Posted by Larry Hoover on November 23, 2002, at 12:26:36
In reply to Thanks for the answer; last question, I promise, posted by bubblegumchewer on November 23, 2002, at 11:28:01
> Thanks, Lar. Of course I posted before seeing your nice, detailed answer. I thought I was pretty sure that the anticoagulation effect was nothing to worry about but I wanted to hear it from someone who seems to know.
Emphasis on the "seemed to know". My advice might be worth what you pay for it.
> Do you happen to know anything about the immunosuppression subject which I touched on? I remember doing research and hearing rumblings of suppression of natural killer cell activity, and of proliferation of colon tumors upon administration of certain PUFAs. Just curious if you know what is up with this subject. Is there a threshhold amount or proportion of blood fats that predisposes one to non-optimal immune status? Thanks in advance for letting me pick your brain.
Again, the modulation of immunoreactivity has to be seen in the context of the baseline immunological function. Omega-6 fats increase immunoreactivity, whereas omega-3 fats diminish it, in broad strokes. The increase in autoimmune disease over the last century alone argues for an excessive immunoreactivity in the general population, which correlates nicely with the massive distortion in omega-6:omega-3 intake ratios over that period. Studies showing inhibition of T-cell lymphocyte activity and so on, after administration of fish oil, are probably a good thing. There is no evidence that high omega-3 intake leads to a compromisation of immune function.
Also, the fact that certain cancer lineages employ products of omega-3 fatty acid metabolism ought not to be too surprising. The cancer cells are, after all, human cells to begin with. For a cancer line to flourish, it must first pass through a number of stages of promotion. In the context of overall morbidity, fish consumption reduces cancer risk in the entire digestive tract, not just the colon.
The PUFAs in fish oil can be thought of as being highly reactive because they have multiple reaction sites (each unsaturated position is a reactive site). Oxidation at a reactive site, under enzymatic control, turns the PUFA into a potential signalling compound. The products are highly specific, and chiral (having three-dimensional uniqueness). Formation of signalling compounds through selective oxidation is just one of the ways we know that the PUFAs in fish oil have regulative capacity. The cancer link is because one such compound promotes the formation of new blood vessels. This feeds the tumour. But, it's perfectly natural.