I've read through study after study and article after article of the "real" story about soy and the isoflavones, and I must say, the most scientific conclusion we have (or atleast I have) is: we need more studies!!!
Genistein and diadzein, the two isoflavones, were repeatedly cited in many articles both pro- and anti- soy. The pro-soy mentioned their effects were ok. The anti-soy mentioned they were not ok. Both cited different studies. One study that used Rhesus monkeys found that soy proteins had no effects on the reproductive hormones of these animals. Testosterone, DHEA, sex hormone binding globulin (SHBG), testicular weight, prostatic weight, and other measurements were taken. No difference was found between male animals who ate soy protein that contained the plant estrogens and those who ate soy with the estrogens removed, leading researchers to conclude:
"Thus, the isoflavones (genistein and diadzein) in soy protein improve cardiovascular risk factors without apparent deleterious effects on the reproductive system...,"
and
"Genistein's effects appear to be tissue specific, with estrogen agonist effects on plasma lipid concentrations, plasma lipoprotein distributions and preservation of bone mass that are similar in magnitude to mammalian estrogens, but without estrogenic effects..."
They finally conclude,
"Our data support an interpretation that soy bean estrogens have tissue specificity in part because of their mixed estrogen agonist and antagonist properties."
From this and other data it seems the phytoestrogens in soy can lower cholesterol and improve heart disease risk without systemic estrogenic effects (i.e. gyno, body fat increases, etc.) that would normally be seen if a bodybuilder took estrogen pills or from the conversion of certain steroids to estrogen.
Now, I could also cite research that's anti-soy, but since Dan already did that above, it would only be redundant. The point is, there seems to be no "definitive" conclusion yet.
And anyway, as Dood mentioned, the soya oil I get there is pretty small. Like every other human being I guess, I drain the can before eating the tuna.
And to Dood,
[b said:
Quote[/b] ]3. With that much tuna consumption, shouldn't you be worried more about trace toxins building up in your body, mercury, PCB's, etc. ?
Is your concern because they come in cans? (Because I don't recall tuna having those specific concerns, but that could simply be because I missed them). If the concerns are about canned foods, well, there really is no other alternative for me right now. Anything that takes longer to prepare than just opening a can and draining the liquid won't work for me. My schedule just won't allow it right now. So canned food is all I can eat right now. In that respect I can also eat other canned goods like Spam or corned beef, but if I eat them instead of tuna, my cholesterol and sodium and saturated fat would skyrocket. So I really have no feasible alternative right now but eat canned tuna. So whether it's the traces toxins mercury and PCB's you are talking about comes from the can or from the tuna itself, I really don't have much of a choice right now.
-JV