Heidi P. Fransen

Indices of diet quality.

Purpose of reviewThe present review provides an overview of the different dietary quality indices in use. In the first decades, most indices were developed for the general adult population and were based on the American dietary guidelines and the Mediterranean diet. This review focuses on new, other dietary quality indices with special attention to the make-up of the score and methodological issues. Recent findingsMost of the new diet quality indices are based on the national dietary recommendations in Europe and Australia. In addition, one index is based on international recommendations and two indices use recommendations for the prevention of specific diseases. In addition, there are dietary scores that focus on specific groups (children, pregnant women), and on dietary variety or diversity. SummaryThe use of diet quality indices becomes more widespread and tailored to the specific purpose and population. However, different approaches are also due to arbitrary choices because of lacking knowledge on healthy diets and unsolved methodological issues. The ways of dealing with differences in energy intake, scoring each component, and combining the different components into one measure are aspects that still need further research.

Adherence to dietary guidelines and cardiovascular disease risk in the EPIC-NL cohort

BACKGROUND Global and national dietary guidelines have been created to lower chronic disease risk. The aim of this study was to assess whether greater adherence to the WHO guidelines (Healthy Diet Indicator (HDI)); the Dutch guidelines for a healthy diet (Dutch Healthy Diet-index (DHD-index)); and the Dietary Approaches to Stop Hypertension (DASH) diet was associated with a lower risk of cardiovascular disease (CVD), coronary heart disease (CHD) or stroke. METHODS A prospective cohort study was conducted among 33,671 healthy Dutch men and women aged 20-70 years recruited into the EPIC-NL study during 1993-1997. We used Cox regression adjusted for relevant confounders to estimate the hazard ratios per standard deviation increase in score and 95% confidence intervals (CI) of the associations between the dietary guidelines and CVD, CHD and stroke risk. RESULTS After an average follow-up of 12.2 years, 2752 CVD cases were documented, including 1630 CHD cases and 527 stroke cases. We found no association between the HDI (0.98, 95% CI 0.94; 1.02) or DHD-index (0.96, 95% CI 0.92; 1.00) and CVD incidence. Similar results were found for these guidelines and CHD or stroke incidence. Higher adherence to the DASH diet was significantly associated with a lower CVD (0.92, 95% CI 0.89; 0.96), CHD (0.91, 95% CI 0.86; 0.95), and stroke (0.90, 95% CI 0.82; 0.99) risk. CONCLUSION The HDI and the DHD-index were not associated with CVD risk, while the DASH diet was significantly associated with a lower risk of developing CVD, CHD and stroke.

A Posteriori Dietary Patterns: How Many Patterns to Retain?

Principal component analysis (PCA) and cluster analysis are used frequently to derive dietary patterns. Decisions on how many patterns to extract are primarily based on subjective criteria, whereas different solutions vary in their food-group composition and perhaps association with disease outcome. Literature on reliability of dietary patterns is scarce, and previous studies validated only 1 preselected solution. Therefore, we assessed reliability of different pattern solutions ranging from 2 to 6 patterns, derived from the aforementioned methods. A validated food frequency questionnaire was administered at baseline (1993-1997) to 39,678 participants in the European Prospective Investigation into Cancer and Nutrition-The Netherlands (EPIC-NL) cohort. Food items were grouped into 31 food groups for dietary pattern analysis. The cohort was randomly divided into 2 halves, and dietary pattern solutions derived in 1 sample through PCA were replicated through confirmatory factor analysis in sample 2. For cluster analysis, cluster stability and split-half reproducibility were assessed for various solutions. With PCA, we found the 3-component solution to be best replicated, although all solutions contained ≥1 poorly confirmed component. No quantitative criterion was in agreement with the results. Associations with disease outcome (coronary heart disease) differed between the component solutions. For all cluster solutions, stability was excellent and deviations between samples was negligible, indicating good reproducibility. All quantitative criteria identified the 2-cluster solution as optimal. Associations with disease outcome were comparable for different cluster solutions. In conclusion, reliability of obtained dietary patterns differed considerably for different solutions using PCA, whereas cluster analysis derived generally stable, reproducible clusters across different solutions. Quantitative criteria for determining the number of patterns to retain were valuable for cluster analysis but not for PCA. Associations with disease risk were influenced by the number of patterns that are retained, especially when using PCA. Therefore, studies on associations between dietary patterns and disease risk should report reasons to choose the number of retained patterns.

A Tiered Approach for Risk-Benefit Assessment of Foods

Risk-benefit analyses are introduced as a new paradigm for old problems. However, in many cases it is not always necessary to perform a full comprehensive and expensive quantitative risk-benefit assessment to solve the problem, nor is it always possible, given the lack of required date. The choice to continue from a more qualitative to a full quantitative risk-benefit assessment can be made using a tiered approach. In this article, this tiered approach for risk-benefit assessment will be addressed using a decision tree. The tiered approach described uses the same four steps as the risk assessment paradigm: hazard and benefit identification, hazard and benefit characterization, exposure assessment, and risk-benefit characterization, albeit in a different order. For the purpose of this approach, the exposure assessment has been moved upward and the dose-response modeling (part of hazard and benefit characterization) is moved to a later stage. The decision tree includes several stop moments, depending on the situation where the gathered information is sufficient to answer the initial risk-benefit question. The approach has been tested for two food ingredients. The decision tree presented in this article is useful to assist on a case-by-case basis a risk-benefit assessor and policymaker in making informed choices when to stop or continue with a risk-benefit assessment.

Dietary patterns in relation to disease burden expressed in Disability-Adjusted Life Years

BACKGROUND Although diet is related to chronic disease risk and mortality, its association with total disease burden is not clear. OBJECTIVE We investigated the minimum impact of different dietary patterns on disability-adjusted life years (DALYs) by using individual longitudinal data. DESIGN A prospective cohort study was conducted in 33,066 healthy men and women aged 20-70 y recruited into the European Prospective Investigation into Cancer and Nutrition-Netherlands study during 1993-1997. We measured adherence to 3 a priori dietary patterns [the modified Mediterranean diet score (mMDS), the WHO-based Healthy Diet Indicator, and the Dutch Healthy Diet index] and 2 a posteriori dietary patterns. Two a posteriori methods were used to extract Western and prudent patterns. Participants were followed until the end of 2007 for the occurrence of and mortality from the most important chronic diseases. The disease burden was expressed in DALYs, which are the sum of Years Lost due to Disability and Years of Life Lost because of premature mortality. The associations between dietary patterns (per SD change in score) and DALYs were estimated by using a 2-part model and adjusted for relevant confounders (sex, age at recruitment, smoking status and intensity, educational level, marital status, job status, energy intake, and physical activity). RESULTS After an average follow-up of 12.4 y, higher adherence to the mMDS or prudent pattern was most strongly associated with healthy survival; per SD higher adherence to the mMDS or prudent pattern, fewer healthy life years were lost [51 d (-0.14 DALYs; 95% CI: -0.21, -0.08 DALYs) and 58 d (-0.16 DALYs; 95% CI: -0.23, -0.09 DALYs), respectively]. CONCLUSION In this Dutch study, of various dietary patterns evaluated, higher adherence to the mMDS or prudent dietary pattern was associated with a lower disease burden as assessed by DALYs.

Association between Lifestyle Factors and Quality-Adjusted Life Years in the EPIC-NL Cohort

The aim of our study was to relate four modifiable lifestyle factors (smoking status, body mass index, physical activity and diet) to health expectancy, using quality-adjusted life years (QALYs) in a prospective cohort study. Data of the prospective EPIC-NL study were used, including 33,066 healthy men and women aged 20–70 years at baseline (1993–7), followed until 31-12-2007 for occurrence of disease and death. Smoking status, body mass index, physical activity and adherence to a Mediterranean-style diet (excluding alcohol) were investigated separately and combined into a healthy lifestyle score, ranging from 0 to 4. QALYs were used as summary measure of healthy life expectancy, combining a persons life expectancy with a weight for quality of life when having a chronic disease. For lifestyle factors analyzed separately the number of years living longer in good health varied from 0.12 year to 0.84 year, after adjusting for covariates. A combination of the four lifestyle factors was positively associated with higher QALYs (P-trend <0.0001). A healthy lifestyle score of 4 compared to a score of 0 was associated with almost a 2 years longer life in good health (1.75 QALYs [95% CI 1.37, 2.14]).

Dietary patterns in relation to quality-adjusted life years in the EPIC-NL cohort.

BACKGROUND Dietary patterns have been associated with the incidence or mortality of individual non-communicable diseases, but their association with disease burden has received little attention. OBJECTIVE The aim of our study was to relate dietary patterns to health expectancy using quality-adjusted life years (QALYs) as outcome parameter. METHODS Data from the EPIC-NL study were used, a prospective cohort study of 33,066 healthy men and women aged 20-70 years at recruitment. A lifestyle questionnaire and a validated food frequency questionnaire were administered at study entry (1993-1997). Five dietary patterns were studied: three a priori patterns (the modified Mediterranean Diet Score (mMDS), the WHO-based Healthy Diet Indicator (HDI) and the Dutch Healthy Diet index (DHD-index)) and two a posteriori data-based patterns. QALYs were used as a summary health measure for healthy life expectancy, combining a persons life expectancy with a weight reflecting loss of quality of life associated with having chronic diseases. RESULTS The mean QALYs of the participants were 74.9 (standard deviation 4.4). A higher mMDS and HDI were associated with a longer life in good health. Participants who had a high mMDS score (6-9) had 0.17 [95% CI, 0.05; 0.30] more QALYs than participants with a low score (0-3), equivalent to two months longer life in good health. Participants with a high HDI score also had more QALYs (0.15 [95% CI, 0.03; 0.27]) than participants with a low HDI score. CONCLUSION A Mediterranean-type diet and the Healthy Diet Indicator were associated with approximately 2months longer life in good health.

Exposure to Famine at a Young Age and Unhealthy Lifestyle Behavior Later in Life

Background A healthy diet is important for normal growth and development. Exposure to undernutrition during important developmental periods such as childhood and adolescence can have effects later in life. Inhabitants of the west of the Netherlands were exposed to severe undernutrition during the famine in the last winter of the second World War (1944–1945). Objective We investigated if exposure of women to the Dutch famine during childhood and adolescence was associated with an unhealthy lifestyle later in life. Design We studied 7,525 women from the Prospect-EPIC cohort, recruited in 1993–97 and aged 0–18 years during the Dutch famine. An individual famine score was calculated based on self-reported information about experience of hunger and weight loss. We investigated the association between famine exposure in early life and four lifestyle factors in adulthood: smoking, alcohol consumption, physical activity level and a Mediterranean-style diet. Results Of the 7,525 included women, 46% were unexposed, 38% moderately exposed and 16% severely exposed to the Dutch famine. Moderately and severely exposed women were more often former or current smokers compared to women that did not suffer from the famine: adjusted prevalence ratio 1.10 (95% CI: 1.05; 1.14) and 1.18 (1.12; 1.25), respectively. They also smoked more pack years than unexposed women. Severely exposed women were more often physically inactive than unexposed women, adjusted prevalence ratio 1.32 (1.06; 1.64). Results did not differ between exposure age categories (0–9 and 10–17 years). We found no associations of famine exposure with alcohol consumption and no dose-dependent relations with diet. Conclusions Exposure to famine early in female life may be associated with higher prevalence of smoking and physical inactivity later in life, but not with unhealthy diet and alcohol consumption.

Adherence to the Dutch Guidelines for a Healthy Diet and cancer risk in the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) cohort.

OBJECTIVE To examine the association between adherence to the Dutch Guidelines for a Healthy Diet created by the Dutch Health Council in 2006 and overall and smoking-related cancer incidence. DESIGN Prospective cohort study. SETTING Adherence to the guidelines, which includes one recommendation on physical activity and nine on diet, was measured using an adapted version of the Dutch Healthy Diet (DHD) index. The score ranged from 0 to 90 with a higher score indicating greater adherence to the guidelines. We estimated the hazard ratios (HR) and 95 % confidence intervals for the association between the DHD index (in tertiles and per 20-point increment) at baseline and cancer incidence at follow-up. SUBJECTS We studied 35 608 men and women aged 20-70 years recruited into the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) study during 1993-1997. RESULTS After an average follow-up of 12·7 years, 3027 cancer cases were documented. We found no significant association between the DHD index (tertile 3 v. tertile 1) and overall (HR = 0·97; 95 % CI 0·88, 1·07) and smoking-related cancer incidence (HR = 0·89; 95 % CI 0·76, 1·06) after adjustment for relevant confounders. Excluding the components physical activity or alcohol from the score did not change the results. None of the individual components of the DHD index was significantly associated with cancer incidence. CONCLUSIONS In the present study, participants with a high adherence to the Dutch Guidelines for a Healthy Diet were not at lower risk of overall or smoking-related cancer. This does not exclude that other components not included in the DHD index may be associated with overall cancer risk.

Benefit-risk assessment of plant sterols in margarine: a QALIBRA case study.

This paper presents the benefit-risk assessment of adding plant sterols to margarine as an illustration of the QALIBRA method and software. With the QALIBRA tool health effects, risks as well as benefits are expressed in a common metric (DALY) which allows quantitative balancing of benefits and risks of food intake. The QALIBRA software can handle uncertainties in a probabilistic simulation. This simple case study illustrates the data need and assumptions that go into a quantitative benefit-risk assessment. The assessment shows that the benefits of plant sterols added to margarine outweigh the risks, if any.