ω-3 Polyunsaturated Fatty Acid Status Testing in Humans: A Narrative Review of Commercially Available Options.

There is an increasing body of evidence supporting a link between low intakes of ω-3 long-chain polyunsaturated fatty acids (LCPUFA) and numerous diseases and health conditions. However, few people are achieving the levels of fish/seafood or eicosapentaenoic acid and docosahexaenoic acid intake recommended in national and international guidelines. Knowledge of a person's ω-3 LCPUFA status will benefit the interpretation of research results and could be expected to lead to an increased effort to increase intake. Dietary intake survey methods are often used as a surrogate for measuring ω-3 PUFA tissue status and its impact on health and functional outcomes. However, because individuals vary widely in their ability to digest and absorb ω-3 PUFA, analytical testing of biological samples is desirable to accurately evaluate ω-3 PUFA status. Adipose tissue is the reference biospecimen for measuring tissue fatty acids, but less-invasive methods, such as measurements in whole blood or its components (e.g., plasma, serum, red blood cell membranes) or breast milk are often used. Numerous commercial laboratories provide fatty acid testing of blood and breast milk samples by different methods and present their results in a variety of reports such as a full fatty acid profile, ω-3 and ω-6 fatty acid profiles, fatty acid ratios, as well as the Omega-3 Index, the Holman Omega-3 Test, OmegaScore, and OmegaCheck, among others. This narrative review provides information about the different ways to measure ω-3 LCPUFA status (including both dietary assessments and selected commercially available analytical tests of blood and breast milk samples) and discusses evidence linking increased ω-3 LCPUFA intake or status to improved health, focusing on cardiovascular, neurological, pregnancy, and eye health, in support of recommendations to increase ω-3 LCPUFA intake and testing.

Adherence to the Mediterranean diet assessed by a novel dietary biomarker score and mortality in older adults: the InCHIANTI cohort study.

BACKGROUND: Dietary biomarkers may complement dietary intake assessment made by dietary questionnaires. We developed an a-posteriori dietary biomarkers score based on Mediterranean diet food groups and evaluated its association with mortality. METHODS: 642 participants (56% female), aged ≥65 years, with complete data on dietary biomarkers were followed during 20 years in the InCHIANTI cohort study (Tuscany, Italy). The main outcomes were all-cause, cardiovascular, and cancer mortality. Dietary biomarkers were selected from literature and from correlation analyses with dietary intakes of Mediterranean diet food groups in the study. The baseline levels of the following dietary biomarkers were chosen: urinary total polyphenols and resveratrol metabolites, and plasma carotenoids, selenium, vitamin B12, linolenic, eicosapentaenoic and docosahexaenoic acids, and the mono-unsaturated/saturated fatty acid ratio. Associations of the Mediterranean diet score using dietary biomarkers and a validated food frequency questionnaire (FFQ) (as tertiles) with mortality were assessed through Cox regression. RESULTS: During the 20-year follow-up [median (Q1-Q3), 14 (8-18) years], and 435 deaths occurred (139 from cardiovascular diseases and 89 from cancer-related causes). In the fully adjusted models, the dietary biomarker-Mediterranean diet score was inversely associated with all-cause (HRT3vs.T1 0.72; 95%CI 0.56-0.91) and cardiovascular (HRT3vs.T1 0.60; 95%CI 0.38-0.93), but not with cancer mortality. Associations between the FFQ-Mediterranean diet score and mortality were not statistically significant. CONCLUSIONS: A greater adherence at baseline to a Mediterranean diet assessed by a dietary biomarker score was associated with a lower risk of mortality in older adults during a 20-year follow-up. The measurement of dietary biomarkers may contribute to guide individualized dietary counseling to older people. TRIAL REGISTRATION: NCT01331512.

Derivation and Validation of a Total Fruit and Vegetable Intake Prediction Model to Identify Targets for Biomarker Discovery Using the UK National Diet and Nutrition Survey.

BACKGROUND: Dietary assessments in research and clinical settings are largely reliant on self-reported questionnaires. It is acknowledged that these are subject to measurement error and biases and that objective approaches would be beneficial. Dietary biomarkers have been purported as a complementary approach to improve the accuracy of dietary assessments. Tentative biomarkers have been identified for many individual fruits and vegetables (FVs), but an objective total FV intake assessment tool has not been established. OBJECTIVES: To derive and validate a prediction model of total FV intake (TFVpred) to inform future biomarker studies. METHODS: Data from the National Diet and Nutrition Survey (NDNS) were used for this analysis. A modeling group (MG) consisting of participants aged >11 years from the NDNS years 5-6 was created (n = 1746). Intake data for 96 FVs were analyzed by stepwise regression to derive a model that satisfied 3 selection criteria: SEE ≤80, R2 >0.7, and ≤10 predictors. The TFVpred model was validated using comparative data from a validation group (VG) created from the NDNS years 7-8 (n = 1865). Pearson's correlation coefficients were assessed between observed and predicted values in the MG and VG. Bland-Altman plots were used to assess agreement between TFVpred estimates and total FV intake. RESULTS: A TFVpred model, comprised of tomatoes, apples, carrots, bananas, pears, strawberries, and onions, satisfied the selection criteria (R2 = 0.761; SEE = 78.81). Observed and predicted total FV intake values were positively correlated in the MG (r = 0.872; P < 0.001; R2 = 0.761) and the VG (r = 0.838; P < 0.001; R2 = 0.702). In the MG and VG, 95.0% and 94.9%, respectively, of TFVpred model residuals were within the limits of agreement. CONCLUSIONS: Intakes of a concise FV list can be used to predict total FV intakes in a UK population. The individual FVs included in the TFVpred model present targets for biomarker discovery aimed at objectively assessing total FV intake.

Can a dietary quality score derived from a short-form FFQ assess dietary quality in UK adult population surveys?

OBJECTIVE: To devise a measure of diet quality from a short-form FFQ (SFFFQ) for population surveys. To validate the SFFFQ against an extensive FFQ and a 24 h diet recall. DESIGN: Population-based cross-sectional survey. SETTING: East Leeds and Bolton in Northern England. SUBJECTS: Adults (n 1999) were randomly selected from lists of those registered with a general practitioner in the study areas, contacted by mail and asked to complete the SFFFQ. Responders were sent a longer FFQ to complete and asked if they would take part in a telephone-based 24 h diet recall. RESULTS: Results from 826 people completing the SFFFQ, 705 completing the FFQ and forty-seven completing the diet recall were included in the analyses. The dietary quality score (DQS), based on fruit, vegetable, oily fish, non-milk extrinsic sugar and fat intakes, showed significant agreement between the SFFFQ and the FFQ (κ=0·38, P<0·001). The DQS for the SFFFQ and the diet recall did not show significant agreement (κ=0·04, P=0·312). A number of single items on the SFFFQ predicted a 'healthy' DQS when calculated from the FFQ. The odds of having a healthy diet were increased by 27 % (95 % CI 9, 49 %, P<0·001) for an increase in fruit of 1 portion/d and decreased by 67 % (95 % CI 47, 79 %, P<0·001) for an increase in crisps of 1 portion/d. CONCLUSIONS: The SFFFQ has been shown to be an effective method of assessing diet quality. It provides an important method for determining variations in diet quality within and across different populations.

Management of Dietary Habits and Diarrhea in Fap Individuals: A Mediterranean Low-Inflammatory Dietary Intervention.

BACKGROUND: A total colectomy and a frequent life-long endoscopic surveillance are guaranteed to patients with Familial Adenomatous Polyposis (FAP) to reduce their risk of duodenal and rectal stump cancers. However, after surgery, individuals with FAP suffer from an increased number of diarrheal discharges that force them to dietary restrictions. A non-randomized pilot study was conducted to assess whether a three-month low-inflammatory Mediterranean dietary intervention reduces gastro-intestinal markers of inflammation in FAP individuals. The aim of the present work is to evaluate the participant's adherence to the proposed dietary recommendations and the change in their number of diarrheal discharges. METHODS: 26 FAP individuals aged >18 years, who underwent a total colectomy with ileo-rectal anastomosis and were involved in the surveillance program at the Fondazione IRCCS Istituto Nazionale Tumori of Milan, were included in the present analysis. RESULTS: FAP individuals significantly reduced the Not recommended foods (p-value: 0.002) and increased the consumption of the Recommended ones (p-value: 0.075). The adherence to the proposed dietary recommendations was accompanied by a significant decrease in the number of diarrheal discharges (p-value: 0.008). CONCLUSIONS: This study suggests that adhering to a low-inflammatory Mediterranean diet has a potential protective effect on the number of diarrheal discharges in FAP individuals.

Association of Dietary Habits with Severity of Acute Pancreatitis.

BACKGROUND: The effect of diet on risk of acute pancreatitis (AP) has been suggested by prior studies, but the association of dietary habits with severity of AP has not been previously evaluated. OBJECTIVE: The objective of the study was to assess differences in reported dietary habits in patients with severe AP compared with those with mild or moderate AP. METHODS: A prospectively maintained cohort of patients with AP was utilized. A brief questionnaire on dietary habits was implemented. Dietary habits were categorized based on the overall type of diet, fruit/vegetable servings, fat content, dairy consumption, dessert/sweets consumption, and fluid intake. Patients were grouped into mild/moderate and severe AP. Multivariate analysis was used to determine whether dietary habits have an independent association with AP severity. RESULTS: 407 patients with AP were studied. Mean patient age was 51 y, and 202 (50%) were men. 29% of patients were smokers and 46% actively consumed alcohol. 225 patients had mild AP, 103 moderate AP, and 79 developed severe AP. The 3 groups were comparable in race, body mass index, etiology of AP, and comorbidities. Dietary factors were overall comparable between the groups except for diet type: subjects with severe AP had a higher percentage of consuming a meat-rich diet (84%) than patients with mild AP (72%) and moderate AP (67%) (P = 0.04). Based on multivariable logistic regression, the OR of developing severe AP was 2.5 (95% CI: 1.24-5.32, P = 0.01) between patients who eat a meat-rich diet and those who consume a vegetable-based diet. CONCLUSIONS: A meat-rich diet is independently associated with the development of persistent organ failure (severe disease) in patients with AP. These findings require further evaluation and could be useful for patient counseling, risk stratification, and disease prevention. This study is registered at clinicaltrials.gov as NCT03075605.

Assessment of dietary compliance in celiac children using a standardized dietary interview.

BACKGROUND & AIMS: Compliance to a gluten free diet (GFD) in celiac disease (CD) is ideally assessed by dietary interviews, albeit time-consuming. Short dietary questionnaires have been developed for adults but not for children. Primary aim was to compare GFD compliance in celiac children, measured by a short dietary questionnaire against a dietary interview. Secondary aims were correlation between both questionnaires and celiac antibodies and identifying variables predicting noncompliance. METHODS: Between 2012 and 2014, participants in the E-health CoelKids study, completed a short dietary questionnaire and standardized dietary interview together with measurement of anti-tissue transglutaminase antibodies (TG2A). Results of the questionnaires were assigned under similar categories. Factors possibly influencing dietary compliance were recorded. Where appropriate, Pearson's Chi-square test for trend, unpaired t-test, Cohen's kappa and one-way ANOVA were used. RESULTS: 151 of 165 participating patients were studied, 66% were female. Mean age was 11.3 years (2-26, SD 5.4), mean age at CD diagnosis was 4.9 years (1-23, SD 4.0). The short questionnaire and dietary interview correlated poorly, detecting problems in dietary adherence in 14% and 52% of the patients, respectively (Cohen's kappa 0.034). Only the short questionnaire correlated with TG2A (p = 0.003). Only older age was associated with noncompliance, the mean age of completely nonadherent, adherent but committing errors, and strictly adherent patients were 15.5, 11.5 and 10.1 years, respectively (p < 0.001). CONCLUSIONS: Compared to the dietary interview, short dietary questionnaires and TG2A serology failed to detect dietary transgressions in CD children, wherein adolescents were shown to be at highest risk.