Friday, September 05, 2008

On the plus side for fish (oils?)

This paper from Chris makes a nice counterbalance to the fish oil and hepatic lipidosis posts. Long term the omega 3s have benefits. Avoiding omega 6s and avoiding "food" which comes in a plastic wrap does even more in combination. I love interventions which improve insulin sensitivity. If you're not going to mainline leptin I'd suggest fish might be a good idea (or maybe the oils)... I love stuff which increases insulin sensitivity.

Peter

BTW The link in this one is interesting too!

2 comments:

ItsTheWooo said...

I think Chris is misinterpreting the findings. Leptin correlates with insulin; leptin signalling is more effective when insulin reduces (that is, per unit of leptin) but absolute leptin effects and leptin levels always decrease as insulin and body fat decreases.

I get the gist from Chris' post that he is under the impression reducing insulin (or body fat, or IR) will increase leptin... this is the opposite of what happens.

Triglycerides (which are increased by insulin) will prevent leptin from crossing the blood brain barrier effectively (which is where effects on satiety occur)... but leptin is less effective peripherally when insulin is decreased (decreased metabolic rate, for example: skeletal muscle oxidizing of fats, or conversion of T4 to T3, as another example).


Another problem is it's not mention what the fish group was compared to... a diet that substitutes 100 cal of snackwells for 100 cal of fat/protein (fish or otherwise) is obviously going to reduce insulin, body fat, IR, and leptin more than the carb diet, if calories are equal and low.

I do think omega 3s have benefits on IR (thus insulin and leptin) via reduced inflammation, though, but we have to keep carb/fat/pro constant and only change types of fat to really measure that, I think.

Bruce K said...

The truth about fish oil supplements is somewhat more complex, as Ray Peat, Guy Schenker, Chris Masterjohn, and Brian Peskin point out. I would not use fish oil except raw fermented cod liver oil, without additives. And only tiny doses like 1-2.5 g (ml) per day, depending on age, sex, pregnancy, nursing, etc.

Ray Peat thinks all PUFAs are toxic and should be limited equally to a low % of calories. Chris Masterjohn shares Ray's view for the most part. Most people eat far too much PUFAs, in the form of nuts, seeds, toxic oils, fried food, mayo and salad dressing, modern eggs, etc.

Brian Peskin believes damaged omega-6 is the whole problem, not too much omega-6 or a lack of omega-3. He thinks a high ratio of omega-6 is ideal, provided the sources are not damaged by heat. Chris Masterjohn believes in keeping PUFAs as low as possible by focusing on saturated fats like red meat, butter, and coconut oil. Other low-PUFA foods are fine, like shellfish, peeled potatoes, etc.

Ray Peat - Articles

Chris Masterjohn - How Essential Are the Essential Fatty Acids?

Brian Peskin - EFA Analysis

Here's a series of newsletters from Guy Schenker, talking about the dangers of high omega-6 and omega-3 oils. He notes many of the issues Brian Peskin brings up for limiting their intake.

http://www.nutri-spec.net/nl/2005-11.html
http://www.nutri-spec.net/nl/2005-12.html
http://www.nutri-spec.net/nl/2006-01.html
http://www.nutri-spec.net/nl/2006-02.html
http://www.nutri-spec.net/nl/2006-03.html
http://www.nutri-spec.net/nl/2006-04.html
http://www.nutri-spec.net/nl/2006-05.html