Distribution, interconversion, and dose response of n-3 fatty acids in humans.

@article{Arterburn2006DistributionIA,
  title={Distribution, interconversion, and dose response of n-3 fatty acids in humans.},
  author={Linda M. Arterburn and Eileen Bailey Hall and Harry A. Oken},
  journal={The American journal of clinical nutrition},
  year={2006},
  volume={83 6 Suppl},
  pages={
          1467S-1476S
        }
}
n-3 Fatty acids have important visual, mental, and cardiovascular health benefits throughout the life cycle. Biodistribution, interconversion, and dose response data are reviewed herein to provide a basis for more rational n-3 dose selections. Docosahexaenoic acid (DHA) is the principal n-3 fatty acid in tissues and is particularly abundant in neural and retinal tissue. Limited storage of the n-3 fatty acids in adipose tissue suggests that a continued dietary supply is needed. A large… 

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References

SHOWING 1-10 OF 113 REFERENCES

Incorporation and washout of orally administered n-3 fatty acid ethyl esters in different plasma lipid fractions

TLDR
EPA ethyl esters are rapidly incorporated into plasma lipids, especially into PL, and the relatively long half-life of EPA in plasma would permit a dosing schedule with intervals of ≥12 h in supplementation studies.

Flaxseed oil increases the plasma concentrations of cardioprotective (n-3) fatty acids in humans.

TLDR
This study demonstrates the efficacy of the conversion of ALA to EPA and DPA in a minority population with chronic disease, and may be an alternative to fish oil; however, additional clinical trials with ALA are warranted.

Dose-response effects of fish-oil supplementation in healthy volunteers.

TLDR
It is indicated that 3 g n-3 ethyl ester fatty acids appears to be the appropriate supplementation dose in humans, at least regarding lipid-profile changes and the ability to incorporate such fatty acids in the plasma phospholipids.

Kinetics of the incorporation of dietary fatty acids into serum cholesteryl esters, erythrocyte membranes, and adipose tissue: an 18-month controlled study.

TLDR
Different (n-3) fatty acids were incorporated with different efficiencies, possibly because of interconversions or different affinities of the enzymatic pathways involved, and these findings may help in assessing the intake of n-3 fatty acids in epidemiological studies.

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

TLDR
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, and these processes may involve a system of feedback control mechanisms responsive to the plasma concentration of 23:5n- 3.

Effect of altered dietary n-3 fatty acid intake upon plasma lipid fatty acid composition, conversion of [13C]α-linolenic acid to longer-chain fatty acids and partitioning towards β-oxidation in older men

TLDR
AlNA conversion was down- regulated by increased product (EPA+DHA) availability, but was not up-regulated by increased substrate (ALNA) consumption, which suggests regulation of ALNA conversion may limit the influence of variations in dietary n-3 fatty acid intake on plasma lipid compositions.

Incorporation of long-chain n-3 fatty acids in tissues and enhanced bone marrow cellularity with docosahexaenoic acid feeding in post-weanling Fischer 344 rats

TLDR
DHA, fed as DHASCOTM, has advantages over low or moderate n-6 diets and chow as it is has both hypolipidemic- and bone marrow-enhancing properties in weanling Fischer 344 rats, suggesting that DHA supplementation may be useful in adjuvant chemotherapy.

Alpha-linolenic acid metabolism in men and women: nutritional and biological implications.

  • G. Burdge
  • Medicine
    Current opinion in clinical nutrition and metabolic care
  • 2004
TLDR
Overall, alpha-linolenic acid appears to be a limited source of longer-chain n-3 fatty acids in man and so adequate intakes of preformed n- 3 polyunsaturated fatty acids, in particular docosahexaenoic acid, may be important for maintaining optimal tissue function.

Compartmental modeling to quantify alpha-linolenic acid conversion after longer term intake of multiple tracer boluses.

TLDR
A low conversion of ALA-derived EPA into DPA might be an additional obstacle for DHA synthesis, and the limited incorporation of dietary ALA into the hepatic phospholipid pool contributes to the low hepatic conversion of AlA into EPA.
...