Video summary
The podcast episode explores the critical distinction between ultra-processed foods and other categories like junk food or minimally processed items, arguing that relying solely on nutrient profiles is insufficient for assessing health risks. While junk food is typically defined by high levels of sugar, saturated fat, and sodium, ultra-processed foods include items like Diet Coke that may lack these specific nutrients but still pose significant dangers due to their chemical composition. The host explains that the harm from these products stems not just from poor nutrition, but from a complex array of additives such as artificial sweeteners, colors, and preservatives. For instance, ingredients like aspartame and red dye number three have been linked to potential carcinogenic effects, while studies suggest that combinations of these additives can negatively impact behavior in children and disrupt the gut microbiome, contributing to conditions like inflammatory bowel disease.
Beyond intentional additives, ultra-processed foods often contain harmful contaminants generated unintentionally during industrial manufacturing and thermal processing methods. The transcript highlights toxins such as acrolein, a substance found in cigarette smoke that forms when fats are cooked at high temperatures, which can be present in fried foods regardless of whether they are homemade or factory-made. Other dangerous byproducts include 3-MCPD, furans, acrylamide, and trans fats, all of which are associated with cancer and cardiovascular disease. Furthermore, the process of cooking animal products leads to the formation of cholesterol oxidation products and advanced glycation end products (AGEs), compounds that are far more toxic than their natural counterparts and are strongly linked to chronic diseases like Alzheimer's, diabetes, and kidney failure. The data reveals that while home-cooked meals contain some of these substances, ultra-processed versions can have levels of AGEs nearly 100 times higher than minimally processed plant foods and thousands of units higher than raw animal products.
The discussion concludes by challenging the "clean label" strategy, which suggests consumers should simply avoid foods with long or artificial ingredient lists. The host argues that this approach is flawed because many of the most dangerous components, such as acrolein and AGEs, are not listed on nutrition labels and are created by the processing itself rather than added ingredients. Even minimally processed foods like roasted pork or canned corn can contain significant levels of these harmful compounds due to heat application, meaning that the act of industrial processing transforms food at a molecular level in ways that simple ingredient lists cannot capture. Ultimately, the episode posits that focusing exclusively on nutrient density or avoiding specific additives misses the broader picture; the very methods used to preserve, flavor, and texture foods for mass consumption introduce a variety of toxic elements that contribute to increased mortality and disease risk, necessitating a more comprehensive view of food safety beyond just what is written on the package.
Read the full video transcript
We have lots of choices to make about
our diet and to that doing the right
thing when it comes to treating a
chronic disease or fighting a virus or
losing weight and suddenly
our nutrition choices can seem almost
overwhelming. Well,
I'm here to help. Welcome to the
Nutrition Facts podcast. I'm your host
Dr. Michael Greger.
Did you know that ultra-processed foods
now supply more than half of daily
calories in the US? And studies have
linked higher [snorts] intake of
obesity, heart disease, type 2 diabetes,
and increased mortality
with increased intake. [music] And not
just because of the nutritional makeup,
but in part due to food [music]
additives.
So-called ultra-processed foods aren't
really real food, but they really can
affect our health.
Why do we need a new term though? Can we
just say we should stay away from junk
food, defined as food and beverages with
high levels of concentrated calories and
added saturated fats, sodium, and sugar?
I mean, that's where most of our sugar
and about half of our calories, salt,
and saturated fat comes from. But
ultra-processed is not synonymous with
junk. There are some junk foods that are
not ultra-processed, and some
ultra-processed foods that don't fit the
definition of junk. For example, while a
sausage is considered an ultra-processed
meat, bacon is considered just a
processed meat. Though bacon would also
meet junk food's definition of a calorie
concentrated food loaded with added
salt.
What about an ultra-processed product
like Diet Coke? It doesn't have any
calories, no sugar, no fat, not junk
food, but still ultra-processed and not
necessarily good for you.
So, there's a limitation to exclusively
focusing on the nutrient profile of
ultra-processed foods, but how can they
be bad if they're fat-free, sugar-free,
salt-free? Health risks are not only
related to the poor nutritional quality
of ultra-processed foods, but also to
the presence of additives.
No apparent calories, fat, salt, or
sugar, but contains caramel color, which
results in the formation of
4-methylimidazole, which is a possible
human carcinogen.
Contains aspartame, too, also recently
classified as possibly cancer-causing in
humans.
And Diet Coke contains phosphoric acid,
which is a phosphate additive that may
be damaging to health. In fact, that's
just the kind of additive that could
help explain the link between
ultra-processed foods and heart and
kidney problems. Contains a benzoate
preservative, too. If you remove
artificial colorings and benzoate
preservatives from the diets of
preschoolers and then randomize the kids
to be slipped the placebo or a cocktail
of colorings and benzoate, you'll see a
significant reduction in hyperactive
behavior during the withdrawal phase,
and a significant increase in
hyperactive behavior when the kids got
the colorings and benzoate compared to
placebo. Of course, it could have been
the colorings, not the benzoate, but
that's one of the problems. As little as
we know about the effects of these
individual additives, we know even less
about what combinations of them can do.
There's a large body of evidence
suggesting toxicity from certain
artificial food colors, benzoate
preservatives, artificial sweeteners,
and emulsifiers, in part sometimes to
our gut microbiome.
This may explain at least part of the
connection between inflammatory bowel
disease and ultra-processed foods.
Now, industry apologists argue that the
US Food and Drug Administration
carefully evaluates food additives to
make sure they're safe.
Until they're not. In fact, to show the
system works, they cite the removal of
six carcinogenic artificial flavors in
2018. Artificial flavors that had been
in the food supply approved for safety
since 1964.
So, we were exposed more than 50 years
before they were banned. Critics of the
ultra-processed food concept puzzle at
the fact that natural yogurt is
considered minimally processed and
yogurt with added sugar is considered a
processed food, but if the yogurt's
sweetened with artificial sweetener and
contains less sugar, it's considered
ultra-processed.
You can see how the critics try to stick
with a nutrient paradigm of hey, less
sugar should be better.
But that was before aspartame, sold as
NutraSweet, was officially recognized as
a potential human carcinogen in 2023.
42 years earlier, when aspartame was
first approved, the FDA's own public
board of inquiry opposed approval of the
artificial sweetener based on brain
tumors in rats and the industry's own
studies. This included several FDA
scientists who didn't think it was safe.
The FDA commissioner rejected these
concerns and approved it anyway before
leaving the agency to enjoy a $1,000
[clears throat]
per day consultancy position with the
aspartame company's PR firm.
And then the FDA actually prevented the
National Toxicology Program from doing
further cancer testing. Meanwhile,
literally tens of millions of pounds
made it into the food supply. Fine,
critics of the ultra-processed label
say, if there are some additives that
are bad, let's find out exactly which
ones they are and get rid of those. No
need to guilty until proven innocent
broad brush all additives as potentially
harmful. Take artificial food colors
though. What level of evidence do we
need to remove something whose sole
reason of existence is to make some
dayglow marshmallows in a kid's cereal
that much more eye-catching?
I've long been concerned about red dye
number three, why it hasn't been banned
from food for example, given the dye was
banned more than 30 years ago from
inclusion in anything going on our skin
due to cancer risk,
but it's okay to eat? Finally, just
recently, the California Food Safety Act
was signed banning red dye number three
from foods and drinks sold in California
as of 2027.
Consumer groups like Center for Science
in the Public Interest continue to
petition the FDA for a national ban to
prohibit use of this carcinogen and in
2025, the FDA finally agreed to ban it
from food, 35 years after they removed
it from cosmetics.
It also starts to take effect in 2027.
Until then, here's a pro tip suggestion
for food companies. Should you want to
make your cherry popsicles red, maybe
try adding some cherries.
If the harm of ultra-processed foods
lies in potentially harmful additives,
why not just stick to so-called clean
label foods made with simple,
recognizable ingredients, no matter how
the food is processed?
But that's assuming additives are the
only reason ultra-processed foods may be
unhealthy. In fact, harmful additives
are just one of many reasons
ultra-processed foods may lead to
increased risk of death and disease.
[music] I'll address some of these
others
next.
One of the reasons the consumption of
ultra-processed foods is associated
[music]
with a higher risk of disease is food
additives like artificial colors and
flavors, sweeteners, emulsifiers, and
more. But at least they're listed in the
ingredients on the label, so you can
avoid them if you wanted to. Unlisted
are some of the sneakier ways
ultra-processed foods can be bad for
you, like contaminants formed during
industrial processing methods. For
example, there's acrolein, a toxin found
in cigarette smoke, that's also
generated during the cooking or frying
of food with fats or oils. So, it can be
found in foods like potato chips, french
fries, donuts. Ironically, canola oil,
considered to be perhaps the most
{quote} heart-healthy type of oil,
appears to generate the highest amounts
of acrolein, and acrolein may cause
cardiovascular disease and probably
causes cancer, too.
In fairness, acrolein would still be a
problem even if you made french fries
from scratch, which would be considered
a minimally processed food rather than
ultra-processed frozen fries or fast
food fries, but if every time you wanted
to have fries, you had to cut up
potatoes yourself and deep fry them,
we'd probably eat a lot fewer fries.
Fried and pre-fried foods may also be
contaminated with 3-MCPD, another
possible carcinogen.
Furans and acrylamide are two other
heat-generated contaminants that are
possibly or probably cancer-causing.
Trans fats are produced in the refining
process to make vegetable oils, so they
may end up as high as half a percent
trans fats.
In fairness, even unprocessed meat dairy
products naturally have a lot more
without much difference between
unprocessed and ultra-processed
products. Similarly problematic are
dietary cholesterol oxidation products,
which are found in meat, eggs, and
dairy. Once absorbed into the
circulation, they can contribute to the
progression of several inflammatory
diseases.
Cholesterol is bad enough. However,
oxidized cholesterol is even more toxic
and disease-causing than cholesterol
itself. And it's also associated with
the initiation and progression of major
chronic diseases, including
atherosclerosis, Alzheimer's,
kidney failure, and diabetes.
Food processing can dramatically trigger
the accumulation of cholesterol
oxidation products in meats, including
fish and poultry, eggs, and dairy
products. But that processing can just
mean cooking the meat. Cholesterol
oxidation products arise during thermal
processing of foods of animal origin,
with maximal cholesterol oxidation at
only 300° F or so.
So, the difference between the levels in
ultra-processed products like pork
sausage aren't that much different from
a minimally processed product like roast
pork.
That's why the levels of oxysterols in
foods, including oxidized phytosterols
in margarine, is split mainly between
ultra-processed and minimally processed
foods. So, many of these contaminants
are not exclusive to ultra-processed
foods. Advanced glycation end products
are another good example. Increasing
evidence shows that the uptake of
dietary AGEs, advanced glycation end
products, is closely related to the
occurrence of many chronic diseases such
as diabetes, chronic kidney disease,
osteoporosis, and Alzheimer's.
In fact, it's hard to find an
age-related disease that doesn't involve
AGEs.
Dietary AGEs are abundant in highly
processed foods because thermal
treatments are commonly used to improve
their flavor, texture, preservation, and
safety.
But, thermal treatment just means heat.
So, you can get AGEs from industrial
processing or home cooking.
Canned corn has 20 units of AGEs per
serving. Corn chips 151, and corn pops
cereal 373.
Rice has nine per serving, rice crackers
275, rice crispies 600.
A boiled potato has 17 AGE units per
serving, potato chips 865, and fast food
fries more than 1,500, whereas homemade
fries have less than half that. So,
ultra-processed plant foods can have
nearly 100 times more AGE units than
minimally processed plant foods.
But, animal foods start out with high
levels even when they're raw and
unprocessed, and just go up from there.
Instead of 10 or 20 like the corn, rice,
and potatoes, fish, poultry, and other
meats start out at around 500 AGE units
or more, and then jump into the
thousands once cooked, which is
considered minimally processed.
For meat that's processed or
ultra-processed, they can exceed 10,000
per serving.
Although these contaminants are by no
means limited to ultra-processed foods,
you can see how considering how good or
bad foods are based only on their listed
nutrients
fails to capture how food processing can
transform food at the molecular level.
And it's clear that just using the clean
label strategy of sticking to foods with
simple ingredient lists won't help
because we're never going to see
acrolein or acrylamide on the label.
It's the processing itself,
>> [music]
>> whether traditional or industrial,
that's affecting the healthfulness of
the food.
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