5 ms·

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

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.

codemac 6y ago
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/ https://pubmed.ncbi.nlm.nih.gov/9637947/ It seems to indicate eating less saturated fat increases your ability to convert ALA ~5x
- chrisco255 6y ago
  https://www.sciencedirect.com/science/article/pii/S0163782715000223 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."
  - codemac 6y ago
    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.
ianai 6y ago
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.

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.

codemac 6y ago

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/ https://pubmed.ncbi.nlm.nih.gov/9637947/ It seems to indicate eating less saturated fat increases your ability to convert ALA ~5x

chrisco255 6y ago
https://www.sciencedirect.com/science/article/pii/S0163782715000223 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."
- codemac 6y ago
  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.

ianai 6y ago

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.