Effect of Dietary Nori (Dried Laver) on Blood Pressure in Young Japanese Children: An Intervention Study.

BACKGROUND: Few studies have examined the association between seaweed intake and blood pressure in children. We conducted an intervention study to investigate whether seaweed intake affects blood pressure. METHODS: Subjects were children aged 4 to 5 years attending a preschool in Aichi Prefecture, Japan, in 2010. Among 99 students, 89 (89.9%) were enrolled in our study. Nori (dried laver), an edible seaweed widely consumed in Japan, was used as a dietary intervention. Children in the intervention group were asked to consume 1.76 grams per day of roasted nori in addition to standard meals for 10 weeks. Children in the control group consumed their usual diet. Before the intervention and at the 10th week of the intervention, children's blood pressure was measured three times successively using an automated sphygmomanometer with subjects in a sitting position. Changes in systolic (SBP) and diastolic blood pressure (DBP) were compared between 55 children in the intervention group and 26 in the control group after adjustment for SBP and DBP before the intervention. RESULTS: Changes in SBP were -8.29 mm Hg in the intervention group and +0.50 mm Hg in the control group (P for difference in change = 0.051). Changes in DBP were -6.77 mm Hg in the intervention group and -0.05 mm Hg in the control group (P = 0.031). In girls, no difference in blood pressure changes was found between the intervention and control groups. CONCLUSION: Nori intake lowered DBP level in boys. Seaweed intake might have preventive effects on elevated blood pressure in childhood.

Associations of Acrylamide Intake With Urinary Sex Hormone Levels Among Preschool-Age Japanese Children.

Acrylamide may affect the sex hormone system in the prepubertal period. This study examined the cross-sectional associations between dietary acrylamide intake and sex hormone levels among preschool-age Japanese children. The study was conducted in 2006 among 230 boys and 198 girls aged 3-6 years in Aichi, Japan. Acrylamide intake was assessed using 3-day diet records. Urinary concentrations of estrone, estradiol, testosterone, and androst-5-ene-3ß, 17ß diol (hereafter referred to as androstenediol) were measured by liquid chromatography-electrospray ionization-tandem mass spectrometry. Sex hormone levels were adjusted for urinary creatinine levels. The estimated acrylamide intake was 1.00 µg/kg of body weight per day. After controlling for age and other covariates, acrylamide intake was significantly positively associated with urinary levels of testosterone and androstenediol in boys. On average, boys in the highest quartile of acrylamide intake had 96.9% higher testosterone (95% confidence interval: -1.8, 295; P for trend = 0.048) and 34.5% higher androstenediol levels (95% confidence interval: -5.9, 92.3; P for trend = 0.04) than boys in the lowest quartile. In girls, there were no significant associations between acrylamide intake and the hormones measured. Acrylamide intake may alter androgen metabolism in preschool-age boys. Because this is a first observation, our findings require confirmation in additional studies.