I’ll start with the bad
news: There are no vegetarian collagen sources. Every collagen
supplement you see on the shelf came from a living organism. Though
somewhere down the line someone will probably grow legitimate
collagen in a lab setting, it’s not available today or for the
Now, some good news: Vegans and vegetarians probably need less
dietary collagen than the average meat eater or Primal eater
because a major reason omnivores need collagen is to balance out
all the muscle meat we eat. When we metabolize methionine, an amino
acid found abundantly in muscle meat, we burn through glycine, an
amino acid found abundantly in collagen. If you’re not eating
muscle meat, you don’t need as much glycine to balance out your
diet, but it’s still a dietary necessity.
Collagen isn’t just about “balancing out meat intake.”
It’s the best source of a conditionally essential amino acid
known as glycine. We only make about 3 grams of glycine a day.
That’s not nearly enough. The human body requires at
least 10 grams per day for basic metabolic processes, so
we’re looking at an average daily deficit of 7 grams that we need
to make up for through diet. And in disease states that disrupt
glycine synthesis, like rheumatoid
arthritis, we need even more.
What About Marine Collagen?
Okay, but eating a product made from a cuddly cow or an
intelligent pig is off limits for most vegetarians. What about
marine collagen—collagen derived from fish bones, scales, and
Back about twenty years ago, “vegetarians” often ate fish. A
number of them still exist out in the wild, people who for one
reason or another avoid eating land animals (including birds) but
do regularly consume marine animals. If it jibes with your ethics,
marine collagen is a legitimate source of collagen for vegetarians.
The constituent amino acids are nearly identical to the amino acids
of mammalian collagen with very similar proportions and
It’s highly bioavailable, with the collagen peptides
often showing up intact in the body and ready to work their
magic—just like bovine or porcine collagen. In fact, if
you ask many marine collagen purveyors, it’s even more
bioavailable than mammalian collagen owing to its lower molecular
I’m not sure that’s actually accurate, though.
According to some sources, marine collagen comes in smaller
particles and is thus more bioavailable than mammalian collagen,
but I haven’t seen solid evidence.
There’s this paper,
which mentions increased bioavailability in a bullet point
off-hand, almost as an assumption or common knowledge.
found low molecular weights in collagen derived from fish waste.
Mammalian collagen generally has higher molecular weights, so that
appears to be correct.
very recent pro-marine collagen paper that makes a strong case
for the use of marine collagen in wound repair, oral
supplementation, and other medical applications does not mention
increased bioavailability. It may be slightly more
bioavailable—the lower the molecular weight, the more true that
is—but I don’t think the effect is very meaningful. Mammalian
collagen is plenty bioavailable (most efficacious studies use
collagen from cows or pigs), even if it’s a few dozen kilodaltons
But even if marine collagen isn’t particularly superior to
mammal collagen, it is equally beneficial.
For skin health: Fish
collagen improves hydration, elasticity, and wrinkling in humans
who eat it. And again.
For metabolism: Fish collagen
improves glucose and lipid metabolism in type 2 diabetics. HDL
and insulin sensitivity go up, triglycerides and LDL go down.
And although fish collagen hasn’t been studied in the
treatment of joint pain, if it’s anything like other types of
collagen, it will help there too.
What Are Strict Vegetarian Options?
What if you absolutely won’t eat collagen from marine
sources? Is there anything you can do as a vegetarian to
make up for it?
Make Your Own
You could cobble together your own facsimile of collagen by
making an amino acid mixture.
arginine don’t cover all the amino acids present in
collagen, but they’re widely available and hit the major
Still, eating the amino acids that make up
collagen separately doesn’t have the same effect on those
collagenous tissues as eating them together in a collagenous
matrix. One reason is that the collagen matrix can
survive digestion more or less intact, giving it different
biological properties and effects.
In one study,
rats with osteoporosis ate collagen hydrolysate that scientists had
marked with a radioactive signature to allow them to track its
course through the body. It survived the digestive tract intact,
made it into the blood, and accumulate in the kidneys. By day 14,
the rats’ thigh bones had gotten stronger and denser with more
organic matter and less water content.
Another study found
similar results, this time for cartilage of the knee. Mice who ate
radioactive collagen hydrolysate showed increased radioactivity in
the knee joint.
In both cases, the collagen remained more or less intact. A
blend of the isolated amino acids would not. The fact is
that collagen is more than glycine. When you feed people
collagen derived from pork skin, chicken feet, and
cartilage, many different
collagenous peptides appear in the blood. You don’t get any
of those from isolated glycine.
That’s not to say it’s pointless. Pure glycine can be a
helpful supplement, used in several studies to improve
multiple markers of sleep quality. Just don’t expect it to
have the same effect as full-blown collagen.
Get Adequate Vitamin C
Acute scurvy, caused by absolute vitamin C deficiency, triggers
the dissolution of your connective tissue throughout the body.
Teeth fall out, no longer held in by gums. Wounds don’t heal,
your body unable to lay down new collagen.
Vegetarians usually don’t have any issues getting adequate
Get Adequate Copper
Copper is a necessary cofactor in the production of collagen.
Studies show that you can
control the production of collagen simply by providing or
The best vegetarian source of copper is probably
dark chocolate, the darker and more bitter the better.
Get Adequate Lysine
Lysine is another amino acid that’s necessary for the
production of collagen.
True vegetarian collagen doesn’t exist. Strict vegetarians
will balk. But if you can bend the rules a bit, realize that making
marine collagen out of fins and scales and bones is far less
wasteful than just throwing it away, and look at the benefits with
an objective eye, you’ll be pleasantly surprised. Even if you
don’t end up using marine collagen, at least you have a few tools
for getting many of the benefits with quick shortcuts and
optimizing your own production of collagen.
Have you ever tried marine collagen? If you’re a vegetarian,
would you consider it?
Thanks for reading, everyone. Take care and be well.