Gender differences in then-3 fatty acid content of tissues

Abstract

Dietary n-3 PUFA have many beneficial effects on cell and tissue function and on human health. In mammals the n-3 essential fatty acid α-linolenic acid (ALNA) can be converted into longer-chain (LC) n-3 PUFA such as EPA and DHA via a series of desaturase and elongase enzymes that are mainly active in the liver. Human studies have identified that males and females appear to differ in their ability to synthesise EPA and DHA from ALNA, with associated differences in circulating concentrations. Based on studies of women using the contraceptive pill or hormone-replacement therapy and of trans-sexual subjects it is suggested that sex hormones play a role in these differences. The rat has been used to investigate gender differences in n-3 PUFA status since this model allows greater dietary control than is possible in human subjects. Like human subjects, female rats have higher plasma DHA concentrations than males. Rats also respond to increased dietary ALNA in a way that is comparable with available human data. The concentrations of LC n-3 PUFA in rat plasma and tissues are positively associated with circulating concentrations of oestradiol and progesterone and negatively associated with circulating concentrations of testosterone. These findings suggest that sex hormones act to modify plasma and tissue n-3 PUFA content, possibly by altering the expression of desaturase and elongase enzymes in the liver, which is currently under investigation.

Brain docosahexaenoic acid (DHA) levels of young rats are related to alpha-linolenic acid (ALA) levels and fat matrix of the diet: impact of dairy fat

“…Nonetheless, as observed by others (Childs et al, 2008;Childs et al, 2010a;Extier et al, 2010), changes in tissue fatty acid levels due to both dietary and gender influences occurred even in the brain (Du et al, 2011). Likewise, we found that the dairy fatbased diets attenuated the gender influence to a greater extent than the palm-oil-based diets.…”

The effect of sex and maturation on liver docosahexaenoic acid status in rats

“…Synthesis of 22 : 5n-3 and 22 :6n-3 appeared to be independent of 20 :5n-3 status and to be down-regulated in adults compared to juveniles. The sex difference in the proportion of 22 :6n-3, but not 22 : 5n-3, in adults is consistent with greater conversion of 22 :5n-6 to 22 : 6n-3 in women than men (1)(2)(3)(4) and with the suggestion that these metabolic reactions are regulated independently of the conversion of 18 :3n-3 to 20 :5n-3 (8) . Our findings support the suggestion that puberty represents an important influence on PUFA metabolism which acts through several regulatory loci.…”

Marked elevations in pro-inflammatory polyunsaturated fatty acid metabolites in females with irritable bowel syndrome

“…We found that total -3 levels were signifi cantly elevated in our IBS cohort compared with controls without any alteration in total -6 levels. The factors behind this shift toward the -3 fatty acids are diffi cult to exdid not take account of possible gender differences in PUFA profi les that have been previously reported ( 35 ).…”