For today’s edition of
Dear Mark, I’m answering two questions from readers. First, is it
possible to become deficient in omega-6 fats as an adult? What
would that even look like, and is there anything that might make
omega-6 more important?
Second is a question related to last week’s
feature on prostate health. Is saw palmetto an effective
supplement for prostate issues? It depends on the issue.
I have a question for “Dear Mark”
Here it is:
I am completely and totally primal for 10 years now. Can I
become O6 deficient ? Since 90% of my fat intake is saturated or
It’s technically possible to become deficient in omega-6 fatty
early rat studies that discovered the essentiality of Omega-6s
found that their complete removal made the subjects consume more
food (without gaining weight), drink more water (without peeing
more than rats on a normal diet), develop scaly skin, lose fur,
urinate blood, go infertile, grow weird tails, and die early. All
this despite eating an otherwise nutrient-dense diet with all the
fat-soluble vitamins (they even removed the fat from cod liver oil
and gave the vitamins), B vitamins, and other nutrients a rat could
ever want. The only thing missing was a source of omega-6 fats.
Once they discovered the issue—a lack of
omega-6—how’d they fix it?
Coconut oil didn’t work, for obvious reasons. It’s almost
pure saturated fat.
Butter worked, but you had to use a lot. The omega-6 fraction of
butter is quite low.
Cod liver oil worked, but it didn’t fully cure the deficiency
Lard worked well, as did corn oil, liver, flax oil, and olive
oil. All of those fat sources fully resolved the issue and
eliminated the symptoms. They were all good to decent sources of
omega-6 fatty acids.
They also tried pure linoleic acid (the shorter-chained omega-6
PUFA found in nuts and seeds and the animals that eat them) and
arachidonic acid (the long-chain omega-6 PUFA found in animal
foods). Both worked, but AA worked best.
Throughout all these trials, exactly how much omega-6
fat did the rats require in their diets to cure deficiency
When they used lard to cure it, the rats got 0.4% of calories
from omega-6 PUFA. If the numbers hold true for humans, and
you’re eating 2500 calories a day, that’s just 10 calories of
omega-6, or about a gram and a half of pure arachidonic acid to
When they used liver to cure it, the rats got 0.1% of calories
from omega-6 PUFA. If the numbers hold true for humans, and
you’re eating 2500 calories a day, that’s just 2.5 calories of
omega-6, or about a third of a gram of arachidonic acid to avoid
The truth is that omega-6 deficiency is extremely hard
to produce, even when you’re trying your hardest. Way
back in the 1930s, the early omega-6 researchers tried to induce
deficiency in an adult by
giving him a 2 grams fat/day diet for months. Nearly all fat
was removed, particularly the omega-6 fats, and the rest of the
diet was fat-free milk, fat-free cottage cheese, orange juice,
potato starch, sugar, and a vitamin/mineral supplement. Maybe not
the ideal Primal diet, but better than some.
He ended up improving his health, not hurting it. There was no
sign of deficiency.
Omega-6 fats are everywhere in the food environment, even if
you’re actively avoiding concentrated sources of them. No one is
developing a deficiency these days. However, certain
conditions might increase the tolerable or beneficial upper limits
of omega-6 intake.
If you’re strength training with the intent to gain lean mass,
extra arachidonic acid can improve your results. The dose used
was 1.5 grams per day. Average intake through food runs about
250-500 mg, though Primal eaters heavy on the animal foods are
probably eating more.
If you’re recovering from injury or healing a wound, a little
extra arachidonic acid can speed it up. AA is an important
co-factor in the inflammatory response necessary for tissue
Well done, Mark. My doc just prescribed saw palmetto to reduce
multiple nighttime visits to the bathroom, though the research
I’m looking at says there’s no clinical evidence to support saw
palmetto for prostate problems. Your take?
It depends on the problem.
Large observational trials have found no
connection between saw palmetto supplementation and prostate cancer
risk. It neither helps nor harms.
Saw palmetto does seem to help
benign prostatic hyperplasia, a non-cancerous growth of the
prostate. This won’t cause serious health issues
directly, but it can impede the flow of urine and lead to multiple
nighttime bathroom visits. Saw palmetto is quite effective
at reducing nighttime urination. If that’s what your doc is
trying to help, I’d say give it a shot.
You might ask about combining saw palmetto with
astaxanthin. It’s been shown to reduce the
conversion of testosterone into estradiol that can sometimes
result from plain old saw palmetto supplementation.
That’s it for today, folks. Take care and be well. Chime in
down below if you have any questions or comments.
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