Relation between dietary intake, serum concentrations, and retinal concentrations of lutein and zeaxanthin in adults in a Midwest population.

BACKGROUND: Information on concentrations of retinal carotenoids (macular pigment, or MP) is of particular interest because MP protects against age-related macular degeneration, the leading cause of irreversible blindness in the United States. OBJECTIVE: This study was designed to evaluate the relation between dietary intake, blood concentrations, and retinal concentrations of carotenoids in a large group of volunteers. DESIGN: Two hundred eighty volunteers in the Indianapolis area completed health and diet questionnaires, donated a blood sample, and participated in MP density assessment to determine retinal carotenoid status. Dietary intake was assessed by food-frequency questionnaire. Serum concentrations of lutein, zeaxanthin, and beta-carotene were measured by HPLC. MP optical density (MPOD) was determined psychophysically with a 460-nm, 1 degrees test stimulus. RESULTS: Average MPOD was 0.21 +/- 0.13. Average intakes of lutein + zeaxanthin and beta-carotene were 1101 +/- 838 and 2935 +/- 2698 microg/d, respectively. Although several key dietary intake variables (eg, lutein + zeaxanthin and beta-carotene) differed by sex, no significant sex differences were found in either serum concentrations of lutein and zeaxanthin or MPOD. Serum beta-carotene concentrations were significantly higher in women than in men. Serum lutein + zeaxanthin and dietary intake of lutein + zeaxanthin were significantly correlated and significantly related to variations in MPOD (r = 0.21, P < 0.001, and r = 0.25, P < 0.001, respectively). CONCLUSIONS: Retinal carotenoids can be measured in epidemiologic studies. In this study, MPOD was associated with lutein + zeaxanthin in the diet and the serum. Retinal concentrations, however, were influenced by other factors as well. To understand the effect of dietary lutein + zeaxanthin intake on the retina and risk of age-related eye disease, future studies should include measures of macular concentrations of these pigments.     

Fruit and Vegetable Intake Assessed by Food Frequency Questionnaire and Plasma Carotenoids: A Validation Study in Adults

Dietary validation studies of self-reported fruit and vegetable intake should ideally include measurement of plasma biomarkers of intake. The aim was to conduct a validation study of self-reported fruit and vegetable intakes in adults, using the Australian Eating Survey (AES) food frequency questionnaire (FFQ), against a range of plasma carotenoids. Dietary intakes were assessed using the semi-quantitative 120 item AES FFQ. Fasting plasma carotenoids (α- and β-carotene, lutein/zeaxanthin, lycopene and cryptoxanthin) were assessed using high performance liquid chromatography in a sample of 38 adult volunteers (66% female). Significant positive correlations were found between FFQ and plasma carotenoids for α-carotene, β-carotene and lutein/zeaxanthin (52%, 47%, 26%, p < 0.001, 0.003, 0.041; respectively) and relationships between plasma carotenoids (except lycopene) and weight status metrics (BMI, waist circumference, fat mass) were negative and highly significant. The results of the current study demonstrate that carotenoid intakes as assessed by the AES FFQ are significantly related to plasma concentrations of α-carotene, β-carotene and lutein/zeaxanthin, the carotenoids commonly found in fruit and vegetables. Lower levels of all plasma carotenoids, except lycopene, were found in individuals with higher BMI. We conclude that the AES can be used to measure fruit and vegetable intakes with confidence.     

Plasma concentrations of carotenoids and vitamin C are better correlated with dietary intake in normal weight than overweight and obese elderly subjects

Carotenoid and vitamin C intakes, assessed by FFQ, have been positively associated with plasma concentrations in different populations. However, the influence of BMI on these associations has not been explored in detail. We explored in a cross-sectional study the relation between dietary carotenoid and vitamin C intakes, using a 135-item FFQ, with their plasma concentrations by BMI categories in 252 men and 293 women, 65 years and older. For men and women combined, significant (P < 0.05) Pearson correlations were observed between energy-adjusted dietary intakes and plasma concentrations (carotenoids adjusted for cholesterol) for: alpha-carotene 0.21, beta-carotene 0.19, lycopene 0.18, beta-cryptoxanthin 0.20 and vitamin C 0.36. Multiple linear regression analyses showed that the intake of carotenoids and vitamin C were significant predictors of their respective plasma concentration (P<0.01), and that BMI was inversely associated with plasma concentration of carotenoids (P< or =0.01) but not with plasma vitamin C. In addition, we observed significant interactions between BMI and the intakes of alpha-carotene and lutein + zeaxanthin, and to a lower extent beta-carotene, suggesting that these intakes in subjects with high BMI were not good predictors of their plasma concentration. The present data suggest that plasma carotenoids and vitamin C may be good markers of dietary intake in elderly subjects, but not so for alpha-carotene, beta-carotene and lutein + zeaxanthin in obese subjects.     

Lutein and Zeaxanthin and Their Roles in Age-Related Macular Degeneration—Neurodegenerative Disease

Lutein and zeaxanthin belong to the xanthophyll family of carotenoids, which are pigments produced by plants. Structurally, they are very similar, differing only slightly in the arrangement of atoms. Key sources of these carotenoids include kale, savoy cabbage, spinach, broccoli, peas, parsley, corn, and egg yolks. The recommended daily intake of lutein is approximately 10.0 mg and that of zeaxanthin is 2 mg. Lutein intake in adults varies, with average intakes being 1–2 mg/day. Due to the lack of synthesis of consumption of these compounds in humans, these substances are extremely important for the proper functioning of certain organs of the body (eye, skin, heart, intestines). Eating a lot of dark leafy vegetables and some fruits can help to prevent our bodies from developing diseases. The protective effects of carotenoids are mainly related to their defense against oxidative stress and their ability to scavenge free radicals. Lutein and zeaxanthin are the only dietary carotenoids that accumulate in the retina, specifically the macula, and are called macular pigments. These carotenoids are concentrated by the action of specific binding proteins such as StARD3, which binds lutein, and GSTP1, which binds zeaxanthin and its dietary metabolite, mesozeaxanthin. It has been shown that supportive therapy with lutein and zeaxanthin can have a beneficial effect in delaying the progression of eye diseases such as age-related macular degeneration (AMD) and cataracts. This article presents the current state of knowledge on the role of lutein and zeaxanthin, especially from human studies targeting their metabolism and bioavailability, with recommendations to consume xanthophyll-rich foods.     

Predictors of optical density of lutein and zeaxanthin in retinas of older women in the Carotenoids in Age-Related Eye Disease Study, an ancillary study of the Women's Health Initiative

BACKGROUND: Lifestyle, diet, and physical and health predictors of xanthophyll carotenoids in the retina are poorly understood. OBJECTIVE: We aimed to investigate the predictors of the density of lutein and zeaxanthin in the macula of the retina. DESIGN: Macular pigment optical density (MPOD) was measured by heterochromatic flicker photometry. Relations to dietary lutein and zeaxanthin and to other predictors were measured in 1698 women aged 53-86 y. The women were members of observational study cohorts of the Women's Health Initiative at Iowa City, IA, Madison, WI, or Portland, OR, and participated in the Carotenoids in Age-Related Eye Disease Study (2001-2004). RESULTS: MPOD at 0.5 degrees from the foveal center was 30% higher in women in the highest quintile for lutein and zeaxanthin intake [x (+/-SD): 0.40 +/- 0.21] than in women in the lowest quintile (0.31 +/- 0.21) and 20% higher after adjustment for other predictors. Dietary intake of lutein, zeaxanthin, fiber, and polyunsaturated fatty acids (% of energy) together explained 3% of the variability in MPOD. Higher waist circumference and diabetes, which are related to lower MPOD, together with study site explained an additional 5% of variation. The total explained variability increased to 12% when lutein and zexanthin concentrations obtained from the serum, which were collected 4-7 y earlier, were added to the model. CONCLUSIONS: MPOD is directly related to dietary intake of lutein and zeaxanthin but even more strongly to serum concentrations, which may reflect unmeasured physical and medical factors that influence the uptake, distribution, and utilization of lutein and zeaxanthin. Higher abdominal body fat and diabetes are related to lower MPOD. Unknown predictors of retinal carotenoids remain.     

Food Predictors of Plasma Carotenoids

Empirical prediction models that weight food frequency questionnaire (FFQ) food items by their relation to nutrient biomarker concentrations may estimate nutrient exposure better than nutrient intakes derived from food composition databases. Carotenoids may especially benefit because contributing foods vary in bioavailability and assessment validity. Our objective was to develop empirical prediction models for the major plasma carotenoids and total carotenoids and evaluate their validity compared with dietary intakes calculated from standard food composition tables. 4180 nonsmoking women in the Nurses’ Health Study (NHS) blood subcohort with previously measured plasma carotenoids were randomly divided into training (n = 2787) and testing (n = 1393) subsets. Empirical prediction models were developed in the training subset by stepwise selection from foods contributing ≥0.5% to intake of the relevant carotenoid. Spearman correlations between predicted and measured plasma concentrations were compared to Spearman correlations between dietary intake and measured plasma concentrations for each carotenoid. Three to 12 foods were selected for the α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin, lycopene, and total carotenoids prediction models. In the testing subset, Spearman correlations with measured plasma concentrations for the calculated dietary intakes and predicted plasma concentrations, respectively, were 0.31 and 0.37 for α-carotene, 0.29 and 0.31 for β-carotene, 0.36 and 0.41 for β-cryptoxanthin, 0.28 and 0.31 for lutein/zeaxanthin, 0.22 and 0.23 for lycopene, and 0.22 and 0.27 for total carotenoids. Empirical prediction models may modestly improve assessment of some carotenoids, particularly α-carotene and β-cryptoxanthin.     

Dietary intake in human immunodeficiency virus-infected adults: a comparison of dietary assessment methods

OBJECTIVE: The objective of this study was to compare estimated nutrient intakes from 3-day food records vs Food Frequency Questionnaire (FFQ) in a large cohort of individuals living with human immunodeficiency virus (HIV) infection. DESIGN: Dietary data from 315 HIV-positive participants enrolled in a longitudinal cohort study were collected. Nutrient intake data estimated from the Block FFQ were compared with multiple 3-day food records done over the same time period. SUBJECTS/SETTING: Participants enrolled in Nutrition for Healthy Living, an ongoing cohort study based in Boston, MA, were studied. STATISTICAL ANALYSES PERFORMED: Using 3-day food records as the gold standard, we compared estimated nutrient intakes between the two assessment methods by (a) median of individual differences in intake, (b) correlation coefficients, (c) quintile ranking, and (d) intakes less than the Dietary Reference Intakes. Nutrient intake estimates between the two methods were compared using Spearman, Pearson, and deattenuated correlation coefficients. RESULTS: Median reported intakes of all macronutrients and most micronutrients were significantly less on the FFQ for both men and women. Deattenuated correlations were less than 0.5 for 86% of the men and for 68% of the women. Mean percent agreement for quintile ranking was 30%. CONCLUSIONS: In this large cohort of HIV-infected adults, we found significant differences between FFQs and food records in estimates of absolute dietary intakes, correlation coefficients, quintile rankings, and proportions of subjects consuming less than the Dietary Reference Intakes. These findings have implications for the interpretation and application of dietary intake data from FFQs in specialized populations.     

Milk and Plasma Lutein and Zeaxanthin Concentrations in Chinese Breast-Feeding Mother–Infant Dyads With Healthy Maternal Fruit and Vegetable Intake*

Objectives: While others have reported that milk from coastal Chinese women contains high levels of lutein and zeaxanthin, no research has determined the corresponding infant plasma response. Whether infant plasma levels increase commensurately provides important guidance for supplementation of these increasingly intriguing carotenoids in breast-feeding mothers and formula-fed infants.

Methods: Fifty-six mother–infant pairs with a maternal diet rich in eggs, green leafy vegetables, and fruit were enrolled between 6 and 16 weeks of lactation. Milk samples and blood samples from both the mother and infant were collected at entry. Maternal 3-day dietary records and a second milk sample were collected 1 to 3 weeks later.

Results: Mean milk lutein concentrations in samples 1 and 2 were 6.5 and 7.7?μg/dL (range 1–22.5?μg/dL), and for zeaxanthin, 1.6 and 1.7?μg/dL (range 1–5.9?μg/dL). Lutein concentrations in infant plasma (18.2?μg/dL) were similar to those in maternal plasma (21.6?μg/dL); zeaxanthin was lower than lutein in both maternal (3.1?μg/dL) and infant (2.9?μg/dL) plasma. Infant and maternal mean plasma lutein and zeaxanthin concentrations were higher than those in both milk samples 1 and 2 (lutein, 6.9 and 8.2?μg/dL; zeaxanthin, 1.9 and 2.0?μg/dL). Infant plasma lutein and zeaxanthin concentrations positively correlated with those in milk sample 1 (lutein, r²?=?0.15, p?=?0.004; zeaxanthin, r²?=?0.21, p?<?0.001).

Conclusions: Together, these results reveal that high milk concentrations of lutein and zeaxanthin driven by healthy maternal intakes of xanthophyll rich foods are associated with high infant plasma concentrations. These findings will be useful for determining appropriate lutein fortification strategies.

Clinical Study.gov registration number: NCT01669655.     

Effect of maternal Chlorella supplementation on carotenoid concentration in breast milk at early lactation

Breast milk carotenoids provide neonates with a source of vitamin A and potentially, oxidative stress protection and other health benefits. Chlorella, which has high levels of carotenoids such as lutein, zeaxanthin and β-carotene, is an effective dietary source of carotenoids for humans. In this study, the effect of maternal supplementation with Chlorella on carotenoid levels in breast milk at early lactation was investigated. Ten healthy, pregnant women received 6?g of Chlorella daily from gestational week 16–20 until the day of delivery (Chlorella group); ten others did not (control group). Among the carotenoids detected in breast milk, lutein, zeaxanthin and β-carotene concentrations in the Chlorella group were 2.6-fold (p?=?0.001), 2.7-fold (p?=?0.001) and 1.7-fold (p?=?0.049) higher, respectively, than those in the control group. Our study shows that Chlorella intake during pregnancy is effective in improving the carotenoid status of breast milk at early lactation.     

Disagreement of energy and macronutrient intakes estimated from a food frequency questionnaire and 3-day diet record in girls 4 to 9 years of age

BACKGROUND: The Block98 food frequency questionnaire (FFQ) has been validated for dietary assessment of usual intakes in adults, but not in children. OBJECTIVE: To assess the agreement of the Block98 FFQ and 3-day diet records for measuring dietary intakes in young girls. SUBJECTS/SETTING: Healthy 4- to 9-year-old girls (N=61; 6.5+/-1.6 years) were recruited from the Athens/Clarke county area in Georgia. DESIGN: Dietary intakes were measured using the Block98 FFQ and 3-day diet records, with nutrient analysis of the 3-day diet records conducted using the Food Processor computer program (ESHA; version 7.21, 1998, ESHA Research, Salem, OR). The Block98 FFQ was completed by a trained interviewer and parent, with input from the child, if able. Food models and portion size pictures were used to increase reporting accuracy. STATISTICAL ANALYSIS: Paired sample t tests and simple regression were conducted to determine whether the two diet instruments reported similar values for energy and macronutrients. RESULTS: Block98 FFQ overestimated intakes from 3-day diet records for energy (2,180+/-692 vs 1,749+/-328 kcal), protein (68.3+/-25.9 vs 57.9+/-14.8 g/day), carbohydrate (298.7+/-97.0 vs 244.7+/-46.1 g/day) and fat (83.6+/-30.5 vs 62.3+/-14.7 g/day) (P<.05). Furthermore, the nutrients assessed using the two different methods were only moderately correlated (range: r=0.40 to 0.55). APPLICATIONS/CONCLUSIONS: The Block98 FFQ agreed weakly to moderately with the 3-day diet records, and resulted in consistently higher intakes of all nutrients. These findings suggest that additional work is needed to develop a FFQ that reflects young children's energy and macronutrient intakes.     

北京地区常见蔬菜中叶黄素、玉米黄素和β-胡萝卜素的测定及其含量

目的测定分析常见蔬菜中叶黄素、玉米黄素和β-胡萝卜素的含量。方法采用高效液相色谱法Develosil C30柱;流动相A:乙腈:甲醇=75:25,B:甲基叔丁基醚,梯度洗脱;紫外检测器,检测波长480nm检测北京市常见市售蔬菜中叶黄素、玉米黄素和β-胡萝卜素的含量。结果叶黄素、玉米黄素和β-胡萝卜素保留时间分别为10.355、10.732和20.789min,实现基线分离。深绿色叶菜,如苋菜、芹菜叶、香菜、菠菜、小白菜中叶黄素含量最为丰富。玉米黄素仅在黄花菜(干)中检出。熟制后,各类蔬菜的平均叶黄素和β-胡萝卜素含量呈上升趋势。结论绿色蔬菜,尤其是深绿色叶菜,是叶黄素、β-胡萝卜素的主要膳食来源,摄入熟制后的蔬菜有利于增加叶黄素、玉米黄素的摄入量和生物利用率。     

Hispanic and non-Hispanic white elders from Massachusetts have different patterns of carotenoid intake and plasma concentrations

Carotenoids have been linked with protective roles against diseases associated with aging, including cancer, cardiovascular disease, cataracts, and age-related macular degeneration. With data from a semiquantitative, validated FFQ, we examined carotenoid intake of 340 Puerto Ricans, 98 Dominicans, and 146 non-Hispanic whites (>60 y old) in Massachusetts. Compared with non-Hispanic white men, Hispanic men reported a higher intake of lycopene and lower intakes of alpha-carotene, lutein + zeaxanthin, beta-carotene (from diet only), and total beta-carotene (diet and supplements) (P < 0.001). Hispanic women reported higher intakes of beta-cryptoxanthin and lycopene but lower intakes of lutein + zeaxanthin (P < 0.001) than non-Hispanic white women. The frequency of consumption of fruit and vegetables was higher among Hispanic women, relative to non-Hispanic white women (P < 0.05). Plasma concentrations of alpha-carotene and lycopene were higher in Hispanic than in non-Hispanic white men and women. For both ethnic groups, higher intakes of carotenoids were associated with higher plasma concentrations of the respective carotenoids, except for lycopene (Hispanics) and lutein + zeaxanthin (non-Hispanic whites). Food sources contributing most to total intakes differed among the groups. The major sources of alpha- and beta-carotene were carrots for non-Hispanic whites and winter squash for Hispanics. The major source of lycopene was cooked tomato products for Hispanics, and pasta dishes for non-Hispanic whites. Traditional foods such as beans and plantains were also important contributors of carotenoids for Hispanics. Because of the potential importance of carotenoids as protective factors against chronic diseases, more attention to food-related practices associated with carotenoid intake in differing population groups is warranted.     

Carotenoid intakes, assessed by dietary questionnaire, are associated with plasma carotenoid concentrations in an elderly population

High intakes of fruits and vegetables and of carotenoids are associated with a lower risk for a variety of chronic diseases. It is therefore important to test the validity of dietary questionnaires that assess these intakes. We compared intakes of five carotenoids, as calculated from responses to the Willett 126-item food-frequency questionnaire, with corresponding biochemical measures. Subjects included 346 women and 201 men, aged 67-93 y, in the Framingham Heart Study. Unadjusted correlations were higher among women than men as follows: alpha-carotene 0.33 and 0.18, beta-carotene, 0.36 and 0.25; beta-cryptoxanthin, 0.44 and 0.32; lycopene, 0.35 and 0.21; and lutein + zeaxanthin, 0.27 and 0.10, respectively. Adjustment for age, energy intake, body mass index (BMI, kg/m2), plasma cholesterol concentrations and smoking reduced the gender differences, respectively, to the following: alpha-carotene 0.30 and 0.28; beta-carotene, 0.34 and 0.31; beta-cryptoxanthin, 0.45 and 0.36; lycopene, 0.36 and 0.31; and lutein + zeaxanthin, 0.24 and 0.14. Plots of adjusted mean plasma carotenoid concentration by quintile of respective carotenoid intake show apparent greater responsiveness among women, compared with men, to dietary intake of alpha- and beta-carotene and beta-cryptoxanthin, but similar blood-diet relationships for lycopene and lutein + zeaxanthin. Reported daily intake of fruits and vegetables correlated most strongly with plasma beta-cryptoxanthin and beta-carotene among women and with plasma alpha- and beta-carotene among men. With the exception of lutein + zeaxanthin, this dietary questionnaire does provide reasonable rankings of carotenoid status among elderly subjects, with the strongest correlations for beta-cryptoxanthin. Appropriate adjustment of confounders is necessary to clarify these associations among men.     

Folate intake assessment: validation of a new approach

OBJECTIVE: To describe the performance characteristics and validate a folate-specific focused recall approach to estimating folate intake. DESIGN: In a cross-sectional study, folate-specific recalls were used to estimate subjects' average daily folate intake from seven days of dietary recall over a one-month period. This estimate was compared to an estimate of the average daily folate intake obtained using the Fred Hutchinson Cancer Research Center Food Frequency Questionnaire (FFQ) and to plasma folate and homocysteine concentrations. SUBJECTS: Subjects were women aged 21 to 47 years and were recruited from the university community. Thirty-three subjects were recruited, and 28 subjects completed the study. INTERVENTION: After an initial clinic visit, during which a baseline blood sample was collected for measurement of plasma folate and total homocysteine concentrations, subjects participated in focused dietary recall interviews by telephone and/or Internet (e-mail). At the end of the month, subjects completed the FFQ. Main outcome measures The main outcome measures were to describe how well the focused recalls were able to describe relative dietary folate intake as compared to the FFQ and if the focused recall method estimate correlated with plasma folate and homocysteine concentrations. Statistical analyses Estimated folate intakes were ranked by tertiles using the two dietary assessment approaches and the rankings were compared. The Spearman correlation test was used to compare the focused recall and the FFQ dietary data to plasma folate and homocysteine concentrations. RESULTS: Estimated folate intake inclusive of supplements was 411.4+/-192.8 (mean+/-SD) microg/day based on focused recalls and 458.5+/-221.5 microg/day based on the FFQ. Exclusive of supplements, estimated folate intake from the diet was 327.8+/-30.2 microg/day based on focused recalls and 373.5+/-155.6 microg/day based on the FFQ. The ranking comparison of focused recalls vs the FFQ demonstrated a concordance of 44% without supplements and 67% with supplements for the highest tertile, and 56% without supplements and 67% with supplements for the lowest tertile. Estimated folate intake based on focused recalls was correlated significantly with plasma homocysteine (r=-0.443, P<.02) and was marginally significantly correlated with plasma folate (r=0.354; P=.06) concentrations. APPLICATIONS: A focused dietary recall approach is a useful method for collecting information on folate intake in women. Estimated folate intake based on the focused recall approach is reasonably correlated with plasma folate and total homocysteine concentrations even in this small sample of women. Accurate data on folate intake can form the basis of dietary counseling to increase intake of this important micronutrient in the target population of young women.     

Intake of Lutein and Zeaxanthin Differ with Age, Sex, and Ethnicity

Lutein and zeaxanthin are carotenoids that are selectively taken up into the macula of the eye, where they may protect against development of age-related macular degeneration. Accurate assessment of their intakes is important in the understanding of their individual roles in eye health. Current dietary databases lack the appropriate information to ascertain valid dietary intakes of these individual nutrients. The purpose of this research is to determine intakes of lutein and zeaxanthin separately in the National Health and Nutrition Examination Survey (NHANES) 2003-2004. The top major food sources for lutein and zeaxanthin intake in NHANES 2003-2004 were analyzed for lutein and zeaxanthin by high-performance liquid chromatography from June to August 2006. Results were applied to dietary data from 8,525 participants in NHANES 2003-2004. Lutein and zeaxanthin food contents were separated into lutein and zeaxanthin in the nutrient database. Mean intakes from two nonconsecutive 24-hour recalls were grouped into food groups based on nutrient composition; these were matched to the new database, and lutein and zeaxanthin intakes were calculated separately. Among all age groups, both sexes, and all ethnicities, intakes of lutein were greater than of zeaxanthin. Relative intake of zeaxanthin to lutein decreased with age, with zeaxanthin to lutein ratios lower in females. Zeaxanthin to lutein ratios in Mexican Americans was considerably greater than other ethnicities (other Hispanics, non-Hispanic white, non-Hispanic black, other races). Lower zeaxanthin to lutein ratios were measured in groups at risk for age-related macular degeneration (eg, older participants, females). Our findings suggest that the relative intake of lutein and zeaxanthin may be important to age-related macular degeneration risk. Future studies are needed to assess the individual associations of lutein and zeaxanthin in eye health.     

Dietary and biochemical selenium status of urban 6- to 24-month-old South Island New Zealand children and their postpartum mothers

A community-based, cross-sectional survey was conducted in the South Island of New Zealand to assess the dietary and biochemical selenium status of children (n = 136) and their mothers (n = 302), and to assess factors influencing selenium status. Serum and plasma samples from children and their mothers were analyzed for selenium using graphite furnace atomic absorption spectrometry. Dietary selenium intakes were analyzed from 3-d weighed diet records, and food sources of selenium were quantified. Mean dietary selenium intakes in infants (6-11.9 mo), toddlers (12-24 mo), and mothers were below recommended levels. Toddlers had higher selenium intakes than infants (13.7 +/- 8.4 and 7.9 +/- 6.2 microg/d, respectively, P = 0.0001) and the selenium density of their diets was also higher [3.2 +/- 1.7 and 2.4 +/- 1.7 microg/(MJ . d), respectively, P = 0.003]. Household smoking was associated with lower serum selenium concentrations in infants and toddlers (P = 0.02). South Island women who were currently pregnant had lower plasma selenium concentrations (0.74 +/- 0.15 micromol/L) than nonpregnant lactating and nonpregnant nonlactating women (0.94 +/- 0.16 and 0.93 +/- 0.16 micromol/L, respectively, P = 0.0001). Clearly, pregnant women, infants and toddlers are at risk of suboptimal selenium status, and further research is warranted to assess potential effects in these groups. The finding of an association between household smoking and lower selenium concentrations in children should be investigated further. Dietary interventions are recommended to improve dietary selenium intakes in South Island children and their mothers.     

Hypo- and hyperresponse to egg cholesterol predicts plasma lutein and beta-carotene concentrations in men and women

The purpose of this study was to determine whether the plasma response to dietary cholesterol from eggs is associated with the plasma carotenoid response and whether gender influences the carotenoid response. Using a crossover design, 40 subjects classified as either hyper- (10 men and 10 women) or hyporesponders (10 men and 10 women) to dietary cholesterol consumed an egg (EGG, 640 mg/d additional dietary cholesterol and 600 microg lutein + zeaxanthin) or placebo (SUB, 0 mg/d cholesterol, 0 microg lutein + zeaxanthin and 568 microg beta-carotene) diet for 30 d, followed by a 3-wk washout period and the alternate diet. Plasma concentrations of lutein and beta-carotene after each dietary period were then examined to determine whether the response to carotenoid intake was similar to that seen for dietary cholesterol. After the EGG period, the increase in plasma lutein in female hyperresponders (mean increase +/- SD; 0.32 +/- 0.19 micromol/L) and male hyperresponders (0.26 +/- 0.11 micromol/L) was significantly greater than that of their hyporesponsive counterparts (0.16 +/- 0.18 micromol/L for women and 0.14 +/- 0.11 micromol/L men). Gender was not a significant factor influencing lutein response. Both men and women classified as hyperresponders significantly increased plasma beta-carotene after the SUB period, whereas their hyporesponsive counterparts were not affected. The increase in plasma beta-carotene in female hyperresponders (0.29 +/- 0.48 micromol/L) was significantly greater than that in male hyperresponders (0.07 +/- 0.07 micromol/L). We conclude that plasma responses to cholesterol and carotenoids are related and that gender influences the beta-carotene response to a greater degree than the lutein response.     

Validation of a phytoestrogen food frequency questionnaire with urinary concentrations of isoflavones and lignan metabolites in premenopausal women

OBJECTIVE: The purpose of this study was to examine the association between dietary intake of phytoestrogens estimated by a food frequency questionnaire (FFQ) with urinary metabolites. METHODS: Participants were 26 premenopausal, Caucasian women aged 25 to 42 years. Dietary intake of isoflavones (genistein and daidzein) and lignans (secoisolariciresinol and matairesinol) were estimated by a 53-item interviewer-administered FFQ on two occasions, reflecting 'habitual' (previous 2 months) and 'recent' (previous 2 days) dietary intake. Isoflavone (genistein, daidzein) and lignan (enterolactone, enterodiol and secoisolariciresinol) concentrations were measured in 24-hour urine samples by gas chromatography-mass spectrometry. Correlations between FFQ (habitual and recent, separately) and urinary metabolite values were assessed using Spearman correlation coefficients. RESULTS: Mean habitual isoflavone and lignan intakes were 13.7 mg/day and 13.8 mg/day, respectively. Mean urinary concentrations of isoflavones and lignans were 17.4 micromol/day and 20.6 micromol/day, respectively. Recent and habitual isoflavone intakes were correlated with urinary excretion of metabolites (r = 0.64, p < 0.001 and r = 0.54, p = 0.004, respectively). Urinary excretion of lignans was also modestly correlated with recent and habitual lignan intakes (r = 0.46, p = 0.02 and r = 0.40, p = 0.05, respectively). CONCLUSIONS: Our results support the use of this FFQ as a measure of dietary isoflavone and lignan intake in epidemiological studies.     

The relationship between antioxidant nutrient intake and cataracts in older people

This study investigated the relationship between the intake of antioxidant nutrients and the suffering of cataracts in 177 institutionalized elderly people (61 men and 116 women) aged > or = 65 years. Dietary intake was monitored for 7 consecutive days using a "precise individual weighing" method. Subjects, who during their earlier years were exposed by their work to sunlight, had a greater risk of suffering cataracts (OR = 3.2; CI: 1.1-9.3, P < 0.05) than those who worked indoors. A relationship was found between increased vitamin C intake and a reduced prevalence of cataracts (i.e., when comparing those above P95 for vitamin C intake with those below P5; (OR = 0.08; CI: 0.01-0.75, P 0.05). Among subjects with cataracts, 12.1% had vitamin C intakes of < 61 mg/day (P10) and only 2.2% had intakes of > 183 mg/day (P95) (p < 0.01). Subjects who consumed > 3290 microg/day (P95) of lutein were less likely to have cataracts (OR = 0.086; CI: 0.007-1.084; p < 0.05) than those whose consumption was < 256 microg/day (P5). In men, high intakes of zeaxanthin seemed to provide a protective effect against the problem (OR = 0.96; CI: 0.91-0.99; p < 0.05). The results suggest an association exists between exposure to sunlight and the development of cataracts, and that vitamin C, lutein, and zeaxanthin offer some protection against this disorder.     

Dietary calcium intake in postmenopausal Malaysian women: comparison between the food frequency questionnaire and three-day food records

The objective of this study was to compare the dietary calcium intakes assessed by a quantitative food frequency questionnaire (FFQ) and the three-day food record method in 230 Chinese postmenopausal women aged 50-65 years in Kuala Lumpur. The results showed that the mean calcium intake from the dietary records was 447+/-168 mg/day and 499+/-211 mg/day from the FFQ. The mean difference in intake by the two methods was 51.3 mg (95% CI = -30.8-77.9; SD = 181.2, P>0.05), which did not differ significantly from zero. Pearson's correlation coefficient of 0.56 was obtained between the two methods. Ninety-five percent of the individuals classified by food records fell into the same or within-one-quartile category when classified by FFQ. Forty-eight percent were classified into the same quartile by both methods. No subjects were grossly misclassified by the FFQ. The FFQ correctly identified subjects with calcium intakes below the Malaysian recommended daily allowance (450 mg/day) with 60% specificity and with 92% specificity for women consuming less than 800 mg calcium/day. In conclusion, the FFQ developed was a useful, rapid clinical tool for assessing calcium intake and identifying postmenopausal Chinese women with low calcium intakes in Malaysia.