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

Impact of diet on mortality from stroke: results from the U.S. multiethnic cohort study

OBJECTIVES

Stroke is the fourth leading cause of death in the United States and stroke mortality rates vary by ethnicity. The purpose of this study was to examine the associations between food group consumption and risk of death from stroke among 5 ethnic groups in the United States.

METHODS

The Multiethnic Cohort includes >215,000 participants, the majority of whom are African American, Native Hawaiian, Japanese American, Latino, and Caucasian men and women recruited by mail survey in Hawaii and Los Angeles in 1993-1996. Deaths from stroke were identified by linkage to the state death files and the U.S. National Death Index. Diet was assessed using a validated food frequency questionnaire. Associations were examined using multivariable Cox proportional hazards models, stratified by ethnicity and gender.

RESULTS

A total of 860 deaths from stroke were identified among the cohort participants. Vegetable intake was associated with a significant reduction in risk for fatal stroke among African American women (relative risk [RR]=0.60; 95% CI: 0.36-0.99). Among Japanese American women only, high fruit intake was significantly associated with a risk reduction for stroke mortality (RR=0.43; 95% confidence interval [CI]: 0.22-0.85), whereas meat intake increased risk (RR=2.36; 95% CI: 1.31-4.26). Among men, a significant reduction in stroke mortality was observed among Native Hawaiians (RR=0.26; 95% CI: 0.07-0.95). After pooling the data for the ethnic groups, the findings support an elevated risk for high meat intake among women overall (RR=1.56; 95% CI: 1.12-2.16); no significant effects of dietary intake on risk for fatal stroke were observed among men.

CONCLUSIONS

Although some variations were observed for the associations between diet and stroke mortality among ethnic groups, the findings suggest that these differences are not substantial and may be due to dietary intake of specific food subgroups. Additional investigations including dietary subgroups and nutrients sources are needed to clarify these findings.

Protective effects of dietary carotenoids on risk of hip fracture in men: the Singapore Chinese Health Study

Experimental and epidemiologic data suggest that carotenoids in vegetables and fruits may benefit bone health due to their antioxidant properties. The relationship between dietary total and specific carotenoids, as well as vegetables and fruits, and risk of hip fracture was examined among Chinese in Singapore. We used data from the Singapore Chinese Health Study, a prospective cohort of 63,257 men and women who were of ages 45 to 74 years between 1993 and 1998. At recruitment, subjects were interviewed on lifestyle factors and medical history. Usual diet was measured using a validated food frequency questionnaire. During a mean follow-up of 9.9 years, we identified 1630 hip fracture incident cases. Among men, consumption of vegetables was associated with lower hip fracture risk. Similarly, dietary total carotenoids and specific carotenoids, α-carotene, β-carotene, and lutein/zeaxanthin were inversely associated with hip fracture risk. Compared to men in the lowest quartile of nutrient density, men in the highest quartile had statistically significant 26% to 39% risk reduction (all p for trend <0.05). When stratified by body mass index (BMI), the greatest protective effects of total vegetables and carotenoids were found in men with BMI <20 kg/m(2) (p for trend ≤0.004). There was no association between dietary carotenoids or vegetables/fruits and hip fracture risk among women. This study suggests that adequate intake of vegetables may reduce risk of osteoporotic fractures among elderly men and that the antioxidant effects of carotenoids may counteract the mechanism of osteoporosis related to leanness.

Sources of vegetables, fruits and vitamins A, C and E among five ethnic groups: results from a multiethnic cohort study

OBJECTIVES

Data are limited on how dietary sources of food and nutrients differ among ethnic groups. The objective of this study was to determine the main sources of fruit, vegetables and vitamins A, C and E for five ethnic groups.

SUBJECTS/METHODS

Dietary data were collected using a validated quantitative food frequency questionnaire from participants in a multiethnic cohort in Hawaii and Los Angeles county between 1993 and 1996. Data were analyzed for 186,916 participants representing five ethnic groups: African-Americans, Japanese-Americans, native Hawaiians, Latinos and Caucasians.

RESULTS

Lettuce was the most consumed vegetable (6.0-9.9%) in all ethnic-sex groups, except among African-American women and Mexican-born Latino men and women. Oranges and bananas contributed more than one-quarter to total fruit intake among all groups. Overall, more ethnic variation in food choices was observed for the top 10 vegetables than for fruits. The top sources of vitamins A, C and E were carrots, orange/grapefruit/pomelo and combined dishes, respectively. Among the micronutrients studied, the greatest ethnic variation in foods consumed was observed for the top 10 food sources of vitamin A.

CONCLUSIONS

This is the first study providing data on the main types of fruit and vegetables consumed and the major sources of vitamins A, C and E among these ethnic groups in the U.S. Such data are valuable for developing and implementing public health strategies to meet the USDA dietary recommendations and for guiding ethnicity-specific nutrition education and intervention programs.

Fruit and vegetable consumption, ethnicity and risk of fatal ischemic heart disease

OBJECTIVE

Mortality rates from ischemic heart disease vary among ethnic groups. Dietary intake of fruits and vegetables has been associated with a lower risk of ischemic heart disease, but ethnic-specific data are limited.

DESIGN

Prospective cohort study.

SETTING

Hawaii and Los Angeles County, between 1993 and 1996.

PARTICIPANTS

These analyses included 164,617 adults age 45 to 75, representing five ethnic groups who were enrolled in the Multiethnic Cohort Study. Dietary data were collected at baseline using a validated food frequency questionnaire and fatal ischemic heart disease cases were identified up to December 31, 2001. Associations between fruit and vegetable consumption and fatal ischemic heart disease were examined using multivariate Cox proportional hazard models.

RESULTS

The associations between fruit and vegetable intake and fatal ischemic heart disease were similar among the five ethnic groups. When data for the ethnic groups were combined, higher vegetable intake was associated with a protective effect against ischemic heart disease in men with all intake levels above 3.4 servings per day (over 6.6 servings per day: hazard ratio, 0.73; 95% confidence interval, 0.58-0.92). Inconsistent results were observed for women, where the protective association was observed only at mid-level vegetable intake levels, but not among women with the highest level of vegetable intake. There was no evidence of an association for fruit intake.

CONCLUSIONS

Associations between fruit and vegetable intake and fatal IHD do not appear to vary among ethnic groups. Additional research is needed to clarify associations for fruit versus vegetable intake and impact on cardiovascular outcomes.

The effects of soy consumption before diagnosis on breast cancer survival: the Multiethnic Cohort Study

This study tested the hypothesis that prediagnostic soy intake was inversely associated with all-cause and breast cancer-specific mortality. The analyses included 3842 women in the Multiethnic Cohort (MEC) study of African Americans, Native Hawaiians, Japanese Americans, Latinos, and Caucasians, who completed a quantitative food frequency questionnaire, aged ≥50 yr at cohort entry, and diagnosed with primary invasive breast cancer following cohort entry (1993-2007). Hazard ratios (HR) and 95% confidence intervals (CI) were estimated from Cox proportional hazards regression with adjustment for known clinical and lifestyle factors. During a mean follow-up after diagnosis of invasive breast cancer of 6.2 ± 3.8 yr, there were 804 deaths including 376 breast cancer-specific deaths. The HR (95%CI) for all-cause and breast cancer-specific morality comparing the highest versus lowest tertiles were 1.03 (0.81-1.33) and 1.03 (0.71-1.50) for soy products and 0.99 (0.82-1.20) and 0.95 (0.71-1.28) for total isoflavones, respectively (Ptrend > 0.60 for all). There was limited evidence of differences by hormone receptor status, tumor stage, or ethnic group. Prediagnostic soy intake was unrelated to mortality in postmenopausal women. Our findings are consistent with the literature that soy consumption does not adversely affect breast cancer survival in women.

The association between dietary omega-3 fatty acids and cardiovascular death: the Singapore Chinese Health Study

BACKGROUND

Although studies suggest that omega-3 fatty acids intake may reduce cardiovascular disease (CVD) mortality risk, few studies have differentiated dietary eicosapentaenoic/docosahexaenoic acid (EPA/DHA) from alpha-linolenic acid (ALA), and epidemiological research in Asian populations is limited.

METHODS

The Singapore Chinese Health Study is a population-based cohort that recruited 63,257 Chinese adults aged 45-74 years from 1993 to 1998. Usual diet was measured at recruitment using a validated semiquantitative food-frequency questionnaire, and mortality information was identified via registry linkage up to 31 December 2011. Cox proportional hazard models were used to calculate hazard ratios (HRs) with adjustment for potential confounders.

RESULTS

We documented 4780 cardiovascular deaths (including 2697 coronary heart disease (CHD) deaths and 1298 stroke deaths) during 890,473 person-years of follow up. Omega-3 fatty acids intake was monotonically associated with reduced risk of cardiovascular mortality. Compared to the lowest quartile, the HR was 0.88 (95% confidence interval, CI, 0.81-0.96), 0.88 (95% CI 0.80-0.97), and 0.83 (95% CI 0.74-0.92) for the second, third, and highest quartile, respectively (p-trend = 0.003). Both EPA/DHA and ALA were independently associated with reduced risk of cardiovascular mortality: HR comparing extreme quartiles was 0.86 (95% CI 0.77-0.96, p-trend = 0.002) and 0.81 (95% CI 0.73-0.90, p-trend < 0.001), respectively. The associations were similar for deaths from CHD and stroke and persisted in participants who were free of CVD at baseline.

CONCLUSIONS

Higher intakes of marine (EPA/DHA) and plant (ALA) omega-3 fatty acids are both associated with reduced risk of cardiovascular mortality in a Chinese population.

Adherence to recommendations for fruit and vegetable intake, ethnicity and ischemic heart disease mortality

BACKGROUND AND AIMS

Ischemic heart disease (IHD) accounts for one-third of annual deaths in the U.S. and mortality rates vary by ethnicity. The association between adherence to dietary guidelines for fruit and vegetable intake with IHD mortality among different ethnic groups has not previously been examined.

METHODS AND RESULTS

A prospective cohort design was used to examine the incidence of fatal IHD among participants in the Multiethnic Cohort Study. Participants included 164,617 men and women from five ethnic groups: African American, Native Hawaiian, Japanese American, Latino, and Caucasian. Cox proportional hazards models, stratified by ethnicity and sex, were used to examine associations between adherence with recommended dietary guidelines for fruit and vegetable intake and risk for fatal IHD. The results did not provide evidence that the association between adherence with dietary recommendations for fruit or vegetable intake and IHD mortality varies by ethnicity. Pooled data did provide evidence that adhering to the recommendations for vegetables lowered risk among men (RR = 0.84, 95% CI: 0.74-0.96) and women (RR = 0.80, 95% CI: 0.69-0.94). No significant effects were observed for fruit intake.

CONCLUSIONS

The effect of dietary intake of fruit and vegetables did not vary by ethnicity, providing evidence that recommendations do not need to be individualized for these special populations. The protective effect observed for vegetable intake among both sexes confirms previous findings and supports the evidence base for promoting diet modification in this direction.

Alcohol consumption and breast cancer risk among women from five ethnic groups with light to moderate intakes: the Multiethnic Cohort Study

Higher alcohol consumption, even at moderate levels, has been associated with an increased risk of breast cancer in epidemiological studies. However, prior studies were conducted in mostly white populations. To assess the relationship of alcohol consumption to postmenopausal breast cancer risk in a multiethnic population of largely never, light or moderate drinkers, we prospectively examined the association in 85,089 women enrolled in the Multiethnic Cohort in Hawaii and California. During a mean follow-up of 12.4 years, 3,885 incident invasive breast cancer cases were identified. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazard models, controlling for potential confounders. Higher alcohol consumption was associated with increased risk of breast cancer: compared to nondrinkers, HRs were 1.23 (95% CI: 1.06-1.42), 1.21 (95% CI: 1.00-1.45), 1.12 (95% CI: 0.95-1.31) and 1.53 (95% CI: 1.32-1.77) for 5-9.9, 10-14.9, 15-29.9 and ≥ 30 g/day of alcohol, respectively. The positive association was seen in African American, Japanese American, Latino and white, but not in Native Hawaiian women, and in those with tumors that were both positive and negative for estrogen and progesterone receptors (ER/PR). This prospective study supports previous findings that light to moderate alcohol consumption increases breast cancer risk, and demonstrates this association in several ethnic groups besides whites, independent of ER/PR status.

Adherence to the USDA dietary recommendations for fruit and vegetable intake and risk of fatal stroke among ethnic groups: a prospective cohort study

BACKGROUND

Stroke is the fourth leading cause of death in the U.S. and stroke mortality rates differ substantially by ethnic group. The impact of adherence to the USDA dietary guidelines on risk for fatal stroke among different ethnic groups has not previously been examined.

METHODS

A prospective cohort design was used to examine associations between adherence with dietary recommendations for fruit and vegetable intake and risk for stroke mortality among 174,888 men and women representing five ethnic groups; African American, Native Hawaiian, Japanese American, Latino, and Caucasian. Dietary intake was assessed using a mailed quantitative food frequency questionnaire. Associations were examined using Cox proportional hazards models.

RESULTS

There was no evidence that ethnicity modified associations between fruit and vegetable intake and stroke mortality. When data for different ethnicities were combined, a reduced risk for fatal stroke was observed among women who were adherent with the USDA dietary recommendations for vegetable intake, although this result did not reach statistical significance (RR = 0.84, 95% CI = 0.68-1.04). No associations were observed among men.

CONCLUSIONS

The results of this study do not provide evidence that dietary intake of fruits and vegetables differentially impacts risk for stroke mortality among different ethnic groups.

Fruit and vegetable intakes are associated with lower risk of bladder cancer among women in the Multiethnic Cohort Study

Fruits and vegetables have been examined for their possible effects on the risk of bladder cancer, as they contain numerous nutrients, phytochemicals, and antioxidants with potentially anticarcinogenic properties. In a prospective analysis of 185,885 older adults participating in the Multiethnic Cohort Study, we examined whether the consumption of fruits and vegetables, or of nutrients concentrated in fruits and vegetables, was associated with bladder cancer risk. Cox proportional hazards models were used to calculate HRs and 95% CIs for bladder cancer in relation to dietary intakes. A total of 581 invasive bladder cancer cases (429 men and 152 women) were diagnosed over a mean follow-up period of 12.5 y. In women, total fruits and vegetables [HR = 0.35 (95% CI: 0.22, 0.56); highest vs. lowest quartile], total vegetables [HR = 0.49 (95% CI: 0.29, 0.83)], yellow-orange vegetables [HR = 0.48 (95% CI: 0.30, 0.77)], total fruits [HR = 0.54 (95% CI: 0.34, 0.85)], and citrus fruits [HR = 0.56 (95% CI: 0.34, 0.90)] were inversely associated with the risk of invasive bladder cancer in risk factor-adjusted models. In addition, women with the highest intakes of vitamins A, C, and E; the carotenoids α-carotene, β-carotene, and β-cryptoxanthin; and folate had a lower risk of bladder cancer. For men, no associations for fruits, vegetables, or nutrients were found overall, although inverse associations were observed for vegetable intake among current smokers, and in ethnic-specific analyses, for fruit and vegetable intake among Latinos specifically. Our findings suggest that greater consumption of fruits and vegetables may lower the risk of invasive bladder cancer among women and highlight the need for specific subgroup analyses in future studies.

Intakes of fruits, vegetables, and related vitamins and lung cancer risk: results from the Shanghai Men's Health Study (2002-2009)

Most epidemiological studies evaluating the association of fruit and vegetable intakes on lung cancer risk were conducted in North American and European countries. We investigated the association of intakes of fruits, vegetables, dietary vitamins A and C, and folate with lung cancer risk among 61,491 adult Chinese men who were recruited into the Shanghai Men's Health Study, a population-based, prospective cohort study. Baseline dietary intake was assessed through a validated food frequency questionnaire during in-home visits. Multivariate Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) of lung cancer risk associated with dietary intakes. During a median follow-up of 5.5 yr, 359 incident lung cancer cases accrued after the first year of follow-up and 68.8% of them were current smokers. Intakes of green leafy vegetables, β-carotene-rich vegetables, watermelon, vitamin A, and carotenoids were inversely associated with lung cancer risk; the corresponding HR (95% CI) comparing the highest with the lowest quartiles were 0.72 (0.53-0.98), 0.69 (0.51-0.94), 0.65 (0.47-0.90), 0.63 (0.44-0.88), and 0.64 (0.46-0.88). Intake of all fruits and vegetables combined was marginally associated with lower risk. Our study suggests that the consumption of carotenoid-rich vegetables is inversely associated with lung cancer risk.

Dietary choline and betaine intakes vary in an adult multiethnic population

Choline and betaine are important nutrients for human health, but reference food composition databases for these nutrients became available only recently. We tested the feasibility of using these databases to estimate dietary choline and betaine intakes among ethnically diverse adults who participated in the Multiethnic Cohort (MEC) Study. Of the food items (n = 965) used to quantify intakes for the MEC FFQ, 189 items were exactly matched with items in the USDA Database for the Choline Content of Common Foods for total choline, choline-containing compounds, and betaine, and 547 items were matched to the USDA National Nutrient Database for Standard Reference for total choline (n = 547) and 148 for betaine. When a match was not found, choline and betaine values were imputed based on the same food with a different form (124 food items for choline, 300 for choline compounds, 236 for betaine), a similar food (n = 98, 284, and 227, respectively) or the closest item in the same food category (n = 6, 191, and 157, respectively), or the values were assumed to be zero (n = 1, 1, and 8, respectively). The resulting mean intake estimates for choline and betaine among 188,147 MEC participants (aged 45-75) varied by sex (372 and 154 mg/d in men, 304 and 128 mg/d in women, respectively; P-heterogeneity < 0.0001) and by race/ethnicity among Caucasians, African Americans, Japanese Americans, Latinos, and Native Hawaiians (P-heterogeneity < 0.0001), largely due to the variation in energy intake. Our findings demonstrate the feasibility of assessing choline and betaine intake and characterize the variation in intake that exists in a multiethnic population.

Evaluating the feasibility of utilizing the Automated Self-administered 24-hour (ASA24) dietary recall in a sample of multiethnic older adults

The ASA24 is a web application which enables the collection of self-administered dietary recalls thus utilizing technology to overcome some of the limitations of traditional assessment methodologies. Older adults, particularly those from certain ethnic groups may have less access to and may be less receptive to technology. This research sought to determine the level of access to the internet as well as evaluate the feasibility of using a web-based alternative dietary data collection method in older, multiethnic adults. Participants completed three telephone administered diet recalls (n=347), and were asked to complete a one day recall via the ASA24. They were also asked to evaluate their experience with using the ASA24 system. Almost 60% of the participants reported no access to a computer or internet access, with African Americans and Latinos less likely than non-Hispanic Whites and Japanese-Americans to have access. Of those with access to the internet (n=100), 44% of the participants accessed the ASA24 system and 37% successfully launched the ASA24 program. However, most respondents preferred the traditional diet recall methodology over the ASA24. Further research is needed to investigate recruitment and use of electronic data collection methodologies in older adults.

Ethnic differences in grains consumption and their contribution to intake of B-vitamins: results of the Multiethnic Cohort Study

BACKGROUND

Research indicates that a diet rich in whole grains may reduce the risk of prevalent chronic diseases, including cardiovascular disease, diabetes, and some cancers, and that risk for these diseases varies by ethnicity. The objective of the current study was to identify major dietary sources of grains and describe their contribution to B vitamins in five ethnic groups.

METHODS

A cross-sectional mail survey was used to collect data from participants in the Multiethnic Cohort Study in Hawaii and Los Angeles County, United States, from 1993 to 1996. Dietary intake data collected using a quantitative food frequency questionnaire was available for 186,916 participants representing five ethnic groups (African American, Latino, Japanese American, Native Hawaiian and Caucasian) aged 45-75 years. The top sources of grain foods were determined, and their contribution to thiamin, riboflavin, niacin, vitamin B6, and folic acid intakes were analyzed.

RESULTS

The top source of whole grains was whole wheat/rye bread for all ethnic-sex groups, followed by popcorn and cooked cereals, except for Native Hawaiian men and Japanese Americans, for whom brown/wild rice was the second top source; major contributors of refined grains were white rice and white bread, except for Latinos. Refined grain foods contributed more to grain consumption (27.1-55.6%) than whole grain foods (7.4-30.8%) among all ethnic-sex groups, except African American women. Grain foods made an important contribution to the intakes of thiamin (30.2-45.9%), riboflavin (23.1-29.2%), niacin (27.1-35.8%), vitamin B6 (22.9-27.5%), and folic acid (23.3-27.7%).

CONCLUSIONS

This is the first study to document consumption of different grain sources and their contribution to B vitamins in five ethnic groups in the U.S. Findings can be used to assess unhealthful food choices, to guide dietary recommendations, and to help reduce risk of chronic diseases in these populations.

Quantifying diet for nutrigenomic studies

The field of nutrigenomics shows tremendous promise for improved understanding of the effects of dietary intake on health. The knowledge that metabolic pathways may be altered in individuals with genetic variants in the presence of certain dietary exposures offers great potential for personalized nutrition advice. However, although considerable resources have gone into improving technology for measurement of the genome and biological systems, dietary intake assessment remains inadequate. Each of the methods currently used has limitations that may be exaggerated in the context of gene × nutrient interaction in large multiethnic studies. Because of the specificity of most gene × nutrient interactions, valid data are needed for nutrient intakes at the individual level. Most statistical adjustment efforts are designed to improve estimates of nutrient intake distributions in populations and are unlikely to solve this problem. An improved method of direct measurement of individual usual dietary intake that is unbiased across populations is urgently needed.

Assessing the validity of a self-administered food-frequency questionnaire (FFQ) in the adult population of Newfoundland and Labrador, Canada

BACKGROUND

The Food- Frequency Questionnaire (FFQ) is a dietary assessment tool frequently used in large-scale nutritional epidemiology studies. The goal of the present study is to validate a self-administered version of the Hawaii FFQ modified for use in the general adult population of Newfoundland and Labrador (NL).

METHODS

Over a one year period, 195 randomly selected adults completed four 24-hour dietary recalls (24-HDRs) by telephone and one subsequent self-administered FFQ. Estimates of energy and nutrients derived from the 24-HDRs and FFQs were compared (protein, carbohydrate, fibre, fat, vitamin A, carotene, vitamin D, and calcium). Data were analyzed using the Pearson's correlation coefficients, cross-classification method, and Bland-Altman plots.

RESULTS

The mean nutrient intake values of the 24-HDRs were lower than those of the FFQs, except for protein in men. Sex and energy-adjusted de-attenuated Pearson correlation coefficients for each nutrient varied from 0.13 to 0.61. Except for protein in men, all correlations were statistically significant with p < 0.05. Cross-classification analysis revealed that on average, 74% women and 78% men were classified in the same or adjacent quartile of nutrient intake when comparing data from the FFQ and 24-HDRs. Bland-Altman plots showed no serious systematic bias between the administration of the two instruments over the range of mean intakes.

CONCLUSION

This 169-item FFQ developed specifically for the adult NL population had moderate relative validity and therefore can be used in studies to assess food consumption in the general adult population of NL. This tool can be used to classify individual energy and nutrient intakes into quartiles, which is useful in examining relationships between diet and chronic disease.

Coffee intake and risk of type 2 diabetes: the Multiethnic Cohort

OBJECTIVE

We evaluated the influence of coffee consumption on diabetes incidence among the Hawaii component of the Multiethnic Cohort (MEC).

DESIGN

Prospective cohort.

SETTING

Population-based sample residing in Hawaii.

SUBJECTS

After exclusions, 75 140 men and women of Caucasian, Japanese American and Native Hawaiian ancestry aged 45-75 years were part of the current analysis. All participants provided information on diet and lifestyle through an FFQ. After 14 years of follow-up 8582 incident diabetes cases were identified using self-reports, medication questionnaires and health plan linkages. Hazard ratios (HR) and 95 % confidence intervals were calculated using Cox regression while adjusting for known covariates.

RESULTS

The risk for diabetes associated with total coffee consumption differed by sex (P interaction < 0·0001). Women consuming ≥3 cups of any type of coffee daily had a significantly lower risk (HR = 0·66; 95 % CI 0·58, 0·77; P trend < 0·0001) than those reporting <1 cup/d, whereas the relationship in men was borderline (HR = 0·89; 95 % CI 0·80, 0·99; P trend = 0·09). The same difference by sex was seen for regular coffee consumption, with HR of 0·65 (95 % CI 0·54, 0·78; P trend < 0·0001) and 0·86 (95 % CI 0·75, 0·98; P trend = 0·09) in men and women, respectively. No significant association with diabetes was apparent for decaffeinated coffee in women (HR = 0·85; 95 % CI 0·72, 1·01; P trend = 0·73) or men (HR = 1·07; 95 % CI 0·93, 1·23; P trend = 0·71). Despite small differences by ethnicity, the interaction terms between coffee intake and ethnicity were not significant.

CONCLUSIONS

In this multiethnic population, regular, but not decaffeinated, coffee intake was much more protective against diabetes in women of all ethnic groups than in men.

Contribution of meat to vitamin B₁₂, iron and zinc intakes in five ethnic groups in the USA: implications for developing food-based dietary guidelines

BACKGROUND

To describe the sources of meat and their contributions to vitamin B₁₂, iron and zinc in five ethnic groups in the USA.

METHODS

Dietary data for the Multiethnic Cohort, established in Hawaii and Los Angeles, were collected using a quantitative food frequency questionnaire from more than 215,000 subjects, aged 45-75 years at baseline (1993-1996). Participants included African American, Latino, Japanese American, Native Hawaiian and Caucasian men and women. Servings of meat items were calculated based on the US Department of Agriculture recommendations and their contributions to intakes of total meat, red meat, vitamin B₁₂, iron and zinc were determined.

RESULTS

Of all types of meat, poultry contributed the most to meat consumption, followed by red meat and fish among all ethnicities, except for Latino (born in Mexico and Central/South America) men who consumed more beef. Lean beef was the most commonly consumed red meat for all ethnic-sex groups (9.3-14.3%), except for Native Hawaiian and Japanese American men, and Japanese American women whose top contributor was stew/curry with beef/lamb and stir-fried beef/pork with vegetables, respectively. The contribution of meat was most substantial for zinc (11.1-29.3%) and vitamin B₁₂ (19.7-40%) and, to a lesser extent, for iron (4.3-14.2%).

CONCLUSIONS

This is the first large multiethnic cohort study to describe meat sources and their contributions to selected nutrients among ethnic minorities in the USA. These findings may be used to develop ethnic-specific recommendations for meat consumption aiming to improve dietary quality among these groups.

Diet impacts mortality from cancer: results from the multiethnic cohort study

PURPOSE

Cancer is the second leading cause of death in the United States and mortality varies by ethnicity. The objective of this study was to examine the association between cancer mortality and dietary intake among a large multiethnic population.

METHODS

A prospective cohort design was used to examine cancer mortality among 146,389 participants. Multiethnic cohort study participants represent five ethnic groups: African American, Native Hawaiian, Japanese American, Latino, and Caucasian. Hazard ratios for cancer mortality by intake levels of five food groups and discretionary fat were calculated using Cox proportional hazards models stratified by sex and ethnicity.

RESULTS

There were a total of 2,028 male and 1,464 female fatal cancer cases at the end of follow-up. Among Japanese American men only, there was a significant protective effect seen in those reporting a high grain intake (HR = 0.49, 95 % CI 0.35-0.69); there was no effect of grain consumption in any other ethnic-sex group. There was no evidence that ethnicity modified associations between fruit, vegetable, meat, dairy, or discretionary fat intake and cancer mortality among men. Associations between food group consumption and risk for cancer mortality among women were similar across ethnic groups.

CONCLUSIONS

The considerable reduction in cancer risk associated with high grain consumption among a specific ethnic-sex group, Japanese American men, warrants further investigation. Additional research is needed to validate this observation and determine whether this was a chance finding, or possibly due to differential intake of specific grain subtypes, and/or related to a sex-specific cancer type.

Dietary patterns and colorectal cancer recurrence and survival: a cohort study

OBJECTIVE

To examine the association between dietary patterns and colorectal cancer (CRC) survival.

DESIGN

Cohort study.

SETTING

A familial CRC registry in Newfoundland.

PARTICIPANTS

529 newly diagnosed CRC patients from Newfoundland. They were recruited from 1999 to 2003 and followed up until April 2010.

OUTCOME MEASURE

Participants reported their dietary intake using a food frequency questionnaire. Dietary patterns were identified with factor analysis. Multivariable Cox proportional hazards models were employed to estimate HR and 95% CI for association of dietary patterns with CRC recurrence and death from all causes, after controlling for covariates.

RESULTS

Disease-free survival (DFS) among CRC patients was significantly worsened among patients with a high processed meat dietary pattern (the highest vs the lowest quartile HR 1.82, 95% CI 1.07 to 3.09). No associations were observed with the prudent vegetable or the high-sugar patterns and DFS. The association between the processed meat pattern and DFS was restricted to patients diagnosed with colon cancer (the highest vs the lowest quartile: HR 2.29, 95% CI 1.19 to 4.40) whereas the relationship between overall survival (OS) and this pattern was observed among patients with colon cancer only (the highest vs the lowest quartile: HR 2.13, 95% CI 1.03 to 4.43). Potential effect modification was noted for sex (p value for interaction 0.04, HR 3.85 for women and 1.22 for men).

CONCLUSIONS

The processed meat dietary pattern prior to diagnosis is associated with higher risk of tumour recurrence, metastasis and death among patients with CRC.

Factors associated with the calibration of a food frequency questionnaire for the Bambuí Project, Brazil

BACKGROUND

The present study aimed to calibrate a food frequency questionnaire (FFQ) using one 24-h recall (R24) associated with foodstuff replicas.

METHODS

Calibration was performed by linear regression. Of a probability sample of 150 individuals (>18 years) of the town of Bambui, 98 completed the study.

RESULTS

The mean age of the participants was 43.8 years and 63.3% were women. The calibration of the FFQ included sex for the estimation of iron, protein and zinc; and an interaction between sex and R24 was significant for vitamin A and cholesterol models. Age contributed to the vitamin C, polyunsaturated fatty acids, proteins and zinc models, and an interaction between age and R24 was significant for protein and zinc.

CONCLUSIONS

Calibration coefficients and many interactions in linear regression models revealed important differences between dietary methods, indicating the complexity encountered when combining two methodologies for estimating food intake.

Total energy intake and breast cancer risk in sisters: the Breast Cancer Family Registry

Energy restriction inhibits mammary tumor development in animal models. Epidemiologic studies in humans generally do not support an association between dietary energy intake and breast cancer risk, although some studies suggest a more complex interplay between measures of energy intake, physical activity, and body size. We examined the association between total energy intake jointly with physical activity and body mass index (BMI) and the risk of breast cancer among 1,775 women diagnosed with breast cancer between 1995 and 2006 and 2,529 of their unaffected sisters, enrolled in the Breast Cancer Family Registry. We collected dietary data using the Hawaii-Los Angeles Multiethnic Cohort food frequency questionnaire. Using conditional logistic regression to estimate the odds ratios (OR) and 95 % confidence intervals (CI) associated with total energy intake, we observed an overall 60-70 % increased risk of breast cancer among women in the highest quartile of total energy intake compared to those in the lowest quartile (Q4 vs. Q1: OR = 1.6, 95 % CI: 1.3-2.0; P (trend) < 0.0001); these associations were limited to pre-menopausal women or women with hormone receptor-positive cancers. Although the associations were slightly stronger among women with a higher BMI or lower level of average lifetime physical activity, we observed a positive association between total energy intake and breast cancer risk across different strata of physical activity and BMI. Our results suggest that within sisters, high energy intake may increase the risk of breast cancer independent of physical activity and body size. If replicated in prospective studies, then these findings suggest that reductions in total energy intake may help in modifying breast cancer risk.

Genetic variation in insulin pathway genes and distal colorectal adenoma risk

BACKGROUND

Insulin, glucose, and other insulin-related proteins that mediate insulin signaling are associated with colorectal neoplasia risk, but associations with common genetic variation in insulin axis genes are less clear. In this study, we used a comprehensive tag single-nucleotide polymorphisms (SNPs) approach to define genetic variation in six insulin axis genes (IGF1, IGF2, IGFBP1, IGFBP3, IRS1, and IRS2) and three genes associated with estrogen signaling (ESR1, ESR2, and PGR).

METHODS

We assessed associations between SNPs and distal colorectal adenoma (CRA) risk in a case-control study of 1,351 subjects. Cases were individuals with one or more adenomas diagnosed during sigmoidoscopy, and controls were individuals with no adenomas at the sigmoidoscopy exam. We used unconditional logistic regression assuming an additive model to assess SNP-specific risks adjusting for multiple comparisons with P (act).

RESULTS

Distal adenoma risk was significantly increased for one SNP in IGF2 [per minor allele OR = 1.41; 95 % confidence interval (CI) = 1.16, 1.67; P (act) = 0.005] and decreased for an ESR2 SNP (per minor allele OR = 0.78; 95 % CI = 0.66, 0.91; P (act) = 0.041). There was no statistically significant heterogeneity of these associations by race, sex, BMI, physical activity, or, in women, hormone replacement therapy use. Risk estimates did not differ in the colon versus rectum or for smaller (<1 cm) versus larger (>1 cm) adenomas.

CONCLUSIONS

These data suggest that selected genetic variability in IGF2 and ESR2 may be modifiers of CRA risk.

Alcohol and breast cancer risk among Asian-American women in Los Angeles County

Introduction

The role of alcohol and breast cancer risk in Asians has not been well studied. Recent studies suggest that even moderate alcohol intake may be associated with an increase in breast cancer risk, and this may be particularly relevant as alcohol intake is traditionally low among Asians.

Methods

We investigated the association between lifetime alcohol intake (including frequency, quantity, duration, timing, and beverage type) and breast cancer in a population-based case-control study of 2,229 Asian Americans diagnosed with incident breast cancer and 2,002 matched control women in Los Angeles County. Additionally, we examined the relation between current alcohol intake and serum concentrations of sex-hormones and growth factors in a subset of postmenopausal control women.

Results

Regular lifetime alcohol intake was significantly higher in US-born than non-US-born Asian Americans (P < 0.001) and almost twice as common in Japanese- than in Chinese- and Filipino-Americans (P < 0.001). Breast cancer risk increased with increasing alcohol intake among US-born Asian Americans; the odds ratios (ORs) per 5 grams per day and per 10 years of drinking were 1.21 (95% confidence interval (CI) 1.00 to 1.45) and 1.12 (95% CI, 0.98 to 1.28), respectively. Regular alcohol intake was a significant risk factor for Japanese-, but not for Chinese- and Filipino-Americans. Current consumers compared with nondrinkers showed lower concentrations of insulin-like growth factor binding protein 3 (P = 0.03) and nonsignificantly higher concentrations of estrone and androgens.

Conclusions

Regular lifetime alcohol intake is a significant breast cancer risk factor in US-born Asian Americans and Japanese Americans, emphasizing the importance of this modifiable lifestyle factor in traditionally low-risk populations.

Dietary sources of five nutrients in ethnic groups represented in the Multiethnic Cohort

Data are limited on how dietary sources of energy and nutrient intakes differ among ethnic groups in the USA. The objective of the present study was to characterise dietary sources of energy, total fat, saturated fat, protein, dietary fibre and added sugar for five ethnic groups. A validated quantitative FFQ was used to collect dietary data from 186,916 men and women aged 45-75 years who were living in Hawaii and Los Angeles between 1993 and 1996. Participants represented five ethnic groups: African-American; Japanese-American; Native Hawaiian; Latino; Caucasian. The top ten dietary sources of energy contributed 36·2-49·6% to total energy consumption, with rice and bread contributing the most (11·4-27·8%) across all ethnic-sex groups. Major dietary sources of total fat were chicken/turkey dishes and butter among most groups. Ice cream, ice milk or frozen yogurt contributed 4·6-6·2% to saturated fat intake across all ethnic-sex groups, except Latino-Mexico women. Chicken/turkey and bread were among the top dietary sources of protein (13·9-19·4%). The top two sources of dietary fibre were bread and cereals (18·1-22%) among all groups, except Latino-Mexico men. Regular sodas contributed the most to added sugar consumption. The present study provides, for the first time, data on the major dietary sources of energy, fat, saturated fat, protein, fibre and added sugar for these five ethnic groups in the USA. Such data are valuable for identifying target foods for nutritional intervention programmes and directing public health strategies aimed at reducing dietary risk factors for chronic disease.

Physical activity and risk of type 2 diabetes among Native Hawaiians, Japanese Americans, and Caucasians: the Multiethnic Cohort

BACKGROUND

Physical inactivity is an established risk factor for diabetes; however, little is known about this association across ethnic groups with different diabetes risk. Therefore, we evaluated the association between physical activity and diabetes and potential effect modification by ethnicity in the Hawaii component of the Multiethnic Cohort.

METHODS

Participants, aged 45 to 75 years, were enrolled by completing a questionnaire on demographics, diet, and self-reported weekly hours of strenuous sports, vigorous work, and moderate activity. Among the 74,913 participants (39% Caucasian, 14% Native Hawaiian, 47% Japanese American), 8561 incident diabetes cases were identified by self-report, a medication questionnaire, and through health plan linkages. Cox regression was applied to estimate hazard ratios (HR) and 95% confidence intervals (95%CI) while adjusting for known confounders.

RESULTS

Engaging in strenuous sports was inversely related to diabetes risk with HRs (4+ hours/week vs. never) of 0.67 (95%CI: 0.57-0.79) in women and 0.80 (95%CI: 0.72-0.88) in men. In stratified analyses, the inverse association was consistent across ethnic groups. The inverse association of vigorous work with diabetes was limited to men, while beneficial effects of moderate activity were observed only in Caucasians.

CONCLUSIONS

These findings support a role of high-intensity physical activity and ethnic-specific guidelines in diabetes prevention.

Intake of vitamins D and A and calcium and risk of non-Hodgkin lymphoma: San Francisco Bay Area population-based case-control study

Several nutrients identified as potentially cancer protective have been inconsistently associated with non-Hodgkin lymphoma (NHL) risk. Dietary history data, including use of vitamin supplements, were collected using a semiquantitative food frequency questionnaire administered during in-person interviews with 4,133 participants (2,052 cases, 2,081 controls) in a San Francisco Bay Area population-based case-control study. Data were used to determine the association of intake levels of vitamins D and A and calcium with risk of NHL and NHL subtypes. Odds ratios (OR) and 95% confidence intervals (CI) were computed as estimates of relative risk using adjusted unconditional logistic regression. Increasing vitamin D intake from food and supplements was positively associated with NHL risk in men (5th quintile: OR = 1.6, 95% CI = 1.0-2.4, P(trend) = 0.07) and with diffuse large B-cell lymphoma (DLBCL) in women and men (5th quintile: OR = 1.6, 95% CI = 1.0-2.5, P(trend) = 0.02); that was largely due to the effect in men (P(trend) = 0.03). These results do not support a strong role for vitamin D intake with NHL risk, with the exception of a potential association for DLBCL risk in men. Our results should be interpreted conservatively until further investigation in larger pooled studies can be conducted to better assess the role of vitamin D intake in lymphomagenesis.

Dietary iron intake and serum ferritin concentration in 213 patients homozygous for the HFEC282Y hemochromatosis mutation

BACKGROUND

HFEC282Y homozygotes have an increased risk for developing increased iron stores and related disorders. It is controversial whether dietary iron restrictions should be recommended to such individuals.

OBJECTIVE

To determine whether dietary iron content influences iron stores in HFEC282Y homozygotes as assessed by serum ferritin concentration.

DESIGN

Serum ferritin concentration was measured and a dietary iron questionnaire was completed as part of the evaluation of 213 HFEC282Y homozygotes who were identified through screening of >100,000 primary care patients at five HEmochromatosis and IRon Overload Screening (HEIRS) Study Field Centers in the United States and Canada.

RESULTS

No significant relationships between serum ferritin concentration and dietary heme iron content, dietary nonheme iron content or reports of supplemental iron use were found.

CONCLUSION

These results do not support recommending dietary heme or nonheme iron restrictions for HFEC282Y homozygotes diagnosed through screening in North America.

Prediagnostic circulating carotenoid levels and the risk of non-Hodgkin lymphoma: the Multiethnic Cohort

This analysis examined the association of non-Hodgkin lymphoma (NHL) with prediagnostic carotenoid levels, a marker for a diet rich in fruits and vegetables. We conducted a nested case-control study within the Multiethnic Cohort with 271 NHL cases and 538 controls matched on sex, ethnicity, location (Hawaii or Los Angeles), birth year, date and time of blood draw, and hours fasting before blood draw. Serum carotenoid levels were obtained by high-pressure liquid chromatography with photodiode array detection. Conditional logistic regression was used to calculate odds ratios (ORs) according to tertiles of serum carotenoids and trend tests using continuous variables. Higher total serum carotenoids (OR(T3 vs T1) = 0.66 [0.46-0.96]; P(trend) = .02), lycopene (OR = 0.54 [0.38-0.78]; P(trend) = .003), and α-cryptoxanthin (OR = 0.53 [0.36-0.78]; P(trend) = .003) were associated with a lower risk of NHL. For retinol (OR = 0.90 [0.61-1.33]; P(trend) = .04), a statistically significant inverse linear trend was detected. Risk estimates remained unchanged with adjustment for NHL risk factors and were similar in analyses stratified by sex and ethnicity; heterogeneity with NHL subtype was detected only for β-carotene. Other carotenoids, including α-carotene, β-carotene, lutein, β-cryptoxanthin, and zeaxanthin, showed no association with risk. These data provide support for a protective role of carotenoid-rich fruits and vegetables in the etiology of NHL.

Susceptibility variants for obesity and colorectal cancer risk: the multiethnic cohort and PAGE studies

Obesity is a leading contributor to colorectal cancer risk. We investigated whether the risk variants identified in genome-wide association studies of body mass index (BMI) and waist size are associated with colorectal cancer risk, independently of the effect of obesity phenotype due to a shared etiology. Twenty-four single nucleotide polymorphisms (SNPs) in 15 loci (BDNF, FAIM2, FTO, GNPDA2, KCTD15, LYPLAL1, MC4R, MSRA, MTCH2, NEGR1, NRXN3, SEC16B, SH2B1, TFAP2B and TMEM18) were genotyped in a case-control study of 2,033 colorectal cancer cases and 9,640 controls nested within the multiethnic cohort study, as part of the population architecture using genomics and epidemiology consortium. Risk alleles for two obesity SNPs were associated with colorectal cancer risk--KCTD15 rs29941 [odds ratio (OR) for C allele = 0.90, 95% confidence interval (CI) 0.83-0.98; p = 0.01] and MC4R rs17782313 (OR for C allele = 1.12, 95% CI 1.02-1.22; p = 0.02). These associations were independent of the effect of BMI. However, none of the results remained significant after adjustment for multiple comparisons. No heterogeneity was observed across race/ethnic groups. Our findings suggest that the obesity risk variants are not likely to affect the risk of colorectal cancer substantially.

Various adiposity measures show similar positive associations with type 2 diabetes in Caucasians, native Hawaiians, and Japanese Americans: the multiethnic cohort

The authors evaluated the association of body mass index (BMI), waist circumference (WC) and hip circumference (HC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) with diabetes in Caucasians, Native Hawaiians, and Japanese Americans aged 45 to 75 years in the Multiethnic Cohort. Diabetes cases were obtained from self-reports and by linkages with health insurance plans. The authors estimated adjusted prevalence odds ratios (PORs) and compared the area under the receiver operating characteristic curves (AUC). All measures were positively associated with diabetes prevalence; the PORs were 1.25 to 1.64 in men and 1.52 to 1.83 in women. In all 3 ethnic groups, the AUCs in men were greater for BMI than for the other measures, whereas in women, the AUCs were greater for combined models than for BMI alone, but the differences were small and not clinically significant. It does not appear that one anthropometric measure best reflects diabetes prevalence or performs better in one ethnic group than in another.

Meat consumption, heterocyclic amines and colorectal cancer risk: the Multiethnic Cohort Study

Greater consumption of red and processed meat has been associated with an increased risk of colorectal cancer in several recent meta-analyses. Heterocyclic amines (HCAs) have been hypothesized to underlie this association. In this prospective analysis conducted within the Multiethnic Cohort Study, we examined whether greater consumption of total, red or processed meat was associated with the risk of colorectal cancer among 165,717 participants who completed a detailed food frequency questionnaire at baseline. In addition, we examined whether greater estimated intake of HCAs was associated with the risk of colorectal cancer among 131,763 participants who completed a follow-up questionnaire that included a meat-cooking module. A total of 3,404 and 1,757 invasive colorectal cancers were identified from baseline to the end of follow-up and from the date of administration of the meat-cooking module to the end of follow-up, respectively. Proportional hazard models were used to estimate basic and multivariable-adjusted relative risks (RRs) and 95% confidence intervals for colorectal cancer associated with dietary exposures. In multivariable models, no association with the risk of colorectal cancer was detected for density-adjusted total meat (RR(Q5 vs. Q1) = 0.93 [0.83-1.05]), red meat (RR = 1.02 [0.91-1.16]) or processed meat intake (RR = 1.06 [0.94-1.19]) or for total (RR = 0.90 [0.76-1.05]) or specific HCA intake whether comparing quintiles of dietary exposure or using continuous variables. Although our results do not support a role for meat or for HCAs from meat in the etiology of colorectal cancer, we cannot rule out the possibility of a modest effect.

Association of total energy intake and macronutrient consumption with colorectal cancer risk: results from a large population-based case-control study in Newfoundland and Labrador and Ontario, Canada

Background

Diet is regarded as one of the most important environmental factors associated with colorectal cancer (CRC) risk. A recent report comprehensively concluded that total energy intake does not have a simple relationship with CRC risk, and that the data were inconsistent for carbohydrate, cholesterol and protein. The objective of this study was to identify the associations of CRC risk with dietary intakes of total energy, protein, fat, carbohydrate, fiber, and alcohol using data from a large case-control study conducted in Newfoundland and Labrador (NL) and Ontario (ON), Canada.

Methods

Incident colorectal cancer cases (n = 1760) were identified from population-based cancer registries in the provinces of ON (1997-2000) and NL (1999-2003). Controls (n = 2481) were a random sample of residents in each province, aged 20-74 years. Family history questionnaire (FHQ), personal history questionnaire (PHQ), and food frequency questionnaire (FFQ) were used to collect study data. Logistic regression was used to evaluate the association of intakes of total energy, macronutrients and alcohol with CRC risk.

Results

Total energy intake was associated with higher risk of CRC (OR: 1.56; 95% CI: 1.21-2.01, p-trend = 0.02, 5^th versus 1^st quintile), whereas inverse associations emerged for intakes of protein (OR: 0.85, 95%CI: 0.69-1.00, p-trend = 0.06, 5^th versus 1^st quintile), carbohydrate (OR: 0.81, 95%CI: 0.63-1.00, p-trend = 0.05, 5^th versus 1^st quintile) and total dietary fiber (OR: 0.84, 95% CI:0.67-0.99, p-trend = 0.04, 5^th versus 1^st quintile). Total fat, alcohol, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, and cholesterol were not associated with CRC risk.

Conclusion

This study provides further evidence that high energy intake may increase risk of incident CRC, whereas diets high in protein, fiber, and carbohydrate may reduce the risk of the disease.

Bias and imprecision in posture percentile variables estimated from short exposure samples

Background

Upper arm postures are believed to be an important risk determinant for musculoskeletal disorder development in the neck and shoulders. The 10^th and 90^th percentiles of the angular elevation distribution have been reported in many studies as measures of neutral and extreme postural exposures, and variation has been quantified by the 10^th-90^th percentile range. Further, the 50^th percentile is commonly reported as a measure of "average" exposure. These four variables have been estimated using samples of observed or directly measured postures, typically using sampling durations between 5 and 120 min.

Methods

The present study examined the statistical properties of estimated full-shift values of the 10^th, 50^th and 90^th percentile and the 10^th-90^th percentile range of right upper arm elevation obtained from samples of seven different durations, ranging from 5 to 240 min. The sampling strategies were realized by simulation, using a parent data set of 73 full-shift, continuous inclinometer recordings among hairdressers. For each shift, sampling duration and exposure variable, the mean, standard deviation and sample dispersion limits (2.5% and 97.5%) of all possible sample estimates obtained at one minute intervals were calculated and compared to the true full-shift exposure value.

Results

Estimates of the 10^th percentile proved to be upward biased with limited sampling, and those of the 90^th percentile and the percentile range, downward biased. The 50^th percentile was also slightly upwards biased. For all variables, bias was more severe with shorter sampling durations, and it correlated significantly with the true full-shift value for the 10^th and 90^th percentiles and the percentile range. As expected, shorter samples led to decreased precision of the estimate; sample standard deviations correlated strongly with true full-shift exposure values.

Conclusions

The documented risk of pronounced bias and low precision of percentile estimates obtained from short posture samples presents a concern in ergonomics research and practice, and suggests that alternative, unbiased exposure variables should be considered if data collection resources are restricted.

Urinary estrogen metabolites during a randomized soy trial

One of the hypothesized protective mechanisms of soy against breast cancer involves changes in estrogen metabolism to 2-hydroxy (OH) and 16α-OH estrogens. The current analysis examined the effect of soy foods on the 2:16α-OH E(1) ratio among premenopausal women during a randomized, crossover intervention study; women were stratified by equol producer status, a characteristic thought to enhance the protective effects of soy isoflavones. The study consisted of a high-soy diet with 2 soy food servings/day and a low-soy diet with <3 servings of soy/wk for 6 mo each; estrogen metabolites were measured in 3 overnight urines (baseline and at the end of the low- and high-soy diet) using gas chromatography mass spectrometry for the 82 women who completed the study. Urinary isoflavonoids were assessed by liquid chromatography mass spectrometry. When applying mixed models, the 2:16α-OH E(1) ratio increased (P = 0.05) because of a nonsignificant decrease in 16α-OH E(1) (P = 0.21) at the end of the high-soy diet. Similar nonsignificant increases in the 2:16α-OH E(1) ratio were observed in equol producers (P = 0.13) and nonproducers (P = 0.23). These findings suggest a beneficial influence of soy foods on estrogen metabolism regardless of equol producer status.

Calcium and vitamin D and risk of colorectal cancer: results from a large population-based case-control study in Newfoundland and Labrador and Ontario

BACKGROUND

Previous epidemiological studies have been suggestive but inconclusive in demonstrating inverse associations of calcium, vitamin D, dairy product intakes with risk of colorectal cancer (CRC). We conducted a large population-based comparison of such associations in Newfoundland and Labrador (NL) and Ontario (ON).

METHODS

A case control study design was used. Colorectal cancer cases were new CRC patients aged 20-74 years. Controls were a sex and age-group matched random sample of the population in each province. 1760 cases and 2481 controls from NL and ON were analyzed. Information on dietary intake and lifestyle was collected using self-administered food frequency and personal history questionnaires.

RESULTS

Controls reported higher mean daily intakes of total calcium and total vitamin D than cases in both provinces. In ON, significant reduced CRC risk was associated with intakes of total calcium (OR of highest vs. lowest quintiles was 0.57, 95% CI 0.42-0.77, p(trend) = 0.03), total vitamin D (OR = 0.73, 95% CI 0.54-1.00), dietary calcium (OR = 0.76, 95% CI 0.60-0.97), dietary vitamin D (OR = 0.77, 95% CI 0.61-0.99), total dairy products and milk (OR = 0.78, 95% CI 0.60-1.00), calcium-containing supplements use (OR = 0.76). In NL, the inverse associations of calcium, vitamin D with CRC risk were most pronounced among calcium- or vitamin D-containing supplement users (OR = 0.67, 0.68, respectively).

CONCLUSIONS

Results of this study add to the evidence that total calcium, dietary calcium, total vitamin D, dietary vitamin D, calcium- or vitamin D-containing supplement use may reduce the risk of CRC. The inverse associations of CRC risk with intakes of total dairy products and milk may be largely due to calcium and vitamin D.

Legume, soy, tofu, and isoflavone intake and endometrial cancer risk in postmenopausal women in the multiethnic cohort study

BACKGROUND

Phytochemicals found in soy and other legumes have been speculated to reduce the risk of endometrial cancer; however, inconsistent findings have been reported in the few epidemiological studies conducted to date.

METHODS

We conducted a prospective analysis of 46 027 nonhysterectomized postmenopausal women who were recruited into the Multiethnic Cohort (MEC) Study between August 1993 and August 1996 and provided detailed baseline information on diet and other endometrial cancer risk factors. A total of 489 women diagnosed with incident endometrial cancer were identified through the Surveillance, Epidemiology, and End Results tumor registry linkages during a median follow-up period of 13.6 years. Cox proportional hazards models were used to estimate multivariable-adjusted relative risks (RRs) and 95% confidence intervals (CIs) for endometrial cancer associated with dietary intake of legumes, soy, and tofu, and for total isoflavones and specific isoflavones (daidzein, genistein, or glycitein). Truncated (age 50-89 years) age-adjusted incidence rates were calculated by applying age-specific rates within isoflavone quintiles to the overall MEC population eligible for endometrial cancer. To estimate the percentage of endometrial cancers that may have been prevented by consuming the highest quintile of total isoflavones, the partial population attributable risk percent was calculated.

RESULTS

A reduced risk of endometrial cancer was associated with total isoflavone intake (highest vs lowest quintile, ≥7.82 vs <1.59 mg per 1000 kcal/d, RR = 0.66, 95% CI = 0.47 to 0.91), daidzein intake (highest vs lowest quintile, ≥3.54 vs <0.70 mg per 1000 kcal/d, RR = 0.64, 95% CI = 0.46 to 0.90), and genistein intake (highest vs lowest quintile, ≥3.40 vs <0.69 mg per 1000 kcal/d, RR = 0.66, 95% CI = 0.47 to 0.91). No statistically significant association with endometrial cancer risk was observed for increasing intake of legumes, soy, tofu, or glycitein. Truncated age-adjusted incidence rates of endometrial cancer for the highest vs lowest quintile of total isoflavone intake were 55 vs 107 per 100 000 women per year, respectively. The partial population attributable risk percent for total isoflavone intake lower than the highest quintile was 26.7% (95% CI = 5.3% to 45.8%).

CONCLUSION

This study suggests that greater consumption of isoflavone-containing foods is associated with a reduced risk of endometrial cancer in this population of nonhysterectomized postmenopausal women.

Dietary fat and breast cancer in postmenopausal women according to ethnicity and hormone receptor status: the Multiethnic Cohort Study

Dietary fat has been widely studied as a risk factor for breast cancer, with little consistency in results. The Multiethnic Cohort Study (MEC) provides an opportunity to assess this relationship for possible heterogeneity across different racial/ethnic groups, as well as by stratification on several other variables associated with risk. Therefore, we investigated the associations between dietary fat, overall and by type, and breast cancer risk among 85,089 postmenopausal women who entered the MEC by completing a comprehensive dietary questionnaire in 1993 to 1996. During a mean follow-up of 12 years, 3,885 incident invasive breast cancer cases were identified. The multivariate HR [95% confidence interval (CI)] for the highest versus lowest quintile of intake was 0.94 (95% CI, 0.85-1.05) for total fat and 0.93 (95% CI, 0.83-1.04) for saturated fat. Other specific types of dietary fat, including individual fatty acids, were not related to risk of postmenopausal breast cancer. We found no heterogeneity in these null findings across the five ethnic groups. Furthermore, we found no evidence that the association between dietary fat and postmenopausal breast cancer risk differed by estrogen/progesterone receptor status, tumor stage, body mass index, hormone replacement therapy use, follow-up period, family history of breast cancer, and smoking status at baseline. In conclusion, this comprehensive prospective analysis in the MEC does not support a role of adult intake of dietary fat in the etiology of postmenopausal breast cancer.

Birth weight and other prenatal factors and risk of breast cancer in Asian-Americans

Little is known about the role of birth weight and other prenatal factors in the etiology of breast cancer in Asian-Americans. We investigated the relation between birth weight and other prenatal factors and breast cancer risk in a population-based case-control study in Los Angeles County that included 2,259 Asian-American women with incident, histologically confirmed breast cancer and 2,019 control women, who were frequency matched to cases on age, Asian ethnicity, and neighborhood of residence. Breast cancer risk nearly doubled (odds ratio (OR) = 1.97, 95% confidence interval (CI) = 1.15-3.39) among those with high (≥ 4000 g) birth weight compared to those with low (<2500 g) birth weight after adjusting for age at menarche, parity, adult body mass index, and other covariates. Risk increased 8% per 500 g increase in birth weight (P trend = 0.10). We observed a significant relationship between birth weight and age at menarche in both cases and controls. Mean birth weight was higher (2948 g) for control women who had early menarche (age ≤ 11 years) compared to those who had menarche late (age ≥ 15 years) (2807 g) (P trend = 0.016); results were similar among case patients (P trend = 0.020). Older maternal age was also a risk factor; risk increased by 6% (95% CI = 1.01-1.12) per 5 years increase in maternal age with adjustment for parity and other risk factors. Our results support the hypothesis that high birth weight and older maternal age at pregnancy may have contributed to the rising breast cancer incidence in Asian-Americans.

Validity of a multipass, web-based, 24-hour self-administered recall for assessment of total energy intake in blacks and whites

To date, Web-based 24-hour recalls have not been validated using objective biomarkers. From 2006 to 2009, the validity of 6 Web-based DietDay 24-hour recalls was tested among 115 black and 118 white healthy adults from Los Angeles, California, by using the doubly labeled water method, and the results were compared with the results of the Diet History Questionnaire, a food frequency questionnaire developed by the National Cancer Institute. The authors performed repeated measurements in a subset of 53 subjects approximately 6 months later to estimate the stability of the doubly labeled water measurement. The attenuation factors for the DietDay recall were 0.30 for blacks and 0.26 for whites. For the Diet History Questionnaire, the attenuation factors were 0.15 and 0.17 for blacks and whites, respectively. Adjusted correlations between true energy intake and the recalls were 0.50 and 0.47 for blacks and whites, respectively, for the DietDay recall. For the Diet History Questionnaire, they were 0.34 and 0.36 for blacks and whites, respectively. The rate of underreporting of more than 30% of calories was lower with the recalls than with the questionnaire (25% and 41% vs. 34% and 52% for blacks and whites, respectively). These findings suggest that Web-based DietDay dietary recalls offer an inexpensive and widely accessible dietary assessment alternative, the validity of which is equally strong among black and white adults. The validity of the Web-administered recall was superior to that of the paper food frequency questionnaire.

Influence of diet on nipple aspirate fluid production and estrogen levels

One possible mechanism how nutritional factors may affect breast cancer risk is through an influence on estrogen levels. Nipple aspirate fluid (NAF) is thought to provide a more direct insight into hormonal influences on breast tissue than serum. The ability to produce NAF may be an indicator of breast cancer risk. The current analysis was conducted as part of a soy trial in 92 premenopausal women and evaluated the relation of usual dietary intake with NAF volume and the most predominant steroidal estrogens in NAF and serum at baseline. Estradiol (E(2)) and estrone sulfate (E(1)S) were assessed in NAF and E(2), estrone (E(1)), and E(1)S, in serum using highly sensitive radioimmunoassays. The statistical analysis applied multivariate, log-linear regression models. Intake of saturated fat and cheese (p = 0.06 for both) indicated a positive trend with NAF volume whereas isoflavonoid and soy consumption suggested inverse associations (p = 0.01 and p = 0.08). For estrogens in NAF, total fat and monounsaturated fat intake was positively associated with E(2) (p = 0.05 and p = 0.02) and in serum, alcohol intake was associated with higher E(1)S levels (p = 0.02). These findings suggest a weak influence of dietary composition on NAF production and estrogen levels in serum and NAF.

Comparison of modifiable health behaviours between persons with and without cancer: the Multiethnic Cohort

OBJECTIVE

To compare the prevalence of modifiable risk factors for cancer and other chronic diseases between adult cancer survivors and persons with no history of cancer.

DESIGN

Cross-sectional.

SETTING

Population-based sample residing in California and Hawaii.

SUBJECTS

A total of 177 003 men and women aged 45-75 years who participated in the Multiethnic Cohort Study (MEC). Logistic regression was used to examine adherence to recommendations regarding modifiable risk factors among cancer survivors (n 16 346) when compared with cohort members with no history of cancer (n 160 657).

RESULTS

Cancer survivors were less likely than cohort members with no history of cancer to meet recommendations specified in the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) 2007 report (OR = 0·97; 95 % CI 0·96, 0·99). No difference between groups was seen for adherence to dietary recommendations alone (OR = 0·99; 95 % CI 0·98, 1·01). Site-specific analyses showed that results for colorectal cancer were similar to those for all cancers combined, but survivors of breast (OR = 1·04; 95 % CI 1·02, 1·07) and prostate (OR = 1·04; 95 % CI 1·01, 1·07) cancer were more likely to meet dietary recommendations. Latino survivors were less likely to adhere to WCRF/AICR recommendations than Latino controls; however, differences across ethnic groups were not significant (Pinteraction = 0·64).

CONCLUSIONS

The modest differences found between adult cancer survivors and persons with no history of cancer suggest that a diagnosis of cancer in itself may not be associated with improvements in health behaviours related to cancer and other chronic diseases.

The preventable proportion of type 2 diabetes by ethnicity: the multiethnic cohort

PURPOSE

To estimate the population-attributable risk (PAR) associated with modifiable risk factors for diabetes among Caucasians, Native Hawaiians, and Japanese Americans in the Hawaii component of the Multiethnic Cohort.

METHODS

This analysis is based on 74,970 cohort participants ages 45-75 years who completed a questionnaire on demographics, diet, and lifestyle factors in 1993-1996. After a mean follow-up time of 12.1 (0.01-14.4) years, 8,559 diabetes cases were identified by self-report, a medication questionnaire, and through health plan linkages. Hazard ratios for diabetes and partial PARs for single and different combinations of modifiable risk factors were estimated.

RESULTS

Overweight, physical inactivity, high meat intake, no alcohol consumption, and smoking were positively associated with diabetes risk in all ethnic groups. The estimated PARs suggested that among men, 78%, and among women, 83%, of new diabetes cases could have been avoided if all individuals had been in the low risk category for all of the modifiable risk factors. The slightly lower PARs in Japanese Americans were not significantly different from those in Caucasian and Native Hawaiian subjects.

CONCLUSIONS

Although PARs varied slightly over ethnicity, our findings do not support ethnic-specific prevention strategies; interventions targeted at multiple behaviors are needed in all ethnic groups.

Food intake of individuals with and without diabetes across different countries and ethnic groups

BACKGROUND/OBJECTIVES

Given the importance of nutrition therapy in diabetes management, we hypothesized that food intake differs between individuals with and without diabetes. We investigated this hypothesis in two large prospective studies including different countries and ethnic groups.

SUBJECTS/METHODS

Study populations were the European Prospective Investigation into Cancer and Nutrition Study (EPIC) and the Multiethnic Cohort Study (MEC). Dietary intake was assessed by food frequency questionnaires, and calibrated using 24h-recall information for the EPIC Study. Only confirmed self-reports of diabetes at cohort entry were included: 6192 diabetes patients in EPIC and 13 776 in the MEC. For the cross-sectional comparison of food intake and lifestyle variables at baseline, individuals with and without diabetes were matched 1:1 on sex, age in 5-year categories, body mass index in 2.5 kg/m(2) categories and country.

RESULTS

Higher intake of soft drinks (by 13 and 44% in the EPIC and MEC), and lower consumption of sweets, juice, wine and beer (>10% difference) were observed in participants with diabetes compared with those without. Consumption of vegetables, fish and meat was slightly higher in individuals with diabetes in both studies, but the differences were <10%. Findings were more consistent across different ethnic groups than countries, but generally showed largely similar patterns.

CONCLUSIONS

Although diabetes patients are expected to undergo nutritional education, we found only small differences in dietary behavior in comparison with cohort members without diabetes. These findings suggest that emphasis on education is needed to improve the current behaviors to assist in the prevention of complications.

Meat consumption and risk of type 2 diabetes: the Multiethnic Cohort

OBJECTIVE

To examine the association of meat consumption with diabetes risk in the Hawaii component of the Multiethnic Cohort and to assess effect modification by ethnicity.

DESIGN

A prospective cohort study. Baseline information on diet and lifestyle was assessed by questionnaire. The cohort was followed up for incident cases of diabetes, which were identified through self-reports, medication questionnaires, or health plan linkages. Cox regression was used to calculate hazard ratios (HR) and 95% confidence intervals for diabetes associated with quintile of meat consumption.

SETTING

Hawaii, USA.

SUBJECTS

A total of 29,759 Caucasian, 35,244 Japanese-American and 10,509 Native Hawaiian men and women, aged 45-75 years at baseline.

RESULTS

During a mean follow-up time of 14 years, 8587 incident diabetes cases were identified. Intake of red meat was positively associated with diabetes risk in men (fifth v. first quintile: HR=1.43; 95% CI 1.29, 1.59) and women (fifth v. first quintile: HR=1.30; 95% CI 1.17, 1.45) in adjusted models. The respective HR for processed red meat intake were 1.57 (95% CI 1.42, 1.75) and 1.45 (95% CI 1.30, 1.62). The association for processed poultry was weaker than for processed red meat, and fresh poultry intake was not associated with diabetes risk. For men only, we observed significant interactions of ethnicity with the red and processed red meat associations, with Caucasians experiencing slightly higher risks than Japanese-Americans.

CONCLUSIONS

Our findings support the growing evidence that red and processed meat intake increase risk for diabetes irrespective of ethnicity and level of BMI.

Health-related characteristics and dietary intakes of male veterans and non-veterans in the Multiethnic Cohort Study (United States)

BACKGROUND: Nationwide surveys in the United States found that certain health-related factors, in particular cigarette smoking and obesity, were more prevalent in veterans than in non-veterans. PURPOSE: The objective of this paper was to compare health-related characteristics and dietary intakes between veterans and non-veterans in the Multiethnic Cohort. MATERIALS AND METHODS: The cohort participants (aged 45-75 years), residing in Hawaii and California at baseline, completed a mailed questionnaire on diet, medical history, and lifestyle in 1993-1996. The current analyses included 20,939 men (14,975 veterans and 5,964 non-veterans) who returned a survey questionnaire on military service in 2007. RESULTS: Compared to non-veterans, veterans were more likely to be overweight and obese (BMI≥25, 61% vs. 55%), former smokers (54% vs. 47%), heavier consumers of red and processed meat, and lighter consumers of fruits and vegetables. Within the veteran group, enlisted men were more likely to be obese, to have a history of smoking, to consume more processed meat and to consume smaller amounts of dairy products and fruits than officers. CONCLUSION: The findings imply that veterans as a group are at somewhat higher risk of developing lifestyle-related chronic diseases than are non-veterans. Comparisons of actual differences in disease incidence and mortality in the Multiethnic Cohort between veterans and non-veterans will require several more years of follow-up.

Application of a repeat-measure biomarker measurement error model to 2 validation studies: examination of the effect of within-person variation in biomarker measurements

Repeat-biomarker measurement error models accounting for systematic correlated within-person error can be used to estimate the correlation coefficient (ρ) and deattenuation factor (λ), used in measurement error correction. These models account for correlated errors in the food frequency questionnaire (FFQ) and the 24-hour diet recall and random within-person variation in the biomarkers. Failure to account for within-person variation in biomarkers can exaggerate correlated errors between FFQs and 24-hour diet recalls. For 2 validation studies, ρ and λ were calculated for total energy and protein density. In the Automated Multiple-Pass Method Validation Study (n=471), doubly labeled water (DLW) and urinary nitrogen (UN) were measured twice in 52 adults approximately 16 months apart (2002-2003), yielding intraclass correlation coefficients of 0.43 for energy (DLW) and 0.54 for protein density (UN/DLW). The deattenuated correlation coefficient for protein density was 0.51 for correlation between the FFQ and the 24-hour diet recall and 0.49 for correlation between the FFQ and the biomarker. Use of repeat-biomarker measurement error models resulted in a ρ of 0.42. These models were similarly applied to the Observing Protein and Energy Nutrition Study (1999-2000). In conclusion, within-person variation in biomarkers can be substantial, and to adequately assess the impact of correlated subject-specific error, this variation should be assessed in validation studies of FFQs.

Soy consumption is not protective against diabetes in Hawaii: the Multiethnic Cohort

Based on the hypothesis that soy consumption may improve glucose tolerance, we examined the association of soy intake with diabetes risk in the Hawaii component of the Multiethnic Cohort. Among 29 719 Caucasian, 35 141 Japanese American and 10 484 Native Hawaiian men and women, 8564 incident diabetes cases were identified during 14 years of follow-up. Cox regression was used to calculate hazard ratios while adjusting for known confounders with stratifications by sex, ethnicity and weight status. We observed no protective effect of soy food consumption on diabetes risk in this population, which has a wide range of soy intakes though lower than in Asian populations. Indeed, higher soy food intake was associated with a weakly elevated diabetes risk across ethnic groups; the higher risk was limited to overweight and obese individuals. The current findings do not support a protective effect of modest levels of soy food consumption against diabetes.