Livin' La Vida Low-Carb Show recently has a podcast featuring one Brian Peskin, who claims that, among other things, that getting omega-3 from fish oil is actually bad for you. Is anyone familiar with his work, and how accurate are his claims?
Hmmm, came across a post by Dr. Stephan Guyenet at Whole Health Source that suggests that Peskin's claims are incorrect:
Dr. Stephan Guyenet said...
I'm familiar with Peskin. I just read his paper in Medical Hypotheses. It's time for me to put this thing to rest. He states that the fact that tumors have low oxygen supports his claim that low oxygen is behind cancer. Tumors have low oxygen because blood vessel growth doesn't keep up with tumor growth. That happens after the tumor has already developed, not beforehand.
His basic hypothesis is that polyunsaturated fats in the membrane determine the cell's permeability to oxygen. He implies that PUFA transport oxygen across the cell membrane. The problem is that oxygen doesn't require PUFA or any other fatty acid to get across the membrane. Molecular oxygen is a non-charged small molecule that diffuses across the membrane freely. His claim that PUFAs influence its transport across the membrane has no support I'm aware of. I followed his reference for that statement, which was this study:
And it didn't support his claims. As far as I can tell, the study has nothing to do with oxygen transport across the cell membrane. It's about fatty acid composition and lipid peroxidation in cancer cell lines. Grossly misquoting papers that are supposed to support your central argument is a characteristic of science abusers. A nice way to put it is that Peskin has a vivid imagination.
February 26, 2010 4:41 PM
Here's a reference showing that oxygen diffuses across the cell membrane quite readily (half as fast as through pure water, which is very fast):
From the abstract:
"It is concluded that oxygen permeation across the cell plasma membrane cannot be a rate-limiting step for cellular respiration."
February 26, 2010 4:46 PM
Peskin is a fraud and his ideas are nonsense.
Jimmy Moore isn't vetting his guests properly, and as a result is wasting everyone's time. Look at Peskin's website, it states "World's must trusted health authority". How could this possibly be correct? WAPF also has an article taking him to task http://www.westonaprice.org/Brian-Peskin-and-Essential-Fatty-Acids.html
The comments Dr. Kurt Harris makes after this blog post at Richard Nikoley's blog, "Free The Animal", might be of interest:
Dr. Harris posted several comments. It is useful to read all of the comments, rather than posting excerpts from those Dr. Harris wrote.
If I have it right, the main point is to reduce 6 rather than supplement 3 on top of eating a grain-fed, PUFA diet.
The standard recommendation: eat grass-fed beef and butter, and eat fish.
And on Dr. Harris' blog, Step number 6, still reads:
...Pastured (grass fed) dairy and grass fed beef or bison has a more optimal 6:3 ratio, more vitamins and CLA. A teaspoon or two of Carlson's fish oil (1-2 g DHA/EPA) daily is good compensatory supplementation if you eat grain-fed beef or no fish.
ETA: Chris Masterjohn, at Cholesterol and Health:
Cod liver oil and fish oils contain EPA, a fatty acid that is probably not essential to mammals and interferes with arachidonic acid. When the total intake of polyunsaturated fatty acids (PUFA) is low, the EPA should be efficiently converted to DHA. When total PUFA intake or EPA intake is very high, however, the EPA may interfere with arachidonic acid metabolism and contribute to deficiency symtoms such as growth retardation, dehydration, flaky and scaly skin, hair loss, gastrointestinal syndromes, or infertility. Moreover, all of the PUFA contribute to oxidative stress when consumed in high amounts, a phenomenon that contributes to heart disease, cancer, fatty liver, diabetes, brain disease, DNA damage, and ageing. Therefore, it makes sense to obtain these precious fatty acids in small amounts. This means avoiding vegetable oils and excessive supplementation with fish oils and obtaining essential fatty acids from liver, muscle meat, butter, occasional fatty fish and very small amounts of high-vitamin cod liver oil.
A recent review by Darisuh Mozaffarian of Brigham and Women's Hospital and Harvard Medical School, cited in Issue 14 of my free newsletter, concluded that the benefits from fish oils plateau at 250 mg of omega-3 fatty acids per day. This is based on studies of populations consuming far too much total PUFA and a great excess of omega-6 fatty acids, and it still only justifies the consumption of one or two servings of fatty fish per week or one-half teaspoon of high-vitamin cod liver oil per day.
Cod liver oil should thus only be consumed in amounts higher than this in order to obtain the fat-soluble vitamins, and one should only consume these higher amounts within the context of a diet rich in vitamin B6, magnesium, and other minerals, low in total PUFA, and balanced by reasonable quantities of liver, muscle meat, and butter to provide adequate arachidonic acid and prevent EPA-induced deficiency symptoms.
This is all covered in more detail in my report, How Essential Are the Essential Fatty Acids?
Hope this is of use.
The Omega-3's from fish oil are fine, but there does seem to be a problem with excess Vit A in cod liver oil (which has nothing to do with oxygen permeability, etc):
for me fish oil is just like olive or sunflower oils - olives and sunflower (just as fish) seeds may be alright, but oils made of them? - i guess, that that sort of extraction and refinement is among the main factors in food-related maladies and overall degeneration of 'civilized' peoples once, having succumbed to fish oil propaganda, i have bought a bottle of COD, drank it for a week or so, but then thought: "is that PALEO? - you must be kidding!"... then i threw the stuff away with no regret
Has everyone looked up in Google the following search: "Brian Peskin Texas Attorney General Fraud."
Years ago, Peskin had a book out that touted some sort of "Essiac Tea" drink that you HAD to have in order to be healthy.
Even if this fellow is wrong, it's still less than ideal to have a 3/6 ratio that is so out of whack that fish oil is needed. If your primary meat source is grass-fed ruminant flesh, fish oil is unnecessary.
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