[Levels of mercury in hair among pregnant women in Iceland].

INTRODUCTION: To limit exposure to methylmercury several countries have implimented specific advice on fish intake to pregnant women as well a measuring compliance through regular human biomonitoring. Despite fish intake being relatively high in Iceland, human biomonitoring data on mercury is scarce. MATERIALS AND MEHODS: We measured mercury in hair from 120 pregnant women recruited in 2021 from the the Reykjavik Capital area. At recruitment, information on fish intake during the past four months was recorded. Hair mercury concentrations were compared to existing health based guidance values and associatons with fish intake was explored. RESULTS: Mean (standard deviation) mercury concentration in hair was 0.48 µg/g (0.33). All participants had concentrations in hair below 1.8 µg/g, which corresponds to the hair value that the tolerable daily intake set by the European Food Safety Authority is derived from, while 5% had concentrations above 1.1 µg/g, which corresponds to the hair value that the US-EPA reference dose is derived from. Mean mercury concentrations in hair increased in a dose dependent manner (p for trend p<0.001) from 0.25 µg/g among women who consumed fish ≤ 3/month (n=24) and up to 0.80 mg/g among those consuming fish 3-4/ week (n=16). The few (n=3) women who reported to have eaten shark (p<1/month) were all at the higher end of the exposure distribution. CONCLUSION: Our results suggest that exposure is generally below the tolerable daily intake set by EFSA but may in some women exceed the reference dose established by the US-EPA.

Whole grain rye intake, reflected by a biomarker, is associated with favorable blood lipid outcomes in subjects with the metabolic syndrome--a randomized study.

BACKGROUND AND AIM: Few studies have explored the possible plasma cholesterol lowering effects of rye consumption. The aim of this secondary analysis in the SYSDIET study was to investigate the association between plasma alkylresorcinols (AR), a biomarker for whole grain wheat and rye intake, and blood lipid concentrations in a population with metabolic syndrome. Furthermore, we analyzed the associations between the AR C17:0/C21:0 ratio, a suggested marker of the relative intake of whole grain/bran rye, and blood lipid concentrations. METHODS: Participants were 30-65 years of age, with body mass index (BMI) 27-40 kg/m2 and had metabolic syndrome. Individuals were recruited through six centers in the Nordic countries and randomized either to a healthy Nordic diet (ND, n = 93), rich in whole grain rye and wheat, as well as berries, fruits and vegetables, rapeseed oil, three fish meals per week and low-fat dairy products, or a control diet (n = 65) for 18/24 weeks. Associations between total plasma AR concentration and C17:0/C21:0 homologue ratio and blood lipids were investigated in pooled (ND + control group) regression analyses at 18/24 weeks adjusted for baseline value for the dependent variable, age, BMI and statin use. RESULTS: When adjusted for confounders, total plasma AR at 18/24 weeks was not significantly associated with blood lipids but the AR ratio C17:0/C21:0 was inversely associated with LDL cholesterol concentrations (B (95% CI): -0.41 (-0.80 to -0.02)), log LDL/HDL cholesterol ratio (-0.20 (-0.37 to -0.03)), log non-HDL cholesterol (-0.20 (-0.37 to -0.03)), log apolipoprotein B (-0.12 (-0.24 to 0.00)) and log triglyceride concentrations (-0.35 (-0.59 to -0.12)). DISCUSSION: Increased proportion of whole grain rye, reflected by a biomarker, in the diet is associated with favorable blood lipid outcomes, a relationship that should be further investigated. TRIAL REGISTRATION: ClinicalTrials.gov NCT00992641.

Plasma alkylresorcinols reflect important whole-grain components of a healthy Nordic diet.

Biomarkers of dietary intake can be important tools in nutrition research. Our aim was to assess whether plasma alkylresorcinol (AR) and ß-carotene concentrations could be used as dietary biomarkers for whole-grain, fruits and vegetables in a healthy Nordic diet (ND). Participants (n = 166), 30-65 y with a body mass index of 27-40 kg/m(2) and two more features of metabolic syndrome (International Diabetes Federation definition, slightly modified), were recruited through six centers in the Nordic countries and randomly assigned to an ND or control diet for 18 or 24 wk, depending on study center. Plasma AR and ß-carotene were analyzed and nutrient intake calculated from 4-d food records. Median fiber intake increased in the ND group from 2.5 g/MJ at baseline to 4.1 g/MJ (P < 0.001) at end point (week 18 or 24), and median (IQR) fasting plasma total AR concentration increased from 73 (88) to 106 (108) nmol/L, or 45%, from baseline to end point (P < 0.001). The AR concentration was significantly higher in the ND group (P < 0.001) than in the control group at end point. ß-Carotene intake tended to increase in the ND group (P = 0.07), but the plasma ß-carotene concentration did not change significantly throughout the study and did not differ between the groups at follow-up. In conclusion, an ND resulted in higher dietary fiber intake and increased plasma total AR concentration compared with the control diet, showing that the total AR concentration might be a valid biomarker for an ND in which whole-grain wheat and rye are important components. No significant difference in plasma ß-carotene concentrations was observed between the ND and control groups, suggesting that ß-carotene may not be a sensitive enough biomarker of the ND.