Impact of prenatal exposure to cadmium on cognitive development at preschool age and the importance of selenium and iodine.

The evidence regarding a potential link of low-to-moderate iodine deficiency, selenium status, and cadmium exposure during pregnancy with neurodevelopment is either contradicting or limited. We aimed to assess the prenatal impact of cadmium, selenium, and iodine on children's neurodevelopment at 4 years of age. The study included 575 mother-child pairs from the prospective "Rhea" cohort on Crete, Greece. Exposure to cadmium, selenium and iodine was assessed by concentrations in the mother's urine during pregnancy (median 13 weeks), measured by ICPMS. The McCarthy Scales of Children's Abilities was used to assess children's general cognitive score and seven different sub-scales. In multivariable-adjusted regression analysis, elevated urinary cadmium concentrations (≥0.8 µg/L) were inversely associated with children's general cognitive score [mean change: -6.1 points (95 % CI -12; -0.33) per doubling of urinary cadmium; corresponding to ~0.4 SD]. Stratifying by smoking status (p for interaction 0.014), the association was restricted to smokers. Urinary selenium was positively associated with children's general cognitive score [mean change: 2.2 points (95 % CI -0.38; 4.8) per doubling of urinary selenium; ~0.1 SD], although the association was not statistically significant. Urinary iodine (median 172 µg/L) was not associated with children's general cognitive score. In conclusion, elevated cadmium exposure in pregnancy of smoking women was inversely associated with the children's cognitive function at pre-school age. The results indicate that cadmium may adversely affect neurodevelopment at doses commonly found in smokers, or that there is an interaction with other toxicants in tobacco smoke. Additionally, possible residual confounding cannot be ruled out.

Belief in life after death, salivary 3-methoxy-4-hydroxyphenylglycol, and well-being among older people without cognitive impairment dwelling in rural Japan.

OBJECTIVES: Research has found that spirituality/religiosity has a salutary association with mental/physical health. However, the association of belief in life after death with well-being has rarely been studied, and the same is true of its association with biological indices, such as monoamine transmitters. Therefore, we examined the associations between well-being and religiosity, salivary 3-methoxy-4-hydroxyphenylglycol (sMHPG), and demographic characteristics. METHODS: The participants were 346 community-dwelling people, aged 65 years or older, without cognitive or mental deficits, in rural Japan. Measures of religiosity consisted of belief in life after death, attachment to life, and experiences related to death and religion. The measures were assessed by scales specifically suited for Japanese religious orientations. Participants' well-being was assessed by a life satisfaction scale containing two subscales. We also measured sMHPG, a major metabolite of noradrenaline that is thought to reflect certain psychological states, such as psychomotor retardation and effortful attention. RESULTS: One subscale of life satisfaction was positively associated with belief in life after death and sMHPG, and the other life satisfaction subscale was positively associated with education and death/religion-related experiences (e.g., visiting family graves or loss of a friend). Gender differences were found in afterlife beliefs and each life satisfaction subscale. CONCLUSIONS: These results suggest that religiosity, including belief in life after death and death/religion-related experiences, is salubriously associated with mental health among older people, especially women, living in rural Japan. The basal level of sMHPG was positively associated with life satisfaction, but not with belief in life after death.

Associations between urine excretion of isoflavonoids and cognition in postmenopausal women in the Women's Isoflavone Soy Health clinical trial.

OBJECTIVES: To determine effect of change in urine excretion of isoflavonoids on cognitive change. DESIGN: Post hoc analysis of isoflavonoid exposure (mean 2.7 years) during the randomized, placebo-controlled, double-blind Women's Isoflavone Soy Health trial. SETTING: General community. PARTICIPANTS: Healthy postmenopausal women (N = 350). INTERVENTION: Twenty-five grams of isoflavone-rich soy protein (91 mg of aglycone weight isoflavones: 52 mg genistein, 36 mg daidzein, 3 mg glycitein) or milk protein-matched placebo provided daily. MEASUREMENTS: Overnight urine excretion, fasting plasma levels of isoflavonoids, and cognitive function measured at baseline and endpoint. RESULTS: Three hundred women (age: mean 61, range 45-92) completed both cognitive assessments and did not use hormone replacement therapy during the trial. Mean on-trial change from baseline in urine excretion of isoflavonoids was not significantly associated with change in a composite score of global cognition (P = .39). Secondary analyses indicated that change in urine excretion of isoflavonoids was inversely associated with change in a factor score representing general intelligence (P = .02) but not with factor scores representing verbal or visual episodic memory. Mean differences in this general intelligence factor score between women in the lowest and highest quartiles of isoflavonoid change were equivalent to an approximate 4.4-year age-associated decline. Analyses based on plasma isoflavonoid levels yielded similar but attenuated results. CONCLUSION: In healthy postmenopausal women, long-term changes in isoflavonoids are not associated with global cognition, supporting clinical trial results, although greater isoflavonoid exposure from dietary supplements is associated with decrements in general intelligence but not memory; this finding requires confirmation in future studies.