Posted by Larry Hoover on September 13, 2003, at 8:08:37
In reply to omega 3, posted by oeps7 on September 13, 2003, at 7:23:29
> It seems like this works for some of you. Is there any weight gain with this?
Each gram of fish oil contains 9 calories. That is trivial, in the greater scheme of things. Moreover, omega-3 *deficiency* is associated with weight gain, so taking fish oil may promote weight loss.
> I am thinking of trying this route, I just came off effexor xr. I tried flaxseed oil but that didn't seem to do anything.
Even if fish oil doesn't obviously affect your mood, I can guarantee, absolutely guarantee, that it will be good for your heart, arteries, insulin sensitivity, and will help prevent Alzheimer's disease. Mood effects would be bonus.
> I have also tried yoga, meditation, cognitive therapy, subliminal tapes, etc. Right now I seem to feel better with no therapy. This website seems to help me more than anything has.
> MaryIn my opinion, there is no substitute for fish oil (except eating fish itself).
I've pasted in a few abstracts here, and they probably have "more information than I wanted to know", but they do tell the tale; flax oil is not efficiently converted to the fatty acids found in fish oil, particularly by males. From the first abstract:
"Since the capacity of adult males to convert ALNA (alpha-linolenic acid, the one if flax oil)to DHA (docosahexaenoic acid, one of the two in fish oil)was either very low or absent, uptake of pre-formed DHA from the diet may be critical for maintaining adequate membrane DHA concentrations in these individuals."
Br J Nutr 2002 Oct;88(4):355-64Eicosapentaenoic and docosapentaenoic acids are the principal products of alpha-linolenic acid metabolism in young men*.
Burdge GC, Jones AE, Wootton SA.
Institute of Human Nutrition, Level C, West Wing, Southampton General Hospital, Tremona Road, Southampton, SO16 6YD, UK.
The capacity for conversion of alpha-linolenic acid (ALNA) to n-3 long-chain polyunsaturated fatty acids was investigated in young men. Emulsified [U-13C]ALNA was administered orally with a mixed meal to six subjects consuming their habitual diet. Approximately 33 % of administered [13C]ALNA was recovered as 13CO2 on breath over the first 24 h. [13C]ALNA was mobilised from enterocytes primarily as chylomicron triacylglycerol (TAG), while [13C]ALNA incorporation into plasma phosphatidylcholine (PC) occurred later, probably by the liver. The time scale of conversion of [13C]ALNA to eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA) suggested that the liver was the principal site of ALNA desaturation and elongation, although there was some indication of EPA and DPA synthesis by enterocytes. [13C]EPA and [13C]DPA concentrations were greater in plasma PC than TAG, and were present in the circulation for up to 7 and 14 d, respectively. There was no apparent 13C enrichment of docosahexaenoic acid (DHA) in plasma PC, TAG or non-esterified fatty acids at any time point measured up to 21 d. This pattern of 13C n-3 fatty acid labelling suggests inhibition or restriction of DHA synthesis downstream of DPA. [13C]ALNA, [13C]EPA and [13C]DPA were incorporated into erythrocyte PC, but not phosphatidylethanolamine, suggesting uptake of intact plasma PC molecules from lipoproteins into erythrocyte membranes. Since the capacity of adult males to convert ALNA to DHA was either very low or absent, uptake of pre-formed DHA from the diet may be critical for maintaining adequate
membrane DHA concentrations in these individuals.Br J Nutr 2002 Oct;88(4):411-421
Conversion of alpha-linolenic acid to eicosapentaenoic, docosapentaenoic and docosahexaenoic acids in young women.
Burdge GC, Wootton SA.
Institute of Human Nutrition, University of Southampton, Southampton, UK.
The extent to which women of reproductive age are able to convert the n-3 fatty acid alpha-linolenic acid (ALNA) to eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) was investigated in vivo by measuring the concentrations of labelled fatty acids in plasma for 21 d following the ingestion of [U-13C]ALNA (700 mg). [13C]ALNA excursion was greatest in cholesteryl ester (CE) (224 (sem 70) &mgr;mol/l over 21 d) compared with triacylglycerol (9-fold), non-esterified fatty acids (37-fold) and phosphatidylcholine (PC, 7-fold). EPA excursion was similar in both PC (42 (sem 8) &mgr;mol/l) and CE (42 (sem 9) &mgr;mol/l) over 21 d. In contrast both [13C]DPA and [13C]DHA were detected predominately in PC (18 (sem 4) and 27 (sem 7) &mgr;mol/l over 21 d, respectively). Estimated net fractional ALNA inter-conversion was EPA 21 %, DPA 6 % and DHA 9 %. Approximately 22 % of administered [13C]ALNA was recovered as 13CO2 on breath over the first 24 h of the study. These results suggest differential partitioning of ALNA, EPA and DHA between plasma lipid classes, which may facilitate targeting of individual n-3 fatty acids to specific tissues. Comparison with previous studies suggests that women may possess a greater capacity for ALNA conversion than men. Such metabolic capacity may be important for meeting the demands of the fetus and neonate for DHA during pregnancy and lactation. Differences in DHA status between women both in the non-pregnant state and in pregnancy may reflect variations in metabolic capacity for DHA synthesis.
Int J Vitam Nutr Res 1998;68(3):159-73
Can adults adequately convert alpha-linolenic acid (18:3n-3) to eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3)?
Gerster H.
Vitamin Research Department, F. Hoffman-Roche Ltd, Basel, Switzerland.
A diet including 2-3 portions of fatty fish per week, which corresponds to the intake of 1.25 g EPA (20:5n-3) + DHA (22:6n-3) per day, has been officially recommended on the basis of epidemiological findings showing a beneficial role of these n-3 long-chain PUFA in the prevention of cardiovascular and inflammatory diseases. The parent fatty acid ALA (18:3n-3), found in vegetable oils such as flaxseed or rapeseed oil, is used by the human organism partly as a source of energy, partly as a precursor of the metabolites, but the degree of conversion appears to be unreliable and restricted. More specifically, most studies in humans have shown that whereas a certain, though restricted, conversion of high doses of ALA to EPA occurs, conversion to DHA is severely restricted. The use of ALA labelled with radioisotopes suggested that with a background diet high in saturated fat conversion to long-chain metabolites is approximately 6% for EPA and 3.8% for DHA. With a diet rich in n-6 PUFA, conversion is reduced by 40 to 50%. It is thus reasonable to observe an n-6/n-3 PUFA ratio not exceeding 4-6. Restricted conversion to DHA may be critical since evidence has been increasing that this long-chain metabolite has an autonomous function, e.g. in the brain, retina and spermatozoa where it is the most prominent fatty acid. In neonates deficiency is associated with visual impairment, abnormalities in the electroretinogram and delayed cognitive development. In adults the potential role of DHA in neurological function still needs to be investigated in depth. Regarding cardiovascular risk factors DHA has been shown to reduce triglyceride concentrations. These findings indicate that future attention will have to focus on the adequate provision of DHA which can reliably be achieved only with the supply of the preformed long-chain metabolite.
poster:Larry Hoover
thread:259580
URL: http://www.dr-bob.org/babble/alter/20030903/msgs/259584.html