Weight and BMI influence the response to omega-3 PUFA supplementation
Data from observational and experimental studies indicate that consuming omega-3 polyunsaturated fatty acids (n-3 PUFA) is beneficial to cardiovascular health in children aged 8 to 15 (they reduce systolic blood pressure and increase high-density lipoproteins (HDL)), while data from randomised, controlled trials support the idea that they have a positive effect on reducing symptoms of depression and mania in children aged 6 to 17.
Recommendations for n-3 PUFA intake in children are based mainly on age. The dose increase with age reflects greater bodily requirements due to changes in weight; from 2 to 8 years, children’s weight increases by approximately 138% in boys and 141% in girls, with an additional increase of 110% and 84% in boys and girls, respectively, between 9 and 18 years. However, interindividual variability in weight at these ages is very high and there are also data indicating body mass index (BMI) is a better predictor of response to n-3 PUFA dietary supplementation than weight, suggesting that recommendations should be mainly based on BMI.
With these premises, a recent double-blind, randomised, controlled trial studied the effects of body weight and BMI on n-3 PUFA concentrations after daily supplementation with 2,000 mg of n-3 PUFA (1,400 EPA, 200 mg DHA and 400 mg other PUFA) or placebo for 12 months in children aged 7 to 14 diagnosed with mood disorder.
In the PUFA-supplemented group, a higher body weight and higher BMI percentile on starting the trial were predictors for significantly lower plasma concentrations of both EPA and DHA at the end of the intervention period. It is worth noting that there were no differences in initial PUFA plasma levels related to weight or BMI at the start of the study; therefore, the final differences found were not due to prior differences before supplementation. In addition, the influence of weight on the degree of increase of n-3 PUFA concentrations after supplementation had already been observed in trials with adults.
After six months’ intervention, no changes were observed in the placebo group.
There is a linear correlation between PUFA plasma concentrations and both weight and BMI percentile. But given that this relationship does not distinguish the BMI category ‘overweight or obese’, the supplementation dose should preferably be related to weight, rather than age or even BMI.
Christian LM, Young AS, Mitchell AM et al. Body weight affects ω-3 polyunsaturated fatty acid (PUFA) accumulation in youth following supplementation in post-hoc analyses of a randomized controlled trial. PLoS One. 2017 Apr 5;12(4):e0173087 pii: