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Comment by ianai | Hacker News Reader

Importantly, fish oils are not the only source of decent omega3/omega6 ratios. Walnuts are roughly 1:4, everyone knows about flaxseeds, etc. as someone else said, too, cutting back on omega6 sources is as important or may just offer greater correction toward the target ratio.

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The plant omega-3s are short chain (ALA) wereas the health benefits come from the longer chain animal omega-3s. Our body has some ability to convert, but it varies from person to person. Some people (especially Men) may be unable to convert enough ALA to get the health benefits.

I used to consume a lot of flaxseed oil as a cheap source of Omega 3. But, then I heard on HN that Om 3 is not very bioavailable in that form. But, that's my only source of info on that.

It depends on what you're looking for I guess, my understanding is:

There are 3 major omega 3 fats people mostly talk about, ALA, DHA, EPA.

ALA is transformed to DHA & EPA through different mechanisms in the body, whereas DHA & EPA are usually only found in other animal sources.

If you eat enough ALA (maybe more than recommended to increase probability of production?), your body will produce all the DHA & EPA you need.

I haven't read through this study yet but it may be interesting: https://pubmed.ncbi.nlm.nih.gov/9637947/ It seems to indicate eating less saturated fat increases your ability to convert ALA ~5x

https://www.sciencedirect.com/science/article/pii/S016378271...

"table isotope methods have typically resulted in estimates of percent conversion of ALA to DHA being less than 1% of the ingested stable-isotope ALA, although estimates vary widely, ranging from 0–9.2% (Table 1). Also, there is typically no increase in plasma total lipid or phospholipid DHA when ALA intake is increased in humans (reviewed in [10], [11]), supporting the conclusion that DHA synthesis from ingested ALA is not an efficient process in humans."

The very top analysis though shows:

"This review summarizes evidence that DHA synthesis from ALA can provide sufficient DHA for the adult brain by examining work in humans and animals involving estimates of DHA synthesis and brain DHA requirements. Also, an update on methods to measure DHA synthesis in humans is presented highlighting a novel approach involving steady-state infusion of stable isotope-labeled ALA that bypasses several limitations of oral tracer ingestion. It is shown that this method produces estimates of DHA synthesis that are at least 3-fold higher than brain uptake rates in rats."

So it seems it's not super efficient, but it's probably far more than sufficient, and we were under estimating how useful ALA is by 3x.

I would take nutritional advice and information on HN with a large grain of salt. Get some books on the material - there’s a lot of bad material out there though so get ready to do some homework.

In defense of myself, I just pointed out what could be found in a search of nutritional value information.

Fish oil (natural!) has longer fatty acids (FA) than plants. Must be processed from natural fish that feeds from algae (at least at some point in the food chain).

Regarding plant oils. Evening prime rose oil is good. Lots of gamma-linoleic acid.

> Must be processed from natural fish that feeds from algae

Why?

Because the long chain FA come from the algae, not from the fish...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6920940/

So your pond raised salmon may lack some of the benefits.

Walnuts and other nuts are often mentioned as sources but they're terrible compared to fish, and most importantly they contain a lot of omega-6, they are to be avoided if the objective is healthy.

Walnuts are also high in phytoestrogens, I believe, if you care about that stuff. Worth being careful

>Phytoestrogen Content of Beverages, Nuts, Seeds,and Oils

https://www.researchgate.net/publication/23141692_Phytoestro...

Is there any evidence of phytoestrogens affecting humans? I have some clue reason suggesting they might actually affect humans but I don't know of anything nearly credible.

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