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Fish Consumption And Diabetes Risk

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There’s little question that fish contain environmental pollutants such as mercury and PCBs with, generally, bigger fish such as shark and tuna containing more and smaller fish like sardines containing less. That’s been common knowledge between health researchers for a while now. The real question is whether  that translates into any of the major degenerative diseases in people (such as cancer or diabetes).


Well, sadly, in the case of diabetes it does appear to be the case.


Here’s a great video by Dr. Michael Greger summarizing the science between diabetes risk and fish consumption:



As he mentioned in the video, besides the pollutants, the causal link could also very well be the oxidative stress causing n-3 fatty acid content of the fish. That obviously goes against the mainstream opinion on diet but one can certainly find smart people that would support that notion and as far as I’ve seen the research on fish oil seems to be quite mixed.


P.S. Is there actually a way to embed a video on this site instead of just posting a link? Thanks.

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P.S. Is there actually a way to embed a video on this site instead of just posting a link? Thanks.



it usually works as a simple top-screen URL, but this time I had to copy the URL in the 'share' link. I've no idea why that.


Great vid from the redoubtable Dr. Greger. Pescetarians beware, LOL!


Edited by mccoy
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More Dr. Gregor bullshit. One should ignore the vegan bias of Dr. Gregor.


There's pollution everywhere -- the vegetables that we all eat grow in the ground, where heavy metals can enter.

When discussing fish, it depends on the fish. Ocean fish are for the most part free of undesirable pollutants -- with the exception of mercury.

Large ocean fish, such as Ahi Tuna, are high in mercury, and IMO best avoided. The same is not true of salmon and other samonids.


Since fish is my main protein source, I have my heavy metals checked, both in serum and urine. In all tests, mercury levels have been 0, to

within the accuracy of the measurement; similarly for lead, etc.


Wierdly, arsenic has been high -- so my nephrologist routinely performs more detailed arsenic tests -- the results: organic arsenic is high; inorganic arsenic is very low.

And organic arsenic is supposed to be benign.


It's probably wise for all health conscious people to have their serum and urine heavy metals checked regularly -- whether or not they are vegan, vegetarian, or fish-and-vegetables

like I am -- or land animal eaters. (But I have it hard to believe that any health conscious person would eat red maeat).


-- Saul

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I haven't looked into the fish/mercury issue  too closely, but I feel it may be a bit more complex than some suggest. I've been eating a minimal amount of red oily fish once every week or two.  I'd probably avoid fish as my main protein source because of high methionine levels--another complex subject.  I'm also concerned about overfishing and commerical fish farms.


Cf. Chris Kresser:


5 Reasons Why Concerns About Mercury in Fish Are Misguided



Mercury Toxicity, Kids & Fish Consumption


Edited by Sibiriak
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If I'm not wrong, Dr. Greger addresses the issue of EPA + DHA as potentially hazardous with a possible causal relationship with T2D.


Dr. Greger simply cites the literature, as many others do, of course those which comply with his vegan agenda, which is also anti-EVOO, a peculiar stance considering the abundance of literature on the beneficial effects of EVOO.


My subjective opinion is that it is impossible to come up to a scientific bottom line with so many sources affirming just opposite conclusions.


DHA+EPA would be beneficial to so many things but detrimental to a few other things. If it depends upon individual genes, then pure chance governs. How the heck am I supposed to know wheter DHA+EPa are going to strenghten my joints and enhance my cognition or increasing the likelyhood to develop T2D or maybe both??? Should I choose weaker joints and denser brain but no T2D?? Is there an optimum and what is it??

Edited by mccoy
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Dr. Greger simply cites the literature,


Dr. Greger has proven himself to be intellectually dishonest,  so he is a highly untrustworthy source.   Any argument he makes must be thoroughly double-checked to see that  he is not selectively citing the literature and/or misrepresenting certain studies.   Of course, that doesn't mean he isn't right a lot of the time or even most of the time.

Edited by Sibiriak
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A  "possible causal relationship with T2D" would hardly  seem to override the massive evidence of DHA/EPA benefits--especially if you are in a  low risk category for T2D based on other known risk factors.  [Greger, combining associational meta-analyses, pointed to a possible 5% increased T2D risk per serving of fish per week,  which even if true (hardly certain at all), doesn't seem that great if you eat fish once a week or less.]



Exactly how much DHA/ EPA, bioavailability concerns, fish oil supplements vs fish, ALA conversion, vegan sources etc. --these are complex issues.   A lot of good information and reasonable recommendations have been developed in other threads.  E.g., https://www.crsociety.org/topic/12378-it-ain%E2%80%99t-easy-eating-greens-evidence-of-bias-toward-vegetarians-and-vegans-from-both-source-and-target/


Personally,   I'm confident that, barring special cases or striking new evidence, a modest amount of high quality supplementation or high quality fish intake adequately addresses the DHA/EPA issue.

Edited by Sibiriak
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Also, we always have the blue zones evidence that a little fish in the diet is not detrimental (sometimes even a little meat is not). We also have a living evidence in this forum (although single cases do not constitute general rules) that substantial amounts of fish in a low-carb context are after all beneficial.


Valter Longo's longevity diet includes fish 2-3 times a week. I do not eat fish but my main concern would be contamination with Hg, PCBs, chlordane, diioxins and so on. But that is something which can be checked or optimized, as Saul's testimony proves.


Besides, we all know that vegan food, even organic, is not without its contaminants...


@ Saul: how much fish/fish protein do you eat usually? 

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(BTW, concerning Dr. Gregor's nonsense about Type 2 Diabetes -- I have one of the best sets of lipid numbers of

anyone in the CR Society -- better than most teenagers.


And I'm 78.


-- Saul


Saul, I remember a few months ago, when I started writing in this forum, I was a lacto-ovo vegetarian, eating a lot of SAFAs. Reading some posts I got concerned and had a lipid profile done. It was perfect. That probably because my lipid metabolism is good and above all because of all the regulating effect of the abundant EVOO, nuts, fibers I've been eating for decades.

That does not rule out that in sensitive people or those prone to CV disease SAFAs are better avoided or minimized.

Ditto for T2D, I reckon.


To understand Dr. Greger you should read his excellent book, 'How not to die'. He admits he has a vegan agenda, he explains his mission and why, in a very quiet style and even gives suggestions to meat eaters. All he earns outside his medical practice goes to research. He has a positive mission and that should be respected.


It is good though that we are able to discern his flaws. Maybe he has some rules dictated by the owners of nutritionfacts.org, who knows., or probably he wants to avoid some confusing truths and go all out for veganism, infusing no doubts whatsoever in people. 

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  • 1 month later...

In another thread I posted two studies indicating that  increases  in plasma EPA/ DHA after salmon intake were significantly higher than after supplemental fish oil capsules.




Just recently the indefatigable Al Pater posted this study:


Comparison of the effect of omega-3 supplements and fresh fish on lipid profile: a randomized, open-labeled trial

Nutrition & Diabetes 7, Article number: 1 (2017)





Our results indicated that treatment by both omega-3 supplements and fresh fish caused a significant decrease in total cholesterol, non-HDL cholesterol, TG levels, and total cholesterol/HDL ratio but this reduction was more prominent in the fresh fish group.


Blood LDL was another factor which was measured between the two groups. The fish oil supplement not only had no beneficial effect on the LDL level but also worsened the situation by significantly increasing the LDL level (18.95 ± 30.46%). However, in the dietary-fish group the LDL level was significantly decreased (−15.25 ± 17.97%, P < 0.001).


HDL level was increased in both groups; again, dietary-fish was more effective in raising the HDL level (11.51 ± 17.93% vs. 27.39 ± 26.76%; P = 0.001).


Both Atherogenic and Castelli II indices showed no significant change with fish oil supplementation but depicted significant decreases with fresh fish consumption. All the comparisons are shown in Table 2.


...we have noticed that fresh fish is far better than omega-3 supplements in modifying lipid profiles. This may be due to the fact that several important nutrients like selenium, vitamin D, and naturally occurring antioxidants are only found in oily fish and fish-oil supplements lack them. The dietary-fish can have another cardiovascular beneficial effect by consistently lowering the C-reactive protein levels, the effect which is absent from fish-oil supplements25, 31, 32.


Salmon contains one interesting compound that doesn't get a lot of attention:  anserine.    Anserine is  the dipeptide  beta-alanyl-3-methyl-l-histidine, a  methylated form of carnosine.  (Carnosine  has gotten a lot of attention as an potential anti-ageing substance.)


Imidazole Dipeptides: Chemistry, Analysis, Function and Effects


Anserine as a Suppressor of Fatigue



Effect of Anserine/Carnosine Supplementation on Verbal Episodic Memory in Elderly People


Anserine (beta-alanyl-3-methyl-L-histidine) improves neurovascular-unit dysfunction and spatial memory in aged AβPPswe/PSEN1dE9 Alzheimer’s-model mice



Anserine and carnosine supplementation in the elderly: Effects on cognitive functioning and physical capacity.



Edited by Sibiriak
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