The reproducibility and validity of a self-administered semiquantitative food frequency questionnaire in subjects from South Dakota and Wyoming

Reliability of a short diet and vitamin supplement questionnaire for retrospective collection of maternal nutrient intake

Background

Gestational nutrition can protect against adverse neurodevelopmental outcomes.

Objectives

We developed a short tool for collecting maternal nutritional intake during pregnancy to facilitate research in this area and compared its retrospective use to prospectively-collected food frequency questionnaires (FFQ).

Methods

Maternal nutritional intake was retrospectively assessed using three versions (full interview, full self-administered online, and shortened interview) of the Early Life Exposure Assessment Tool (ELEAT) among participants of the MARBLES pregnancy cohort study of younger siblings of autistic children. Retrospective responses were compared with responses to supplement questions and the validated 2005 Block FFQ prospectively collected in MARBLES during pregnancies 2-7 years prior. ELEAT nutrient values were calculated using reported food intake frequencies and nutrient values from the USDA nutrient database. Correlations between retrospectively- and prospectively-reported intake were evaluated using Kappa coefficients, Youden's J, and Spearman Rank Correlation Coefficients (rs).

Results

MARBLES FFQ dietary intakes were compared among 54 women who completed the ELEAT full form including 12 online, and among 23 who completed the ELEAT short form. Correlations across most foods were fair to moderate. Most ELEAT quantified nutrient values were moderately correlated (rs = 0.3-0.6) with those on the Block FFQ. Supplement questions in both MARBLES and the ELEAT were completed by 114 women. Kappas were moderate for whether or not supplements were taken, but modest for timing. Correlations varied by version and child diagnosis or concerns, and were higher when mothers completed the ELEAT when their child was 4 years old or younger.

Conclusions

With recall up to several years, ELEAT dietary and supplement module responses were modestly to moderately reliable and produced nutrient values moderately correlated with prospectively-collected measures. The ELEAT dietary and vitamin supplements modules can be used to rank participants in terms of intake of several nutrients relevant for neurodevelopment.

Association between malnutrition and post-acute COVID-19 sequelae: A retrospective cohort study

BACKGROUND

Long coronavirus disease consists of health problems people experience after being infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). These can be severe and include respiratory, neurological, and gastrointestinal symptoms, with resulting detrimental impacts on quality of life. Although malnutrition has been shown to increase risk of severe disease and death during acute infection, less is known about its influence on post-acute COVID-19 outcomes. We addressed this critical gap in knowledge by evaluating malnutrition's impact on post-COVID-19 sequelae.

METHODS

This study leveraged the National COVID Cohort Collaborative to identify a cohort of patients who were at least 28 days post-acute COVID-19 infection. Multivariable Cox proportional hazard models evaluated the impact of malnutrition on the following postacute sequelae of SARS-CoV-2: (1) death, (2) long COVID diagnosis, (3) COVID-19 reinfection, and (4) other phenotypic abnormalities. A subgroup analysis evaluated these outcomes in a cohort of hospitalized patients with COVID-19 with hospital-acquired (HAC) malnutrition.

RESULTS

The final cohort included 4,372,722 individuals, 78,782 (1.8%) with a history of malnutrition. Individuals with malnutrition had a higher risk of death (adjusted hazard ratio [aHR]: 2.10; 95% CI: 2.04-2.17) and SARS-CoV-2 reinfection (aHR: 1.52; 95% CI: 1.43-1.61) in the postacute period than those without malnutrition. In the subgroup, those with HAC malnutrition had a higher risk of death and long COVID diagnosis.

CONCLUSION

Nutrition screening for individuals with acute SARS-CoV-2 infection may be a crucial step in mitigating life-altering, negative postacute outcomes through early identification and intervention of patients with malnutrition.

Fatty Acids, Amphiregulin Production, and Lung Function in a Cohort of Midwestern Veterans

Rationale

The relationship between many fatty acids and respiratory outcomes remains unclear, especially with regard to mechanistic actions. Altered regulation of the process of lung repair is a key feature of chronic lung disease and may impact the potential for pulmonary rehabilitation, but underlying mechanisms of lung repair following injury or inflammation are not well-studied. The epidermal growth factor receptor agonist amphiregulin (AREG) has been demonstrated to promote lung repair following occupational dust exposure in animals. Studies suggest the polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA) may enhance the production of AREG. The objective of this study was to determine the relationship between fatty acids and lung function in a population of veterans and determine if fatty acid status is associated with concentrations of AREG.

Materials and Methods

Data were collected from a cross-sectional study of veterans within the Nebraska-Western Iowa Health Care System. Whole blood assays were performed to quantify AREG concentrations via a commercially available ELISA kit. Fatty acids from plasma samples from the same patients were measured using gas-liquid chromatography. Intakes of fatty acids were quantified with a validated food frequency questionnaire. Linear regression models were used to determine whether plasma fatty acids or intakes of fatty acids predicted lung function or AREG concentrations. A p < 0.05 was considered statistically significant.

Results

Ninety participants were included in this analysis. In fully adjusted models, plasma fatty acids were associated with AREG production, including the PUFA eicosapentaenoic acid (EPA) (β = 0.33, p = 0.03) and the monounsaturated fatty acid octadecenoic acid: (β = −0.56, p = 0.02). The omega-3 PUFA docosapentaenoic acid (DPA) was positively associated with lung function (β = 0.28, p = 0.01; β = 26.5, p = 0.05 for FEV₁/FVC ratio and FEV₁ % predicted, respectively), as were the omega-6 PUFAs eicosadienoic acid (β = 1.13, p < 0.001; β = 91.2, p = 0.005 for FEV₁/FVC ratio and FEV₁ % predicted, respectively) and docosadienoic acid (β = 0.29, p = 0.01 for FEV₁/FVC ratio). Plasma monounsaturated and saturated fatty acids were inversely associated with lung function.

Conclusion

Opposing anti- and pro-inflammatory properties of different fatty acids may be associated with lung function in this population, in part by regulating AREG induction.

Dairy Food Intake Is Not Associated with Measures of Bone Microarchitecture in Men and Women: The Framingham Osteoporosis Study

Previous studies reported that dairy foods are associated with higher areal bone mineral density (BMD) in older adults. However, data on bone strength and bone microarchitecture are lacking. We determined the association of dairy food intake (milk, yogurt, cheese, milk + yogurt, and milk + yogurt + cheese, servings/week) with high resolution peripheral quantitative computed tomography (HR-pQCT) measures of bone (failure load, cortical BMD, cortical thickness, trabecular BMD, and trabecular number). This cross-sectional study included participants with diet from a food frequency questionnaire (in 2005–2008 and/or 1998–2001) and measurements of cortical and trabecular BMD and microarchitecture at the distal tibia and radius (from HR-pQCT in 2012–2015). Sex-specific multivariable linear regression estimated the association of dairy food intake (energy adjusted) with each bone measure adjusting for covariates. Mean age was 64 (SD 8) years and total milk + yogurt + cheese intake was 10.0 (SD 6.6) and 10.6 (6.4) servings/week in men and women, respectively. No significant associations were observed for any of the dairy foods and bone microarchitecture measures except for cheese intake, which was inversely associated with cortical BMD at the radius (p = 0.001) and tibia (p = 0.002) in women alone. In this cohort of primarily healthy older men and women, dairy intake was not associated with bone microarchitecture. The findings related to cheese intake and bone microarchitecture in women warrant further investigation.

The Cancer Prevention Study-3 FFQ Is a Reliable and Valid Measure of Nutrient Intakes among Racial/Ethnic Subgroups, Compared with 24-Hour Recalls and Biomarkers

BACKGROUND

Valid assessment of dietary intake in diverse populations is important for studies of chronic disease risk in the United States.

OBJECTIVES

We evaluated the reproducibility and validity of a food frequency questionnaire (FFQ) modified for the American Cancer Society's Cancer Prevention Study-3 (CPS-3) prospective cohort, among a racially/ethnically diverse subgroup.

METHODS

The Diet Assessment Substudy included 677 CPS-3 participants (64% women; 61% non-Hispanic white, 24% non-Hispanic black, 15% Hispanic), aged 31-70 y, who completed 2 FFQs 1 y apart (FFQ1, FFQ2), 4-6 telephone-administered 24-h dietary recalls (24HRs), and 2 fasting blood samples and 24-h urine collections ∼6 mo apart in the interim. Spearman rank correlation coefficients (ρ) were used to evaluate FFQ reproducibility and validity compared with 24HRs for 67 nutrient exposures. For 18 of these nutrients, we used the method of triads to calculate validity coefficients (VCs, ρ) from pairwise correlations of FFQ2, 24HRs, and biomarkers. Analyses were stratified by sex, race/ethnicity, education, and BMI.

RESULTS

Mean (range) FFQ reproducibility correlations were ρ = 0.65 (0.50-0.91) for men and ρ = 0.63 (0.37-0.89) for women; mean (range) energy-adjusted, deattenuated correlations of FFQ2 with 24HRs were ρ = 0.60 (0.33-0.84) for men and ρ = 0.55 (0.21-0.79) for women. FFQ2 VCs (ρ) among men ranged from 0.42 for β-cryptoxanthin to 0.91 for omega-3 (n-3) fatty acids and, among women, from 0.41 for sodium to 0.79 for total vitamin D. Mean FFQ reproducibility and validity were highest among whites (ρ = 0.68, ρ = 0.58, respectively) and slightly lower among blacks (ρ = 0.57, ρ = 0.49, respectively) and Hispanics (ρ = 0.59, 0.55, respectively). FFQ reproducibility and validity were slightly lower among those with less than a 4-y college degree, and those with a BMI ≥30 kg/m2.

CONCLUSIONS

Reproducibility and validity of the CPS-3 FFQ were comparable with similar studies for most nutrients, among all subgroups. These findings support future dietary analyses in the contemporary CPS-3 cohort and other similar cohorts.

A meta-analysis of the reproducibility of food frequency questionnaires in nutritional epidemiological studies

BACKGROUND

Reproducibility of FFQs measures the consistency of the same subject at different time points. We performed a meta-analysis to explore the reproducibility of FFQs and factors related to reproducibility of FFQs.

METHODS AND FINDINGS

A systematic literature review was performed before July 2020 using PubMed and Web of Science databases. Pooled intraclass and Spearman correlation coefficients (95% confidence interval) were calculated to assess the reproducibility of FFQs. Subgroup analyses based on characteristics of study populations, FFQs, or study design were performed to investigate factors related to the reproducibility of FFQs. A total of 123 studies comprising 20,542 participants were eligible for the meta-analysis. The pooled crude intraclass correlation coefficients ranged from 0.499 to 0.803 and 0.499 to 0.723 for macronutrients and micronutrients, respectively. Energy-adjusted intraclass correlation coefficients ranged from 0.420 to 0.803 and 0.507 to 0.712 for macronutrients and micronutrients, respectively. The pooled crude and energy-adjusted Spearman correlation coefficients ranged from 0.548 to 0.851 and 0.441 to 0.793, respectively, for macronutrients; and from 0.573 to 0.828 and 0.510 to 0.744, respectively, for micronutrients. FFQs with more food items, 12 months as dietary recall interval (compared to less than 12 months), and a shorter time period between repeated FFQs resulted in superior FFQ reproducibility.

CONCLUSIONS

In conclusion, FFQs with correlation coefficients greater than 0.5 for most nutrients may be considered a reliable tool to measure dietary intake. To develop FFQs with higher reproducibility, the number of food items and dietary recall interval should be taken into consideration.

Vitamin D intake is associated with dementia risk in the Washington Heights-Inwood Columbia Aging Project (WHICAP)

INTRODUCTION

Low vitamin D intake and low vitamin D circulating levels have been associated with increased risk for dementia. We aimed to examine the association between vitamin D intake and dementia in a multiethnic cohort.

METHODS

A longitudinal study of 1759 non-demented older (≥65 years) participants of the Washington Heights-Inwood Columbia Aging Project with follow-up visits and completed a food frequency questionnaire. Dementia was diagnosed by consensus using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria. Cox hazard regression was performed.

RESULTS

During a mean follow-up of 5.8 years, 329 participants developed dementia. Participants with the highest tertile of vitamin D intake from food sources had decreased risk (hazard ratio [HR] 0.72, 95% confidence interval [CI] 0.54-0.97, P = .030) for dementia compared with those with the lowest tertile, adjusting for age, sex, race/ethnicity, education, apolipoprotein E (APOE)-ε4, physical activity, Mediterranean diet (MeDI) score, income, depression, hypertension, diabetes, cardiovascular disease, and smoking.

DISCUSSION

Higher vitamin D intake is associated with decreased risk of dementia in a multiethnic cohort.

Validation of semiquantitative FFQ administered to adults: a systematic review

Objective:

To conduct a systematic review of studies for the validation of semiquantitative FFQ (SFFQ) that assess food intake in adults.

Design:

The authors conducted a systematic search in PubMed for articles published as late as January 2020 in Spanish, English, French and Portuguese. Individual searches (twelve in total) paired three hyphenated and non-hyphenated variations of ‘semiquantitative food frequency questionnaire’ with both ‘validity’ and ‘validation’ using the ‘all fields’ and the ‘title/abstract’ retrieval categories. Independent extraction of articles was performed by four authors using predefined data fields.

Setting:

We searched for original SFFQ validation studies that analysed general diet composition (nutrients with or without food groups or energy analysis) in healthy adults, in any setting, and that also reported correlation coefficients.

Participants:

Healthy adults.

Results:

Sixty articles were included. The preferred comparison standard for validation was food records (n 37). The main correlation coefficients used were Pearson’s (n 41), and validity coefficients varied from −0·45 to 1. Most correlation coefficients were adjusted by energy (twelve studies presented only crude values). The elements mentioned most frequently were energy, macronutrients, cholesterol, SFA, PUFA, fibre, vitamin C, Ca and Fe.

Conclusions:

Although all these SFFQ are reported as validated, coefficients may vary across groups of foods and nutrients. Based on our findings, we suggest researchers to consult our revision before choosing a SFFQ and to review important issues about them, such as their validation, number of items, number of participants, etc. Systematic Review Registration: PROSPERO number CRD42017064716. Available at: http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42017064716.

Relative Validity and Reproducibility of a Short FoodFrequency Questionnaire to Assess Nutrient Intakesof New Zealand Adults

There is no recent validated short food frequency questionnaire (FFQ) for use in NewZealand (NZ) adults. This study aimed to evaluate the relative validity and reproducibility of a shortFFQ in free-living NZ adults aged 30-59 years. A 57-item, semi-quantitative FFQ was developedand pre-tested. During a 12-month study period the FFQ was administrated twice with a 9-monthinterval between administrations. Four two-day diet records were collected at months 0, 3, 6, and 9and a blood sample was taken at month 9. Spearman correlations were used to evaluate the validityof the FFQ with the eight-day diet records and selected biomarkers. Cross-classification analysisand the Bland-Altman method were used to assess the agreement between the FFQ and the dietrecord. Reproducibility over nine months was assessed using intra-class correlations. A total of 132males and females completed both FFQs, the eight-day diet record, and provided a blood sample.The highest energy-adjusted correlation coefficients were observed for alcohol (0.81), cholesterol(0.61), and carbohydrate (0.61), with the lowest for sodium (0.29), thiamin (0.33), and niacinequivalents (0.34). More than three quarters of the participants were correctly classified into thesame or adjacent quartile for most nutrients, with a low proportion of participants being grosslymisclassified (< 10%). For most nutrients, the limits of agreement from the Bland-Altman analyseswere between 50% and 250%. A positive correlation was observed between dietary intakes andplasma biomarkers for all selected nutrients. The FFQ showed moderate to good reproducibility,with almost all reliability coefficients ranging from 0.60 to 0.80. This short FFQ was shown to validlyand reliably rank individuals by their habitual intake of most major nutrients, indicating that theFFQ will offer a time-efficient way to assess the nutrient intake of NZ adults in future research.

Insufficient zinc intake enhances lung inflammation in response to agricultural organic dust exposure

Organic dust exposure particularly within hog confinement facilities is a significant cause of airway inflammation and lung disease. In a cohort of Midwestern veterans with COPD and agricultural work exposure we observed reduced zinc intakes which were associated with decreased lung function. Because insufficient zinc intake is common within the U.S. and a potent modulator of innate immune function, we sought to determine whether deficits in zinc intake would impact the airway inflammatory response to hog confinement facility dust extract (HDE). Adult male C57BL/6 mice were randomized to zinc deficient or matched zinc sufficient diets for 3 weeks and subsequently treated with intranasal HDE inhalation or saline once or daily for 3 weeks while maintained on specific diets. Lavage fluid and lung tissue was collected. Conditions of zinc deficiency were also studied in macrophages exposed to HDE. Single and repetitive HDE inhalation exposure resulted in increased influx of total cells and neutrophils, increased mediator hyper-responsiveness (TNFα, IL-6, CXCL1, and amphiregulin), and enhanced tissue pathology that was more pronounced in zinc deficient mice compared to normal dietary counterparts. Airway inflammation was most pronounced in zinc deficient mice treated with repetitive HDE for 3 weeks. Similarly, macrophages maintained in a zinc deficient environment exhibited increased CXCL1 and IL-23 production as a result of increased NF-κB activation. Conclusion: Given the relatively high incidence of dietary deficiencies in agriculture workers, we anticipate that zinc intake, or a lack thereof, may play an important role in modulating the host response to organic dust exposure.

Validity of an FFQ to measure nutrient and food intakes in Tanzania

OBJECTIVE

FFQ are often used to estimate food and nutrient intakes to rank individuals by their level of intake. We evaluated the relative validity of a semi-quantitative FFQ created for use in Tanzania by comparing it with two 24 h diet recalls.

DESIGN

We measured relative validity of the FFQ with deattenuated energy-adjusted rank correlations for nutrients, deattenuated rank correlations for food groups, and performed a cross-classification analysis of energy-adjusted nutrient quartiles using percentage of agreement and Bland-Altman analysis.

SETTING

Interviews were conducted in 2014 in participants' homes in Ukonga, Dar es Salaam, Tanzania.

SUBJECTS

We surveyed 317 adults aged 40 years or older from the general public.

RESULTS

Deattenuated energy-adjusted rank correlation coefficients of nutrients ranged from -0·03 for riboflavin to 0·41 for percentage of energy from carbohydrates, with a median correlation of 0·21. Coefficients for food groups ranged from 0·00 for root vegetables to 0·51 for alcohol, with a median of 0·35. Relative to the average of the two 24 h diet recalls, the FFQ overestimated energy intake and intakes of all nutrients and food groups, other than tea, with ratios among nutrients ranging from 1·34 for SFA to 7·08 for vitamin A; and among food groups from 0·92 for tea to 9·00 for fruit. The percentage of participants classified into the same nutrient intake quartile ranged from 23 % for SFA to 32 % for both niacin and pantothenic acid, with a median of 28 %.

CONCLUSIONS

The FFQ performed moderately well in urban Tanzanian adults.

Fat-soluble vitamins A and E and health disparities in a cohort of pregnant women at delivery

The objective of the present study was to evaluate intakes and serum levels of vitamin A, vitamin E, and related compounds in a cohort of maternal-infant pairs in the Midwestern USA in relation to measures of health disparities. Concentrations of carotenoids and tocopherols in maternal serum were measured using HPLC and measures of socio-economic status, including food security and food desert residence, were obtained in 180 mothers upon admission to a Midwestern Academic Medical Center labour and delivery unit. The Kruskal-Wallis and independent-samples t tests were used to compare measures between groups; logistic regression models were used to adjust for relevant confounders. P < 0·05 was considered statistically significant. The odds of vitamin A insufficiency/deficiency were 2·17 times higher for non-whites when compared with whites (95 % CI 1·16, 4·05; P = 0·01) after adjustment for relevant confounders. Similarly, the odds of being vitamin E deficient were 3·52 times higher for non-whites (95 % CI 1·51, 8·10; P = 0·003). Those with public health insurance had lower serum lutein concentrations compared with those with private health insurance (P = 0·05), and living in a food desert was associated with lower serum concentrations of β-carotene (P = 0·02), after adjustment for confounders. Subjects with low/marginal food security had higher serum levels of lutein and β-cryptoxanthin compared with those with high food security (P = 0·004 and 0·02 for lutein and β-cryptoxanthin). Diet quality may be a public health concern in economically disadvantaged populations of industrialised societies leading to nutritional disadvantages as well.

Reproducibility and validity of an FFQ to assess usual intake of methyl-group donors

OBJECTIVE

To develop and validate a novel FFQ to assess the daily intake of four methyl-group donors (methionine, choline, betaine and folate).

DESIGN

The relative validity of the FFQ was assessed by comparison with 7 d estimated diet records (n 80) and its reproducibility was evaluated by repeated administrations 6 weeks apart (n 92). Paired Student t tests were used to compare group means and de-attenuated intra-class correlations to investigate the ability of the FFQ to rank individuals according to their methyl-group donor intake. De-attenuated intra-class correlation coefficients were calculated between the test and reference method for methionine, choline, betaine, folate and the sum of methyl-group donors. The weighted kappa (κ w) was calculated as a measure of tertile agreement.

SETTING

Flanders, Belgium.

SUBJECTS

The FFQ was validated among Flemish women of reproductive age (18-35 years).

RESULTS

The questionnaire had an acceptable ranking ability (r=0·32-0·68; κ w=0·10-0·35), but overestimated the daily intake of folate (280·6 μg v. 212·0 μg) and betaine (179·1 mg v. 147·0 mg) compared with the 7 d estimated diet record. Cross-classification analysis indicated that 20 % (choline) of the participants were grossly misclassified in the validation study. The correlation between repeated administrations was good (r=0·62-0·83) with a maximal misclassification of 7 % for betaine (κ w=0·44-0·66).

CONCLUSIONS

These results indicate that this newly developed FFQ is a reliable instrument with acceptable validity for ranking individuals according to methyl-group donor intake (except for a poor agreement for choline (κ w=0·10) and a fair ranking ability for betaine (r=0·32)) in Flemish women of reproductive age.

Validation of a food-frequency questionnaire assessment of methyl-group donors using estimated diet records and plasma biomarkers: the method of triads

In this study, the intake of methyl-group donors (methionine, folate, betaine, and choline) among Flemish women of reproductive age (n = 30) assessed by a 7-d estimated diet record (7 d EDR) and food-frequency questionnaire (FFQ) was compared with plasma S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), and SAH:SAM ratio. Pearson correlation coefficients were calculated between each of the dietary methods and the validity coefficient was calculated using the method of triads. Correlations were higher between intake assessed by the FFQ and biomarkers than between 7 d EDR and biomarkers. The validity coefficients of the FFQ, when using SAH as a biomarker, were high (0.86 for methionine to 0.94 for folate), when the SAH:SAM ratio was used as a biomarker the validity coefficients ranged from 0.63 to 1.00. These data indicate that the FFQ is a reliable tool to estimate the intake of the methyl-group donors in women of reproductive age.

A comprehensive FFQ developed for use in New Zealand adults: reliability and validity for nutrient intakes

OBJECTIVE

To evaluate the reliability and relative validity of a semi-quantitative FFQ for assessing the habitual intake of multiple nutrients in New Zealand (NZ) adults over the past 12 months.

DESIGN

A 154-item FFQ was developed. After initial pre-testing, reliability was assessed using intra-class correlations. Relative validity was assessed by comparing nutrient intakes derived from the FFQ v. those from an 8 d diet record (8dWDR) collected over 12 months and selected blood biomarkers, using Spearman correlations. Supplementary cross-classification and Bland-Altman analyses were performed to assess validity of the FFQ v. the 8dWDR.

SETTING

Dunedin, NZ.

SUBJECTS

One hundred and thirty-two males and females aged 30-59 years who completed all FFQ and 8dWDR and provided a blood sample.

RESULTS

Reliability coefficients ranged from 0·47 for Ca to 0·83 for alcohol, with most values falling between 0·60 and 0·80. The highest validity coefficients for energy-adjusted data were observed for alcohol (0·74), cholesterol (0·65) and β-carotene (0·58), and the lowest for Zn (0·24) and Ca (0·28). For all energy-adjusted nutrients mean percentage correct classification was 77·9% and gross misclassification was 4·5%. Results of Bland-Altman analyses showed wide limits of agreement for all micronutrients but high agreement was observed for most macronutrients (99% for protein, 103% for total fat). When compared with biomarkers, energy-adjusted coefficients were 0·34 for β-carotene and 0·33 for vitamin C.

CONCLUSIONS

The FFQ provides highly repeatable measurements and good validity in ranking individuals' intake, suggesting that it will be a useful tool to assess nutrient intake of NZ adults in future research.

Dietary patterns and risk of pancreatic cancer in a large population-based case-control study in the San Francisco Bay Area

Pancreatic cancer is highly lethal, and identifying modifiable risk factors could have substantial public health impact. In this population-based case-control study (532 cases, 1701 controls), we used principal component analysis and multivariable unconditional logistic regression models to examine whether a particular dietary pattern was associated with risk of pancreatic cancer, adjusting for other known risk factors. A prudent dietary pattern, characterized by greater intake of vegetables, fruit, fish, poultry, whole grains, and low-fat dairy, was associated with an approximate 50% reduction in pancreatic cancer risk among men [odds ratio (OR) = 0.51, 95% confidence intervals (CI) = 0.31-0.84, P trend = 0.001] and women (OR = 0.51, 95% CI = 0.29-0.90, P trend = 0.04). A Western dietary pattern, characterized by higher intake of red and processed meats, potato chips, sugary beverages, sweets, high fat dairy, eggs, and refined grains, was associated with a 2.4-fold increased risk of pancreatic cancer among men (95% CI = 1.3-4.2, P trend = 0.008) but was not associated with risk among women. Among men, those in the upper quintiles of the Western diet and lower quintiles of the prudent diet had a threefold increased risk. Consistent with what has been recommended for several other chronic diseases, consuming a diet rich in plant-based foods, whole grains, and white meat, might reduce risk of pancreatic cancer.

Calcium intake is not associated with increased coronary artery calcification: the Framingham Study

BACKGROUND

Adequate calcium intake is known to protect the skeleton. However, studies that have reported adverse effects of calcium supplementation on vascular events have raised widespread concern.

OBJECTIVE

We assessed the association between calcium intake (from diet and supplements) and coronary artery calcification, which is a measure of atherosclerosis that predicts risk of ischemic heart disease independent of other risk factors.

DESIGN

This was an observational, prospective cohort study. Participants included 690 women and 588 men in the Framingham Offspring Study (mean age: 60 y; range: 36-83 y) who attended clinic visits and completed food-frequency questionnaires in 1998-2001 and underwent computed tomography scans 4 y later in 2002-2005.

RESULTS

The mean age-adjusted coronary artery-calcification Agatston score decreased with increasing total calcium intake, and the trend was not significant after adjustment for age, BMI, smoking, alcohol consumption, vitamin D-supplement use, energy intake, and, for women, menopause status and estrogen use. Multivariable-adjusted mean Agatston scores were 2.36, 2.52, 2.16, and 2.39 (P-trend = 0.74) with an increasing quartile of total calcium intake in women and 4.32, 4.39, 4.19, and 4.37 (P-trend = 0.94) in men, respectively. Results were similar for dietary calcium and calcium supplement use.

CONCLUSIONS

Our study does not support the hypothesis that high calcium intake increases coronary artery calcification, which is an important measure of atherosclerosis burden. The evidence is not sufficient to modify current recommendations for calcium intake to protect skeletal health with respect to vascular calcification risk.

Dietary assessment methods for intakes of iron, calcium, selenium, zinc and iodine

The EURopean micronutrient RECommendations Aligned (EURRECA) Network of Excellence is working towards developing aligned micronutrient recommendations across Europe. The purpose of the present study was to conduct a review of methods used in validation studies carried out in adults assessing dietary intake of EURRECA priority minerals. A search strategy and inclusion criteria were defined and a scoring system was developed to rate the quality of each validation study that produced a quality index with possible scores obtained ranging from 0.5 to 7. A MEDLINE and EMBASE literature review was conducted. Articles/validation studies meeting the inclusion criteria included: 79/88 for Fe; 95/104 for Ca; 13/15 for Se; 29/30 for Zn; 7/9 for iodine. The most frequently used method to ascertain dietary intake was the Food Frequency Questionnaire (FFQ), whereas dietary records (DR) and 24 h recalls were the most used reference methods. The correlation coefficients (CC) between study mineral intakes estimated by FFQ and the reference method were weighted according to the study's quality index and obtained acceptable to good ratings, ranging from 0.36 to 0.60 when the reference method was DR and from 0.41 to 0.58 when the reference was 24 h recalls. A minority of studies (n 9) used biomarkers for validation and among these, five included iodine obtaining a CC of 0.47. The FFQ was seen as a valid method for assessing mineral intake, particularly for Ca and, to a lower extent, for iodine and Zn. Se and Fe showed only acceptable correlations. The present review provides new insights regarding the characteristics that assessment methods for dietary mineral intakes should fulfil.

Dietary assessment methods for micronutrient intake: a systematic review on vitamins

The EURRECA Network of Excellence is working towards the development of aligned micronutrient recommendations across Europe. The purpose of the present study was to define how to identify dietary intake validation studies in adults pertaining to vitamins. After establishing a search strategy, we conducted a MEDLINE and EMBASE literature review. A scoring system was developed to rate the quality of each validation study according to sample size, statistical methods, data collection procedure, seasonality and vitamin supplement use. This produced a quality index with possible scores obtained ranging from 0.5 to 7. Five thousand four-hundred and seventy-six papers were identified. The numbers meeting the inclusion criteria were: for vitamin A, 76; vitamin C, 108; vitamin D, 21; vitamin E, 75; folic acid, 47; vitamin B12, 19; vitamin B6, 21; thiamine, 49; riboflavin, 49; and niacin, 32. The most frequently used method to ascertain dietary intake was the Food Frequency Questionnaire (FFQ), whereas dietary records (DR) and 24-h recalls were the most used reference methods. The correlation coefficients (CC) between vitamin intakes estimated by FFQ and the reference method were weighted according to the study's quality index and ranged from 0.41 to 0.53 when the reference method was the DR and from 0.43 to 0.67 when the reference was 24-h recalls. A minority of studies (n 33) used biomarkers for validation and in these the CC ranged from 0.26 to 0.38. The FFQ is an acceptable method of assessing vitamin intake. The present review provides new insights regarding the characteristics that assessment methods for dietary intake should fulfil.

Relative validity of a FFQ in measuring carbohydrate fractions, dietary glycaemic index and load: exploring the effects of subject characteristics

FFQ require validation as part of epidemiological research of diet–disease relationships. Studies exploring associations between carbohydrate type and chronic diseases are rapidly increasing, but information on the validity of carbohydrate fractions, dietary glycaemic index (GI) and the glycaemic load (GL) estimated by FFQ is scarce. Likewise, the effects of subject characteristics on FFQ validity have been poorly documented. The present study evaluates the relative validity of an 131-item FFQ in relation to two 3 d food records (FR) performed 6 months apart focusing on the intake of carbohydrate fractions, dietary GI and the GL. Furthermore, we assessed the extent to which subjects' age, education and BMI explain differences between these methods. The study sample comprised 218 men and 292 women aged 25–74 years participating in a large population-based survey in Finland. Energy-adjusted Spearman's rank correlations ranged from 0·27 (sugars) to 0·70 (lactose) for men and from 0·37 (sugars) to 0·69 (lactose) for women. On average, 73 % of the subjects were categorised into the same or adjacent distribution quintile based on the two methods. In general, the FFQ overestimated the intakes compared with FR. Especially in women, FFQ validity for some nutrients was associated with the level of intake, subjects' age and, to a lesser extent, education but not BMI. In conclusion, the FFQ appears to be reasonably valid in the assessment of carbohydrate exposure variables, but the findings show a need for adjustment of diet–disease relationships for subjects' age and education.

Vegetable and fruit intake after diagnosis and risk of prostate cancer progression

Cruciferous vegetables, tomato sauce and legumes have been associated with reduced risk of incident advanced prostate cancer. In vitro and animal studies suggest these foods may inhibit progression of prostate cancer, but there are limited data in men. Therefore, we prospectively examined whether intake of total vegetables, and specifically cruciferous vegetables, tomato sauce and legumes, after diagnosis reduce risk of prostate cancer progression among 1,560 men diagnosed with non-metastatic prostate cancer and participating in the Cancer of the Prostate Strategic Urologic Research Endeavor, a United States prostate cancer registry. As a secondary analysis, we also examined other vegetable subgroups, total fruit and subgroups of fruits. The participants were diagnosed primarily at community-based clinics and followed from 2004 to 2009. We assessed vegetable and fruit intake via a semi-quantitative food frequency questionnaire, and ascertained prostate cancer outcomes via urologist report and medical records. We observed 134 events of progression (53 biochemical recurrences, 71 secondary treatments likely due to recurrence, 6 bone metastases and 4 prostate cancer deaths) during 3,171 person-years. Men in the fourth quartile of post-diagnostic cruciferous vegetable intake had a statistically significant 59% decreased risk of prostate cancer progression compared to men in the lowest quartile (hazard ratio (HR): 0.41; 95% confidence interval (CI): 0.22, 0.76; p-trend: 0.003). No other vegetable or fruit group was statistically significantly associated with risk of prostate cancer progression. In conclusion, cruciferous vegetable intake after diagnosis may reduce risk of prostate cancer progression.

Nutritional supplements, COX-2 and IGF-1 expression in men on active surveillance for prostate cancer

BACKGROUND

Nutritional factors are associated with reduced risk of prostate cancer progression, yet mechanisms remain unclear. We examined the effects of lycopene and fish oil supplements versus placebo on the normal prostate microenvironment, among men pursuing active surveillance for low-burden prostate cancer. We hypothesized that lycopene or fish oil supplements would down-regulate insulin-like growth factor-1 (IGF-1) and cyclooxygenase 2 (COX-2) gene expression, respectively, reflecting putative proliferation (IGF-1) and inflammatory (COX-2) pathways relevant to carcinogenesis.

METHODS

We conducted a 3-month randomized, double-blinded, clinical trial comparing prostate tissue gene expression profiles (assessed by qRT-PCR) among men with favorable-risk prostate cancer receiving either 30 mg/day lycopene, 3 g/day fish oil (including 1,098 mg eicosapentaenoic and 549 mg docosahexaenoic fatty acids) or placebo.

RESULTS

Among 69 men (22 assigned to lycopene, 21 to fish, and 26 to placebo), there was no difference in the change from baseline to the 3 months in IGF-1 expression level between the placebo and lycopene arms (p = 0.93) nor in COX-2 expression between the placebo and fish arms (p = 0.99).

CONCLUSION

Compared to placebo, 3-month intervention with lycopene or fish oil did not significantly change IGF-1 and COX-2 gene expression in the normal prostate microenvironment in men with low-burden prostate cancer. Further analysis of global gene expression profiles may shed light on the bioactivity and relevance of these nutrients in prostate cancer.

Development and validation of a comprehensive semi-quantitative food frequency questionnaire that includes FODMAP intake and glycemic index

BACKGROUND

Fermentable, short chain carbohydrates (FODMAPs) have been identified as triggers for functional gastrointestinal symptoms. In addition, excess FODMAP consumption has been implicated in the onset of Crohn's disease, and animal studies suggest that a low glycemic index diet can impair absorption of fructose, a major dietary FODMAP. Such hypotheses cannot be tested without the ability to quantify FODMAP ingestion with a validated dietary assessment tool.

OBJECTIVE

To assess the validity and reproducibility of a 297-item comprehensive, semi-quantitative food frequency questionnaire (FFQ) in estimating intake of macro- and micronutrients, FODMAPs, and glycemic index/load.

SUBJECTS/SETTING

One hundred healthy participants were recruited to complete the FFQ on two occasions, plus four 1-week food diaries kept during a 12-month period. Participants exhibiting major dietary change during the study period or low energy reporting on the FFQ were excluded.

MAIN OUTCOME MEASURES

Validation and reproducibility of the semi-quantitative FFQ by comparison with the mean of four 1-week food diaries.

STATISTICAL ANALYSES PERFORMED

Validation was assessed using Wilcoxon signed rank test, Spearman's correlation, Bland-Altman, and weighted κ statistics. Reproducibility was examined using Shrout-Fleiss intraclass correlation coefficient.

RESULTS

Seventy-two participants fulfilled inclusion and exclusion criteria. Demographics of the participants were comparable with 2006 Australian Census data. Consistent with other reported FFQs, the FFQ overestimated nutrient intake by a mean 140% (range=95% to 249%). However, based on the other analyses performed, it demonstrated validity for intake of sugars, fiber, alcohol, glycemic index, glucose, FODMAPs, calcium, folate, phosphate, potassium, iron, and magnesium; moderate validation for energy, total fat, saturated fat, carbohydrates, sodium, thiamin, sucrose, and retinol; poor validation for protein, mono/polyunsaturated fat, starch, glycemic load, niacin, and zinc. Riboflavin intake was not validated. Intraclass correlation coefficients for reproducibility ranged from 0.352 to 0.928.

CONCLUSIONS

The FFQ was validated for assessment of a wide range of nutrients, including the new class of carbohydrates, FODMAPs, and glycemic index. This provides a useful tool for dietary research, particularly in the area of gastroenterological disorders.

Atherosclerosis in survivors of Kawasaki disease

OBJECTIVES

To test the hypothesis that long-term survivors of low-risk Kawasaki disease (KD) have ongoing vascular inflammation and dysfunction and a higher risk of accelerated atherosclerosis than healthy control subjects.

STUDY DESIGN

Twenty-eight patients with KD (7-20 years after acute illness) and 27 age-matched healthy control subjects were examined for medical and dietary history, serum markers of atherosclerotic risk and inflammation, carotid intimal-medial thickness (CIMT) with vascular ultrasound scanning and arterial stiffness with applanation tonometry.

RESULTS

Patients and control subjects were similar in age, sex, body mass index, waist-to-hip ratio, blood pressure, cigarette smoking, family history, diet, high-density lipoprotein cholesterol level, lipoprotein (a) level, homocysteine level, glucose level, insulin level, CIMT, arterial stiffness, C-reactive protein level, and inflammatory cytokine level. Levels of total cholesterol and apolipoprotein B were significantly higher in patients with KD than in control subjects.

CONCLUSIONS

There was no evidence of increased atherosclerosis. Small but significant differences in cholesterol and apolipoprotein B levels could suggest increased future risk for atherosclerosis and warrant further study.

Sweets, sweetened beverages, and risk of pancreatic cancer in a large population-based case-control study

OBJECTIVE

We examined the associations between sweets, sweetened and unsweetened beverages, and sugars and pancreatic cancer risk.

METHODS

We conducted a population-based case-control study (532 cases, 1,701 controls) and used multivariate logistic regression models to calculate odds ratios (OR) and 95% confidence intervals (CI). Because associations were often different by sex, we present results for men and women combined and separately.

RESULTS

Among men, greater intakes of total and specific sweets were associated with pancreatic cancer risk (total sweets: OR = 1.9, 95% CI: 1.0, 3.6; sweet condiments: OR = 1.9, 95% CI: 1.2, 3.1; chocolate candy: OR = 2.4, 95% CI: 1.1, 5.0; other mixed candy bars: OR = 3.3, 95% CI: 1.5, 7.3 for 1 + servings/day versus none/rarely). Sweets were not consistently associated with risk among women. Sweetened beverages were not associated with increased pancreatic cancer risk. In contrast, low-calorie soft drinks were associated with increased risk among men only; while other low-/non-caloric beverages (e.g., coffee, tea, and water) were unassociated with risk. Of the three sugars assessed (lactose, fructose, and sucrose), only the milk sugar lactose was associated with pancreatic cancer risk (OR = 2.0, 95% CI: 1.5, 2.7 comparing extreme quartiles).

CONCLUSION

These results provide limited support for the hypothesis that sweets or sugars increase pancreatic cancer risk.

Validation of a food frequency questionnaire for assessment of calcium and bone-related nutrient intake in rural populations

OBJECTIVE

To assess the ability of a semiquantitative food frequency questionnaire (FFQ) to measure calcium and bone-related nutrient intakes in a rural South Dakota population.

DESIGN

Intake estimates from FFQ were compared with four 24-hour recalls obtained quarterly during the preceding year.

SUBJECTS

Convenience sample of 100 participants of the South Dakota Rural Bone Health Study were recruited, with 81 completing the FFQ.

MAIN OUTCOME MEASURES

Calcium and bone-related nutrient intakes were expressed as milligrams per day, milligrams per 1,000 kcal, or quartiles.

STATISTICAL ANALYSES PERFORMED

Intakes by FFQ and 24-hour recalls were compared using paired t test and quartiles were formed to examine cross-classification.

RESULTS

Calcium intakes from FFQ and recalls were 1,287 and 1,141 mg/day (P=0.01), but calcium per 1,000 kcal did not differ. Calcium intake by FFQ correlated with intake by recall when expressed as milligrams per day (r=0.49, P<0.001) or milligrams per 1,000 kcal (r=0.59, P<0.001). Bland-Altman graphs indicated fairly good agreement between methods. Seventy-eight percent of subjects fell into the same or within one quartile category when calcium intake was expressed as milligrams per day and 83% when expressed as milligrams per 1,000 kcal. Gross misclassification occurred in 0% to 4% of the nutrients.

CONCLUSIONS

Although FFQ may not be a valid indicator of an individual's intake, it does adequately classify rural populations into quartiles of calcium and bone-related nutrient intakes, making it a useful tool for assessing dietary calcium and bone related intake in rural populations.

Assessing dietary intake of drug-abusing Hispanic adults with and without human immunodeficiency virus infection

OBJECTIVE

Drug abuse is an important risk factor for the human immunodeficiency virus (HIV) among Hispanics living in the northeastern United States, and both drug abuse and HIV are associated with nutritional deficiencies. The selection of a dietary assessment method most appropriate for Hispanic adults with/without HIV infection who may be drug abusers remains unclear.

DESIGN

Participants were recruited into one of the three groups: HIV-infected drug abusers, HIV-noninfected drug abusers, and HIV-infected non-drug abusers. Subjects who completed two of the three dietary methods were included in cross-sectional pairwise comparisons.

SETTING

The baseline data from a prospective cohort study of the role of drug abuse in HIV/acquired immunodeficiency syndrome-related weight loss.

RESULTS

The 286 enrolled participants completed 282 food frequency questionnaires (FFQs), 142 3-day diet records, and 270 24-hour recalls. Energy-adjusted and deattenuated correlations between the FFQ and 3-day diet records ranged from 0.11 (carbohydrate) to 0.75 (caffeine). Twenty-seven of 33 nutrient intakes estimated by 3-day diet record were significantly lower than by FFQ (P<0.05). Three-day diet records underestimated dietary intake relative to the FFQ and 24-hour recall methods. Fifty percent of records were not completed. Energy estimates from the FFQ and 24-hour recall were similar to each other.

CONCLUSIONS

The 24-hour recall gave higher mean dietary intake estimates, but would require multiple contacts with this difficult-to-reach population. The FFQ that was specifically designed for this Hispanic population performed well relative to the other methods.

Validation of a food frequency questionnaire measurement of selected nutrients using biological markers in African-American men

OBJECTIVE

To validate selected nutrients assessed by the food frequency questionnaire (FFQ) used in the Harvard cohort studies in an African-American group.

DESIGN

Blood aliquots were pooled for each decile of intake of two carotenoids and alpha tocopherol as measured by FFQ. These pooled samples were analyzed for nutrient content, and the resultant blood levels were plotted against the median for each decile of intake. In addition, adipose tissue samples taken from each man were analyzed for content of specific fatty acids. We calculated the Spearman correlations comparing intakes of specific fatty acids as percent of total fat intake, adjusted for energy intake, as measured by FFQ, with the percentage of the corresponding fatty acid in adipose tissue.

SUBJECTS AND SETTINGS

African-American men (N=104) with prostate cancer were recruited from a Detroit physician's practice and completed a detailed FFQ.

RESULTS

Comparing decile 10 with decile 1 intake of nutrients as measured by FFQ, there was a 32% higher blood level of lycopene, a 288% higher blood level of beta carotene and a 100% higher blood level of alpha tocopherol. The Spearman correlation coefficients between intakes of linoleic acid, alpha linolenic acid, long-chain n-3 fatty acids and trans fatty acid measured by FFQ and the corresponding adipose tissue levels were between 0.10 and 0.47.

CONCLUSION

The FFQ was able to distinguish meaningful differences in biochemical measurements of selected nutrients and presumably corresponding differences in the extremes of intake in African-American men with prostate cancer who were likely to be motivated to report accurately. However, the results found are similar to those found in other populations.

Validity of a food frequency questionnaire varied by age and body mass index

BACKGROUND AND OBJECTIVE

The validity of food frequency questionnaires (FFQs) in measuring food consumption and nutrient intake has to be assessed. The objective of this study was to assess the validity of a 128-item FFQ in specific subgroups of Finnish adults.

METHODS

The study included 294 subjects (137 men and 157 women). A 3-day food record was used as the reference method.

RESULTS

The mean intake of all nutrients except alcohol was higher measured with the FFQ than with the food records. In general, the Pearson correlations for energy adjusted nutrients between the FFQ and the food records were higher in women than in men. The correlations ranged from 0.14 (retinol) to 0.66 (fiber and alcohol) in men, and from 0.20 (long-chain n-3 fatty acids) to 0.70 (alcohol) in women. The results in subgroups showed that measuring nutrient intakes is more difficult among younger (30-50 years) women and overweight men and women than among others.

CONCLUSIONS

The study showed that the FFQ is a useful tool in epidemiologic studies in measuring the diet of Finnish adults given that the problems among specific subgroups are taken into account in interpretation.

Dietary genistein intake and cognitive performance in a multiethnic cohort of midlife women

OBJECTIVE

To examine the relationship between food frequency questionnaire estimated isoflavone intakes and cognitive performance.

DESIGN

The Study of Women's Health Across the Nation (SWAN), is a multiethnic, community based, longitudinal study of women aged 42 to 52 years at entry. Dietary isoflavone intakes were estimated from an interviewer-administered food frequency questionnaire at baseline. Intakes of genistein and daidzein were highly correlated (r = 0.98); therefore, analyses were conducted using genistein only. The SWAN includes white, African American, Hispanic, Chinese, and Japanese women; this analysis was performed only in the latter two ethnic groups because the others had minimal genistein intake (median, <4 microg/day). Cognitive function tests were measured at the fourth annual follow-up visit using the East Boston Memory Test (Immediate and Delayed), Symbol Digit Modalities Test, and Digit Span Backward Test. Ethnicity-specific general linear models were used to examine the relationship between each of these cognitive tests and energy-adjusted genistein intake controlling for age, menopause stage, ever-use of any hormones, and current use of any hormones.

RESULTS

Among 195 Japanese and women and 185 Chinese women, median intakes of genistein (mug/day) were 6,788 and 3,534, respectively. No associations between genistein intake and measures of cognitive performance were found in either ethnic group.

CONCLUSIONS

Our results did not support the hypothesis that genistein intake, at the levels consumed by the study sample, benefits cognitive performance. It also possible that the bioavailability of genistein in food sources is insufficient to exert a neurophysiological effect or that the potential effect of genistein is only manifest in low-estrogen states; the current study is not able to address these possibilities.

Assessment of a dietary questionnaire in cancer patients receiving cytotoxic chemotherapy

PURPOSE

Few studies have examined the influence of diet on survival and chemotherapy-associated toxicities in patients with cancer. Although several comprehensive dietary questionnaires have been validated and calibrated in healthy populations, similar studies have not been performed among cancer patients.

METHODS

Two hundred patients with colorectal, breast, or neuroendocrine cancer undergoing treatment with cytotoxic chemotherapy completed a self-administered, 131-item, semiquantitative food frequency questionnaire. Using the questionnaire, we calculated dietary intakes of carotenoids, tocopherols, and fatty acids, and correlated these values with relevant biomarkers measured in simultaneously collected plasma specimens.

RESULTS

The Pearson correlation coefficients for various carotenoids as measured by the questionnaire, with the corresponding measurements in plasma specimens, ranged from 0.33 to 0.44 (all P < .001), adjusted for total energy intake, body mass index, age, sex, smoking status, and total plasma cholesterol. Similarly, the adjusted correlation between self-reported total vitamin E intake and plasma alpha-tocopherol was 0.34 (P < .001). Correlations between questionnaire and plasma measurements of trans-fat, eicosapentaenoic acid, and docosahexaenoic acid were 0.55, 0.29, and 0.42 (all P < .001), respectively. These levels of correlation are consistent with those reported in similar studies of self-reported diet in otherwise healthy populations.

CONCLUSION

Among patients with cancer receiving cytotoxic chemotherapy, questionnaire-based measurements of various micronutrients and dietary factors appeared to predict meaningful differences in the corresponding measurements in plasma specimens. This dietary questionnaire could offer an informative and practical means for assessing the influence of diet in cancer patients receiving chemotherapy.

Dietary factors and risk of non-hodgkin lymphoma in men and women

BACKGROUND

The incidence of non-Hodgkin lymphoma (NHL) has increased worldwide in recent decades. Diet could influence NHL risk by modulating the immune system, although evidence is limited. We did a population-based case-control study to determine whether differences in diet were associated with NHL risk.

METHODS

A total of 597 NHL cases and 467 population controls in Sweden completed a semiquantitative food frequency questionnaire evaluating their dietary habits 2 years before the interview. Unconditional logistic regression was used to estimate the odds ratios (OR) and corresponding 95% confidence intervals (95% CI) for associations between food intake and risk of NHL.

RESULTS

High consumption of dairy products and fried red meat was associated with increased risk of NHL. The OR of NHL for individuals in the highest quartile compared with the lowest quartile of dairy intake was 1.5 (95% CI, 1.1-2.2; P(trend) = 0.003). The OR for the highest versus lowest quartile of fried red meat intake was 1.5 (95% CI, 1.0-2.1; P(trend) = 0.02). In contrast, high consumption of fruits and vegetables was associated with reduced risk of NHL, particularly follicular lymphoma, among women but not men. Compared with the lowest quartile of vegetable intake, the OR of follicular lymphoma among women in the highest quartile of vegetable intake was 0.3 (95% CI, 0.1-0.7; P(trend) = 0.002).

CONCLUSIONS

The positive associations of NHL risk with dairy products and fried red meat and the inverse association with fruits and vegetables suggest that diet affects NHL risk and could explain the increase of some histopathogic subtypes.

Alcohol intake and risk of dementia

OBJECTIVES

To examine the association between intake of alcoholic beverages and risk of Alzheimer's disease (AD) and dementia associated with stroke (DAS) in a cohort of elderly persons from New York City.

DESIGN

Cohort study.

SETTING

The Washington Heights Inwood-Columbia Aging Project.

PARTICIPANTS

Nine hundred eighty community-dwelling individuals aged 65 and older without dementia at baseline and with data on alcohol intake recruited between 1991 and 1996 and followed annually.

MEASUREMENTS

Intake of alcohol was measured using a semiquantitative food frequency questionnaire at baseline. Subjects were followed annually, and incident dementia was diagnosed using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria and classified as AD or DAS.

RESULTS

After 4 years of follow-up, 260 individuals developed dementia (199 AD, 61 DAS). After adjusting for age, sex, apolipoprotein E (APOE)-epsilon 4 status, education, and other alcoholic beverages, only intake of up to three daily servings of wine was associated with a lower risk of AD (hazard ratio=0.55, 95% confidence interval=0.34-0.89). Intake of liquor, beer, and total alcohol was not associated with a lower risk of AD. Stratified analyses by the APOE-epsilon 4 allele revealed that the association between wine consumption and lower risk of AD was confined to individuals without the APOE-epsilon 4 allele.

CONCLUSIONS

Consumption of up to three servings of wine daily is associated with a lower risk of AD in elderly individuals without the APOE epsilon-4 allele.

Validation of a semi-quantitative food-frequency questionnaire used among 12-month-old Norwegian infants

OBJECTIVE

To assess the validity of a semi-quantitative food-frequency questionnaire (SFFQ) used in a large nation-wide dietary survey among 12-month-old Norwegian infants.

METHODS

The SFFQ was administered to the parents about 1 week before the infants turned 12-month-old. The participants filled in the SFFQ and 1-2 weeks later they kept weighed food records for a total of 7 days. Both methods were completed for 64 infants.

RESULTS

The SFFQ overestimated energy intake with 25% and gave significantly higher estimates of all nutrients compared with the records, except for calcium. Much of the difference between the methods disappeared when nutrient density was compared. Spearman correlation coefficients between pairwise measurements of nutrient intakes from the food records and the SFFQ ranged from 0.18 for vitamin D to 0.72 for polyunsaturated fatty acid intake (median r=0.50). On average 38% of the infants were classified in the same quartile with the two methods, and 3% in the opposite quartile. The correlations for food items varied from 0.28 for sweetened drinks to 0.83 for commercial porridge (median r=0.62).

CONCLUSION

This study indicated that the SFFQ overestimates average absolute nutrient intakes. However, the questionnaire gave better estimates for average nutrient densities than for absolute nutrient intakes. The capability of the questionnaire to rank infants according to intake of nutrients and food items was moderate, but at the same level as others have observed with food-frequency questionnaires.

The internal validity of a dietary pattern analysis. The Framingham Nutrition Studies

STUDY OBJECTIVES

To examine the internal validity of a dietary pattern analysis and its ability to discriminate clusters of people with similar dietary patterns using independently assessed nutrient intakes and heart disease risk factors.

DESIGN AND PARTICIPANTS

Population based study characterising dietary patterns using cluster analysis applied to data from the semiquantitative Framingham food frequency questionnaire collected from 1942 women ages 18-76 years, between 1984-88.

SETTING

Framingham, Massachusetts.

MAIN RESULTS

Of 1942 women included in the cluster analysis, 1828 (94%) were assigned to one of the five dietary pattern clusters: Heart Healthy, Light Eating, Wine and Moderate Eating, High Fat, and Empty Calorie. Dietary patterns differed substantially in terms of individual nutrient intakes, overall dietary risk, heart disease risk factors, and predicted heart disease risk. Women in the Heart Healthy cluster had the most nutrient dense eating pattern, the lowest level of dietary risk, more favourable risk factor levels, and the lowest probability of developing heart disease. Those in the Empty Calorie cluster had a less nutritious dietary pattern, the greatest level of dietary risk, a heavier burden of heart disease risk factors, and a relatively higher probability of developing heart disease. Cluster reproducibility using discriminant analysis showed that 80% of the sample was correctly classified. The cluster technique was highly sensitive and specific (75% to 100%).

CONCLUSIONS

These findings support the internal validity of a dietary pattern analysis for characterising dietary exposures in epidemiological research. The authors encourage other researchers to explore this technique when investigating relations between nutrition, health, and disease.

Comparative validation of the Block, Willett, and National Cancer Institute food frequency questionnaires : the Eating at America's Table Study

Researchers at the National Cancer Institute developed a new cognitively based food frequency questionnaire (FFQ), the Diet History Questionnaire (DHQ). The Eating at America's Table Study sought to validate and compare the DHQ with the Block and Willett FFQs. Of 1,640 men and women recruited to participate from a nationally representative sample in 1997, 1,301 completed four telephone 24-hour recalls, one in each season. Participants were randomized to receive either a DHQ and Block FFQ or a DHQ and Willett FFQ. With a standard measurement error model, correlations for energy between estimated truth and the DHQ, Block FFQ, and Willett FFQ, respectively, were 0.48, 0.45, and 0.18 for women and 0.49, 0.45, and 0.21 for men. For 26 nutrients, correlations and attenuation coefficients were somewhat higher for the DHQ versus the Block FFQ, and both were better than the Willett FFQ in models unadjusted for energy. Energy adjustment increased correlations and attenuation coefficients for the Willett FFQ dramatically and for the DHQ and Block FFQ instruments modestly. The DHQ performed best overall. These data show that the DHQ and the Block FFQ are better at estimating absolute intakes than is the Willett FFQ but that, after energy adjustment, all three are more comparable for purposes of assessing diet-disease risk.

Assessing the accuracy of a food frequency questionnaire for estimating usual intake of phytoestrogens

The primary objective of this study was to assess the accuracy of a modified Block food frequency questionnaire (FFQ) with respect to its ability to assess usual dietary intakes of daidzein and genistein. Participants were a convenience sample of 51 Japanese and 18 Caucasian women. All interviews were conducted between February 1997 and October 1997. At each of the four study visits, participants provided a 24-hour urine specimen and a 48-hour dietary recall. At the first visit, participants also completed an interviewer-administered modified Block FFQ. The daidzein and genistein intakes estimated using the FFQ were moderately correlated with the mean estimates of daidzein and genistein intake calculated from four 48-hour dietary recalls (correlation for daidzein = 0.49-0.58 and correlation for genistein = 0.45-0.54) and estimates of urinary concentrations of these compounds calculated from four collections (correlations for daidzein and genistein = 0.49 and 0.30, respectively). The accuracy of the modified Block FFQ for assessment of usual daidzein and genistein intakes is supported by this study. These results support the use of this instrument in epidemiological studies as an easy and low-cost method to assess the usual dietary daidzein or genistein intake.

Use of biological markers to validate self-reported dietary intake in a random sample of the European Prospective Investigation into Cancer United Kingdom Norfolk cohort

BACKGROUND

The validity of dietary assessment methods should be established before diet-disease associations are reported.

OBJECTIVE

Our objective was to validate a 7-d food diary and a food-frequency questionnaire (FFQ) against independent biomarkers of intake in urine (nitrogen, potassium, and sodium) and blood (plasma ascorbic acid).

DESIGN

A total of 146 healthy middle-aged men and women were recruited from the European Prospective Investigation into Cancer UK Norfolk cohort, a free-living cohort of approximately 25000 persons. Over a 9-mo period, urinary nitrogen, potassium, and sodium were estimated from 2-6 complete 24-h urine collections in 134 subjects and plasma ascorbic acid was estimated from 2-3 fasting blood samples in 118 subjects. Subjects completed 2 FFQs and two 7-d food diaries.

RESULTS

In men and women combined, correlations between 24-h urinary nitrogen excretion and dietary intake from the 7-d food diary were high (r = 0.57-0.67) compared with those for the FFQ (r = 0.21-0.29). Similarly, correlations between urinary potassium and dietary potassium were higher for the 7-d food diary (r = 0.51-0.55) than for the FFQ (r = 0.32-0.34). There was no overall difference in correlations between plasma ascorbic acid and dietary vitamin C between the 7-d food diary (r = 0.40-0.52) and the FFQ (r = 0.44-0.45).

CONCLUSIONS

These data indicate that, despite increased subject burden, the 7-d food diary provided a better estimate of nitrogen and potassium intakes than did the FFQ in this study population. However, with respect to plasma ascorbic acid, both the FFQ and 7-d food diary provided a similar ranking of subjects according to vitamin C intake.

Alcohol consumption and risk of prostate cancer: The Harvard Alumni Health Study

BACKGROUND

Although many studies suggest that consumption of alcohol increases the risk of several site-specific cancers, the evidence remains unclear for prostate cancer. Few data exist on beverage-specific associations as well as lifetime patterns of alcohol consumption and prostate cancer risk.

METHODS

We prospectively followed 7612 Harvard alumni (mean age 66.6 years) from 1988 through 1993, during which 366 cases of incident prostate cancer occurred. Self-reported alcohol consumption was assessed at baseline from wine, beer, and liquor intake. Previous assessments during college and in 1977 were also available.

RESULTS

Overall, the mean total alcohol consumption in 1988 was 123.1 g/week, of which 28.6% was from wine, 15.8% from beer, and 55.6% from liquor. Compared to men reporting almost never drinking alcohol in 1988, the multivariate relative risks (95% CI) for 1 drink/month to < 3 drinks/week, 3 drinks/week to < 1 drink/ day, 1 to < 3 drinks/day, and > or = 3 drinks/day were 1.33 (0.88-2.01), 1.65 (1.12-2.44), 1.85 (1.29-2.64), and 1.33 (0.86-2.05), respectively. Wine or beer consumption was unassociated with prostate cancer; however, moderate liquor consumption was associated with a significant 61-67% increased risk of prostate cancer (P, non-linear trend < 0.001). Men initiating alcohol consumption between 1977 and 1988 had a twofold increased risk of prostate cancer compared to men with almost no alcohol consumption at both times.

CONCLUSIONS

In contrast to the majority of previous studies, we found a positive association between moderate alcohol consumption and the risk of prostate cancer. Liquor, but not wine or beer, consumption was positively associated with prostate cancer.

If you drink alcoholic beverages do so in moderation: what does this mean?

The changes in content of the alcohol guideline of the various editions of the Dietary Guidelines for Americans from 1980 to 2000 are discussed. This is followed by a capsule summary of the history and evolution of the discipline of alcohol epidemiology compared with that of nutrition epidemiology. Methods of assessment are discussed, and issues surrounding the validity and reliability of self-report of alcohol consumption are then outlined. Relevant objectives from Healthy People 2010 are discussed. Surveillance of the alcohol guideline discloses that, at present, very few American drinkers follow the recommendations of the alcohol guideline. Indications for future research needs to address this issue conclude the discussion.

Differences and trends in antioxidant dietary intake in smokers and non-smokers, 1980-1992: the Minnesota Heart Survey

PURPOSE

Differences and secular trends in dietary antioxidant vitamin intake (vitamins E, C, and beta-carotene) in current non-smokers, light smokers, and heavy smokers were examined as part of the Minnesota Heart Survey.

METHODS

Three cross-sectional surveys were conducted in adults ages 25-74 years in 1980-82 (N = 1682), 1985-87 (N = 2326), and 1990-92 (N = 2487). Dietary information was obtained from a 24-hour dietary recall. Smoking was assessed through self-report. Intakes were adjusted for age, energy intake, body mass index, education level, and exercise level (vitamins E, C and beta-carotene).

RESULTS

Antioxidant vitamin intakes were significantly higher in non-smokers than in light (1-20 cig/day) and heavy smokers (>20 cig/day) when all three survey periods were combined. In men, mean vitamin E intake was 9.2 mg, 8.6 mg, and 7.8 mg for non-smokers, light smokers, and heavy smokers, respectively. Results were similar in men for beta-carotene (non-smokers 1408 microg, light smokers 1287 microg, and heavy smokers 1064 microg), and vitamin C (non-smokers 81 mg, light smokers 67 mg, and heavy smokers 56 mg). Women had results of similar magnitude and direction. From 1980-92, secular trends in men showed non-significant increases from 1980-82 to 1990-92 in beta-carotene (+6.1%), while decreases were observed in vitamins E (-1.1%) and C (-2.6%). In contrast, women had large decreases in all antioxidant vitamin intakes: vitamin E (-13%), vitamin C (-18.6%), and beta-carotene (-16.2%).

CONCLUSIONS

Light and heavy smokers had a significantly lower overall mean dietary antioxidant vitamin intake than non-smokers. Over the decade, antioxidant dietary intake remained relatively stable in men and decreased in women in Minneapolis-St. Paul, despite improvements in access to antioxidant rich fruits and vegetables.

Validation of the American Cancer Society Cancer Prevention Study II Nutrition Survey Cohort Food Frequency Questionnaire

We assessed the validity and reproducibility of a self-administered 68-item food frequency questionnaire completed in 1992-1993 by approximately 185,000 adults. Four hundred forty-one participants completed four 24-hour dietary recall interviews over a 1-year period and a repeat administration of the food frequency questionnaire. For 20 nutrients and 10 food groups, measured nutrient intakes, but not food group intakes, were consistently lower by food frequency questionnaire than by recall. Energy-adjusted, attenuation-corrected Pearson validity correlations ranged from 0.12 to 0.80, with a median of 0.58. Reproducibility measures were generally high, with a median of 0.69. The food frequency questionnaire performed similarly to food frequency questionnaires used in other cohort studies, indicating similar ability to examine diet-disease relations.

Genetic and behavioral determinants of waist-hip ratio and waist circumference in women twins

OBJECTIVES

This study examines genetic and behavioral determinants of waist-hip ratio (WHR) and waist circumference among women twins.

RESEARCH METHODS AND PROCEDURES

Six hundred eighty participants from the second examination of the Kaiser-Permanente Women Twins Study (1989 to 1990) were included. Women ranged in age from 31 to 90 years, and included 59% monozygotic and 41% dizygotic twins. Heritabilities of WHR and waist circumference were estimated (range=0 to 1) using three different statistical methods. Linear regression models that adjusted for the lack of independence within twin pairs were used to assess associations between behavioral variables, WHR, and waist circumference.

RESULTS

Age and body mass index-adjusted heritability estimates ranged from 0.36 to 0.61 for WHR and 0.72 to 0.82 for waist circumference. When considered individually, after adjusting for age and body mass index, all behavioral characteristics, except calorie-adjusted fat intake, were significantly (p<0. 10) associated with waist circumference and WHR. Greater central adiposity was associated with lower education, higher alcohol consumption, lower physical activity, current cigarette smoking, higher parity, and postmenopausal status without hormone replacement therapy. In multivariate models, these associations persisted, except neither educational attainment nor alcohol intake was significantly associated with waist circumference. In longitudinal analyses, both measures were positively associated with current or recent-past smoking; infrequent or inconsistent physical activity; and long-term, daily consumption of alcohol.

DISCUSSION

These cross-sectional and longitudinal associations are consistent with genetic and behavioral predictors of waist circumference and WHR. Whereas the evidence for genetic influences is stronger for waist circumference, both body fat measures may be similarly influenced by the behavioral factors considered.

A three-day weighed food record and a semiquantitative food-frequency questionnaire are valid measures for assessing the folate and vitamin B-12 intakes of women aged 16 to 19 years

The purpose of this study was to validate a food-frequency questionnaire (FFQ) and a 3-d weighed food record (3d-WFR) by comparing nutrient intakes estimated using these methods with serum folate, RBC folate and serum vitamin B-12 concentrations in 105 females aged 16-19 y. During an early morning clinic visit, subjects completed a self-administered, 116-item FFQ, blood was collected and they were trained to complete a 3d-WFR. Folate intakes as determined by the 3d-WFR (r = 0.65, P < 0.01) exhibited a stronger association with serum folate than did intakes from the FFQ (r = 0.48, P < 0.01) (P = 0.017). The correlations between folate intakes and RBC folate as determined by the FFQ (r = 0.42, P < 0.01) and 3d-WFR (r = 0.50, P < 0.01) methods did not differ. Vitamin B-12 intakes showed only a modest association with serum vitamin B-12 when supplement users were included in the analyses (FFQ, r = 0.25, P < 0.05; 3d-WFR, r = 0.32, P < 0.05). After excluding supplement users from the analyses, the relationship between vitamin B-12 intakes as determined by FFQ and serum vitamin B-12 was no longer significant. Median daily folate intakes (346 vs. 212 microgram) and vitamin B-12 (4.9 vs. 1.9 microgram) estimated from the FFQ were higher than those obtained from the 3d-WFR. In sum, these data suggest that both the FFQ and 3d-WFR are valid measures of assessing the folate intake of young women, and both appear to be useful in determining vitamin B-12 intake when supplemental users are included. The markedly different conclusions about absolute folate and vitamin B-12 intakes obtained using these two dietary methodologies should be taken into consideration when making recommendations about optimal folate intakes in relation to disease prevention.

Validity and reproducibility of a self-administered food frequency questionnaire in older people

This study assesses the validity and reproducibility of a 145-item self-administered food frequency questionnaire (FFQ) in a representative older population aged 63 to 80. Semi-quantitative FFQs were completed by 89% of 3,654 residents attending a community-based eye study in Sydney, Australia. The FFQ's validity was assessed against three, four-day weighed food records (WFRs) completed four months apart by 79 people. A further 152 subjects completed a repeat FFQ about a year after the baseline FFQ, of whom 131 completed a second repeat FFQ about six weeks later. Both short and long-term reproducibility of the FFQ were assessed using data from these subjects. Comparison of the FFQ with the average of the three, four-day weighed food records resulted in energy-adjusted Spearman correlations above 0.5 for most of the nutrients. The proportion of subjects correctly classified to within one quintile category for each nutrient intake ranged from 57% for zinc to 82% for vitamin C. with most nutrients correctly classified within one quintile for about 70% of subjects. Quadratic weighted kappas were reasonable, between 0.3 and 0.5 for most nutrients. The FFQ was highly reproducible in the short term, with correlations for most nutrients about 0.70 to 0.80 and acceptably reproducible in the longer term, with correlations mostly 0.60 to 0.70. The results verify that it is possible to use relatively simple, but comprehensive, self-administered FFQs to study nutrient exposures in large-scale epidemiological studies of the elderly and to expect reasonably high FFQ response rates.

Telephone vs face-to-face interviews for quantitative food frequency assessment

OBJECTIVE

To develop and test a quantitative food frequency method for administration by telephone.

DESIGN

A comparison study of telephone and face-to-face interviews was conducted among a representative sample of the five major ethnic groups in Oahu, Hawaii. Two interviews were administered 4 to 6 months apart by trained interviewers using identical questionnaires and color photographs of food items showing three different portion sizes. The order of the interviewing methods was randomly assigned. The questionnaire included 115 food items selected to estimate 80% or more of usual dietary intakes. Frequencies and quantities of each item consumed during the past year were obtained.

SUBJECTS/SETTING

Subjects were recruited from the Health Surveillance Program of the Hawaii State Department of Health and consisted of 167 men and 158 women, aged 45 to 74 years, who provided a telephone number. Eighty percent of the face-to-face interviews were conducted in the subjects' homes and 20% were conducted at the workplace or the University of Hawaii Cancer Research Center, if requested.

STATISTICAL ANALYSES

The paired t test was used to compare the mean daily intakes obtained by the telephone and face-to-face methods. Agreement was measured by the intraclass correlation coefficient (ICC), Pearson correlation coefficient and weighted kappa statistic.

RESULTS

The means of energy and each nutrient were slightly higher in the first interview than the second, regardless of the interviewing method. Because of close correspondence among all 3 statistical measures of agreement, only the ICCs are reported. The ICCs ranged from .61 for protein and vitamin A to .69 for dietary cholesterol among men, and from .61 for vitamin C to .74 for saturated fat among women. Agreement was not significantly affected by age, gender, ethnicity, order of interview, or educational level.

APPLICATIONS

Telephone interviews to obtain quantitative food frequencies are cost-efficient methods for estimating usual dietary intakes among persons in widely scattered geographic areas. Photographs of the foods in 3 portion sizes mailed in advance help the respondents estimate amounts eaten.

Reproducibility and validity of a food frequency questionnaire in European and Polynesian New Zealanders

The reproducibility and validity of a self-administered 142-item food-frequency questionnaire (FFQ) was assessed in a population comprising 124 European and 52 Polynesian (17 Maori and 35 Pacific Island) New Zealanders aged 40-65 years. Reproducibility correlation coefficients, determined by administration of the same questionnaire on two occasions 3 years apart, were higher in European than Maori and Pacific Island participants, ranging from 0.47 to 0.87 in Europeans (median 0.66) and from 0.41 to 0.79 in Maori and Pacific Island people (median 0.44). In general, there were no significant differences in mean nutrient intakes calculated from the two FFQs by Europeans or Maori and Pacific Island participants despite their cultural and language differences. When the FFQ was compared with a 3-day food diary in a subsample of 101 Europeans, 15 Maori and 22 Pacific Islanders, the validity was good for most nutrients, with overestimation of a few nutrients in each ethnic group. Correlation coefficients between the 3-day food diary and FFQ ranged from 0.41 to 0.81 in Europeans (median 0.48) and from 0.36 to 0.56 in Maori and Pacific Island people (median 0.55). Ratios of energy intake to resting metabolic rate suggested that Maori and Pacific Island people were more likely to underestimate their habitual energy intake by the 3-day diet diary method compared to Europeans, but that Europeans were more likely to underestimate total energy intake by the food frequency method and Pacific Island participants to overestimate it. Obese Europeans and Maori were more likely to under-report dietary intakes by the 3-day diary method. We conclude that our FFQ performed better in European than Maori and Pacific Island participants.

Obesity as a major determinant of underreporting in a self-administered food frequency questionnaire: results from the EPIC-Potsdam Study

The phenomenon of underreporting of dietary intake has been observed previously in many epidemiologic studies. In this study it was investigated whether dependencies exist between energy intake obtained by a semi-quantitative, self-administered food frequency questionnaire and lifestyle or anthropometric factors, particularly obesity. The study population consisted of 2,531 subjects, men aged 40 to 64 years and women aged 35 to 64 years from the general population of Potsdam and the surrounding areas. First, subjects were allocated into quintiles of the ratio 'reported energy intake (EI)' to 'calculated basal metabolic rate (BMR)' as a measure of age and weight adjusted energy intake. No apparent dependencies between socio-economic variables and the ratio EI/BMR were observed. Among anthropometric variables, BMI and related measures of obesity were inversely related to the ratio EI/BMR in men and women. While dietary intake was directly related to the ratio EI/BMR in absolute quantities, energy adjusted intake of fat, protein, carbohydrate, and alcohol was found to be independent of this ratio. Energy adjusted food group consumption was also found to be independent of the ratio EI/BMR, showing only slightly increasing trends across quintiles of EI/BMR for cereals and fats, and a slightly decreasing trend for sweet foods in women. When subjects were classified into three categories of BMI, reported energy intake decreased across categories. Estimated energy expenditure based on BMR was increasing with BMI categories. A close direct relationship was observed between BMI categories and the difference between reported energy intake and estimated energy expenditure. It is concluded that obesity is a major determinant of under-reporting. Energy adjusted dietary variables were found to be largely independent of such methodological influences.