<b></b>OBJECTIVE
<br>To investigate associations between intakes of total fish, lean
fish, fatty fish, and long chain n-3 polyunsaturated fatty acid
(LCn-3PUFA) supplements and risk of type 2 diabetes in women after
pregnancy. Furthermore, to compare the estimated intakes of
methylmercury (MeHg) and sum of dioxins and dioxin-like polychlorinated
biphenyls (dl-PCBs) to tolerable weekly intakes (TWI).
<br>RESEARCH DESIGN AND METHODS
<br>Women free of diabetes at baseline (n=60,831) who participated in
the population-based Norwegian Mother, Father, and Child Cohort study
(MoBa) were prospectively evaluated for incident type 2 diabetes
identified through medication usage more than 90 days after delivery
ascertained by the Norwegian Prescription Database. Dietary intake data
was obtained by a validated 255-item food frequency questionnaire (FFQ)
which assessed habitual diet during the first four to five months of
pregnancy. MeHg and sum of dioxins and dl-PCBs intakes were derived
using a contaminant database and the FFQ.
<br>RESULTS
<br>Median (IQR) age was 31 (27, 34) years at time of delivery and
follow-up time was 7.5 (6.5, 8.5) years. Type 2 diabetes occurred in 683
(1.1%) participants. Multivariable Cox regression analyses identified
lower risk of type 2 diabetes with increasing energy-adjusted lean fish
intake per 25 g/1000 kcal (HR 0.71, 95% CI 0.53-0.95, p=0.022). However,
in stratified analyses, a lower risk was found only in women with
pre-pregnancy BMI ≥25 kg/m2. There were no associations between intake
of total fish, fatty fish, or LCn-3PUFA supplements and type 2 diabetes.
MeHg intake was low, but the sum of dioxins and dl-PCBs (pg TEQ/kg
bw/wk) exceeded the TWI set by the European Food and Safety Authority
(EFSA) for the majority of participants.
<br>CONCLUSIONS
<br>Intake of lean fish, but not fatty fish or LCn-3PUFA supplements,
was associated with lower risk of pharmacologically treated type 2
diabetes in Norwegian women who were overweight or obese. Fatty fish,
which contain dioxins and dl-PCBs, did not increase the risk of type 2
diabetes, but the exceedance of the EFSA TWI for dioxins and dl-PCBs is a
health concern.
<br>
Dietary fish, n-3 polyunsaturated fatty acid consumption, and depression risk in Japan: a population-based prospective cohort study