One [study] looked at ALA metabolism in males and indicated that approximately 8% of dietary ALA is converted to EPA and 4% is converted to DHA.
This references the same article as the first.
So my question is why do these two statements conflict when they are using the same source? My knowledge of nutrition is not good enough to read the source article and find the reason for myself, so ideally it would be good to hear from someone who can read the source article and point out where this discrepancy is coming from.
Thanks for picking up on this @bdax; I’ve had to use my brain more than I’m used to on a Monday morning!
I originally wrote our article, I think, about 3 years ago, and, on reflection, I don’t think that section is worded correctly and referenced well enough and we will update asap.
In the meantime, to provide confidence, these references indicate adequate conversion to DHA:
And in a study comparing blood EPA and DHA levels in non-fish-eaters (who had a 57-80% lower omega-3 intake) with fish eaters, both groups had similar circulating levels of both fatty acids, suggesting that there are different conversion rates with people with different dietary habits.
I hope this provides sufficient confidence while we update the article. Any other queries, please let us know.
It’s on our list to be updated Tom, the content team are a bit snowed under at the moment!
Here’s some of the updated text with references:
Some papers have cited that human conversion of ALA into EPA ranges from 8% to 20% and conversion of ALA to DHA ranges from 1% to 9%. One study indicated that ALA conversion is about 6% for EPA and 3.8% for DHA; another report stated 5-10% and 2-5% respectively . The factors mentioned above are the reason for these huge variations of rates.
Interesting, and the numbers you cite are not obtained from averaging the male and female results? Because of course if it’s 8% for women, and 0% for men, then that averages out to 4% for ‘humans’. I’m waiting to see the article updated as I’m keen to see what the average is for men specifically, and if this can reasonably ever be 0% as is suggested by your current source.