Evaluation of Nutri-Score in Relation to Dietary Guidelines and Food Reformulation in The Netherlands.

An unhealthy dietary pattern is an important risk factor for non-communicable diseases. Front-of-Pack nutritional labels such as Nutri-Score can be used to improve food choices. In addition, products can be improved through reformulation. The current study investigates to what extent Nutri-Score aligns with the Dutch Health Council dietary guidelines and whether it can be used as an incentive for reformulation. Nutri-Score calculations were based on the Dutch Branded Food database (2018). The potential shift in Nutri-Score was calculated with product improvement scenarios. The Nutri-Score classification is in line with these dietary guidelines: increase the consumption of fruit and vegetables, pulses, and unsalted nuts. It is, however, less in line with the recommendations to limit (dairy) drinks with added sugar, reduce the consumption of red meat and replace refined cereal products with whole-grain products. The scenario analyses indicated that a reduction in sodium, saturated fat or sugars resulted in a more favourable Nutri-Score in a large variety of food groups. However, the percentage of products with an improved Nutri-Score varied greatly between the different food groups. Alterations to the algorithm may strengthen Nutri-Score in order to help consumers with their food choices.

Salt Reductions in Some Foods in The Netherlands: Monitoring of Food Composition and Salt Intake.

BACKGROUND AND OBJECTIVES: High salt intake increases blood pressure and thereby the risk of chronic diseases. Food reformulation (or food product improvement) may lower the dietary intake of salt. This study describes the changes in salt contents of foods in the Dutch market over a five-year period (2011-2016) and differences in estimated salt intake over a 10-year period (2006-2015). METHODS: To assess the salt contents of foods; we obtained recent data from chemical analyses and from food labels. Salt content of these foods in 2016 was compared to salt contents in the 2011 version Dutch Food Composition Database (NEVO, version 2011), and statistically tested with General Linear Models. To estimate the daily dietary salt intake in 2006, 2010, and 2015, men and women aged 19 to 70 years were recruited through random population sampling in Doetinchem, a small town located in a rural area in the eastern part of the Netherlands. The characteristics of the study population were in 2006: n = 317, mean age 49 years, 43% men, in 2010: n = 342, mean age 46 years, 45% men, and in 2015: n = 289, mean age 46 years, 47% men. Sodium and potassium excretion was measured in a single 24-h urine sample. All estimates were converted to a common metric: salt intake in grams per day by multiplication of sodium with a factor of 2.54. RESULTS: In 2016 compared to 2011, the salt content in certain types of bread was on average 19 percent lower and certain types of sauce, soup, canned vegetables and legumes, and crisps had a 12 to 26 percent lower salt content. Salt content in other types of foods had not changed significantly. Between 2006, 2010 and 2015 the estimated salt intake among adults in Doetinchem remained unchanged. In 2015, the median estimated salt intake was 9.7 g per day for men and 7.4 g per day for women. As in 2006 and 2010, the estimated salt intake in 2015 exceeded the recommended maximum intake of 6 g per day set by the Dutch Health Council. CONCLUSION: In the Netherlands, the salt content of bread, certain sauces, soups, potato crisps, and processed legumes and vegetables have been reduced over the period 2011-2016. However, median salt intake in 2006 and 2015 remained well above the recommended intake of 6 g.

Diet and cognitive decline at middle age: the role of antioxidants.

To assess the relationship between dietary intake of antioxidants (vitamin C, vitamin E, ß-carotene, lutein, flavonoids and lignans) and cognitive decline at middle age, analyses were performed on data from the population based Doetinchem Cohort Study. Habitual diet and cognitive function were assessed twice with a 5-year interval in 2613 persons aged 43-70 year at baseline (1995-2002). Diet was assessed with a validated 178-item semi-quantitative FFQ. Cognitive function was assessed with a neuropsychological test battery, consisting of the 15 Words Learning Test, the Stroop Test, the Word Fluency test, and the Letter Digit Substitution Test. Scores on global cognitive function, memory, processing speed, and cognitive flexibility were calculated. In regression analyses, quintiles of antioxidant intake were associated with change in cognitive domain scores. Results showed that higher lignan intake was linearly associated with less decline in global cognitive function (P= 0.01), memory (P< 0.01) and processing speed (P= 0.04), with about two times less declines in the highest v. the lowest quintile. In the lowest quintile of vitamin E intake, decline in memory was twice as fast as in all higher quintiles (P< 0.01). Global cognitive decline in the highest lutein intake group was greater than in the lowest intake group (P< 0.05). Higher flavonoid intake was associated with greater decline in cognitive flexibility (P for trend = 0.04). Intakes of other antioxidants were not associated with cognitive decline. We conclude that within the range of a habitual dietary intake, higher intake of lignans is associated with less cognitive decline at middle age.

Food supply and actions to improve dietary behaviour of students - a comparison between secondary schools participating or not participating in the 'Healthy School Canteen Program'.

OBJECTIVE: (i) To identify determinants of participation in the 'Healthy School Canteen Program', a programme that encourages schools to set up their canteen in a way that promotes healthy dietary behaviour. (ii) To compare food supply and actions between participating and non-participating schools. (iii) To investigate what reasons schools have to increase attention for nutrition in the curriculum. DESIGN: A cross-sectional study based on information from questionnaires performed in 2010/2011. SETTING: All secondary schools (age group 12-18 years) in the Netherlands (n 1145). SUBJECTS: Response was 33 % (n 375). Analyses included all schools with a canteen in which food is offered (28 %, n 325). RESULTS: None of the investigated determinants was associated with participation. Participating schools offered significantly (P < 0·001) more of eleven inventoried healthy foods (e.g. sandwiches, (butter)milk, fruit, light soft drinks, yoghurt and salad) than non-participating schools. However, there was no difference in the number of less healthy products offered (e.g. candy bars, cakes and regular soft drinks). Participating schools reported more often that they took actions to improve dietary behaviour and more often had a policy on nutrition. Participating schools more often increased attention for nutrition in the curriculum in recent years than non-participating schools (57 % v. 43 %, P = 0·01). Reported reasons were similar and included media attention, eating behaviour of students and 'overweight'. CONCLUSIONS: Schools that participate in the programme seemed to offer more healthy products in their canteens and took more actions to improve dietary behaviour than non-participating schools. However, at all schools less healthy foods were also available.

Changes in weight and health-related quality of life. The Doetinchem Cohort Study.

BACKGROUND: The cross-sectional association between obesity and a lower health-related quality of life (HRQL) is clear. However, less is known about the association between changes in weight and HRQL. We examined the association between weight changes and changes in HRQL in a population-based sample of 2005 men and 2130 women aged 26-70 years. METHODS: Weight was measured two or three times with 5-year intervals between 1995 and 2009, and was categorised as stable (change ≤2 kg, 40%), weight loss (19%), or weight gain 2.1-4.0 kg, 4.1-6.0 kg, or >6 kg (41%). Changes in HRQL (SF36 questionnaire, including physical and mental scales) per weight change category were compared with a stable weight using generalised estimating equations. RESULTS: Weight gain was associated with declines of up to 5 points on five mainly physical scales and holds for different age categories. Especially for women, a dose-response relationship was observed, that is, larger weight gain was associated with larger declines in HRQL. Changes in HRQL for those with weight loss were small, but particularly on the mental scales, changes were in the negative direction compared to a stable weight. CONCLUSIONS: Weight gain and weight loss were associated with unfavourable changes in HRQL compared with a stable weight. For weight gain, this was most pronounced on the physical scales and for weight loss, although less consistent, on the mental scales.

Behavior change in a lifestyle intervention for type 2 diabetes prevention in Dutch primary care: opportunities for intervention content.

BACKGROUND: Despite the favorable effects of behavior change interventions on diabetes risk, lifestyle modification is a complicated process. In this study we therefore investigated opportunities for refining a lifestyle intervention for type 2 diabetes prevention, based on participant perceptions of behavior change progress. METHODS: A 30 month intervention was performed in Dutch primary care among high-risk individuals (FINDRISC-score ≥ 13) and was compared to usual care. Participant perceptions of behavior change progress for losing weight, dietary modification, and increasing physical activity were assessed after18 months with questionnaires. Based on the response, participants were categorized as 'planners', 'initiators' or 'achievers' and frequencies were evaluated in both study groups. Furthermore, participants reported on barriers for lifestyle change. RESULTS: In both groups, around 80% of all participants (intervention: N = 370; usual care: N = 322) planned change. Except for reducing fat intake (p = 0.08), the number of initiators was significantly higher in the intervention group than in usual care. The percentage of achievers was high for the dietary and exercise objectives (intervention: 81-95%; usual care: 83-93%), but was lower for losing weight (intervention: 67%; usual care: 62%). Important motivational barriers were 'I already meet the standards' and 'I'm satisfied with my current behavior'. Temptation to snack, product taste and lack of time were important volitional barriers. CONCLUSIONS: The results suggest that the intervention supports participants to bridge the gap between motivation and action. Several opportunities for intervention refinement are however revealed, including more stringent criteria for participant inclusion, tools for (self)-monitoring of health, emphasis on the 'small-step-approach', and more attention for stimulus control. TRIAL REGISTRATION: Netherlands Trial Register: NTR1082.

Exploring the reach and program use of Hello World, an email-based health promotion program for pregnant women in the Netherlands.

BACKGROUND: In 2006, the Dutch government initiated Hello World, an email-based program promoting healthy lifestyles among pregnant women through quizzes with pregnancy-related questions. In 2008, an updated version was released.The present study aimed to (1) examine the reach of Hello World and the representativeness of its users for all pregnant women in the Netherlands, (2) explore the relationship between program engagement and lifestyle characteristics, and (3) explore the relationship between the program content participants accessed (content on smoking, physical activity, and nutrition) and their lifestyle characteristics. METHODS: Data from 4,363 pregnant women were included. After registration, women received an online questionnaire with demographic and lifestyle questions. To evaluate their representativeness, their demographic characteristics were compared with existing data for Dutch (pregnant) women. Women were classified on the following lifestyle characteristics: smoking, nutrition, physical activity, and pre-pregnancy weight status. Program use was tracked and the relationships between lifestyle characteristics, program engagement, and the percentage of smoking, physical activity, and nutrition questions accessed after opening a quiz were explored using Mann-Whitney U tests and Kruskal-Wallis tests. RESULTS: Hello World reached ±4% of its target population. Ten percent of participants were low educated and 22% immigrants. On average, women received 6.1 (SD:2.8) quiz emails and opened 32% of the associated quizzes (2.0, SD:2.1). A significant positive association was found between the number of quizzes opened and the number of healthy lifestyle characteristics. After opening a quiz, women accessed most smoking, nutrition, and physical activity questions. Significant relationships were found between several lifestyle characteristics and the percentage of smoking, physical activity, and nutrition questions accessed. However, between-group differences were small, quiz topics were largely unrelated to their lifestyle characteristics, and inconsistencies were found regarding the directions of these associations. CONCLUSIONS: Hello World reached ±4% of its target population, which is lower than the reach of its previous version (±8%). Relatively few low educated and immigrant women registered for the program. Active participation in the program was positively associated with the number of healthy behaviours participants engaged in. The program content participants chose to access was largely unrelated to their lifestyle characteristics.

Implementation of a lifestyle intervention for type 2 diabetes prevention in Dutch primary care: opportunities for intervention delivery.

BACKGROUND: As in clinical practice resources may be limited compared to experimental settings, translation of evidence-based lifestyle interventions into daily life settings is challenging. In this study we therefore evaluated the implementation of the APHRODITE lifestyle intervention for the prevention of type 2 diabetes in Dutch primary care. Based on this evaluation we discuss opportunities for refining intervention delivery. METHODS: A 2.5-year intervention was performed in 14 general practices in the Netherlands among individuals at high risk for type 2 diabetes (FINDRISC-score ≥ 13) (n = 479) and was compared to usual care (n = 446). Intervention consisted of individual lifestyle counselling by nurse practitioners (n = 24) and GPs (n = 48) and group-consultations. Drop-out and attendance were registered during the programme. After the intervention, satisfaction with the programme and perceived implementation barriers were assessed with questionnaires. RESULTS: Drop-out was modest (intervention: 14.6 %; usual care: 13.2 %) and attendance at individual consultations was high (intervention: 80-97 %; usual care: 86-94 %). Providers were confident about diabetes prevention by lifestyle intervention in primary care. Participants were more satisfied with counselling from nurse practitioners than from GPs. A major part of the GPs reported low self-efficacy regarding dietary guidance. Lack of counselling time (60 %), participant motivation (12 %), and financial reimbursement (11 %) were regarded by providers as important barriers for intervention implementation. CONCLUSIONS: High participant compliance and a positive attitude of providers make primary care a suitable setting for diabetes prevention by lifestyle counselling. Results support a role for the nurse practitioner as the key player in guiding lifestyle modification. Further research is needed on strategies that could increase cost-effectiveness, such as more stringent criteria for participant inclusion, group-counselling, more tailor-made counselling and integration of screening and / or interventions for different disorders.

Lifestyle counseling for type 2 diabetes risk reduction in Dutch primary care: results of the APHRODITE study after 0.5 and 1.5 years.

OBJECTIVE To study the overall effect of the Active Prevention in High-Risk Individuals of Diabetes Type 2 in and Around Eindhoven (APHRODITE) lifestyle intervention on type 2 diabetes risk reduction in Dutch primary care after 0.5 and 1.5 years and to evaluate the variability between general practices. RESEARCH DESIGN AND METHODS Individuals at high risk for type 2 diabetes (Finnish Diabetes Risk Score ≥13) were randomly assigned into an intervention group (n = 479) or a usual-care group (n = 446). Comparisons were made between study groups and between general practices regarding changes in clinical and lifestyle measures over 1.5 years. Participant, general practitioner, and nurse practitioner characteristics were compared between individuals who lost weight or maintained a stable weight and individuals who gained weight. RESULTS Both groups showed modest changes in glucose values, weight measures, physical activity, energy intake, and fiber intake. Differences between groups were significant only for total physical activity, saturated fat intake, and fiber intake. Differences between general practices were significant for BMI and 2-h glucose but not for energy intake and physical activity. In the intervention group, the nurse practitioners' mean years of work experience was significantly longer in individuals who were successful at losing weight or maintaining a stable weight compared with unsuccessful individuals. Furthermore, successful individuals more often had a partner. CONCLUSIONS Risk factors for type 2 diabetes could be significantly reduced by lifestyle counseling in Dutch primary care. The small differences in changes over time between the two study groups suggest that additional intervention effects are modest. In particular, the level of experience of the nurse practitioner and the availability of partner support seem to facilitate intervention success.

Changes in lifestyle habits after counselling by nurse practitioners: 1-year results of the Groningen Overweight and Lifestyle study.

OBJECTIVES: The Groningen Overweight and Lifestyle (GOAL) study primarily aims at preventing weight gain by nurse practitioners (NP) guided by a standardized computerized software program. Since favourable changes in physical activity (PA) and diet may improve health independently of weight (loss), insight into effects on lifestyle habits is essential. We examined the 1-year effects of lifestyle counselling by NP on PA and diet, compared with usual care from the general practitioner (GP-UC). DESIGN: A randomized controlled trial. SETTING: Eleven general practice locations in the Netherlands. SUBJECTS: A total of 341 GOAL participants with overweight or obesity and either hypertension or dyslipidaemia, or both, who completed an FFQ and Short Questionnaire to Assess Health-Enhancing Physical Activity (SQUASH) at baseline and after 1 year. RESULTS: After 1 year, the NP group spent 33 min/week more on walking compared with the GP-UC group who spent -5 min/week on walking (P = 0.05). No significant differences were found between the NP and GP-UC groups on the percentage of persons complying with the PA guidelines. In both groups, nutrient intake changed in a favourable direction and participants complied more often with dietary guidelines, but without overall difference between the NP and GP-UC groups. CONCLUSIONS: With the exception of an increase in walking (based on self-reported data) in the NP group, no intervention effects on PA and diet occurred. Positive changes in nutrient intake were seen in both groups.

Nationwide implementation of Hello World: a Dutch email-based health promotion program for pregnant women.

BACKGROUND: In November 2006, an email-based health promotion program for pregnant women was implemented nationally in the Netherlands. The program consisted of emails containing quizzes with pregnancy-related questions tailored to the number of weeks of pregnancy. Emails were sent out once every 4 weeks, up to a maximum of nine emails. OBJECTIVES: The aims of the study were (1) to assess the recruitment of participants and their representativeness of the Dutch population and (2) to study differences in recruitment, program use, and program appreciation among women with different levels of education. METHODS: Data from 13,946 pregnant women who enrolled during the first year of the program were included. Upon registration, participants were asked how they found out about the program and subsequently received an email questionnaire to assess demographic, lifestyle, and Internet characteristics. Program use was tracked, and participants were classified into five user groups (inactive to very active). Program appreciation (low, intermediate, and high) was assessed twice with an email questionnaire that was sent after the woman had received her third and sixth quiz email. Information about pregnant women and their characteristics was obtained from Dutch registries to assess representativeness of the study population. RESULTS: About 8% of the pregnant women in the Netherlands enrolled in the program. Immigrants were underrepresented, and women with a low level of education seemed to be slightly underrepresented. Most women knew about the program from a promotional email sent by the organization (32%), followed by the Internet (22%) and midwives (16%). Women with little education were more often inactive users of the program than were highly educated women (15% vs 11%, P < .001), whereas highly educated women were more often very active users compared with women with little education (25% vs 20%, P< .001). However, women with less education were more likely than women with more education to have a high appreciation of the program after receiving three quiz emails (52% vs 44%, P = .001). CONCLUSIONS: In this real-life setting, pregnant women can be reached through an email-based health promotion program. Selective engagement by education level remains a challenge.

Lifestyle counseling in hypertension-related visits--analysis of video-taped general practice visits.

BACKGROUND: The general practitioner (GP) can play an important role in promoting a healthy lifestyle, which is especially relevant in people with an elevated risk of cardiovascular diseases due to hypertension. Therefore, the aim of this study was to determine the frequency and content of lifestyle counseling about weight loss, nutrition, physical activity, and smoking by GPs in hypertension-related visits. A distinction was made between the assessment of lifestyle (gathering information or measuring weight or waist circumference) and giving lifestyle advice (giving a specific advice to change the patient's behavior or referring the patient to other sources of information or other health professionals). METHODS: For this study, we observed 212 video recordings of hypertension-related visits collected within the Second Dutch National Survey of General Practice in 2000/2001. RESULTS: The mean duration of visits was 9.8 minutes (range 2.5 to 30 minutes). In 40% of the visits lifestyle was discussed (n = 84), but in 81% of these visits this discussion lasted shorter than a quarter of the visit. An assessment of lifestyle was made in 77 visits (36%), most commonly regarding body weight and nutrition. In most cases the patient initiated the discussion about nutrition and physical activity, whereas the assessment of weight and smoking status was mostly initiated by the GP. In 35 visits (17%) the GP gave lifestyle advice, but in only one fifth of these visits the patient's motivation or perceived barriers for changing behavior were assessed. Supporting factors were not discussed at all. CONCLUSION: In 40% of the hypertension-related visits lifestyle topics were discussed. However, both the frequency and quality of lifestyle advice can be improved.

Relation between plasma enterodiol and enterolactone and dietary intake of lignans in a Dutch endoscopy-based population.

Enterolignans are phytoestrogenic compounds derived from the conversion of dietary lignans by the intestinal microflora that may be protective against cardiovascular diseases and cancer. To evaluate the use of enterolignans as biomarkers of dietary lignan intake, we studied the relation between plasma and dietary lignans. We determined the dietary intake of 4 lignans (secoisolariciresinol (SECO), matairesinol (MAT), pinoresinol, and lariciresinol) using the European Prospective Investigation into Cancer and Nutrition FFQ, and plasma enterodiol (END) and enterolactone (ENL) concentrations were determined by liquid chromatography-tandem mass spectrometry. The population consisted of 637 men and women, aged 19-75 y, participating in a case-control study on colorectal adenomas. Participants did not use antibiotics in the preceding calendar year. We found a modest association between lignan intake and plasma END (Spearman r = 0.09, P = 0.03) and ENL (Spearman r = 0.18, P <0.001). The correlation of total lignan intake with plasma enterolignans was slightly stronger than that of only SECO plus MAT. The plasma concentrations of both END and ENL were associated with intake of dietary fiber and vegetable protein but not with intake of other macronutrients. The relation between lignan intake and plasma END was modulated by age and previous use of antibiotics, whereas for ENL, it was modulated by weight, current smoking, and frequency of defecation. However, even when we included these nondietary factors in the regression models, the explained variance in plasma END and ENL remained low (2 and 13%, respectively).

Intakes of 4 dietary lignans and cause-specific and all-cause mortality in the Zutphen Elderly Study.

BACKGROUND: Plant lignans are converted to enterolignans that have antioxidant and weak estrogen-like activities, and therefore they may lower cardiovascular disease and cancer risks. OBJECTIVE: We investigated whether the intakes of 4 plant lignans (lariciresinol, pinoresinol, secoisolariciresinol, and matairesinol) were inversely associated with coronary heart disease (CHD), cardiovascular diseases (CVD), cancer, and all-cause mortality. DESIGN: The Zutphen Elderly Study is a prospective cohort study in which 570 men aged 64-84 y were followed for 15 y. We recently developed a database and used it to estimate the dietary intakes of 4 plant lignans. Lignan intake was related to mortality with the use of Cox proportional hazards analysis. RESULTS: The median total lignan intake in 1985 was 977 microg/d. Tea, vegetables, bread, coffee, fruit, and wine were the major sources of lignan. The total lignan intake was not related to mortality. However, the intake of matairesinol was inversely associated with CHD, CVD, and all-cause mortality (P

Intake of the plant lignans secoisolariciresinol, matairesinol, lariciresinol, and pinoresinol in Dutch men and women.

Enterolignans (enterolactone and enterodiol) are phytoestrogens that are formed by the colonic microflora from plant lignans. They may reduce the risk of certain types of cancer and cardiovascular diseases. Initially, only secoisolariciresinol and matairesinol were considered to be enterolignan precursors, but recently, new precursors such as lariciresinol and pinoresinol were identified. We recently developed a lignan database including 4 major enterolignan precursors. We used this database to estimate lignan intake in a representative sample of Dutch men and women participating in the Dutch Food Consumption Survey, carried out in 1997-1998. Median total lignan intake among 4660 adults (19-97 y old) was 979 microg/d. Total lignan intake did not differ between men and women; thus, the lignan density of the diet was significantly higher (P < 0.001) in women than in men. Lignan intake was strongly skewed toward higher values (range 43-77584 microg/d, mean 1241 microg/d). Lariciresinol and pinoresinol contributed 75% to lignan intake, whereas secoisolariciresinol and matairesinol contributed only 25%. The major food sources of lignans were beverages (37%), vegetables (24%), nuts and seeds (14%), bread (9%), and fruits (7%). Lignan intake was significantly (P < 0.001) correlated with intake of dietary fiber (r = 0.46), folate (r = 0.39), and vitamin C (r = 0.44). Older persons, nonsmokers, vegetarians, and persons with a low BMI or a high socioeconomic status had higher lignan intakes than their counterparts. In brief, this study shows that the amount of enterolignan precursors in the diet has previously been largely underestimated.

Lignan contents of Dutch plant foods: a database including lariciresinol, pinoresinol, secoisolariciresinol and matairesinol.

Enterolignans (enterodiol and enterolactone) can potentially reduce the risk of certain cancers and cardiovascular diseases. Enterolignans are formed by the intestinal microflora after the consumption of plant lignans. Until recently, only secoisolariciresinol and matairesinol were considered enterolignan precursors, but now several new precursors have been identified, of which lariciresinol and pinoresinol have a high degree of conversion. Quantitative data on the contents in foods of these new enterolignan precursors are not available. Thus, the aim of this study was to compile a lignan database including all four major enterolignan precursors. Liquid chromatography-tandem mass spectrometry was used to quantify lariciresinol, pinoresinol, secoisolariciresinol and matairesinol in eighty-three solid foods and twenty-six beverages commonly consumed in The Netherlands. The richest source of lignans was flaxseed (301,129 microg/100 g), which contained mainly secoisolariciresinol. Also, lignan concentrations in sesame seeds (29,331 microg/100 g, mainly pinoresinol and lariciresinol) were relatively high. For grain products, which are known to be important sources of lignan, lignan concentrations ranged from 7 to 764 microg/100 g. However, many vegetables and fruits had similar concentrations, because of the contribution of lariciresinol and pinoresinol. Brassica vegetables contained unexpectedly high levels of lignans (185-2321 microg/100 g), mainly pinoresinol and lariciresinol. Lignan levels in beverages varied from 0 (cola) to 91 microg/100 ml (red wine). Only four of the 109 foods did not contain a measurable amount of lignans, and in most cases the amount of lariciresinol and pinoresinol was larger than that of secoisolariciresinol and matairesinol. Thus, available databases largely underestimate the amount of enterolignan precursors in foods.

Optimization of a liquid chromatography-tandem mass spectrometry method for quantification of the plant lignans secoisolariciresinol, matairesinol, lariciresinol, and pinoresinol in foods.

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the quantification of the four major enterolignan precursors [secoisolariciresinol, matairesinol, lariciresinol, and pinoresinol] in foods. The method consists of alkaline methanolic extraction, followed by enzymatic hydrolysis using Helix pomatia (H. pomatia) beta-glucuronidase/sulfatase. H. pomatia was selected from several enzymes based on its ability to hydrolyze isolated lignan glucosides. After ether extraction samples were analyzed and quantified against secoisolariciresinol-d8 and matairesinol-d6. The method was optimized using model products: broccoli, bread, flaxseed, and tea. The yield of methanolic extraction increased up to 81%, when it was combined with alkaline hydrolysis. Detection limits were 4-10 microg/(100 g dry weight) for solid foods and 0.2-0.4 microg/(100 mL) for beverages. Within- and between-run coefficients of variation were 6-21 and 6-33%, respectively. Recovery of lignans added to model products was satisfactory (73-123%), except for matairesinol added to bread (51-55%).