Calibration of the dietary questionnaire for a multiethnic cohort in Hawaii and Los Angeles

Variation in folate pathway genes and distal colorectal adenoma risk: a sigmoidoscopy-based case-control study

Background

Folate-associated one-carbon metabolism (FOCM) is an important pathway in colorectal neoplasia risk but data on genetic variation in this pathway are largely limited to studies of single SNPs in selected genes.

Methods

We used a comprehensive tagSNP approach to study the association between genetic variation in 11 genes in the FOCM pathway and risk of incident distal colorectal adenomas in a sigmoidoscopy-based case–control study. We included 655 cases (one or more adenomas) and 695 controls (no adenomas) recruited from one of two Kaiser Permanente clinics between 1991 and 1995. We assessed a total of 159 tagSNPs selected using Haploview Tagger as well as selected non-synonymous SNPs. We used unconditional logistic regression to model the association between SNPs and risk of distal adenomas, assuming a log-additive model.

Results

Five SNPs in the SLC19A1 (RFC1) gene: rs1051266 (G80A), rs283895, rs2236484, rs12482346, and rs2838958 were associated with adenoma risk after correction for multiple testing (all corrected p values ≤0.043). The non-synonymous SLC19A1 SNP G80A interacted significantly with the MTHFRC677T genotype (interaction p value = 0.018).

Conclusion

Our data suggest that genetic variation in SLC19A1 may modify the risk of distal colorectal adenoma.

Electronic supplementary material

The online version of this article (doi:10.1007/s10552-011-9726-7) contains supplementary material, which is available to authorized users.

Balancing community and university aims in community-based participatory research: a Pacific Islander youth study

BACKGROUND

Community-based participatory research (CBPR) holds the promise of improving the planning, conduct, and long-term translation of research findings into community settings.

OBJECTIVES

This 2-year, exploratory study applied CBPR structures and processes to the identification of individual, cultural and community factors associated with obesity among Pacific Islander (PI) youth in Southern California.

METHODS

We describe the CBPR principles and strategies used by a community-university partnership to develop, implement, and report on the findings from assessments of obesity, physical activity, and nutritional intake among PI youth.

RESULTS

Although CBPR planning processes led to successes in community-based youth recruitment and retention, we learned key lessons regarding implementation of tailored assessment protocols, often involving problems arising from the university side of the CBPR collaborative.

CONCLUSION

CBPR has its strengths and limits; more studies are needed that report on processes to increase our understanding of how to balance research rigor with community sustainability.

Ethnic differences in weight gain and diabetes risk: the Multiethnic Cohort Study

AIM

To improve our understanding of excess body weight and risk for diabetes type 2, the study examined the influence of weight change in the Hawaii component, including 78,006 Caucasians, Japanese Americans and Native Hawaiians, of the Multiethnic Cohort Study.

METHODS

Participants aged 58.5±9.2 years completed a questionnaire at cohort entry (Qx1), including weight at age 21, and a follow-up questionnaire 5 years later (Qx2). After 14 years of follow-up, 8892 incident diabetes cases were identified through self-reports or linkups with the major health plans in Hawaii. Cox regression analysis was applied, stratified by age and adjusted for confounders, to estimate hazard ratios (HRs).

RESULTS

The mean weight gain from age 21 to Qx1 was 10.5±11.0 kg and, between Qx1 and Qx2, 0.8±5.6 kg. Diabetes risk showed a significant dose-response relationship with weight gain from age 21 (P<0.0001). The respective HRs for a weight gain of 5-10 kg and greater or equal to 25 kg were 1.8 (95% CI: 1.7-2.0) and 7.7 (95% CI: 7.1-8.4), while weight loss of greater than 5 kg significantly reduced diabetes risk (HR=0.7; 95% CI: 0.6-0.9). The interaction term of weight change since age 21 with ethnicity was also highly significant (P<0.0001). Compared with stable-weight Caucasians, the adverse effects of weight gain were more pronounced in those of Japanese and Native Hawaiian descent. Weight change between Qx1 and Qx2 conferred a smaller risk.

CONCLUSION

These findings support the current public-health recommendations for weight control and particularly among ethnic groups at high risk for diabetes.

Calibration of the dietary data obtained from the Brazilian center of the Natural History of HPV Infection in Men study: the HIM Study

The objective of this study was to estimate the regressions calibration for the dietary data that were measured using the quantitative food frequency questionnaire (QFFQ) in the Natural History of HPV Infection in Men: the HIM Study in Brazil. A sample of 98 individuals from the HIM study answered one QFFQ and three 24-hour recalls (24HR) at interviews. The calibration was performed using linear regression analysis in which the 24HR was the dependent variable and the QFFQ was the independent variable. Age, body mass index, physical activity, income and schooling were used as adjustment variables in the models. The geometric means between the 24HR and the calibration-corrected QFFQ were statistically equal. The dispersion graphs between the instruments demonstrate increased correlation after making the correction, although there is greater dispersion of the points with worse explanatory power of the models. Identification of the regressions calibration for the dietary data of the HIM study will make it possible to estimate the effect of the diet on HPV infection, corrected for the measurement error of the QFFQ.

Web-enabled and improved software tools and data are needed to measure nutrient intakes and physical activity for personalized health research

Food intake, physical activity (PA), and genetic makeup each affect health and each factor influences the impact of the other 2 factors. Nutrigenomics describes interactions between genes and environment. Knowledge about the interplay between environment and genetics would be improved if experimental designs included measures of nutrient intake and PA. Lack of familiarity about how to analyze environmental variables and ease of access to tools and measurement instruments are 2 deterrents to these combined studies. This article describes the state of the art for measuring food intake and PA to encourage researchers to make their tools better known and more available to workers in other fields. Information presented was discussed during a workshop on this topic sponsored by the USDA, NIH, and FDA in the spring of 2009.

Development of a dish-based, semi-quantitative FFQ for the Korean diet and cancer research using a database approach

We used a database approach in developing a dish-based, semi-quantitative FFQ for Korean diet and cancer research. Cancer-related dietary factors (CRDF) recognised in the scientific community and dietary intake data from the 2001 Korean National Health and Nutrition Examination Survey and the 2002 Korean National Nutrition Survey by Season were used. The list of dishes (n 993) was those reported to be consumed by individuals over 30 years of age during all four seasons. The resulting 112-dish list was selected using contribution analyses and variability analyses to detect between-person variation for CRDF and non-CRDF nutrients. Variations of each dish were grouped into one dish for the final list of 112 dishes, which were then linked to the nutrient database. The final 112 dish items consisted of nine Korean staple dishes, including rice and noodles, twenty-five soups and stews, fifty-four side dishes, nine beverages, nine fruit dishes and six alcoholic beverages. The percentage coverages of energy, protein, fat, carbohydrate and alcohol intake in the selected 112 dishes were 82·4, 76·4, 68·9, 86·0 and 99·8 %, respectively. Dietary exposure to cancer-related Korean dietary factors can be assessed by this new dish-based, semi-quantitative FFQ. This new instrument can calculate the intake of CRDF along with non-CRDF nutrient intake for cancer research.

Validation of a quantitative FFQ for the Barbados National Cancer Study

OBJECTIVE

To assess the validity of a 148-item quantitative FFQ (QFFQ) that was developed for the Barbados National Cancer Study (BNCS) to determine dietary intake over 12 months and examine the dietary risk factors.

DESIGN

A cross-sectional validation study of the QFFQ against 4 d food diaries. Spearman's rank correlations (ρ), intra-class correlation coefficients (ICC) and weighted κ were computed as measures of concordance, adjusting for daily variations in the food diaries. Cross-classification tables and Bland-Altman plots were created for further assessment.

SETTING

BNCS is a case-control study of environmental risk factors for breast and prostate cancer in a predominantly African-origin population in Barbados.

SUBJECTS

Fifty-four individuals (21 years and older) were recruited among controls in the BNCS who were frequency-matched on sex and age group to breast and prostate cancer cases.

RESULTS

Similar mean daily energy intake was derived from the food diary (8201 kJ (1960 kcal)) and QFFQ (7774 kJ (1858 kcal)). Rho for energy and macronutrients ranged from 0·66 (energy) to 0·17 (dietary fibre). The percentage of energy from carbohydrates and protein showed the highest and lowest ICC among macronutrients (0·63 and 0·27, respectively). The highest weighted κ was observed for energy (0·45). When the nutrient intake was divided into quartiles, approximately 34 % of the observations were in the same quartile.

CONCLUSIONS

This investigation supports the validity of the QFFQ as a method for assessing long-term dietary intake except for dietary fibre, folate, vitamins A, E and B12. The instrument will be a useful tool in the analysis of diet-cancer associations in the BNCS.

Use of folic acid-containing supplements after a diagnosis of colorectal cancer in the Colon Cancer Family Registry

BACKGROUND

Supplement use among cancer patients is high, and folic acid intake in particular may adversely affect the progression of colorectal cancer. Few studies have evaluated the use of folic acid-containing supplements (FAS) and its predictors in colorectal cancer patients.

OBJECTIVE

To assess the use of FAS, change in use, and its predictors after colorectal cancer diagnosis.

DESIGN

We used logistic regression models to investigate predictors of FAS use and its initiation after colorectal cancer diagnosis in 1,092 patients recruited through the Colon Cancer Family Registry.

RESULTS

The prevalence of FAS use was 35.4% before and 55.1% after colorectal cancer diagnosis (P = 0.004). Women were more likely than men to use FAS after diagnosis [odds ratio (OR), 1.47; 95% confidence interval (95% CI), 1.14-1.89], as were those consuming more fruit (P(trend) < 0.0001) or vegetables (P(trend) = 0.001), and U.S. residents (P < 0.0001). Less likely to use FAS after diagnosis were nonwhite patients (OR, 0.66; 95% CI, 0.45-0.97), current smokers (OR, 0.67; 95% CI, 0.46-0.96), and those with higher meat intake (P(trend) = 0.03). Predictors of FAS initiation after diagnosis were generally similar to those of FAS use after diagnosis, although associations with race and vegetable intake were weaker and those with exercise stronger.

CONCLUSIONS

Our analysis showed substantial increases in the use of FAS after diagnosis with colorectal cancer, with use or initiation more likely among women, Caucasians, U.S. residents, and those with a health-promoting life-style.

IMPACT

Studies of cancer prognosis that rely on prediagnostic exposure information may result in substantial misclassification.

A candidate gene study of folate-associated one carbon metabolism genes and colorectal cancer risk

BACKGROUND

Folate-associated one-carbon metabolism (FOCM) may play an important role in colorectal carcinogenesis. Variation in FOCM genes may explain some of the underlying risk of colorectal cancer.

METHODS

This study utilized data from 1,805 population-based colorectal cancer cases and 2,878 matched sibling controls from the Colon Cancer Family Registry. We used a comprehensive haplotype tagging single nucleotide polymorphism (tagSNP) approach to select 395 tagSNPs in 15 genes involved in folate and vitamin B(12) metabolism. Genotyping was done using the Illumina GoldenGate or Sequenom platforms. Risk factor and dietary data were collected using self-completed questionnaires. Microsatellite instability (MSI) status was determined using standard techniques, and tumor subsite was obtained from pathology reports. The association between SNPs and colorectal cancer was assessed using conditional logistic regression with sibships as the matching factor and assuming a log additive or codominant model.

RESULTS

In the log additive model, two linked (r(2) = 0.99) tagSNPs in the DHFR gene (rs1677693 and rs1643659) were associated with a significant decrease in colorectal cancer risk after correction for multiple testing (odds ratio, 0.87; 95% confidence interval, 0.71-0.94; P = 0.029; and odds ratio, 0.87; 95% confidence interval, 0.71-0.95; P = 0.034 for rs1677693 and rs1643659, respectively). These two linked (r(2) = 0.99) tagSNPs and one tagSNP in the MTR gene (rs4659744) were significantly associated with reduced colorectal cancer risk only among individuals not using multivitamin supplements.

CONCLUSIONS

Overall, we found only moderate evidence that genetic variation in 15 folate pathway genes may affect colorectal cancer risk except in non-multivitamin users.

IMPACT

This study suggests that multivitamin supplement use may modify the association between folate pathway genes and colorectal cancer risk in a post-folic-acid-supplemented population.

Well-done meat consumption, NAT1 and NAT2 acetylator genotypes and prostate cancer risk: the multiethnic cohort study

BACKGROUND

Prostate cancer (PC) is the most common male malignancy in the United States and disparities in risk exist among ethnic/racial groups. A high intake of well-done meat and the presence of the rapid NAT1 and slow NAT2 acetylator genotypes, as modifiers of the carcinogenic effect of heterocyclic amines, were hypothesized to increase PC risk and possibly explain these ethnic differences in risk.

METHODS

This study examined the associations between well-done (red) meat consumption, NAT1 and NAT2 acetylator genotypes, and PC risk among five ethnicities (African American, Native Hawaiian, Japanese American, Latino, and Caucasian) in a case-control study of PC nested within the Multiethnic Cohort study. Cases (n = 2,106) and controls (n = 2,063) were genotyped for eight single nucleotide polymorphisms in NAT1 and seven single nucleotide polymorphisms in NAT2 that characterized all common alleles for these genes. Well-done meat intake was computed based on responses to a detailed food frequency questionnaire including a question on meat preference. Conditional logistic regression was used in the analysis.

RESULTS

There was no evidence of an increased risk associated with preference for well-done meat, intake of well-done meat, and NAT1 or NAT2 genotypes (jointly or separately).

CONCLUSIONS

These results do not support the hypothesis that exposure to heterocyclic amines is associated with risk of PC. However, additional studies with more precise exposure measures are needed.

Pickled meat consumption and colorectal cancer (CRC): a case-control study in Newfoundland and Labrador, Canada

OBJECTIVE

Although a large body of epidemiological research suggests that red meat intake increases the risk of colorectal cancer, little is known regarding how such an association varies across populations and types of red meat. The objective of this study was to assess whether an association exists between the intakes of total red meat and pickled red meat and the risk of colorectal cancer in study subjects residing in Newfoundland and Labrador.

METHODS

This case-control study of 1,204 residents of Newfoundland and Labrador was part of a larger study on colorectal cancer. Personal history food frequency questionnaires were used to collect retrospective data from 518 individuals diagnosed with colorectal cancer and 686 controls. Intakes were ranked and divided into tertiles. Logistic regression was used to examine the possible association between meat intakes and colorectal cancer diagnosis while controlling for possible confounding factors.

RESULTS

A positive, but non-statistically significant, association between total red meat intake and CRC was observed in this study. Pickled red meat consumption was found to be significantly associated with an increased risk of CRC (men, OR = 2.07, 95% CI 1.37-3.15; women, OR = 2.51, 95% CI 1.45-4.32), the odds ratios increasing with each tertile of consumption, suggesting a dose-response effect.

CONCLUSION

Intake of pickled red meat appears to increase the risk of colorectal cancer in Newfoundland and Labrador.

Associations between obesity and serum lipid-soluble micronutrients among premenopausal women

Elucidating potential pathways that micronutrients may reduce/promote chronic disease may contribute to our understanding of the underlying etiology of disease and their utility as markers of risk. In the current study, we examined associations of serum lipid-soluble micronutrients with body mass index (BMI). We hypothesized that obesity may differentially influence serum micronutrient levels, thereby affecting risk for chronic disease incidence and mortality. Baseline serum samples from 180 premenopausal women from a nutritional trial were analyzed for leptin, C-reactive protein, 25-hydroxyvitamin D, carotenoids, and tocopherols. Participants were stratified into normal-weight (18.5-24.9), overweight (25-29.9), and obese (>or=30) subgroups by BMI (in kilograms per square meter). Differences in serum biomarkers among BMI subgroups were adjusted for Asian ethnicity and smoking status. As expected, obese individuals had significantly higher serum levels of leptin and C-reactive protein (Ps < .05) compared with normal-weight women. gamma-Tocopherol levels were significantly higher in obese individuals (P < .05), whereas alpha-tocopherol levels did not differ among BMI subgroups. Serum levels of 25-hydroxyvitamin D and carotenoids (except lycopene) were significantly lower in obese than in normal-weight women (Ps < .05). The associations between BMI and carotenoids were independent of dietary intake. The obesity-associated reduction for total provitamin A carotenoids (45%) was approximately 3-fold greater than that observed for non-provitamin A carotenoids (16%). Our results indicate potential influences of obesity on serum levels of lipid-soluble micronutrients and suggest that metabolism of provitamin A carotenoids may contribute to the differences observed.

Genetic variability in the MTHFR gene and colorectal cancer risk using the colorectal cancer family registry

BACKGROUND

The MTHFR C677T TT genotype is associated with a 15% to 18% reduction in colorectal cancer risk, but it is not clear if other variants of the gene are associated with colorectal cancer risk.

METHODS

We used a tagSNP approach to comprehensively evaluate associations between variation in the MTHFR gene and colorectal cancer risk using a large family-based case-control study of 1,750 population-based and 245 clinic-based families from the Colon Cancer Family Registry. We assessed 22 TagSNPs, selected based on pairwise r(2) >95%, using the Haploview Tagger and genotyped the TagSNPs on the Illumina GoldenGate or Sequenom platforms. The association between single nucleotide polymorphisms and colorectal cancer was assessed using log-additive, codominant, and recessive models.

RESULTS

From studying the population-based families, the C677T (rs1801133) and A1298C (rs1801131) polymorphisms were associated with a decreased colorectal cancer risk overall [odds ratio (OR), 0.81; 95% confidence interval (95% CI), 0.63-1.04; and OR, 0.82; 95% CI, 0.64-1.07, respectively]. The 677 TT genotype was associated with a decreased risk of microsatellite-stable/microsatellite-low tumors (OR, 0.69; 95% CI, 0.49-0.97) and an increased risk of microsatellite-high tumors (OR, 2.22; 95% CI, 0.91-5.43; P(interaction) = 0.01), as well as an increased risk of proximal cancers and a decreased risk of distal and rectal cancers (P(interaction) = 0.02). No other single nucleotide polymorphism was associated with risk overall or within subgroups.

CONCLUSION

The 677 TT and 1298 CC genotypes may each be associated with a decrease in colorectal cancer risk. We observed little evidence of additional genetic variability in the MTHFR gene relevant to colorectal cancer risk.

Dietary patterns and risk for diabetes: the multiethnic cohort

OBJECTIVE The high diabetes incidence among Japanese Americans and Native Hawaiians cannot be explained by BMI. Therefore, we examined the influence of three dietary patterns of "fat and meat," "vegetables," and "fruit and milk" on diabetes risk in the Hawaii component of the Multiethnic Cohort with 29,759 Caucasians, 35,244 Japanese Americans, and 10,509 Native Hawaiians. RESEARCH DESIGN AND METHODS Subjects aged 45-75 years completed a baseline food frequency questionnaire. After 14 years of follow-up, 8,587 subjects with incident diabetes were identified through self-reports or health plan linkages. Risk was assessed using Cox regression stratified by age and adjusted for ethnicity, BMI, physical activity, education, total energy, smoking, alcohol intake, marital status, and hypertension. RESULTS Fat and meat was significantly associated with diabetes risk in men (hazard ratio 1.40 [95% CI 1.23-1.60], P(trend) < 0.0001) and women (1.22 [1.06-1.40], P(trend) = 0.004) when extreme quintiles were compared. Except in Hawaiian women, the magnitude of the risk was similar across ethnic groups although not always significant. After stratification by BMI, fat and meat remained a predictor of disease primarily among overweight men and among overweight Japanese women. Vegetables lowered diabetes risk in men (0.86 [0.77-0.95], P(trend) = 0.004) but not in women, whereas fruit and milk seemed to be more beneficial in women (0.85 [0.76-0.96], P(trend) = 0.005) than in men (0.92 [0.83-1.02], P(trend) = 0.04). CONCLUSIONS Foods high in meat and fat appear to confer a higher diabetes risk in all ethnic groups, whereas the effects of other dietary patterns vary by sex and ethnicity.

Biochemical validation of food frequency questionnaire-estimated carotenoid, alpha-tocopherol, and folate intakes among African Americans and non-Hispanic Whites in the Southern Community Cohort Study

Few food frequency questionnaires (FFQs) have been developed specifically for use among African Americans, and reports of FFQ performance among African Americans or low-income groups assessed using biochemical indicators are scarce. The authors conducted a validation study within the Southern Community Cohort Study to evaluate FFQ-estimated intakes of alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin, lycopene, folate, and alpha-tocopherol in relation to blood levels of these nutrients. Included were 255 nonsmoking participants (125 African Americans, 130 non-Hispanic whites) who provided a blood sample at the time of study enrollment and FFQ administration in 2002-2004. Levels of biochemical indicators of each micronutrient (alpha-tocopherol among women only) significantly increased with increasing FFQ-estimated intake (adjusted correlation coefficients: alpha-carotene, 0.35; beta-carotene, 0.28; beta-cryptoxanthin, 0.35; lutein/zeaxanthin, 0.28; lycopene, 0.15; folate, 0.26; alpha-tocopherol, 0.26 among women; all P's < 0.05). Subjects in the top decile of FFQ intake had blood levels that were 27% (lycopene) to 178% (beta-cryptoxanthin) higher than those of subjects in the lowest decile. Satisfactory FFQ performance was noted even for participants with less than a high school education. Some variation was noted in the FFQ's ability to predict blood levels for subgroups defined by race, sex, and other characteristics, but overall the Southern Community Cohort Study FFQ appears to generate useful dietary exposure rankings in the cohort.

Complete blood count, measures of iron status and inflammatory markers in inner-city African Americans with undiagnosed hepatitis C seropositivity

BACKGROUND

Hepatitis C virus (HCV) infection may be associated with thrombocytopenia and increased iron stores in patients receiving medical care. We aimed to determine how often changes in hematologic, iron metabolic and inflammatory markers occur in individuals with undiagnosed HCV in the community.

METHODS

Inner-city African Americans (n=143) were recruited from the community according to reported ingestion of alcohol. They were divided broadly into those who drank more or less than 56 g alcohol/day as assessed by dietary questionnaire. HCV serology was determined and laboratory values were compared according to HCV seropositivity in analyses that adjusted for alcohol consumption.

RESULTS

The prevalence of HCV seropositivity was 23% among men and 29% among women. Levels of hepatocellular enzymes were higher with HCV seropositivity (P<0.0001) but hemoglobin concentrations, white blood cell and platelet counts and serum ferritin concentrations did not differ. The globulin fraction of the serum protein concentration (P=0.002) was increased with HCV seropositivity as expected with chronic inflammation. However, erythrocyte sedimentation rate and serum iron and haptoglobin levels did not differ significantly according to HCV status. Furthermore, multivariate analysis revealed that C-reactive protein was decreased and transferrin concentration was increased with both HCV and alcohol consumption (P<0.014).

CONCLUSIONS

Previously undiagnosed HCV seropositivity has little effect on the complete blood count and body iron stores but appears to perturb the response to an inflammatory stimulus, causing reduced rather than increased circulating CRP concentrations and increased rather than decreased transferrin concentrations.

Consumption of restaurant foods and incidence of type 2 diabetes in African American women

BACKGROUND

Type 2 diabetes is a major problem in Western nations. Profound secular changes in the food environment and eating habits may play a role. In particular, consumption of foods prepared outside the home has greatly increased.

OBJECTIVE

We investigated the relation of restaurant meal consumption to incidence of type 2 diabetes among African American women with the use of data from the prospective Black Women's Health Study.

DESIGN

The participants have completed mailed follow-up questionnaires every 2 y since 1995, including food-frequency questionnaires that asked about the frequency of eating restaurant meals of various types. Cox proportional hazards models were used to calculate incidence rate ratios and 95% CIs for the association of type 2 diabetes incidence with various categories of consumption of each restaurant food relative to the lowest category, with adjustment for diabetes risk factors.

RESULTS

Among 44,072 participants aged 30-69 y and free of diabetes at baseline, 2873 incident cases of type 2 diabetes occurred during 10 y of follow-up. Consumption of restaurant meals of hamburgers, fried chicken, fried fish, and Chinese food were independently associated with an increased risk of type 2 diabetes. Incidence rate ratios for > or = 2 such meals per week relative to none were 1.40 (95% CI: 1.14, 1.73) for hamburgers and 1.68 (95% CI: 1.36, 2.08) for fried chicken. Control for body mass index greatly reduced the estimates, which suggests that the associations are mediated through weight gain and obesity.

CONCLUSION

The present study has identified a risk factor for type 2 diabetes that may be readily modifiable by dietary changes.

Genetic variation in the vitamin D receptor (VDR) and the vitamin D-binding protein (GC) and risk for colorectal cancer: results from the Colon Cancer Family Registry

Epidemiologic evidence supports a role for vitamin D in colorectal cancer (CRC) risk. Variants in vitamin D-related genes might modify the association between vitamin D levels and CRC risk. In this analysis, we did a comprehensive evaluation of common variants in the vitamin D receptor (VDR) and the vitamin D-binding protein (GC; group-specific component) genes using a population-based case-unaffected sibling control design that included 1,750 sibships recruited into the Colon Cancer Family Registry. We also evaluated whether any associations differed by calcium supplement use, family history of CRC, or tumor characteristics. Heterogeneity by calcium and vitamin D intake was evaluated for a subset of 585 cases and 837 sibling controls who completed a detailed food frequency questionnaire. Age- and sex-adjusted associations were estimated using conditional logistic regression. Overall, we did not find evidence for an association between any single-nucleotide polymorphism (SNP) in VDR or GC and risk for CRC (range of unadjusted P values 0.01-0.98 for VDR and 0.07-0.95 for GC). None of these associations was significant after adjustment for multiple comparisons. We also found no evidence that calcium or vitamin D intake (food and supplement) from the food frequency questionnaire modified the association estimates between VDR and GC SNPs and CRC. We did observe associations between SNPs in GC and microsatellite unstable CRC, although these results should be confirmed in additional studies. Overall, our results do not provide evidence for a role of common genetic variants in VDR or GC in susceptibility to CRC.

Dietary fiber, magnesium, and glycemic load alter risk of type 2 diabetes in a multiethnic cohort in Hawaii

The influence of dietary fiber, magnesium (Mg), and glycemic load (GL) on diabetes was examined in the Hawaii component of the Multiethnic Cohort. The 75,512 Caucasian, Japanese American, and Native Hawaiian participants aged 45-75 y at baseline completed a FFQ. After 14 y of follow-up, 8587 incident diabetes cases were identified through self-reports and health plans. We applied Cox regression stratified for age at cohort entry and adjusted for ethnicity, BMI, physical activity, education, and total energy with further stratifications by sex and ethnicity. When comparing extreme quintiles, total fiber intake was associated with reduced diabetes risk among all men [hazard ratio (HR): 0.75; 95% CI: 0.67, 0.84; P-trend < 0.001) and women (HR: 0.95; 95% CI: 0.85, 1.06; P-trend = 0.05). High intake of grain fiber reduced diabetes risk significantly by 10% in men and women. High vegetable fiber intake lowered risk by 22% in all men but not women. Mg intake reduced risk (HR = 0.77 and 0.84 for men and women, respectively) and, due to its strong correlation with fiber (r = 0.83; P < 0.001), may explain the protective effect of fiber. The top GL quintile was associated with a significantly elevated diabetes incidence in Caucasian men and in all women except Japanese Americans. Overall, several associations were more pronounced in Caucasians than in the other groups. These findings suggest that protection against diabetes can be achieved through food choices after taking into account body weight, but, due to differences in commonly consumed foods, risk estimates may differ by ethnic group.

Genes involved with folate uptake and distribution and their association with colorectal cancer risk

Folate status is an important predictor of colorectal cancer risk. Common genetic variants in genes involved in regulating cellular folate levels might also predict risk, but there are limited data on this issue. We conducted a family-based case-control association study of variants in four genes involved in folate uptake and distribution: FOLR1, FPGS, GGH and SLC19A1, using 1,750 population-based and 245 clinic-based cases of pathologically confirmed colorectal cancer and their unaffected relatives participating in the Colon Cancer Family Registries. Standardized questionnaires, administered to all participants, collected information on risk factors and diet. Standard molecular techniques were used to determine microsatellite instability (MSI) status on cases. tagSNPs (n = 29) were selected based on coverage as assessed by pairwise r2. We found no evidence that tagSNPs in these genes were associated with risk of colorectal cancer. For the SLC19A1-rs1051266 (G80A, Arg27His) missense polymorphism, the A/A genotype was not associated with risk of colorectal cancer using population-based (OR = 1.00; 95% CI = 0.81-1.23) or clinic-based (OR = 0.75; 95% CI = 0.44-1.29) families compared to the G/A and G/G genotypes. We found no evidence that the association between any tagSNP and CRC risk was modified by multivitamin use, folic acid use and dietary folate intake and total folate intake. The odds ratios were similar, irrespective of MSI status, tumor subsite and family history of colorectal cancer. In conclusion, we found no significant evidence that genetic variants in FOLR1, GGH, FPGS and SLC19A1 are associated with the risk of colorectal cancer.

Validation of nutrient intake using an FFQ and repeated 24 h recalls in black and white subjects of the Adventist Health Study-2 (AHS-2)

OBJECTIVE

To validate a 204-item quantitative FFQ for measurement of nutrient intake in the Adventist Health Study-2 (AHS-2).

DESIGN

Calibration study participants were randomly selected from the AHS-2 cohort by church, and then subject-within-church. Each participant provided two sets of three weighted 24 h dietary recalls and a 204-item FFQ. Race-specific correlation coefficients (r), corrected for attenuation from within-person variation in the recalls, were calculated for selected energy-adjusted macro- and micronutrients.

SETTING

Adult members of the AHS-2 cohort geographically spread throughout the USA and Canada.

SUBJECTS

Calibration study participants included 461 blacks of American and Caribbean origin and 550 whites.

RESULTS

Calibration study subjects represented the total cohort very well with respect to demographic variables. Approximately 33 % were males. Whites were older, had higher education and lower BMI compared with blacks. Across fifty-one variables, average deattenuated energy-adjusted validity correlations were 0.60 in whites and 0.52 in blacks. Individual components of protein had validity ranging from 0.40 to 0.68 in blacks and from 0.63 to 0.85 in whites; for total fat and fatty acids, validity ranged from 0.43 to 0.75 in blacks and from 0.46 to 0.77 in whites. Of the eighteen micronutrients assessed, sixteen in blacks and sixteen in whites had deattenuated energy-adjusted correlations >or=0.4, averaging 0.60 and 0.53 in whites and blacks, respectively.

CONCLUSIONS

With few exceptions validity coefficients were moderate to high for macronutrients, fatty acids, vitamins, minerals and fibre. We expect to successfully use these data for measurement error correction in analyses of diet and disease risk.

Dietary vitamin D and risk of non-Hodgkin lymphoma: the multiethnic cohort

The present study explored the association between dietary vitamin D and non-Hodgkin's lymphoma (NHL) risk. The multiethnic cohort (MEC) includes more than 215 000 Caucasians, African Americans, Native Hawaiians, Japanese Americans and Latinos, aged 45-75. After 10 years of follow-up, 939 incident NHL cases were identified. Risk was estimated using proportional hazards' models adjusted for possible confounders. Vitamin D intake was not associated with NHL risk in the entire cohort (P(trend) = 0.72 for men and P(trend) = 0.83 for women), but significantly lowered disease risk in African American women (hazard ratio (HR) = 0.50, 95 % CI: 0.28, 0.90, P(trend) = 0.03) and was borderline protective in African American men (HR = 0.68; 95 % CI: 0.39, 1.19; P(trend) = 0.31) when the highest to the lowest tertile was compared. In NHL subtype analyses, a 19, 36 and 32 % lowered risk, although not significant, was observed for diffuse large B-cell lymphoma, follicular lymphoma and small lymphocytic lymphoma/chronic lymphocytic leukemia in women, respectively. High dietary intake of vitamin D did not show a protective effect against NHL within the MEC except among African Americans, possibly because vitamin D production due to sun exposure is limited in this population.

How dietary intake methodology is adapted for use in European immigrant population groups - a review

Immigrants comprise a noteworthy segment of the European population whose numbers are increasing. Research on the dietary habits of immigrants is critical for correctly providing diet counselling and implementing effective interventions. The aim of the present study was to identify the presently used methods and adaptations required for measuring dietary intake in European immigrant groups. A comprehensive review strategy included a structured MEDLINE search, related references and key expert consultations. The review targeted adults from non-European union (European union-15 countries) ethnic groups having the largest populations in Europe. As studies evaluating nutrient intake were scarce, papers evaluating intake at the level of foods were included. Forty-six papers were selected. Although Eastern Europe, Turkey, Africa (North, Sub-Saharan and Afro-Caribbean), Asia and Latin America represented the most numerous immigrant groups, papers on dietary intake were not available for all populations. Interview-administered FFQ and repeated 24 hour recalls were the most frequently applied instruments. Inclusion of ethnic foods and quantification of specific portion sizes of traditional foods and dishes in assessment tools as well as food composition databases were commonly identified problems. For FFQ, food list elaboration required particular consideration to reflect key ethnic foods and relative contribution to nutrient intake. Extra efforts were observed to overcome cultural barriers to study participation. Evaluating dietary intake of immigrant populations requires special attention to various methodological aspects (sampling, recruiting, instruments used, method of administration, food composition database, acculturation, etc.) so as to adequately address the range of socio-cultural factors inherent in these nutritionally at risk target groups.

Validity and calibration of food frequency questionnaires used with African-American adults in the Jackson Heart Study

OBJECTIVE

To examine the relative validity of two food frequency questionnaires (FFQs) developed for use in investigating diet and disease relationships within the adult African-American population in the southern United States.

DESIGN

Cross-sectional analyses of dietary nutrient intake data, comparing four 24-hour dietary recalls with an FFQ developed by the Lower Mississippi Delta Nutrition Intervention Research Initiative, and its shorter version adapted for use in the Jackson Heart Study.

SUBJECTS

A representative subset of participants (n=499, aged 35 to 81 years) from the baseline Jackson Heart Study cohort (N=5,302) was selected for this study. Data collection took place between winter 2000 and spring 2004.

STATISTICAL ANALYSES

Pearson's correlation coefficients (energy adjusted and de-attenuated) for 26 nutrients estimates from each of the FFQs, comparing them with the mean of four 24-hour dietary recalls. The ability of the FFQs to rank individuals based on nutrient intakes was compared to that of the mean of four 24-hour dietary recalls and attenuation coefficients were also calculated.

RESULTS

Median nutrient intake estimates tended to be higher on the long and lower on the short FFQ compared to the median for the mean of four 24-hour dietary recalls. Energy adjusted and deattenuated correlations of FFQ intake estimates with recalls ranged from 0.20 for sodium to 0.70 for carbohydrate for the short FFQ and from 0.23 for polyunsaturated fat to 0.75 for dietary fiber and magnesium for the long. Attenuation coefficients for men on average were 0.42 for the short and 0.49 for the long FFQ. For women, these were 0.31 for the short and 0.42 for the long FFQ.

CONCLUSIONS

Both FFQs appear to be reasonably valid for assessment of dietary intake of adult African Americans in the South. The Lower Mississippi Delta Nutrition Intervention Research Initiative FFQ exhibited higher intake estimates and stronger correlations with recalls than the Jackson Heart Study FFQ for most nutrients analyzed, more so for women than men.

Meat and heterocyclic amine intake, smoking, NAT1 and NAT2 polymorphisms, and colorectal cancer risk in the multiethnic cohort study

BACKGROUND

N-acetyltransferases (NAT) 1 and 2 are polymorphic enzymes catalyzing the metabolic activation of heterocyclic amines. We investigated the modifying effects of NAT1 and NAT2 polymorphisms on the association of meat consumption, heterocyclic amine intake, and smoking with colorectal cancer risk.

METHOD

In the Multiethnic Cohort study, participants completed a smoking history and a food-frequency questionnaire at recruitment and a cooked meat module 5 years later to estimate heterocyclic amine intake (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline). Blood samples were collected from incident cases and age-, sex-, ethnicity-, frequency-matched controls to determine genotypes. For analysis of meat intake and smoking, data were available for 1,009 cases and 1,522 controls; for heterocyclic amine intake analyses, 398 cases and 1,444 controls were available. Multivariate logistic regression models were used to estimate odds ratios.

RESULTS

Smoking was associated with an increased colorectal cancer risk (odds ratio, 1.51; 95% confidence interval, 1.17-1.95) for > or =30 pack-years compared with never smokers (P trend = 0.0004). The association was stronger with presence of the "rapid" compared with the "slow/intermediate" NAT2 genotype (P interaction = 0.003). No significant associations were observed for intakes of red meat, processed meat, and heterocyclic amine, or meat doneness preference, but a dietary pattern high in meat showed a weak positive interaction with the NAT2 genotype (P interaction = 0.05).

CONCLUSION

The enhanced association between smoking and colorectal cancer risk in subjects with the NAT2 rapid genotype supports a role for NAT2 and tobacco smoke heterocyclic amines in the etiology of colorectal cancer. This study only provides weak support for a similar association with meat heterocyclic amines.

Estimating nutrient intake from a food frequency questionnaire: incorporating the elements of race and geographic region

Assignment of nutrient values to food frequency questionnaire (FFQ) items does not usually account for participant characteristics (besides age or sex) that may influence eating patterns. For the Southern Community Cohort Study, the authors developed and assessed results from a nutrient database system incorporating sex-, race-, and census-region-specific food lists, using 24-hour recall data from the National Health and Nutrition Examination Survey (NHANES III, NHANES 1999-2000, NHANES 2001-2002, and NHANES 2003-2004) and the Continuing Survey of Food Intakes by Individuals that permitted estimation of nutrients tailored to participants' characteristics. For each of 15 nutrients, comparisons were made to a "standard" nutrient scoring system based on nationwide race-blind 24-hour recalls from these same sources. Using FFQ data from 67,926 Southern Community Cohort Study participants (47,038 African-American, 20,888 non-Hispanic white) aged 40-79 years who enrolled in the study during 2002-2008, the region- and race-informed system tended to produce increased estimated intake for most nutrients for black women, particularly for saturated fat (7.1%), monounsaturated fat (8.3%), and polyunsaturated fat (7.2%); smaller but significant changes (<5%) were also observed for nutrient intake for men and white women. These types of refinements in nutrient databases can be considered a means of enhancing the accuracy of dietary estimation using FFQs.

Biomarkers in nutritional epidemiology: applications, needs and new horizons

Modern epidemiology suggests a potential interactive association between diet, lifestyle, genetics and the risk of many chronic diseases. As such, many epidemiologic studies attempt to consider assessment of dietary intake alongside genetic measures and other variables of interest. However, given the multi-factorial complexities of dietary exposures, all dietary intake assessment methods are associated with measurement errors which affect dietary estimates and may obscure disease risk associations. For this reason, dietary biomarkers measured in biological specimens are being increasingly used as additional or substitute estimates of dietary intake and nutrient status. Genetic variation may influence dietary intake and nutrient metabolism and may affect the utility of a dietary biomarker to properly reflect dietary exposures. Although there are many functional dietary biomarkers that, if utilized appropriately, can be very informative, a better understanding of the interactions between diet and genes as potentially determining factors in the validity, application and interpretation of dietary biomarkers is necessary. It is the aim of this review to highlight how some important biomarkers are being applied in nutrition epidemiology and to address some associated questions and limitations. This review also emphasizes the need to identify new dietary biomarkers and highlights the emerging field of nutritional metabonomics as an analytical method to assess metabolic profiles as measures of dietary exposures and indicators of dietary patterns, dietary changes or effectiveness of dietary interventions. The review will also touch upon new statistical methodologies for the combination of dietary questionnaire and biomarker data for disease risk assessment. It is clear that dietary biomarkers require much further research in order to be better applied and interpreted. Future priorities should be to integrate high quality dietary intake information, measurements of dietary biomarkers, metabolic profiles of specific dietary patterns, genetics and novel statistical methodology in order to provide important new insights into gene-diet-lifestyle-disease risk associations.

A brief dietary screener: appropriate for overweight Latino adolescents?

The objective of this article is to assess whether a brief dietary screener designed to assess fast-food and beverage consumption in a primarily white, adolescent population, is also valid and reliable in an overweight, adolescent Latina population. This screener was developed by the University of Minnesota to assess beverage consumption (nine items) and fast-food consumption (13 items) in normal weight, primarily white adolescents (ages 11 to 18 years). Thirty-five at risk for overweight (body mass index > or = 85th percentile) adolescent (ages 14 to 17 years) Latina females were recruited from East Los Angeles, CA, and completed the screener twice, approximately 7 to 14 days apart, during the fall of 2007. Dietary intake was also assessed by 3-day diet records. Spearman correlation and simple kappa were employed for test-retest assessment and comparisons between the screener and the records. Test-retest assessment yielded a mean Spearman or kappa statistic of 0.49 with 17 of 21 responses being significant (P<0.05). Validity was much lower and yielded a kappa statistic of only 0.08 and no responses were significant. Although this screener appeared to be a valid and reliable measure to assess beverage and fast-food consumption in a primarily white, adolescent population, it does not appear to be appropriate for an overweight Latina female adolescent population.

Race/ethnic variation in serum levels of IGF-I and IGFBP-3 in US adults

OBJECTIVES

The IGF axis plays a significant role in normal growth and development and variation in IGFs is associated with health outcomes. Past studies report variation in IGF levels among race/ethnic groups known to differ in disease incidence. This paper reports on race/ethnic variation in serum levels of IGF-I and IGF-BP3 in a nationally representative and ethnically diverse sample of US adults.

DESIGN

Serum IGF-I and IGFBP-3 levels from the fasting subsample (n = 6061) of respondents to the US National Health and Nutrition Examination Survey III (NHANES III) were analyzed using an IGF-I ELISA (Diagnostic Systems Laboratory (DSL) 10-5600) and an IGFBP-3 IRMA (DSL 6600). The NHANES is a combined examination and interview survey of a nationally representative sample of US adults. Regression analyses were used to estimate cross-sectional associations between the IGF axis and demographic variables.

RESULTS

In unadjusted analyses, serum IGF-I levels were higher in males than in females, and IGFBP-3 levels were higher in females than in males. Both analytes were lower in older adults. Univariate analyses indicate that serum levels of IGF-I are lower in female Non-Hispanic Whites (NHW) (256 [4.9]) and Hispanics (249 [6.6]) than in Non-Hispanic Blacks (NHB) (281 [4.9]). However, in males, IGF levels in NHWs (287 [3.6]) and NHBs (284 [4.3]) are similar and levels in Mexican-Americans are only moderately reduced (265 [3.4]). Notably, NHB's have the highest molar ratio of IGF-I:IGFBP-3 at all ages. After adjustment for age and BMI, gender and race/ethnicity differences persist.

CONCLUSIONS

These cross-sectional data support exploration of the IGF axis as an explanation for some race/ethnic differences in cancer incidence.

Dietary patterns and breast cancer risk in Asian American women

BACKGROUND

The role of diet as a cause of breast cancer in Asian Americans has not been adequately studied.

OBJECTIVE

We investigated the association between dietary patterns and breast cancer risk in Asian Americans.

DESIGN

This population-based case-control study in Los Angeles County compared dietary patterns between 1248 Asian American women with incident breast cancer and 1148 age-, ethnicity-, and neighborhood-matched controls. The relation between dietary patterns and serum concentrations of estrogens, androgens, and sex hormone-binding globulin (SHBG) was investigated in 2172 postmenopausal control women.

RESULTS

We used a scoring method proposed by Trichopoulou et al (1) and found that adherence to a Mediterranean diet was inversely associated with risk; the odds ratio (OR) was 0.65 (95% CI: 0.44, 0.95) in women with the highest scores (> or = 8; most adherent) compared with those with the lowest scores (0-3; P for trend = 0.009), after adjustment for key covariates. We also used factor analysis and identified 3 dietary patterns (Western-meat/starch, ethnic-meat/starch, and vegetables/soy). In a combined index of the 3 patterns, women who were high consumers of Western and ethnic meat/starch and low consumers of the vegetables/soy diets showed the highest risk (OR: 2.19; 95% CI: 1.40, 3.42; P for trend = 0.0005). SHBG concentrations were 23% lower in women with a high intake of the meat/starch pattern and a low intake of the vegetables/soy pattern than in those with a low intake of the meat/starch pattern and a high intake of the vegetables/soy pattern (P for trend = 0.069).

CONCLUSION

Our results suggest that a diet characterized by a low intake of meat/starches and a high intake of legumes is associated with a reduced risk of breast cancer in Asian Americans.

Carotenoid intake and colorectal cancer risk: the multiethnic cohort study

BACKGROUND

A protective effect of fruits and vegetables against colorectal cancer has been supported by many epidemiologic studies. This suggests that the carotenoids frequently found in these foods play a role in the prevention of this common cancer. To examine associations between the intake of individual and total carotenoids and the risk of colorectal cancer, we analyzed prospective data from the Multiethnic Cohort Study.

METHODS

This analysis includes 85 898 men and 105 106 women who completed a quantitative food frequency questionnaire in 1993-1996. The participants were African Americans, Native Hawaiians, Japanese Americans, Latinos, and whites aged 45-75 years at cohort entry. After an average follow-up of 8.2 years, 1292 and 1086 incident cases of colorectal cancer were identified in men and women, respectively. Cox proportional hazard models were used to estimate relative risks of colorectal cancer.

RESULTS

No significant associations were found between intake of individual and total carotenoids and colorectal cancer risk either in men or women, except for beta-cryptoxanthin, which showed a mild protective effect in men. When the associations were investigated separately for colon and rectal cancer, lycopene intake was related to an increased risk of rectal cancer in men. A decreased risk was seen for total beta-carotene in male current smokers, but the test for interaction with smoking status was not significant. No association was observed in each ethnic-sex group.

CONCLUSION

Overall, our findings do not support a significant association between carotenoid intake and colorectal cancer, although some associations were seen in subgroup analyses.

Using physiological dysregulation to assess global health status: associations with self-rated health and health behaviors

Six measures of physiological dysregulation were derived from 11 clinically assessed biomarkers, and related to health outcomes and health behaviors for the Hawaii Personality and Health cohort (N = 470). Measures summing extreme scores at one tail of the biomarker distributions performed better than ones summing both tails, and continuous measures performed better than count scores. Health behaviors predicted men's dysregulation but not women's. Dysregulation and health behaviors predicted self-rated health for both men and women, and depressive symptoms predicted self-rated health only for women. These findings provide preliminary guidelines for constructing valid summary measures of global health status for use in health psychology.

A review of food frequency questionnaires developed and validated in Japan

BACKGROUND

The food frequency questionnaire (FFQ) has been used throughout the world for epidemiological purposes. Because dietary habits vary greatly, the FFQ must be tailored for use with specific populations. The usefulness of FFQs in Japan was assessed by reviewing questionnaires developed and validated in that country.

METHODS

A literature search was conducted to identify articles on the development and/or validation of FFQs for Japanese populations. For each FFQ identified, validation studies were used to abstract its characteristics and information. The correlation coefficients between diet records (DRs) and FFQ estimates and those between the same FFQs completed twice were used to evaluate validity and reproducibility, respectively, of the questionnaires.

RESULTS

Twenty-one eligible FFQs were identified. They were found to be reasonably valid and reproducible. The median of correlation coefficients between DRs and FFQs ranged from 0.31 to 0.56 for target nutrients, and that between the same FFQs completed twice within a period of 9 months to 1 year ranged from 0.50 to 0.72. Relatively poor validity was found for FFQ estimates on consumption of potatoes, seaweed, sodium, niacin, and polyunsaturated fatty acids. For the purpose of analysis, FFQs were divided into long FFQs (97 or more food items) and short FFQs (<70 items); the former had slightly higher validity.

CONCLUSION

FFQs are useful for assessing dietary intake in Japan, although careful consideration is required for the food groups and nutrients for which FFQs had low validity.

Diabetes prevalence and body mass index differ by ethnicity: the Multiethnic Cohort

OBJECTIVE

The high prevalence of diabetes in non-Caucasian populations is reported not only for Native Hawaiians who suffer from high rates of obesity, but also for Japanese with a relatively low body weight. The objectives of this study were to estimate the prevalence of diabetes among participants of the Multiethnic Cohort (MEC) and to examine the association of body mass index (BMI) with self-reported diabetes by ethnicity.

DESIGN

Cross-sectional analysis of baseline questionnaire at cohort entry.

PARTICIPANTS

187,439 MEC subjects in Hawaii and California from five ethnic groups.

MAIN OUTCOME MEASURES

Participants completed a 26-page, self-administered survey with questions concerning anthropometrics, demographic, medical, lifestyle, and food consumption behavior. Age-adjusted prevalence of diabetes was calculated by sex and ethnicity and stratified by BMI. Prevalence ratios were determined using logistic regression while adjusting for variables that are known to be related to diabetes. The c statistic was computed to compare models with different confounders.

RESULTS

The prevalence of self-reported diabetes in the MEC was 11.6%. The age-adjusted diabetes prevalence ranged from 6.3% in Caucasians to 10.2% in Japanese, 16.1% in Native Hawaiians, 15.0% in African Americans, and 15.8% in Latinos. After adjustment for known risk factors, the prevalence ratio by ethnicity ranged between 2.1 (African American and Latino), 2.8 (Japanese), and 3.0 (Native Hawaiian) as compared to Caucasians. These differences were observed among all BMI categories.

CONCLUSIONS

Ethnic differences in the prevalence of diabetes persisted after stratification by BMI. The prevalence of diabetes was at least two-fold higher in all ethnic groups than among Caucasians.

A food pattern that is predictive of flavonol intake and risk of pancreatic cancer

BACKGROUND

In the Multiethnic Cohort (MEC) study, we showed inverse associations between flavonols and pancreatic cancer risk.

OBJECTIVE

We aimed to define a food pattern associated with intakes of quercetin, kaempferol, and myricetin; to examine the association of that pattern with pancreatic cancer risk; and to investigate the associations in an independent study.

DESIGN

Reduced rank regression was applied to dietary data for 183,513 participants in the MEC. A food group pattern was extracted and simplified and applied to dietary data of 424,978 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Dietary intake in both studies was assessed by using specially developed questionnaires. Multivariate Cox proportional hazards models were used to estimate relative risks for pancreatic cancer in the MEC (610 cases) and the EPIC (517 cases) studies.

RESULTS

The food group pattern consisted mainly of tea, fruit, cabbage, and wine. In the MEC, inverse associations with pancreatic cancer in smokers were observed for the food group pattern [relative risk: 0.59 (95% CI: 0.31, 1.12) when extreme quintiles were compared; P for trend = 0.03]. In the EPIC study, the simplified pattern was not associated with pancreatic cancer risk (P for trend = 0.78).

CONCLUSIONS

A food pattern associated with the intake of quercetin, kaempferol, and myricetin was associated with lower pancreatic cancer risk in smokers in a US-based population. However, failure to replicate the associations in an independent study weakens the conclusions and raises questions about the utility of food patterns for flavonols across populations.

Red meat intake, doneness, polymorphisms in genes that encode carcinogen-metabolizing enzymes, and colorectal cancer risk

Colorectal cancer literature regarding the interaction between polymorphisms in carcinogen-metabolizing enzymes and red meat intake/doneness is inconsistent. A case-control study was conducted to evaluate the interaction between red meat consumption, doneness, and polymorphisms in carcinogen-metabolizing enzymes. Colorectal cancer cases diagnosed 1997 to 2000, ages 20 to 74 years, were identified through the population-based Ontario Cancer Registry and recruited by the Ontario Family Colorectal Cancer Registry. Controls were sex-matched and age group-matched random sample of Ontario population. Epidemiologic and food questionnaires were completed by 1,095 cases and 1,890 controls; blood was provided by 842 and 1,251, respectively. Multivariate logistic regression was used to obtain adjusted odds ratio (OR) estimates. Increased red meat intake was associated with increased colorectal cancer risk [OR (> 5 versus < or = 2 servings/wk), 1.67 (1.36-2.05)]. Colorectal cancer risk also increased significantly with well-done meat intake [OR (> 2 servings/wk well-done versus < or = 2 servings/wk rare-regular), 1.57 (1.27-1.93)]. We evaluated interactions between genetic variants in 15 enzymes involved in the metabolism of carcinogens in overcooked meat (cytochrome P450, glutathione S-transferase, UDP-glucuronosyltransferases, SULT, NAT, mEH, and AHR). CYP2C9 and NAT2 variants were associated with colorectal cancer risk. Red meat intake was associated with increased colorectal cancer risk regardless of genotypes; however, CYP1B1 combined variant and SULT1A1-638G>A variant significantly modified the association between red meat doneness intake and colorectal cancer risk. In conclusion, well-done red meat intake was associated with an increased risk of colorectal cancer regardless of carcinogen-metabolizing genotype, although our data suggest that persons with CYP1B1 and SULT1A1 variants had the highest colorectal cancer risk.

Ferroportin Q248h, dietary iron, and serum ferritin in community African-Americans with low to high alcohol consumption

BACKGROUND

Alcohol consumption is associated with increased iron stores. In sub-Saharan Africa, high dietary ionic iron and the ferroportin Q248H allele have also been implicated in iron accumulation. We examined the associations of ferroportin Q248H, alcohol and dietary iron with serum ferritin, aspartate aminotransaminase (AST) and alanine aminotransaminase (ALT) concentrations in African-Americans.

METHODS

Inner-city African-Americans (103 men, 40 women) were recruited from the community according to reported ingestion of >4 alcoholic drinks/d or <2/wk. Typical daily heme iron, nonheme iron and alcohol were estimated using University of Hawaii's multiethnic dietary questionnaire. Based on dietary questionnaire estimates we established categories of < versus > or =56 g alcohol/d, equivalent to 4 alcoholic drinks/d assuming 14 g alcohol per drink.

RESULTS

Among 143 participants, 77% drank <56 g alcohol/d and 23%> or =56 g/d as estimated by the questionnaire. The prevalence of ferroportin Q248H was 23.3% with alcohol >56 g/d versus 7.5% with lower amounts (p = 0.014). Among subjects with no history of HIV disease, serum ferritin concentration had positive relationships with male gender (p = 0.041), alcohol consumption (p = 0.021) and ALT concentration (p = 0.0001) but not with dietary iron intake or ferroportin Q248H. Serum AST and ALT concentrations had significant positive associations with male gender and hepatitis C seropositivity but not with alcohol or dietary iron intake or ferroportin Q248H.

CONCLUSIONS

Our findings suggest a higher prevalence of ferroportin Q248H with greater alcohol consumption, and this higher prevalence raises the possibility that the allele might ameliorate the toxicity of alcohol. Our results suggest that alcohol but not dietary iron contributes to higher body iron stores in African-Americans. Studies with larger numbers of participants are needed to further clarify the relationship of ferroportin Q248H with the toxicity of alcohol consumption.

The association of glycemic load and carbohydrate intake with colorectal cancer risk in the Multiethnic Cohort Study

BACKGROUND

High-glycemic-load diets may increase colorectal cancer risk through hyperinsulinemic effects.

OBJECTIVE

We analyzed data for 191,004 participants in the Multiethnic Cohort Study to determine the risk of colorectal cancer associated with glycemic load (GL), carbohydrate, and sucrose and to ascertain whether this risk was modified by sex and ethnicity.

DESIGN

During 8 y of follow-up, 2379 incident cases of colorectal adenocarcinoma occurred. We used baseline quantitative food-frequency questionnaire data to assess usual dietary intake over the preceding year. Using Cox regression, we calculated adjusted relative risks (RRs) and 95% CIs for colorectal cancer associated with quintiles of GL, carbohydrate, and sucrose.

RESULTS

For both men and women in this cohort, white rice was the major contributor to GL. In multivariate models, RRs for colorectal cancer decreased significantly with increasing GL in women (RR for the highest quintile versus the lowest: 0.75; 95% CI: 0.57, 0.97; P for trend = 0.02) but not in men (RR: 1.15; 95% CI: 0.89, 1.48; P for trend = 0.19). Results for carbohydrate and sucrose were similar. The inverse association with GL was found in women of all ethnic groups (P for interaction = 0.58). In men, an interaction was found between ethnicity and GL (P < 0.01): white men had a positive association with increasing GL (RR: 1.69; 95% CI: 0.98, 2.92; P for trend < 0.01), but men of other ethnic groups did not.

CONCLUSION

GL and carbohydrate intake appear to protect against colorectal cancer in women in the Multiethnic Cohort, perhaps because a major source of GL is white rice.

Association of vegetable, fruit, and grain intakes with colorectal cancer: the Multiethnic Cohort Study

BACKGROUND

It is uncertain whether or not vegetables, fruit, or grains protect against colorectal cancer.

OBJECTIVE

In a large prospective study, we investigated the association of vegetable, fruit, and grain intakes with colorectal cancer risk.

DESIGN

Between 1993 and 1996, 85 903 men and 105 108 women completed a quantitative food-frequency questionnaire that included approximately 180 foods and beverages in the Multiethnic Cohort Study. A diagnosis of colorectal cancer was made in 1138 men and 972 women after an average follow-up of 7.3 y. Cox proportional hazards models were used to calculate multivariate-adjusted relative risks and 95% CIs for colorectal cancer.

RESULTS

In men, multivariate adjustment for energy intake, dietary, and nondietary variables resulted in relative risks in the highest quintile group of 0.74 (95% CI: 0.59, 0.93; P for trend = 0.02) for vegetables and fruit combined, 0.80 (95% CI: 0.64, 0.99; P for trend = 0.09) for fruit alone, and 0.85 (95% CI: 0.69, 1.05; P for trend = 0.05) for vegetables alone. When colon and rectal cases were separated among men, the inverse associations were stronger for colon than for rectal cancer. In women, none of the associations with vegetables, fruit, or vegetables and fruit combined were significant. Grain intake was not associated with colorectal cancer for either men or women.

CONCLUSION

The intake of vegetables and fruit was inversely related to colorectal cancer risk among men but not among women. The association appears stronger for colon than for rectal cancer.

Legume and isoflavone intake and prostate cancer risk: The Multiethnic Cohort Study

Findings from studies of legume, soy and isoflavone intake and prostate cancer risk are as yet inconclusive, although soy has received considerable attention due to its high phytoestrogen content. Therefore, the present study investigated the relationship of these dietary exposures to prostate cancer risk in the Multiethnic Cohort Study in Hawaii and Los Angeles. The analyses included 82,483 men who completed a detailed quantitative food frequency questionnaire in 1993-1996. A total of 4,404 prostate cancer cases including 1,278 nonlocalized or high-grade cases were recorded during the average follow-up period of 8 years. Multivariate relative risks (RR) and 95% of confidence intervals (CI) were estimated using Cox proportional hazards models with age as the time metric. Among men with the highest intake of legumes, the risk reduction was 11% for total prostate cancer (RR = 0.89, 95% CI = 0.80-0.99, p for trend = 0.007) and 26% for nonlocalized or high-grade cancer (RR = 0.74, 95% CI = 0.61-0.90, p for trend = 0.007) compared to men with the lowest intake. Similar risk reductions were observed for soy products and for legumes excluding soy products in separate analyses. We found no significant risk reduction associated with intake of total or specific isoflavones for either total prostate cancer or for nonlocalized or high-grade cancer. The findings of our study suggest that legume intake is associated with a moderate reduction in prostate cancer risk and that the isoflavones in soy products are probably not responsible for this effect.

Dietary assessment in the California Teachers Study: reproducibility and validity

OBJECTIVE

To evaluate the reproducibility and validity of the food-frequency questionnaire (FFQ) used in the California Teachers Study (CTS) cohort and to use this data to quantify the effects of correcting nutrient-breast cancer relative risks for measurement error.

METHODS

One hundred and ninety five CTS cohort members participated in a 10-month dietary validation study that included four 24-h dietary recalls and pre- and post-study FFQs. Shrout-Fleiss intraclass correlations for reproducibility were computed. Under several standard assumptions concerning the correlations of errors in the FFQs and 24-h recalls, we calculated energy-adjusted deattenuated Pearson correlations for validity and tested for differences in validity according to a number of demographic and other risk factors. For each nutrient, we compared the performance of the FFQ versus the 24-h recalls, estimating the number of days of recalls that give equivalent information about true intake as does a single FFQ. Finally, the effects of adjustment for measurement error on risk estimates were evaluated in 44,423 postmenopausal cohort members, 1,544 of whom developed breast cancer during seven years of follow-up. Relative risks (RR) and confidence intervals (CI) were calculated using Cox proportional hazards with and without correction for measurement error.

RESULTS

Reproducibility correlations for the nutrients ranged from 0.60 to 0.87. With a few exceptions, validity correlations were reasonably high (range: 0.55-0.85), including r = 0.74 for alcohol. Performance of the FFQ differed by age for percent of calories from fat and by body mass index and hormone therapy use for alcohol consumption. For most nutrients examined, our FFQ is comparable to two to six recalls for each subject in capturing true intake. In the measurement error-adjusted risk analyses, corrected RRs were within 13% of uncorrected values for all nutrients examined except for linoleic acid. For alcohol consumption the corrected RR (per 20 g/1,000 kcal/d) was 1.36 (95% CI: 1.03-1.51) compared to the uncorrected estimate of 1.25 (95% CI: 1.10-1.42).

CONCLUSION

The FFQ dietary assessment used in the CTS is reproducible and valid for all nutrients except the unsaturated fatty acids. Correcting relative risk estimates for measurement error resulted in relatively small changes in the associations between the majority of nutrients and the risk of postmenopausal breast cancer.

Serum ferritin concentrations and body iron stores in a multicenter, multiethnic primary-care population

How often elevated serum ferritin in primary-care patients reflects increased iron stores (normally 0.8 g in men, 0.4 g in women) is not known. The Hereditary Hemochromatosis and Iron Overload Screening (HEIRS) study screened 101,168 primary-care participants (44% Caucasians, 27% African-Americans, 14% Asians/Pacific Islanders, 13% Hispanics, 2% others). Follow-up clinical evaluation was performed in 302 of 333 HFE C282Y homozygotes regardless of iron measures and 1,375 of 1,920 nonhomozygotes with serum ferritin >300 microg/L (men), >200 microg/L (women) and transferrin saturation >50% (men), >45% (women). Quantitative phlebotomy was conducted in 122 of 175 C282Y homozygotes and 122 of 1,102 nonhomozygotes with non-transfusional serum ferritin elevation at evaluation. The estimated prevalence in the Caucasian population of C282Y homozygotes with serum ferritin >900 microg/L at evaluation was 20 per 10,000 men and 4 per 10,000 women; this constellation was predictive of iron stores >4 g in men and >2 g in women. The estimated prevalence per 10,000 of non-C282Y homozygotes with serum ferritin >900 microg/L at evaluation was 7 among Caucasians, 13 among Hispanics, 20 among African Americans, and 38 among Asians and Pacific Islanders, and this constellation was predictive of iron stores >2 g but <4 g. In conclusion, serum ferritin >900 microg/L after initial elevations of both serum ferritin and transferrin saturation is predictive of mildly increased iron stores in multiple ethnic populations regardless of HFE genotype. Serum ferritin >900 microg/L in male C282Y homozygotes is predictive of moderately increased iron stores.

Elevated plasma gamma-tocopherol and decreased alpha-tocopherol in men are associated with inflammatory markers and decreased plasma 25-OH vitamin D

Chronic inflammation is a risk factor for many diseases of aging. Endogenous oxidants are thought to mediate the effects of inflammation and gamma-Tocopherol (gamma-Toc) may mitigate damage from nitrogen-based oxidants; however, no physiological requirement for gamma-Toc has been established. Regulation of tocopherols and their functional significance are poorly defined, thereby limiting their application in prevention. Using stored plasma samples from 657 male control subjects in a previous study of prostate cancer, we have analyzed associations of the tocopherols, inflammation markers, and 25-hydroxy (OH) vitamin D. Plasma alpha-Toc and gamma-Toc were inversely correlated, whereas delta-Toc and alpha-Toc levels were positively correlated, suggesting a unique regulatory mechanism. gamma-Toc levels were positively and alpha-Toc negatively associated with plasma C-reactive protein (CRP) and urinary isoprostane F(2t), which are markers of inflammation and oxidation. Ethnic variability in tocopherols was observed; however, this may be explained by differences in plasma 25-OH vitamin D, as gamma-Toc levels varied inversely and alpha-Toc positively with 25-OH vitamin D. In these data, all-cause mortality appeared to be positively associated with CRP and inversely with 25-OH vitamin D. We hypothesize that plasma levels of tocopherols may serve as markers of systemic inflammation, complicating epidemiologic assessment of their role in cancer etiology.

Accuracy and precision of two short screeners to assess change in fruit and vegetable consumption among diverse populations participating in health promotion intervention trials

Two short frequency questionnaires, the NCI 19-item Fruit and Vegetable Screener (FVS) and a single question on overall fruit and vegetable consumption (1-item), were evaluated for their ability to assess change in fruit and vegetable (FV) consumption over time and in response to intervention among participants in 5 health promotion trials in the Behavior Change Consortium. Cross-sectional differences and correlations of FV estimates at baseline and at follow-up were compared for the FVS (n = 315) and the 1-item (n = 227), relative to multiple 24-h recall interviews (24HR). The FVS significantly overestimated daily intake by 1.27 servings at baseline among men and by 1.42 and 1.59 servings at baseline and follow-up, respectively, in women, whereas the 1-item measure significantly underestimated intake at both time points in men (0.98 serving at baseline, 0.75 serving at follow-up) and women (0.61 and 0.41 serving). Cross-sectional deattenuated correlations with 24HR at follow-up were 0.48 (FVS) and 0.50 (1-item). To evaluate the capacity of the 2 screeners to assess FV change, we compared mean posttest effects with 24HR by treatment group overall and by gender. Treatment group differences were not significant for either 24HR or 1-item. Among 315 subjects, the FVS treatment group differences were significant both overall and within gender but not when repeated in the sample of 227. Findings suggest multiple 24HR at multiple time points in adequate sample sizes remain the gold standard for FV reports. Biases in FVS estimates may reflect participants' lifestyles and sociodemographic characteristics and require further examination in longitudinal samples representative of diverse populations.

Validity and reproducibility of the food-frequency questionnaire used in the Shanghai men's health study

We evaluated the validity and reproducibility of the FFQ used in the Shanghai Men's Health Study (SMHS). The study included 195 randomly selected participants of the SMHS who completed one FFQ at baseline, twelve 24-hour dietary recalls (24-HDR) (once a month for twelve consecutive months) and a second FFQ at the end of the study. The FFQ accounted for 88.78% of the foods recorded in the 24-HDR surveys. The validity of the FFQ was evaluated by comparing nutrient and food group intake levels from the second FFQ and the multiple 24-HDR. Correlation coefficients ranged from 0.38 to 0.64 for macronutrients, 0.33 to 0.58 for micronutrients and 0.35 to 0.72 for food groups. Misclassification to opposite quartiles for nutrients and food groups was rare, ranging from 1.5 to 7.7%, while exact agreement rates were between 31.8 and 53.3%. The reliability of the FFQ was assessed by comparing the intake levels from the two FFQ. Correlation coefficients were 0.39 to 0.53 for macronutrients, 0.38 to 0.52 for micronutrients and 0.39 to 0.64 for food groups. Exact agreement rates for quartile distribution were between 31.8 and 49.2%, while misclassification to opposite quartiles was between 1.5 and 6.2%. These data indicate that the SMHS FFQ can reasonably categorise usual intake of nutrients and food groups among men living in urban Shanghai.

Fat and meat intake and prostate cancer risk: the multiethnic cohort study

Dietary fat and meat as potential risk factors for prostate cancer have been the focus of many epidemiologic investigations, and findings from recent studies in particular have been inconsistent. Therefore, we examined the association between these exposures and prostate cancer risk in the Multiethnic Cohort Study. The analyses included 82,483 men in Hawaii and Los Angeles aged >or=45, who completed a detailed quantitative food frequency questionnaire in 1993-1996. During the follow-up period of 8 years, a total of 4,404 incident cases, including 1,278 nonlocalized or high-grade cancer cases, were identified. Cox proportional hazard models were used to estimate relative risks of prostate cancer after adjustment for time on study, ethnicity, family history of prostate cancer, education, body mass index, smoking status and energy intake. Intake of different types of fat (total, saturated, monounsaturated or polyunsaturated), n-6 fatty acid, cholesterol, various meats, and fats from meat showed no association with overall prostate cancer risk or with nonlocalized or high-grade prostate cancer. Furthermore, we found little evidence of any relation of fat and meat intake with prostate cancer risk within any of the 4 racial/ethnic groups (African Americans, Japanese Americans, Latinos and Whites). There was a suggestion of a protective effect of n-3 fatty acid intake that was limited to Latinos and Whites. However, overall, our findings from a large cohort study of ethnically diverse population give no indication that intake of fat and meat substantially affects prostate cancer risk.