Are polyunsaturated fats necessary in our diet at all? I am having difficulty researching this and sorting through all of the BS which gets planted on all of the pages of results. I am sorry if this is a dumb question LOL but I have been so busy and I have been spending a large amount of time also researching many other topics. I just want to eat some hemp butter: I have three tablespoons of Olive Oil a day and I wanted to add some hemp seeds to my diet since they lack phytic acid and trypsin inhibitors. Their Omega ratio is 3:1 with Poly being in the majority. But Olive Oil has a much higher ratio in favor of Mono. I was dumb thinking that Omega- 3 is good from vegetable sources because it was uncooked but now I remembered something I read a long time ago how DHA and EPA are made so I will be adding more grass-fed fat and fish to my diet. But I still want to eat about three servings of hemp seed a day and I won't have any other source of Poly except for Olive Oil and meat.
Is three servings of hemp seed too high? I would eat more fatty meat but I want a balance with cooked fat and uncooked fat and of course my wallet. Thank you for anyone who has any advice or who has tried to help.
asked byMatt_21 (313)
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on January 18, 2012
at 07:45 AM
Eat pastured egg yolks...
Yes we need PUFAs:
Current reviews and textbooks call the omega-6 linoleic acid and the omega-3 alpha-linolenic acid "essential fatty acids" (EFA) and cite the EFA requirement as one to four percent of calories. Research suggests, however, that the omega-6 arachidonic acid (AA) and the omega-3 docosahexaenoic acid (DHA) are the only fatty acids that are truly essential.
Two types of polyunsaturated fatty acids (PUFA), omega-6 (n-6) and omega-3 (n-3) PUFA, are essential for the vertebrate body, because they cannot be formed de novo and need to be ingested from the diet.
on January 18, 2012
at 09:09 AM
You don't really need all that much polyunsaturated fat. The general paleo take on things is that you should limit it, and in particular omega-6 PUFA, and even more in particular rancid omega-6 PUFA.
Eric is right to the best of my knowledge about the EFAs (essential fatty acids) and the classic take on them (linoleic + ALA) and the more sophisticated take on them (AA + DHA).
The one article you can read to get all of this under your belt is this one, by Chris Masterjohn:
Hmm, that one should really have a subtitle. No matter. Read it and all will be clear. He talks about just how small the requirement for the EFAs is -- but also addresses the question of whether or not additional EFAs can be healthy.
As for that hemp seed, I don't quite see why you would need it. I think the general consensus these days is eat your pastured meat and your pastured egg yolks and make sure to get some wild-caught fish. There are probably some benefits to supplementing omega-threes for some people, or maybe most, but to be honest I'm not the best person to ask about omega-3 supplementation because I just do the everything-pastured-plus-occasional-sushi-and-salmon-and-oysters route.
on January 23, 2012
at 08:07 AM
I don't think we know for sure that polyunsaturated fats are essential. Ray Peat has some discussion on this. http://raypeat.com/articles/articles/fats-degeneration3.shtml
Even if polyunsaturated fats are essential, there's considerable controversy as to the upper limit of what can be considered a safe intake. www.theiem.org/documents/ISSFAL2010DinnerDebateReport.pdf
Dr. Bill Lands suggests that more than one or two percent of total caloric intake of polyunsaturated fats might be the safe upper limit. http://www.youtube.com/watch?v=dgU3cNppzO0
However this matter is eventually decided, it's clear that excessive omega-6 consumption is a global trend. http://articles.orlandosentinel.com/2003-09-28/news/0309270148_1_overweight-or-obese-women-were-overweight-south-africa
Interestingly, the edible oils industry has bred seed oils that are lower in omega-6s. http://www.foodandbeveragepeople.com/cm/news/saturated_fats
on January 18, 2012
at 11:58 AM
Yes, there are essential polyunsaturated fats.
Paleo likes to minimize processed, refined, oxidized fats. That's why seed oils are out, hell of a lot of processing necessary to get oil out of a seed or "vegetables". Additionally, seed oils also have god-awful ratios of omega-3s to omega-6s. Those are definitely some reasons to avoid seed oils, but PUFAs?
You can the idea that any and all PUFAs are just the devil. I'm not so sure that PUFA-hate is warranted. Pork and chicken do have 10% PUFAs as a proportion of fat. Salmon is 33% of fats are PUFA. Raw avocados have 12% fats as PUFA. Those are natural, whole sources, unprocessed, unrefined. Their ratios (aside from Salmon) are biased towards omega-6s. However, there's simply no comparison in PUFA quality between refined seed oil and unprocessed animal fat.
Not eating seed oils, you'd be hard-pressed to break even 10% PUFA total in your diet. With a couple percent of those being omega-3, you'd have a very appropriate ratio.