Elsevier

Environment International

Volume 121, Part 2, December 2018, Pages 1098-1105
Environment International

Fatty fish, hair mercury and cognitive function in Norwegian preschool children: Results from the randomized controlled trial FINS-KIDS

https://doi.org/10.1016/j.envint.2018.10.022Get rights and content
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Highlights

  • A fatty fish intervention increased mercury hair-concentration in preschoolers.

  • Mercury exposure from the intervention was below the tolerable weekly intake.

  • The mercury hair-concentration remained below points of departures shown by EFSA.

  • Mercury hair-concentration was not related to cognition in the preschoolers.

Abstract

Background

The toxic effects of prenatal methylmercury (MeHg) include neurological abnormalities and developmental delay of which infants and children are particular susceptible. Studies on the effects of low and moderate exposure show conflicting results. Seafood is the main dietary source of MeHg, but also contributes with nutrients regarded as beneficial for development.

Objectives

To measure the change in total hair mercury concentration (THHg) after an intervention of lunch meals with fatty fish or meat in Norwegian preschool children, and to examine the associations between THHg and cognitive function.

Methods

Children (n = 232) 4–6 years old were randomized to lunch meals with fatty fish (n = 114) or meat (n = 118) three times a week for 16 weeks. THHg was determined using a Direct Mercury Analyzer, and cognitive function was assessed by the Wechsler Preschool and Primary Intelligence Scale-III (WPPSI-III) pre- and post-intervention. Linear mixed effect models were used to analyze changes in THHg and WPPSI-III scores.

Results

The mean (SD) THHg pre-intervention was 0.373 (0.204) mg kg−1. Children in the fish group had an increase in THHg (change 0.162, 95% CI 0.111, 0.213 mg kg−1), whereas children in the meat group had decreased THHg (−0.053, 95% CI −0.103, −0.002 mg kg−1). There were no notable associations between THHg and the WPPSI-III raw scores at baseline or after 16 weeks of the fish/meat intervention.

Conclusions

Lunch meals including fatty fish led to a significant increase in THHg, but the values remain below the point of departures used for risk assessment by the EFSA, WHO and US-EPA. We observed no associations between THHg and cognitive function.

Abbreviations

bw
birth weight
CNS
central nervous system
DHA
docosahexaenoic acid
EFSA
European Food Safety Authority
EPA
eicosapentaenoic acid
FFQ
food frequency questionnaire
Hg
mercury
IMR
Institute of Marine Research
LOD
limit of detection
LOQ
limit of quantification
MeHg
methylmercury
n-3 LC-PUFA
long chain n-3 polyunsaturated fatty acids
RBC
red blood cells
RfD
reference dose
RCT
randomized controlled trial
SES
socio-economic status
THHg
total hair mercury concentration
TWI
tolerable weekly intake
UFGC
ultrafast gas chromatographic
US-EPA
United States Environmental Protection Agency
VKM
Norwegian Scientific Committee for Food Safety
WPPSI-III
Wechsler Preschool and Primary Scale of Intelligence, 3rd edition
FIQ
Full-Scale IQ
VIQ
Verbal IQ
PIQ
Performance IQ
PSI
processing speed index

Keywords

Hair mercury
Methylmercury
Fish consumption
Cognitive development
Preschool children

Cited by (0)

1

These authors share first authorship.

2

Current affiliation: NORCE Norwegian Research Center, Bergen, Norway.

3

Current affiliation: Directorate of Fisheries, Bergen, Norway.