Validity and reliability of an omega-3 fatty acid food frequency questionnaire for first-generation Midwestern Latinas

This study tested the hypothesis that a culturally developed omega-3 (n-3) fatty acid food frequency questionnaire (FFQ) could be an accurate instrument to capture n-3 fatty acid food intakes of first-generation Midwestern Latinas. The goal of the study was to assess validity and test-retest reliability of an FFQ to estimate total n-3 fatty acid (total n-3), α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) intakes. An n-3 FFQ was developed and pilot tested. Two FFQs and 3 nonconsecutive 24-hour recalls were collected from 162 participants. Pearson correlation and paired t test were used to test the hypothesis. Correlation of the 2 FFQs was 0.71 for total n-3, 0.65 for ALA, 0.74 for EPA, and 0.54 for DHA (P < .01). The means of the 2 FFQs and of the 24-hour recalls were not significantly different for total n-3 and ALA (P > .05), but were significantly different for EPA and DHA. The n-3 FFQ had acceptable reliability, validated only total n-3 and ALA, and provided relevant findings about the n-3 eating habits of Midwestern Latinas.     

Biomarker and dietary validation of a Canadian food frequency questionnaire to measure eicosapentaenoic and docosahexaenoic acid intakes from whole food, functional food, and nutraceutical sources

BackgroundCanadian dietary sources of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) include marine and non-marine whole foods, functional foods, and nutraceuticals.Objective/designIn the present study, these sources were incorporated into a nutrient-specific, semi-quantitative food frequency questionnaire (FFQ) and the ability to measure the EPA and DHA intakes of Canadian adults was assessed. Specifically, the EPA and DHA intakes estimated by FFQ of 78 men and women, 20 to 60 years of age, were compared with EPA and DHA measurements from 3-day food records and measures of EPA and DHA in fasting whole blood.ResultsMean (±standard deviation) and median intakes of EPA+DHA were 0.34±0.34 and 0.21 g/day by FFQ and 0.47±0.71 and 0.13 g/day by food record, with no significant differences between mean intakes (P=0.93). The FFQ provided higher estimates than the food record at low intakes of EPA and DHA and lower estimates at high intakes based on Bland-Altman plots. The FFQ was moderately correlated with food record (r=0.31 to 0.49) and with blood biomarker measures of EPA and DHA (r=0.31 to 0.51). Agreement analysis revealed that 42% of participants were classified in the same and 77% into same or adjacent quartile when EPA and DHA intake was assessed by food record and by FFQ. Similar quartile agreement was found for EPA and DHA intakes by FFQ with blood biomarker EPA and DHA. The range of the validity coefficients, calculated using the method of triads, was 0.43 to 0.71 for FFQ measurement of EPA+DHA.ConclusionsThe FFQ is an adequate tool for estimating usual EPA and DHA intakes and ranking Canadian adults by their intakes.     

Relative Validity and Reproducibility of a Food Frequency Questionnaire to Assess Food Group Intake in Pregnant Jordanian Women

BackgroundResearch on the relationship between maternal diet and pregnancy outcomes requires valid dietary assessment tools in pregnancy.ObjectiveThis study aimed to develop and examine the relative validity and reproducibility of a quantitative food frequency questionnaire (FFQ) to estimate food group intake in a sample of pregnant Jordanian women.DesignIn this validation study, food group intake from a culturally sensitive quantitative FFQ was compared with food group intake from three 24-hour dietary recalls.Participants and settingThe validation study was conducted from 2015 to 2017 at the maternity clinics in Jordan University Hospital among 131 healthy singleton pregnant Jordanian women. Of these women, 30 also took part in the reproducibility phase, which involved repeated completion of the FFQ in a time frame of 1 month. Pregnant women who had gestational diabetes, preeclampsia, and chronic diseases were excluded.Main outcome measuresRelative validity and reproducibility of a 117-item quantitative FFQ used to estimate usual food intake over a period of 1 month.Statistical analyses performedIntraclass correlation coefficients and weighted κ statistics were calculated to test the reproducibility between the two administrations of the FFQ. Pearson correlations were estimated to validate the FFQ against 24-hour dietary recalls. Cross-classification and Bland-Altman plots were used to examine the agreement between the two dietary assessment methods.ResultsThe intraclass correlation coefficients between the two FFQs ranged from 0.24 for legumes to 0.93 for processed meats. A moderate level of agreement was observed between two FFQs. De-attenuated and energy-adjusted correlations ranged from 0.08 for sweets and sugar to 0.93 for sugary drinks. On average, 50.9% and 45.2% of participants were classified by the FFQ and the 24-hour dietary recalls into the same quartile based on their crude and energy-adjusted food group intake, respectively. Bland-Altman plots showed satisfactory agreement between two methods for most food groups.ConclusionsThe FFQ showed moderate reproducibility and good relative validity for most food groups.     

Reproducibility of a food frequency questionnaire: Korea Nurses' Health Study

BACKGROUND/OBJECTIVESThis study aimed to examine the reproducibility of food frequency questionnaires (FFQs) designed for young female nurses in the Korea Nurses'' Health Study.SUBJECTS/METHODSThe reproducibility of web-based, self-administered FFQs was evaluated among 243 Korean female nurses. The first FFQ (FFQ1) was administered from March 2014 to February 2019 and the second FFQ (FFQ2) from November 2019, with a mean interval of 2.8 years between the FFQs (range, 9 months–5.6 years). Pearson and Spearman correlation coefficients (r values) and quartile agreements between FFQ1 and FFQ2 were calculated for intakes of energy, nutrients, and foods.RESULTSPearson correlation coefficients ranged from 0.41 to 0.55 (median r = 0.51) for energy and raw nutrients and from 0.16 to 0.46 (median r = 0.36) for energy-adjusted nutrients. Spearman correlation coefficients ranged from 0.25 to 0.72 (median r = 0.41) for food items. The percentages of women who were classified into the same or adjacent quartile were 77% to 84% (median = 82%) for raw nutrients and 69% to 86% (median = 78%) for foods.CONCLUSIONSThe results indicated that the web-based FFQ used in the Korea Nurses'' Health Study has acceptable reproducibility.     

Evaluation of a Quantitative Food Frequency Questionnaire for 5-Year-Old Children in an Asian Population

BackgroundFood frequency questionnaires (FFQs) are often used to assess dietary intakes due to their ability to assess intake over extended periods, their low respondent burden, and their cost-effectiveness. A quantitative FFQ that includes locally appropriate food items for 5-year-old children in a multiethnic Asian population was developed, but its validity has not previously been evaluated.ObjectiveTo evaluate the relative validity of a newly developed FFQ as a dietary assessment tool for 5-year-old children in a multiethnic Asian population.DesignThe 112 –food item FFQ was administered by trained interviewers to caregivers of children. Frequency of food items consumed in the previous month and portion size information were collected. The FFQs were evaluated against 3-day nonweighed diet records (DRs) completed by caregivers.Participants/settingThe dietary data of 361 children aged 5 years from the Growing Up in Singapore Towards Healthy Outcomes mother-offspring cohort were collected in 2015-2016.Main outcome measuresNutrients of interest included energy, macronutrients, fiber, cholesterol, vitamin A, beta carotene, calcium, and iron, calculated from the FFQs and DRs.Statistical analyses performedNutrient intakes according to FFQs in relation to DRs were assessed using Pearson’s correlation, Lin’s concordance, Bland-Altman plots, quintile joint classification, and Cohen’s κ statistics.ResultsThe highest energy-adjusted correlation (Pearson’s r=0.71) and concordance (Lin’s concordance=0.69) were observed for calcium. Fiber, saturated fat, polyunsaturated fatty acids (PUFA), cholesterol, and iron also showed correlation coefficients and concordance of at least 0.40. Bland-Altman plots suggested no substantial bias across ranges of intakes for the nutrients with correlations and concordance of 0.40 or above. Quintiles joint classification showed substantial agreement for calcium (κ=0.66), and moderate agreement for iron, fiber, saturated fat, polyunsaturated fat, and beta carotene (κ=0.59, 0.54, 0.49, 0.44, 0.43, respectively).ConclusionsThe newly developed FFQ is in reasonable agreement with DR for estimating intakes of calcium, fiber, saturated fat, PUFA, cholesterol, and iron. In addition, the FFQ is able to classify children according to quintiles of nutrient intakes, with moderate to substantial quintile agreements between FFQ and DR for calcium, iron, fiber, saturated fat, PUFA, and beta carotene. To assess the remaining nutrients, DR method is recommended instead of the FFQ.     

Assessing long-chain ω-3 polyunsaturated fatty acids: A tailored food-frequency questionnaire is better

ObjectivePolyunsaturated fatty acids (PUFAs), including the long-chain (LC) ω-3 PUFAs, are important for health. The aim was to assess if the Anti-Cancer Council of Victoria Dietary Questionnaire (ACC DQ) accurately determines PUFA intakes compared with the recently validated electronic PUFA food-frequency questionnaire (FFQ).MethodsForty-one study volunteers were recruited from the local Illawarra region of New South Wales, Australia. The method of triads was used to determine validity coefficients by comparing the ACC DQ intakes against a 3-d weighed food record and appropriate blood biomarkers (erythrocytes and plasma fatty acids). These validity coefficients were subsequently compared with previously published validity coefficients from the PUFA FFQ.ResultsUsing erythrocytes as the biomarker, the electronic PUFA FFQ had much higher validity coefficients compared with the ACC DQ for eicosapentaenoic acid (0.92 versus 0.19), docosahexaenoic acid (0.69 versus 0.26), and total LC ω-3 PUFAs (0.78 versus 0.23), respectively, whereas ω-6 PUFAs were comparable. Using plasma as the biomarker, the electronic PUFA FFQ had much higher validity coefficients compared with the ACC DQ for α-linolenic acid (0.96 versus 0.49), eicosapentaenoic acid (0.87 versus 0.19), docosahexaenoic acid (0.64 versus 0.24), and total LC ω-3 PUFAs (0.73 versus 0.21), respectively, whereas ω-6 PUFAs were comparable.ConclusionThe validated electronic PUFA FFQ is better suited to determine ω-3 PUFA intakes than the ACC DQ.     

Validation of a FFQ to estimate the intake of PUFA using plasma phospholipid fatty acids and weighed foods records

Due to the growing knowledge about the role of specific fatty acids in health and disease, dietary intake measurements of individual fatty acids or classes of fatty acids are becoming increasingly important. The objective of this study was to evaluate the ability of the Nambour FFQ to estimate intakes of specific fatty acids, particularly PUFA. The study population was a sub-sample of adult participants in a randomised controlled trial of beta-carotene and sunscreen in the prevention of skin cancer (n 43). Dietary intake was assessed by a self-administered FFQ and a weighed food record (WFR). Non-fasting blood samples were collected and analysed for plasma phospholipid fatty acids. Median intakes on the FFQ were generally higher than the WFR except for the n-3 PUFA groups, where the FFQ estimated higher intakes. Correlations between the FFQ and WFR were moderate (r 0 x 32-0 x 59) except for trans fatty acids (r 0 x 03). Correlations between each of the dietary assessment methods and the plasma phospholipids were poor for all fatty acids other than the PUFA. Using the methods of triads approach, the FFQ validity coefficients for total n-3 fatty acids, total long chain n-3 fatty acids, EPA, arachidonic acid, docosapentaenoic acid and DHA were 0 x 50, 0 x 63, 0 x 45 and 0 x 62 and 0 x 62, respectively. For most fatty acids, the FFQ adequately estimates group mean fatty acid intakes and can adequately rank individuals; however, the ability of this FFQ to estimate trans fatty acids was poor.     

Validation of a food frequency questionnaire to assess intake of n-3 polyunsaturated fatty acids in subjects with and without major depressive disorder

The role of n-3 polyunsaturated fatty acids (PUFAs) in psychiatric illness is a topic of public health importance. This report describes development and biomarker validation of a 21-item, self-report food frequency questionnaire (FFQ) intended for use in psychiatric research to assess intake of α-linolenic acid (18:3n-3 [ALA]), docosahexaenoic acid (22:6n-3 [DHA]), and eicosapentaenoic acid (20:5n-3 [EPA]). In a cross-sectional study conducted from September 2006 to September 2008, sixty-one ethnically diverse adult participants with (n=34) and without (n=27) major depressive disorder completed this n-3 PUFA FFQ and provided a plasma sample. Plasma levels of n-3 PUFAs EPA and DHA, and n-6 PUFA arachidonic acid (20:4n-6 [AA]) were quantified by gas chromatography. Using Spearman's ρ, FFQ-estimated intake correlated with plasma levels of DHA (r=0.50; P<0.0001) and EPA (r=0.38; P=0.002), but not with ALA levels (r=0.22; P=0.086). Participants were classified into quartiles by FFQ-estimated intake and plasma PUFA concentrations. Efficacy of the FFQ to rank individuals into same or adjacent plasma quartiles was 83% for DHA, 78.1% for EPA, and 70.6% for ALA; misclassification into extreme quartiles was 4.9% for DHA, 6.5% for EPA, and 8.2% for ALA. FFQ-estimated EPA intake and plasma EPA were superior to plasma AA levels as predictors of the plasma AA to EPA ratio. This brief FFQ can provide researchers and clinicians with valuable information concerning dietary intake of DHA and EPA.     

A Review of Food Frequency Questionnaires Developed ?and Validated in Japan

Background

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

Methods

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

Results

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

Conclusion

FFQs are useful for assessing dietary intake in Japan, although careful consideration is required for the food groups and nutrients for which FFQs had low validity.Key words: food frequency questionnaire, validity, reproducibility, nutrient, food group     

Using the method of triads in the validation of a food frequency questionnaire to assess the consumption of fatty acids in adults

Background

It is of great value to develop valid instruments to estimate food consumption; for this purpose, the triads method has been applied in validation studies of dietary intake to evaluate the correlation between three measurements [food frequency questionnaire (FFQ), reference method and biomarker]. The main aim of the present study was to validate a FFQ for Brazilian adults by means of the method of triads by estimating the ingestion of total fatty acids based on the level of saturation.

Methods

The present study enrolled 152 Brazilian adults of both sexes, who were residents in the city of Viçosa, Brazil. The ingestion of total saturated, monounsaturated, polyunsaturated, trans, linoleic and linolenic fatty acids was assessed by means of a FFQ, two food records, and biomarkers, which were detected by gas chromatography. The validation coefficients were calculated using the method of triads and concordance was determined by Kappa statistics.

Results

The FFQ was considered an adequate dietary method, because, based on the validation coefficients, it estimates the intake of total fat (0.84), as well as linolenic (0.90) and linoleic acids (0.31). A high concordance rate was confirmed for all nutrients assessed by the FFQ and food records. Regarding the biomarkers, linolenic acid and linoleic acid presented greater concordance.

Conclusions

According to the validation coefficients, the FFQ precisely estimated total fat, linolenic acid and linoleic acid contents.     

Maternal fat intake during pregnancy and wheeze and eczema in Japanese infants: the Kyushu Okinawa Maternal and Child Health Study

PurposeThis cohort study examined the relationship between maternal intake of individual fatty acids, meat, and fish during pregnancy and the risk of wheeze and eczema in children aged 23–29 months because epidemiologic evidence on this topic is inconclusive.MethodsSubjects were 1354 Japanese mother-child pairs. Data on maternal intake during pregnancy were assessed with a validated diet history questionnaire. Data on symptoms of wheeze and eczema were based on criteria of the International Study of Asthma and Allergies in Childhood.ResultsSignificant inverse exposure-response relationships were observed between maternal intake of eicosapentaenoic acid (EPA) and EPA plus docosahexaenoic acid (DHA) during pregnancy and infantile wheeze although the adjusted odds ratios between extreme quartiles fell just short of the significance level. No such inverse relationships were detected for infantile eczema. Maternal intake of total fat, saturated fatty acids, monounsaturated fatty acids, total n-3 polyunsaturated fatty acids (PUFA), α-linolenic acid, DHA, total n-6 PUFA, linoleic acid, arachidonic acid, cholesterol, fish, and meat and the ratio of n-3 to n-6 PUFA consumption were not significantly related to infantile wheeze or eczema.ConclusionsHigher maternal intake of EPA and EPA plus DHA during pregnancy may reduce the risk of infantile wheeze.     

Repeatability and validity of a food frequency questionnaire in free-living older people in relation to cognitive function

Objectives: To determine the repeatability and validity of a self-administered, 175-item food frequency questionnaire (FFQ) in free-living older people and to assess whether these are influenced by cognitive function.Participants and setting: 189 free-living people aged 64–80y were recruited from participants in a previous study.Design: To assess repeatability, 102 (52M, 50F) participants completed the FFQ on two occasions three months apart. To assess validity, another 87 participants (44 M, 43 F) completed the FFQ and a four-day weighed diet record three months later. 25 nutrients were studied.Results: For repeatability, Spearman rank correlation coefficients were above 0.35 (p<0.05) for all nutrients. Cohen’s weighted Kappa was above 0.4 for all nutrients except starch, riboflavin, retinol, β-carotene, and calcium. There were no substantial differences in correlation coefficients between sub-groups divided by short-term memory test score. There was no clear pattern for correlation coefficients in sub-groups divided by executive function test score. For validity, the Spearman rank correlation coefficients were above 0.2 (p<0.05) for all nutrients except fat, mono-unsaturated fatty acids, niacin equivalents and vitamin D, and Cohen’s weighted kappa was above 0.4 for alcohol and was above 0.2 for 13 other nutrients. Participants in the lowest-score groups of short-term memory and executive function had the lowest median Spearman correlation coefficient.Conclusions: The FFQ had reasonable repeatability and validity in ranking nutrient intakes in this population though the results varied between nutrients. Poor short-term memory or executive function may affect FFQ validity in ranking nutrient intakes.     

Validation of an Australian electronic food frequency questionnaire to measure polyunsaturated fatty acid intake

Objective

To develop and validate a simple non-invasive method that estimates the intakes of omega-3 and omega-6 polyunsaturated fatty acids (PUFA) in a healthy adult population.

Methods

A new electronic PUFA food frequency questionnaire (FFQ) was validated by comparison with a 3-d weighed food record and blood biomarkers (erythrocytes and plasma) using the method of triads model and tested for reproducibility. Healthy subjects were recruited from the local Illawarra Region, New South Wales, Australia.

Results

The PUFA FFQ adequately estimated intakes for eicosapentaenoic acid, docosahexaenoic acid, total long chain omega-3 PUFA, linoleic acid, total omega-6 PUFA, and total PUFA, which were comparable with results from the 3-d food record. Eicosapentaenoic acid, docosahexaenoic acid, and total long chain omega-3 showed high validity coefficients for erythrocytes (and plasma) 0.92 (0.87), 0.69 (0.64), and 0.78 (0.73) (P < 0.05), respectively. Spearman’s rank correlation coefficients ranged from 0.48 to 0.76 when the PUFA FFQ was tested for reproducibility (P < 0.05).

Conclusion

The electronic PUFA questionnaire was found to be reproducible and is a valid tool to assess PUFA intakes in a healthy adult population.     

A valid semiquantitative food frequency questionnaire to measure fish consumption

OBJECTIVE: To validate a detailed semiquantitative food frequency questionnaire designed to measure habitual fish and seafood consumption. DESIGN: Cross-sectional validation study using an independent biomarker of fish consumption. SETTING: Perth metropolitan area, Western Australia. SUBJECTS: Ninety-one healthy volunteers of both sexes aged 21-75 years. METHODS: Participants completed the questionnaire and provided a fasting blood sample for erythrocyte membrane omega-3 fatty acid (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) analysis. The questionnaire was then validated by linear regression analysis of EPA and DHA levels on categories of fish and seafood and overall consumption, adjusted for age, sex, smoking status, body mass index (BMI) and alcohol intake. RESULTS: Regression coefficients were statistically significant for most fish and seafood items with both EPA and DHA. The strongest association was observed between oily fish and EPA, whereas no significant association was observed between lean fish and omega-3 fatty acids. Variation in omega-3 fatty acids was best accounted for by a model containing variables representing different categories of fish and seafood consumption (R (2) 0.484), rather than a single variable representing overall fish and seafood consumption (R (2) 0.313). CONCLUSIONS: This study confirms that the varying content of omega-3 fatty acids in foods are reflected in omega-3 biomarkers, and that the questionnaire is a valid measure of fish consumption that enables differentiation between cooking and processing methods and oily versus lean fish intake.     

Reproducibility and Validity of a Food Frequency Questionnaire among Vietnamese in Ho Chi Minh City

Objective: Our objective was to assess the reproducibility and validity of a food frequency questionnaire (FFQ) among individuals living in Ho Chi Minh City, Vietnam.

Methods: A total of 116 food items in our FFQ were selected by ranking food items according to their contribution to the population intake of nutrients, based on multiple 24-hour recalls (24HRs) from 144 participants in July 2001. The FFQ was validated by using three 24HRs for 118 men and women in Ho Chi Minh City, Vietnam in August 2002. The reproducibility of the FFQ was assessed by repeated administration at 7 ± 3.4 days.

Results: The reproducibility study showed that Spearman correlation coefficients, adjusted for energy intake, ranged from 0.47 to 0.72, and that weighted kappa values ranged from 0.42 for lipid to 0.65 for potassium. In the validation study, correlation coefficients, adjusted for energy intake, between the FFQ and the 24HRs ranged from 0.16 (calcium) to 0.45 (retinol). The proportion of subjects classified by the FFQ into the same third as determined by the 24HRs was between 42% and 62%.

Conclusions: This food frequency questionnaire measured the usual intake of major nutrients for Vietnamese adults living in Ho Chi Minh City and its urban area, where dietary patterns are similar to those of the Vietnamese population.     

Estimation of eicosapentaenoic acid and docosahexaenoic acid intakes in pregnant Japanese women without nausea by using a self-administered diet history questionnaire

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intakes during pregnancy affect fetal development and maternal mental health; therefore, an accurate assessment of EPA and DHA intakes is required. We hypothesized that a self-administered diet history questionnaire (DHQ) that was developed for non-pregnant adults could be used for estimating EPA and DHA intakes in pregnant Japanese women; thus, we evaluated the validity and reproducibility of the DHQ during pregnancy. We recruited 262 healthy participants with singleton pregnancies during their second trimester at a university hospital in Tokyo between June 2010 and July 2011. Plasma concentrations of EPA and DHA were measured as reference values. Fifty-eight women completed the DHQ twice, within a 4- to 5-week period to assess the reproducibility of the results. Among the participants without pregnancy-associated nausea (n = 180), significantly positive correlations were observed between energy-adjusted intakes and plasma concentrations of EPA (r_s = 0.388), DHA (r_s = 0.264), and EPA + DHA (r_s = 0.328). More than 60% of the participants without nausea fell into the same or adjacent quintiles according to energy-adjusted intakes and plasma concentrations of EPA, DHA, and EPA + DHA. Meanwhile, among the participants with nausea, a low correlation for EPA and no correlation for DHA and EPA + DHA were found. Intraclass correlation coefficients for the 2-time DHQ measurements were 0.691 (EPA) and 0.663 (DHA). The results indicate that the DHQ has an acceptable level of validity and reproducibility for assessing EPA, DHA, and EPA + DHA intakes in pregnant Japanese women without nausea.     

A valid food frequency questionnaire for measuring dietary fish intake

There is considerable interest in the potentially protective effects of high fish consumption on many chronic diseases. Many epidemiological studies use food frequency questionnaires (FFQ) to quantify usual dietary fish intake, so it is important to validate this assessment against objective markers. The objective of this study was to determine the relationship between plasma percentage fatty acids and dietary fish intake as assessed by a FFQ. A semiquantitative FFQ was completed by 174 adults from the community (aged 26-49 years) who also had venous blood analysed for plasma percentage fatty acids. Following linear regression modelling, total non-fried fish intake was a significant predictor of n-3 (regression coefficient, B = 0.94; 95% CI = 0.60-1.28), docosahexaenoic acid (DHA; B = 0.73; 95% CI = 0.47-0.99) and the ratio of n-6: n-3 fatty acids (B = -1.0; 95% CI = - 1.35- -0.65). Steamed, grilled or baked fish was a small but significant predictor of eicosapentaenoic acid (EPA) levels (B = 0.13; 95% CI = 0.05-0.21) while total fish intake was a predictor of n-6 fatty acids (B = -0.88; 95% CI = -1.41- -0.36). This semiquantitative FFQ could be useful for ranking subjects according to their likely plasma n-3, DHA, and n-6 fatty acid intake and the ratio of n-6: n-3 fatty acids, when the available resources may simply not permit biological markers to be used.     

Eicosapentaenoic and docosahexaenoic acids, cognition, and behavior in children with attention-deficit/hyperactivity disorder: a randomized controlled trial

ObjectiveTo determine the effects of an eicosapentaenoic acid (EPA)–rich oil and a docosahexaenoic acid (DHA)–rich oil versus an ω-6 polyunsaturated fatty acid–rich safflower oil (control) on literacy and behavior in children with attention-deficit/hyperactivity disorder (ADHD) in a randomized controlled trial.MethodsSupplements rich in EPA, DHA, or safflower oil were randomly allocated for 4 mo to 90 Australian children 7 to 12 y old with ADHD symptoms higher than the 90th percentile on the Conners Rating Scales. The effect of supplementation on cognition, literacy, and parent-rated behavior was assessed by linear mixed modeling. Pearson correlations determined associations between the changes in outcome measurements and the erythrocyte fatty acid content (percentage of total) from baseline to 4 mo.ResultsThere were no significant differences between the supplement groups in the primary outcomes after 4 mo. However, the erythrocyte fatty acid profiles indicated that an increased proportion of DHA was associated with improved word reading (r = 0.394) and lower parent ratings of oppositional behavior (r = 0.392). These effects were more evident in a subgroup of 17 children with learning difficulties: an increased erythrocyte DHA was associated with improved word reading (r = 0.683), improved spelling (r = 0.556), an improved ability to divide attention (r = 0.676), and lower parent ratings of oppositional behavior (r = 0.777), hyperactivity (r = 0.702), restlessness (r = 0.705), and overall ADHD symptoms (r = 0.665).ConclusionIncreases in erythrocyte ω-3 polyunsaturated fatty acids, specifically DHA, may improve literacy and behavior in children with ADHD. The greatest benefit may be observed in children who have comorbid learning difficulties.     

Validity and reliability of a quantitative food frequency questionnaire measuring n-3 fatty acid intakes in cardiac patients in the Midwest: a validation pilot study

The purpose of this pilot study was to test the validity and reliability of a quantitative n-3 fatty acid food frequency questionnaire (FFQ) for later use with larger groups of individuals. A convenience sample of heart patients provided dietary data via three 24-hour food recalls and FFQs. Participants were women (n=17) and men (n=11), 43 to 77 years of age. The association of mean daily intake of n-3 fatty acids obtained using food recalls and the FFQ was assessed by Pearson correlation. The reliability of the FFQ was assessed using coefficient alpha. Correlation of n-3 fatty acid intake using the food recalls and the FFQ was r=0.42 (P<0.05). The coefficient alpha for the test-retest of the FFQ was .83. The top two foods, walnuts and flaxseed, contributed 58% of the n-3 fatty acid intake, and the third food, salmon, contributed 5%. This quantitative n-3 FFQ is a valid instrument for use in place of food recalls for estimating n-3 fatty acid intakes in heart patients and is a reliable instrument to estimate n-3 fatty acid intakes from plant, animal, and seafood sources. The FFQ should be tested in a larger population. Registered dietitians can use this FFQ to screen for intakes, educate patients on food sources, and measure change in intakes after nutrition intervention.     

Longitudinal relationship between dietary ω-3 fatty acids and periodontal disease

ObjectiveFish oil has anti-inflammatory actions that may benefit periodontal health. We investigated the longitudinal relation between dietary ω-3 fatty acids (FAs), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) to periodontal disease in community-dwelling elderly.MethodsFifty-five participants aged 74 y were randomly selected from a longitudinal interdisciplinary study of aging. Dietary intake data were obtained by a 3-d weighed food intake. The dietary intakes of energy, DHA, and EPA were calculated based on the Standard Food Composition Tables in Japan. Dental examinations were carried out at baseline and once a year for 5 y. The number of teeth with periodontal progression over 5 y per person was calculated as “periodontal disease events.” Negative binomial regression analysis was conducted, which included DHA, EPA, and other covariates as independent variables to estimate the influence on periodontal disease events. Longitudinal data were analyzed for participants for whom data were available for 5 y (n = 36).ResultsLow DHA intake was significantly associated with more periodontal disease events. The mean number of periodontal disease events for participants who consumed the lowest tertile of DHA was approximately 1.5 times larger (lowest tertile, incidence rate ratio 1.49, 95% confidence interval 1.01–2.21) than the reference group (highest tertile of DHA consumption), after simultaneously adjusting for possible confounders.ConclusionThe findings suggest there may be an inverse, independent relation of dietary DHA intake to the progression of periodontal disease in older people.