 22.7 [+ or -] 4.8 20.7 [+ or -] 2.5 ([section]) LA referred to college students at California State University, Los Angeles ([double dagger]) TW referred to college students at China Medical University, Taichung, Taiwan * Age, height, weight and BMI were described as mean [+ or -] SD. [+ or -] Body mass index was calculated as weight in kilograms divided by the square of height in meters. (a.) Gender, LA vs TW, p>0.05; (b.) Age, LA vs TW, p>0.05; (c.) Height, LA vs TW, p>0.05; (d.) Weight, LA vs TW, p<0.05; (e.) BMI, LA vs TW, p<0.05 Table 2. Dietary Intake of Lutein and Zeaxanthin in LA ([section]) and TW ([double dagger]) by Gender Sample Size Lutein and Zeaxanthin (mcg) * LA ([section]) Total 137 4149.4 [+ or -] 467.5 (a) Female 101 4142.4 [+ or -] 548.9 (b,d) Male 36 4169.1 [+ or -] 903.9 (b,e) TW ([double dagger]) Total 93 4994.2 [+ or -] 533.4 (a) Female 71 4920.4 [+ or -] 543.3 (c,d) Male 22 5232.4 [+ or -] 1445.8 (c,e) ([section]) LA referred to college students at California State University, Los Angeles ([double dagger]) TW referred to college students at China Medical University, Taichung, Taiwan. * Data were expressed as Mean [+ or -] SEM (a.) LA Total vs TW Total, p>0.05; (b.) LA Female vs LA Male, p>0.05; (c.) TW Female vs TW Male, p>0.05; (d.) LA Female vs TW Female, p>0.05; (e.) LA Male vs TW Male, p>0.05. All comparisons were not significant. Table 3. Related Food Preference of Lutein and Zeaxanthin: Top Ten Food Choices ([??]) and Mean Serving Size in LA ([section]) by Gender LA ([section]) Total (N=137) Food Choices (% ([paragraph])) Mean Serving Size * (serving/day) 1. Bread (62.0) 1.3 [+ or -] 0.9 2. Banana (54.7) 0.6 [+ or -] 0.4 3. Apple (48.9) 0.7 [+ or -] 0.7 4. Orange Juice (44.5) 0.8 [+ or -] 0.6 5. Lettuce (43.1) 0.5 [+ or -] 0.5 6. Cereal (42.3) 0.7 [+ or -] 0.7 7. Egg (41.6) 0.7 [+ or -] 0.4 8. Tomato (39.4) 0.4 [+ or -] 0.3 9. Orange (37.2) 0.7 [+ or -] 0.5 10. Broccoli (35.0) 0.6 [+ or -] 0.3 LA ([section]) Female (N=101) Food Choices (% ([paragraph])) Mean Serving Size * (serving/day) Bread (61.4) 3.8 [+ or -] 2.6 Banana (54.5) 1.8 [+ or -] 1.1 Apple (54.5) 2.0 [+ or -] 1.2 Tomato (46.5) 1.3 [+ or -] 0.9 Cereal (45.5) 1.6 [+ or -] 0.8 Lettuce (43.6) 1.4 [+ or -] 1.1 Orange Juice (42.6) 1.6 [+ or -] 0.8 Orange (38.6) 1.9 [+ or -] 1.3 Egg (37.6) 1.8 [+ or -] 1.3 Broccoli (36.6) 1.6 [+ or -] 0.9 LA ([section]) Male (N=36) Food Choices (% ([paragraph])) Mean Serving Size * (serving/day) Bread (63.9) 4.1 [+ or -] 2.9 Banana (55.6) 2.3 [+ or -] 1.5 Egg (52.8) 2.3 [+ or -] 1.2 Orange Juice (50.0) 3.9 [+ or -] 2.4 Lettuce (41.7) 1.9 [+ or -] 2.4 Cereal (33.3) 3.3 [+ or -] 3.8 Orange (33.3) 2.3 [+ or -] 2.4 Apple (33.3) 3.1 [+ or -] 3.9 Broccoli (30.6) 2.1 [+ or -] 1.2 Tomato (19.4) 1.4 [+ or -] 0.9 Grape (19.4) 1.9 [+ or -] 1.5 ([??]) Only indicated food items which contained lutein and zeaxanthin; food items which did not contain lutein and zeaxanthin were excluded. ([section]) Referred to college students enrolled at California State University, Los Angeles ([paragraph]) Data were expressed as Frequency (%) * Data were expressed as Mean [+ or ] SD Table 4. Related Food Preference of Lutein and Zeaxanthin: Top Ten Food Choices ([??]) and Mean Serving Size in TW ([double dagger]) by Gender TW ([double dagger]) Total (N=93) Food Choices(% ([paragraph])) Mean Serving Size * (serving/day) l. Egg (79.6) 0.6 [+ or -] 0.4 2. Leafy Greens (67.7) 0.6 [+ or -] 0.5 3. Cabbage (63.4) 0.4 [+ or -] 0.4 4. Bread (58.1) 1.9 [+ or -] 1.5 5. Mix Vegetables (35.5) 0.9 [+ or -] 1.0 6. Carrot (26.9) 0.2 [+ or -] 0.1 7. Lettuce (23.7) 0.3 [+ or -] 0.4 8. Tomato (21.5) 0.6 [+ or -] 0.3 9. Apple (19.4) 0.6 [+ or -] 0.6 10. Cucumber (19.4) 0.3 [+ or -] 0.3 TW ([double dagger]) Female (N=93) Food Choices(% ([paragraph])) Mean Serving Size * (serving/day) Egg (78.9) 1.8 [+ or -] 1.1 Leafy Greens (69.0) 1.9 [+ or -] 1.6 Bread (62.0) 5.8 [+ or -] 4.8 Cabbage (57.7) 1.3 [+ or -] 1.4 Mix Vegetables (31.0) 2.5 [+ or -] 3.1 Carrot (29.6) 0.4 [+ or -] 0.5 Lettuce (22.5) 1.1 [+ or -] 1.2 Apple (21.1) 1.9 [+ or -] 1.7 Broccoli (19.7) 0.9 [+ or -] 0.6 Tomato (18.3) 1.6 [+ or -] 0.7 Corn (18.3) 0.5 [+ or -] 0.5 TW ([double dagger]) Male Total (N=93) Food Choices(% ([paragraph])) Mean Serving Size * (serving/day) Egg (81.8) 1.9 [+ or -] 1.3 Cabbage (81.8) 1.2 [+ or -] 0.6 Leafy Greens (63.6) 1.6 [+ or -] 0.9 Mix Vegetables (50.0) 3.4 [+ or -] 2.8 Bread (45.5) 4.7 [+ or -] 2.2 Tomato (31.8) 1.9 [+ or -] 1.2 Cucumber (31.8) 1.0 [+ or -] 0.8 Lettuce (27.3) 0.8 [+ or -] 0.7 Pakchoy (22.7) 0.5 [+ or -] 0.3 Carrot (18.2) 0.5 [+ or -] 0.5 ([??]) Only indicated food items which contained lutein and zeaxanthin; food items which did not contain lutein and zeaxanthin were excluded. ([double dagger]) Referred to college students at China Medical University, Taichung, Taiwan ([paragraph]) Data were expressed as Frequency (%) * Data were expressed as Mean [+ or -] SD
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|Title Annotation:||Los Angeles, California|
|Author:||Wang, Li Hui; Tam, Chick F.; Yang, Hsin Ling; Chen, Yin Chang; Davis, Rebecca; Schwartz, Miriam E.|
|Publication:||College Student Journal|
|Date:||Dec 1, 2008|
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