Posted by Larry Hoover on October 30, 2002, at 10:33:06
I am a research addict. I can't help myself. <big grin>
The more I read about the beneficial health effects of long-chain omega-3
fatty acids, the more convinced I am that every person should be taking
them. If you have any sort of mental disorder, I cannot emphasize enough,
take fish oil! There is now evidence that DHA, the longer of the two omega-3
in fish oil, actually regulates transcription of DNA in the brain. It not
only acts as a functional component of neuronal membranes, making the
receptors work better, it also helps control the number of receptors, and
how sensitive they are (among other things).People sometimes report that they have problems taking fish oil, due to
stomach upset. There may be a good scientific reason for that......if you're
deficient in essential fatty acids, you do not secrete bile sufficient for
the absorption of fatty acids, and you get stomach upset, gas, and
possibly, diarrhea. The only solution is to start at a low dose, and
gradually work up as tolerance builds. (The same holds true for many
nutrients, by the way. Deficiency of some nutrients is actually caused by
deficiency of those same nutrients, because of malabsorption.) Another
reason for stomach upset is poor quality fish oil. If you break a capsule
open,
it should not smell strongly 'fishy'. In any case, if stomach upset occurs,
try
changing brands. Look for one with tocopherol added (a natural preservative,
vitamin E).I've posted links to Medline articles, from which I've extracted some
quotations. If your browser does not show the whole link as highlighted
text, make sure you paste in the wrapped portion.Some of these articles also have links to full-text versions. If so, there
will be a link right below the title, on the Medline page.http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=12002796&dopt=Abstract"Dietary n-3 FA deficiency influences specific neurotransmitter systems,
particularly the dopamine systems of the frontal cortex."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=11929197&dopt=Abstract"Phospholipid supplementation induced a significant increase of b-wave
amplitude in both control and deficient groups and restored normal fatty
acid composition in brain regions and retina in deficient mice. DHA-rich
phospholipids may improve learning ability, visual function and reverse
biochemical modifications in old mice fed an n-3 polyunsaturated fatty
acid-deficient diet; they also may improve visual function in old mice fed a
balanced diet."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=11724460&dopt=Abstract"Comprehensive clinical studies have shown that dietary supplementation with
marine oil or single-cell oil sources of LC-PUFA results in increased blood
levels of DHA and arachidonic acid, as well as an associated improvement in
visual function in formula-fed infants matching that of human breast-fed
infants. The effect is mediated not only by the known effects on membrane
biophysicalproperties, neurotransmitter content, and the corresponding
electrophysiological correlates but also by a modulating gene expression of
the developing retina and brain.....DHA also has significant effects on
photoreceptor membranes and neurotransmitters involved in the signal
transduction process; rhodopsin activation, rod and cone development,
neuronal dendritic connectivity, and functional maturation of the central
nervous system."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=2139096&dopt=Abstract"The results of serial biopsy samples of the cerebral cortex indicated that
the changes of brain fatty acid composition began as early as 1 week after
fish oil feeding and stabilized at 12 weeks. The DHA content of the
phosphatidylethanolamine of the frontal cortex increased progressively from
3.9 +/- 1.2 to 28.4 +/- 1.7 percent of total fatty acids. The n-6 fatty
acid, 22:5, abnormally high in the cerebral cortex of n-3 deficient monkeys,
decreased reciprocally from 16.2 +/- 3.1 to 1.6 +/- 0.4%. The half-life (t
1/2) of DHA in brain phosphatidylethanolamine was estimated to be 21
days....The biochemical evidence of n-3 fatty acid deficiency was completely
corrected."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=11590222&dopt=Abstract"These results indicate that the altered learning behavior associated with a
long-term n-3 fatty acid deficiency is reversed by supplementing 22:6n-3
after weaning, when the levels of competing n-6 fatty acids in the diet and
brain lipids are limited."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=11880617&dopt=Abstract"The altered genes included those controlling synaptic plasticity,
cytosceleton and membrane association, signal transduction, ion channel
formation, energy metabolism, and regulatory proteins. This effect seems to
be independent of the chain length of fatty acids, but the n-3 structure
appears to be important. Because n-3 polyunsaturated fatty acids have been
shown to play an important role in maintaining normal mental functions and
docosahexaenoic acid-containing ethanolamine phosphoglyceride (18:0/22:6)
molecular species accumulated in response to n-3 fatty acid feeding, a
casual relationship between the two events can be surmised."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=12296294&dopt=Abstract"Feeding fish oil results in partial replacement of arachidonic acid in
inflammatory cell membranes by EPA. This change leads to decreased
production of arachidonic acid-derived mediators. This response alone is a
potentially beneficial anti-inflammatory effect of n-3 PUFA. However, n-3
PUFA have a number of other effects which might occur downstream of altered
eicosanoid production or might be independent of this activity. For example,
animal and human studies have shown that dietary fish oil results in
suppressed production of pro-inflammatory cytokines and can decrease
adhesion molecule expression. These effects occur at the level of altered
gene expression. This action might come about through antagonism of the
effects of arachidonic acid-derived mediators or through more direct actions
on the intracellular signalling pathways which lead to activation of
transcription factors such as nuclear factor kappa B (NFB). Recent studies
have shown that n-3 PUFA can down regulate the activity of the nuclear
transcription factor NFB."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=11725696&dopt=Abstract"The supplement group received the ingredients in chow inserts at a dosage
that was equivalent to three times the maximum safe daily dosage for fish
oil and the usual daily dosage for garlic (the maximum safe daily dosage
recommended by the United States Food And Drug Administration for a 70-kg
human is a total of 3 g/day intake of EPA and HDA omega-3 fatty acids from
conventional and dietary sources....Acutely and chronically, there were no
differences in external appearance, level of activity, daily food
consumption, blood cell count, kidney function, thyroid function,
prothrombin time (PT), and activated partial prothrombin time (PTT), which
remained within normal ranges in the supplement group. Organ histology
remained unchanged. Although during the chronic toxicity period the
triglyceride and LDL suppression persisted, it was noted that total
cholesterol and HDL levels increased."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=10617969&dopt=Abstract"In the United States, intake of n-3 fatty acids is approximately 1.6 g/d
( approximately 0.7% of energy), of which 1.4 g is alpha-linolenic acid
(ALA; 18:3) and 0.1-0.2 g is eicosapentaenoic acid (EPA; 20:5) and
docosahexaenoic acid (DHA; 22:6)....Attaining the proposed recommended
combined EPA and DHA intake of 0.65 g/d will require an approximately 4-fold
increase in fish consumption in the United States."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=11844977&dopt=Abstract"For adults, n-3 long chain polyunsaturated fatty acid supplementation is
implicated in improving a wide range of clinical pathologies involving
cardiac, kidney, and neural tissues. Studies generally agree that whole body
conversion of 18:3n-3 to 22:6n-3 is below 5% in humans, and depends on the
concentration of n-6 fatty acids and long chain polyunsaturated fatty acids
in the diet."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=11478378&dopt=Abstract"...brain slices from Et-DHA-treated fetuses formed less oxidation products,
as detected by thiobarbituric acid (TBA), compared to controls. Furthermore,
brain-lipid extracts from Et-DHA but not ethyl-oleate treated fetuses,
exhibited hydroxyl radical scavenging activity, as demonstrated by electron
spin-resonance technique. Part of the beneficial effect of Et-DHA
administration on the fetal brain may be attributed to enhanced free-radical
scavenging capability, a phenomenon not directly related to vitamin E or
lipid-soluble antioxidant levels."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=8093816&dopt=Abstract"In our experiments, feeding animals with oils that have a low
alpha-linolenic content results in all brain cells and organelles and
various organs in reduced amounts of 22:6(n-3), compensated by an increase
in 22:5(n-6). The speed of recuperation from these anomalies is extremely
slow for brain cells, organelles and microvessels, in contrast with other
organs. A decrease in alpha-linolenic series acids in the membranes results
in a 40% reduction in the Na-K-ATPase of nerve terminals and a 20% reduction
in 5'-nucleotidase. Some other enzymatic activities are not affected,
although membrane fluidity is altered. A diet low in ALNA induces
alterations in the electroretinogram which disappear with age: motor
function and activity are little affected but learning behaviour is markedly
altered. The presence of ALNA in the diet confers a greater resistance to
certain neurotoxic agents, i.e. triethyl-lead."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=2564887&dopt=Abstract"The amounts estimated to prevent deficiencies in the elderly are 800-1100
mg/d of alpha-linolenic acid and 300-400 mg/d of EPA and DHA combined. "http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=9323581&dopt=Abstract"The adequate supply of essential fatty acids (EFA) to the body depends upon
sufficient dietary intake and subsequent efficient intestinal absorption.
Lipid malabsorption is not only a leading cause of EFA deficiency (EFAD),
but also occurs secondarily to EFAD....EFAD in itself affects the deficiency
state by impairment of EFA absorption due to its effects on bile formation
and on chylomicron secretion."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=11115801&dopt=Abstract"Data from the Rotterdam Study showed that high intakes of the following
nutrients were associated with an increased risk of dementia after
adjustment for confounders: total fat (RR=2.4 (95%CI: 1.1-5.2)), saturated
fat (RR=1.9 (95%CI: 0.9-4.0)), and cholesterol (RR=1.7 (95%CI: 0.9-3.2)). A
high fish consumption, an important source of n-3 PUFAs, reduced the risk of
dementia (RR=0.4 (95%CI: 0.2-0.9)). In the Zutphen Elderly Study a high
linoleic acid intake was associated with cognitive impairment (OR=1.8
(95%CI: 1.0-3.0)). A high fish consumption tended to be inversely associated
with cognitive impairment and decline (RR=0.5, 95%CI: 0.2-1.2)."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_ui
ds=8192673&dopt=Abstract"Feeding animals with diets high in saturated fat induces insulin
resistance, and replacing saturated fat isocalorically with poly-unsaturated
fat, especially long-chain omega-3 fatty acids, will prevent the development
of insulin resistance in skeletal-muscle tissue....Insulin binding to intact
sarcolemmal vesicles prepared from rats fed on diets high in omega-3 fatty
acids increased 14-fold compared with animals fed on the low-omega-3 diet (P
< 0.0001)."
poster:Larry Hoover
thread:125809
URL: http://www.dr-bob.org/babble/20021025/msgs/125809.html