"Plant-Based Protein: Are Pea and Soy Protein Isolates Harmful?"
So, are these plant-based burgers healthy or not?
And the answer is… compared to what?
Eating is kind of a zero-sum game; every food has an opportunity cost.
I mean, every time we put something in our mouth
it’s a lost opportunity to put something even healthier in our mouth.
So, if you want to know if something is healthy,
you have to compare it to what you’d be eating instead.
So, for example, are eggs healthy?
Compared to a breakfast link sausage? Yes!
But compared to oatmeal? Not even close.
But look, sausage is considered a group 1 carcinogen.
In other words, we know consumption of processed meat causes cancer.
Each 50-gram serving a day, that’s a single breakfast link,
was linked to an 18% higher risk of colorectal cancer.
So, the risk of getting colorectal cancer eating one link a day
is about the same as the increased risk of lung cancer you’d get
breathing secondhand smoke all day living with a smoking spouse.
So, compared to sausage, eggs are healthy,
but compared to oatmeal, eggs are not.
So, when it comes to Beyond Meat and Impossible Burger,
yeah, they may be better in that they have less saturated fat,
but, hey, you want less saturated fat?
Plant-based meat alternatives are no match
for unprocessed plant foods, such as beans or lentils.
And a bean burrito or lentil soup could certainly fill
the same culinary niche as a lunchtime burger.
But if you are going to have some kind of burger,
it’s easy to argue that the plant-based versions are healthier.
There is a sodium issue, and it’s not that much, if any, lower,
in saturated fat, since they use coconut oil,
which is basically just as bad as animal fat;
there’s not much advantage on that front.
Though the total protein is similar across the board,
does this matter? Or Is there any advantage to eating plant protein
over animal protein? Let’s look at the association
between animal and plant protein intake and mortality.
In the twin Harvard cohorts, following more than 100,000 men
and women over decades, “…after adjusting for other dietary
and lifestyle factors, animal protein intake was associated
with a higher risk [of] mortality, particularly [dying from
cardiovascular disease], whereas higher plant protein intake
was associated with [a] lower all-cause mortality”,
meaning a lower risk of dying from all causes put together.
So, “replacing animal protein of various origins
with plant protein was associated with lower mortality”,
especially if you’re replacing processed meat and egg protein,
which were the worst. But when it comes to living a longer life,
plant protein sources beat out each and every animal protein source.
Not just better than bacon and eggs,
but better than burgers, chicken, turkey, fish, and dairy protein.
Together with other studies, these “findings support the importance
of protein sources for the long-term health outcome
and suggest plants constitute a preferred protein source
compared [to] animal foods.” Why?
Well, unlike animal protein, plant protein has not been associated
with increased levels of the cancer-promoting
growth hormone IGF-1, for example.
Now, soy protein is similar enough to animal protein
that at high enough doses, like eating two Impossible Burgers a day,
you may bump your IGF-1.
But the only reason we care about IGF-1 is cancer risk,
and if anything, higher soy intake is associated with
a decreased risk of cancer.
For example, a recent systematic review and meta-analysis found
that soy protein intake was associated with a decreased risk
in breast cancer mortality; we’re talking “a 12 percent reduction
in breast cancer death [associated with] each 5-gram-a-day
increase in soy protein intake.”
But the high soy groups in these studies
were on the order of more than 16 grams a day,
associated with a whopping 62% lower risk
of dying from breast cancer.
More than 10 grams of soy protein a day may be good,
associated with cutting breast cancer mortality risk
nearly in half, and getting more than 16 grams a day
may be better, which is like one Impossible Burger a day.
But we simply don’t know what happens
at consumption levels far above that.
Plant protein has also been linked to lower blood pressure,
reduced LDL cholesterol, and improved insulin sensitivity.
No wonder “substitution of plant protein for animal protein
has been related to a lower incidence
of cardiovascular disease and type 2 diabetes.”
Indeed, 21 different studies following nearly a half million people,
and “high… animal protein intakes [were] associated with
an increased risk of [type 2 diabetes],
whereas [even just] moderate plant protein intake
is associated with a decreased risk of [type 2 diabetes].”
OK, but these were just observational studies.
They all tried to control for other dietary and lifestyle factors,
but you can’t prove cause-and-effect, until...you put it to the test.
The “Effect of Replacing Animal Protein with Plant Protein
on [blood sugar] Control in Diabetes: A Systematic Review
and Meta-Analysis of Randomized Controlled Trials.”
Even just switching out about a third of your protein
from animal to plant sources yielded significant improvements
in long-term blood sugar control, and fasting blood sugars, and insulin.
You can do the same thing looking at cholesterol.
Here’s a systematic review and meta-analysis of randomized
controlled trials on the effect of plant protein on blood fats.
And indeed, swapping in plant protein for animal protein
decreases LDL cholesterol, and this benefit occurs
whether you start out at high cholesterol or low cholesterol,
whether you’re swapping out dairy, or meat, and eggs,
and whether you’re swapping in soy or other plant proteins.
We’ve known about the beneficial effects of soy on cholesterol
going back nearly 40 years, but other sources of plant protein
can do it as well. Yeah, but we’re not swapping beans for beef.
These products are mostly just isolated plant proteins,
mostly pea protein isolate in the case of Beyond,
and concentrated soy protein in the case of Impossible.
If you just isolate out the plant proteins themselves
are you still going to get benefits?
Yes, surprisingly. Check it out.
Interestingly, the researchers concluded, that they did not ﬁnd
a signiﬁcant difference between protein isolate products
and whole food sources, “suggesting that the cholesterol-lowering
effects are at least, in part, attributable
to the plant protein itself rather than just
the associated nutrients.”
So, it’s not just because plant protein travels
with fiber or less saturated fat.
Plant proteins break down into a different distribution
of amino acids; and so, it’s like if you give people arginine,
an amino acid found more in plant foods,
that alone can bring down people’s cholesterol.
And even plant protein concentrates used in these products
aren’t pure protein, retaining a few active compounds
such as phytosterols and antioxidants,
which also can have beneficial effects.