Effects of beef- and fish-based diets on the kinetics of n−3 fatty acid metabolism in human subjects

Abstract

The primary effect of a fish-based diet on the kinetics of n-3 metabolism involves processes that inhibit the synthesis of 22:6n-3 from 22:5n-3. These processes may involve a system of feedback control mechanisms responsive to the plasma concentration of 22:6n-3.

Conversion of α-linolenic acid to longer-chain polyunsaturated fatty acids in human adults

“…There was a 76% reduction in EPA synthesis and an 88% reduction in DHA synthesis in the group receiving the DHA supplement. Others have reported a decrease in the conversion efficiency of DPAn-3 to DHA following consumption of a fish-based diet (containing EPA + DHA) compared to a beef-based diet in a mixed group of men and women [57]. However, when the fractional conversion of DPAn-3 to DHA was calculated separately for men and women, the decrease in DHA synthesis as a result of consuming a fish-based diet was only found in the female subjects [58].…”

“…While there are advantages in terms of safety, there are unresolved issues regarding standardisation of quantification of data (particularly how conversion between fatty acids should be estimated), kinetic modelling, variation between subjects including age and gender, the method of administration of the labelled fatty acid, the duration of the study, the extent to which the background diet is controlled and the use of measurements of labelled fatty acids in blood (including which lipid pool should be measured) as a marker of fatty acid metabolism within tissues [53]. Together these factors have resulted in considerable heterogeneity in the findings of studies of αLNA metabolism in humans using stable isotope tracers [21,23,25,27,32,[54][55][56][57]. This presents a considerable challenge to any attempt to reach a consensus view on αLNA metabolism in man.…”

Metabolism and functional effects of plant-derived omega-3 fatty acids in humans

“…The estimated mean net conversion rate of ALA to EPA in women (mean age 28 years) was 21% compared to 8% in men (age range 27 to 40 years) and the estimated mean net conversion rate of ALA to DHA was 9% in the women and 0% in the men [30,31]. Pawlosky et al reported a decrease in the conversion of DPA to DHA in women, but not men,after consuming a fish based diet providing EPA+DHA [115]. Modification of the diet by increasing consumption of EPA in combination with DHA, or of DHA alone, may affect the extent of ALA conversion, as there is potential for feedback inhibition of the pathway.…”

Effect of Diet and Exercise on Plaque Psoriasis in Children

“…Relation between food and psoriasis and metabolic syndrome was investigated proving our idea about food and an auto immune disease like psoriasis [21][22][23][24][25][26][27][28].…”