Animal Protein and Cancer Risk: What the Science Really Says

Recently, Mark Hyman posted on X (formerly Twitter) that a new study suggests eating more animal protein might actually lower your risk of cancer. The study he pointed to came from the NHANES dataset—a U.S. survey of diet and health. It sounded reassuring, but it doesn’t line up with the bulk of the evidence. Here is the story about Animal protein and cancer risk:

Let’s dig into what the science really shows.

Red and Processed Meats: Where the Risk Is Clear

If you want the strongest evidence, look at red and processed meats. Large prospective cohort studies and systematic reviews consistently show that higher intake of these foods increases cancer risk. The effect is clearest for colorectal cancer, but we also see it in breast, endometrial, and even lung cancer.[1–6]

How big is the risk? Recent meta-analyses and systematic reviews find relative risks (RRs) and hazard ratios (HRs) in the 1.10–1.30 range for the highest vs. lowest intakes. For example, a comprehensive meta-analysis reported that every 50–70 grams per day of red or processed meat increased colorectal cancer risk by 15–32% (HR 1.15–1.32).[3,5] Processed meat generally carries more risk than unprocessed red meat.[2–3,6]

That’s why the American Cancer Society recommends limiting red and processed meats. Their advice is clear: swap them out for fish, poultry, or legumes when possible.[15]

Fish: A Safer Bet

The data on fish tells a different story. Multiple studies and meta-analyses find a modest reduction in colorectal cancer risk with higher fish intake (SRR 0.94, 95% CI 0.89–0.99).[7–8] In fact, adding 50 grams of fish per day reduces risk by about 4%.

Pescatarian diets (no red meat, but including fish) show even more protection. Compared to meat-eaters, pescatarians had a 9% lower overall and colorectal cancer risk (RR 0.91, 95% CI 0.86–0.96).[9]

Poultry: Mostly Neutral

Chicken and turkey usually get lumped in with “animal protein.” But when you pull the data apart, poultry tells a different story. Most meta-analyses show a neutral or even slightly protective association with colorectal cancer (RR 0.79, 95% CI 0.63–0.99 for white meat).[10–12]

That said, a few studies hint at possible links with certain blood cancers, but those findings aren’t strong or consistent.[5,10] For most people, poultry is a much safer choice than red or processed meats.

Dairy: A Mixed Picture

Dairy is tricky. On one hand, milk and calcium-rich foods are consistently linked to a lower risk of colorectal cancer (RR 0.93, 95% CI 0.91–0.94).[4,13] On the other hand, high intake of milk or calcium may slightly increase the risk of prostate and endometrial cancers (RR 1.09–1.10).[13–14]

No consistent associations are found for breast or ovarian cancer. Cheese intake in particular may even have protective effects, but results vary.

Why the Confusion?

So why did that NHANES study Mark Hyman highlighted find a small reduction in cancer mortality with higher animal protein? A few reasons:

• NHANES relies on a single dietary recall—one snapshot in time that may not reflect long-term habits.
• It doesn’t separate red and processed meat from healthier animal proteins like fish or poultry.
• Residual confounding (differences in lifestyle factors that aren’t fully accounted for) may skew the results.

When you put NHANES side by side with larger, longer-term studies and meta-analyses, it looks like the outlier. The overwhelming weight of evidence shows that red and processed meats increase cancer risk, while fish, poultry, and some dairy products are safer or even protective in specific cases. Animal protein and cancer risk is positive.

The Bottom Line

Protein matters—but the source matters more.

• Red and processed meats: consistently linked to higher cancer risk
• Fish: modestly protective, especially for colorectal cancer
• Poultry: generally neutral, sometimes protective
• Dairy: lowers colorectal risk, but may raise prostate and endometrial cancer risk

The American Cancer Society sums it up well: limit red and processed meats, and lean into fish, poultry, beans, and plant-based proteins.[15]

References

[1] Rock CL, Thomson C, Gansler T, et al. CA Cancer J Clin. 2020;70(4):245-271.

[2] Abid Z, Cross AJ, Sinha R. Am J Clin Nutr. 2014;100 Suppl 1:386S-93S.

[3] Lippi G, Mattiuzzi C, Cervellin G. Crit Rev Oncol Hematol. 2016;97:1-14.

[4] Boada LD, Henríquez-Hernández LA, Luzardo OP. Food Chem Toxicol. 2016;92:236-244.

[5] Diallo A, Deschasaux M, Latino-Martel P, et al. Int J Cancer. 2018;142(2):230-237.

[6] Farvid MS, Sidahmed E, Spence ND, et al. Eur J Epidemiol. 2021;36(9):937-951.

[7] Poorolajal J, Mohammadi Y, Fattahi-Darghlou M, et al. PLoS One. 2024;19(6):e0305994.

[8] Vieira AR, Abar L, Chan DSM, et al. Ann Oncol. 2017;28(8):1788-1802.

[9] Parra-Soto S, Ahumada D, Petermann-Rocha F, et al. BMC Med. 2022;20(1):79.

[10] Nielsen TB, Würtz AML, Tjønneland A, et al. Br J Nutr. 2022;127(4):563-569.

[11] Bonfiglio C, Tatoli R, Donghia R, et al. Nutrients. 2025;17(8):1370.

[12] Wang F, Chandler PD, Zeleznik OA, et al. Nutrients. 2022;14(5):978.

[13] Willett WC, Ludwig DS. N Engl J Med. 2020;382(7):644-654.

[14] Watling CZ, Kelly RK, Dunneram Y, et al. Br J Cancer. 2023;129(4):636-647.

[15] American Cancer Society. Guidelines for Diet and Physical Activity for Cancer Prevention. CA Cancer J Clin. 2020;70(4):245-271.

>> Dr. Terry Simpson: Eating more animal protein means less cancer.

Well, so tweets Mark Hyman. You may have heard of

him. He's a low carb enthusiast, a MAHA supporter,

a supplement salesman, and now a nutrition

revisionist. He wants you to believe that more

animal protein lowers cancer risk, pointing to an

outlier study that boils decades of flaw survey

data into one thin gruel of a conclusion. This

isn't science. It's the conjuring trick of a

salesman. We would probably call it the arrogance

of certainty. Without the burden of proof, Hyman

waves away mountains of evidence from serious

researchers, cancer epidemiologists on five

continents because it doesn't suit his narrative

or his business model. And so we're left with a

choice. Do we follow the global consensus of

scientists, or do we buy into the gospel according

to a man whose medical insights can be measured in

the half life of a supplement fad? I'm your chief

medical explanation. It's Dr. Terry Simpson, and

this is Fork U Fork University, where we make

sense of the madness, bust a few myths, and teach

you a little bit about food and medicine. Mark

Hyman didn't start out as the the guru you see

today. He was once a family doctor, then a spa

doctor. Then he discovered something far more

profitable than medicine. Selling supplements and

pseudoscience. Out of that came functional

medicine. What is functional medicine? Well, if

you're a nurse, a dentist, or even a chiropractor,

you can take a six month zoom course and suddenly

call yourself a functional medicine doctor. You've

probably seen the ads for the 300 tests they'll

run on you for a few hundred dollars each. So why

don't real physicians order 300 tests at once?

Because modern medicine is based on history and a

physical exam. If you shotgun three to 400 lab

tests, you will always find some abnormalities

statistically guaranteed. And once you've scared a

patient with those numbers, you just happen to

have the solution. A few hundred dollars worth of

supplements every month. Maybe supplement really

does stand for supplemental income. For a while,

Hyman even carried the banner of the prestigious

Cleveland Clinic. Why they eventually parted ways,

no one knows. But what we do know is Hyman is

camera ready. He has just enough jargon to impress

the non doctor and his platitudes are exceeded

only by his inability or unwillingness to read

scientific research correctly.

Which brings us to his latest misfire. On

September 19, Mark Hyman tweeted that researchers

analyzed the NHANES 3 data from 15,937 US adults

followed for 20 to 30 years. According to Hyman.

They found no link between animal protein and

mortality and, um, even a modest reduction in

cancer deaths with higher animal protein intake.

Sounds like good news, right? Steak every night.

But not so fast. NHANES is actually a valuable

data set. It's helped us learn a lot about diet

and health in America. It covers a large diverse

population and tracks outcomes over decades.

That's the good news. The bad news. The NHAIDES

relies on a single 24 hour dietary recall. Asking

someone once what they ate yesterday and then

projecting that forward over decades. Worse, it

lumps salmon, bacon, chicken, yogurt and steak

into one bucket called animal protein. That kind

of broad brush smooths over critical differences.

Fish is not bacon, chicken is not salami, and milk

is not steak. We have learned things from the

NHANES study, yes, but anyone who reads these

studies for a living will tell you the skill is

knowing how to separate good data from junk

analysis. And Hyman's is, unfortunately, junk

analysis. So let's go to the evidence. When you

turn to systematic reviews and large cohort

studies, the picture becomes clear and far more

precise than the NHANES snapshot. Let's look at

red and processed meats. Multiple independent

studies across different populations consistently

show the same thing. Higher intake means higher

cancer risks. Add 50 to 70 grams a day of red or

unprocessed meat and colorectal cancer risk rises

15 to 32%. Processed meats carry an even greater

risk. Let's go to fish. Several carefully

separated analyses show that 50 grams a day lowers

colorectal cancer risk by, uh, 4%. Pescatarians,

those who eat fish predominantly as their meat

source, have roughly, uh, a 9% lower overall

cancer risk than regular meat eaters. Poultry?

Well, independent studies show that it's neutral

to maybe even slightly protective. Unlike red

meat, poultry hasn't been linked to higher

colorectal cancer risk when carefully analyzed.

What about dairy? You know, Greek yogurt? Large

cohorts demonstrate that milk and calcium lower

the colorectal cancer risk. But at very high

intakes, dairy, especially milk, has been linked

to increased risk of prostate and endometrial

cancer. Now let's just contrast this with plant

protein. And the data here is so remarkably

consistent. Higher plant protein is associated

with a lower risk of overall cancer incidence and

cancer mortality, particularly when plant protein

replaces animal protein, especially red and

processed meats. Multiple prospective cohorts,

meaning we take a group of people and we follow

them over time and, and meta analysis, meaning

we've taken a lot of these studies together, show

that plant protein is Inversely associated with

all cause cardiovascular mortality, meaning it's

heart healthy. And when we substitute animal

protein with plant protein, it reduces the overall

risk of total and site specific cancers,

especially colorectal. Now here's the key. Every

major cancer body, whether it's the American

Cancer Society, the World Cancer Research Fund,

the European Union, or cancer research institutes

in Canada, Australia and beyond, document these

same trends. The problem isn't with protein

itself. It's with lumping it all together, as N.

Hayden's does. That fuzzes the picture. But when

you separate the sources, as these independent,

carefully done studies have, the information

becomes crystal clear. Red and processed meat

increases cancer risk. Fish tends to protect.

Poultry is neutral. Dairy is mixed. And plant

protein is protective, especially when it replaces

red and processed meats. Now, Hyman writes, I

Recommend Aiming for 4 to 6 ounces of high quality

animal protein per meal, twice a day. Now, that

might sound like sensible advice, but this isn't

what cancer prevention is made up for. This is

bodybuilding math dressed up as medicine. Follow

that prescription, literally, and you're eating

steak at lunch, steak at dinner, with eggs,

poultry and dairy filling in the gaps. That's not

building resilience, that's building cancer risks.

Multiple cohort studies show that diets highest in

red and processed meats, the very food his

prescription promotes, carry the highest rates of

colorectal, breast and endometrial cancer

substitution. Studies are clear. Replace red meat

with plant protein or fish and the risk goes down.

Follow his advice and it goes up. And here's the

kicker. There is no cancer society, no cardiology

body, no public health organization on earth that

recommends 1 gram of protein per pound of body

weight. Every major health body recommends the

opposite. Cut red and processed meats and replace

them with other healthier sources. Now contrast

that with the Mediterranean diet, the most studied

diet for longevity. It allows up to 4 ounces of

red meat in a day or less. And people who follow

it don't just live longer, they live healthier

with lower cancer and heart disease rates. So when

Hyman prescribes his four to six ounces twice

daily, the question is, is he reading the data or

is he just selling to the low carb crowd? Because

it isn't medicine, it's marketing.

Next on his thread, Hyman advises, and I quote,

choose grass fed pasture, raised meat, organic

poultry and eggs, wild caught fish. They're higher

in omega 3s, B12, zinc, and lower in hormones,

antibio and inflammatory fats. Now that sounds

great, but here's the truth. The difference

between grass fed and corn fed beef is minimal

when it comes to cancer risk. Grass fed beef may

have a touch more Omega 3s, but it's still red

meat. It is still produced in the same DNA

damaging compounds when grilled or smoked. And the

biggest difference? Taste. Grass fed beef often

tastes grassy or gamey. Corn fed beef is richer,

marbled. And frankly, I'll admit I prefer the

taste of corn fed beef. But preference doesn't

change cancer data. If you want real nutritional

benefit, you'd be far better off eating farmed

fish other than any kinds of beef. Fish has more

omega 3s, fewer carcinogens, and protective effect

against colorectal cancer. Choosing grass fed over

corn fed steak isn't a health choice. It's a

palate choice. So when Hyman pitches quality meat

as though a, uh, marketing label erases decades of

cancer research, he isn't giving medical advice,

he's selling a lifestyle brand. Hyman also wrote,

quote, for decades, scientists have thought high

protein raised cancer risk by raising IGF1. But

this study showed there was no link between IGF1

and mortality. This is a classic sleight of hand,

IGF1, which is a pathway. It's not the whole

story. But cancer begins with DNA damage. When red

meat is processed, it forms nitrates and nitrites

that become carcinogens. When red meat is grilled

or charred, it produces heterocyclic amines and

polycyclic aromatic hydrocarbons. These chemicals

damage DNA directly. And if your repair systems

fail, mutations build and cancer can begin. So to

say no IGF link means no risk is like pointing at

the matchbook and ignoring the bonfire. The risk

isn't theory, it's chemistry. Hyman closes with.

Moderate intake of animal protein does not raise

risk. Prioritize nutrient dense sources, balance

with colorful plants, and lifestyle factors like

smoking and inactivity matter more than protein

intake. Sure, plants help. Fruits, vegetables, and

whole grains do mitigate some of the cancer risk

of unprocessed red meat. That's good news. But

plants don't cancel out bacon. A salad with your

hot dog doesn't erase the hot dog. And I love a

Chicago style hot dog that has lots of vegetables

on it. And relish. It's delicious. But smoking

inactivity are stronger risk factors than diet.

But that doesn't mean diet doesn't matter. Smoking

is worse than asbestos, too, but that doesn't make

asbestos safe. Cancer risk is cumulative. Every

preventable risk counts. So when Hyman wraps

himself up in a platitude about colorful plants,

he's not doing science, he's doing spin. So here's

the bottom don't be fooled by viral nutrition

tweets. The overwhelming evidence shows that red

and processed meat raise cancer risk, fish helps,

poultry is neutral, dairy is mixed, and plant

protein is protective, especially when it replaces

red and processed meats. And as much as I would

love to sit down and have a big steak every night,

I don't because I believe the data. And the data

says less red and processed meat, more fish, more

plants, and better health. For references and the

full breakdown, check the blog

post@yourdoctorsorders.com and 4Q.com Please

subscribe to this podcast, share it with friends

and help spread the evidence, not the hype. This

podcast was distributed by our friends at Simpler

Media and my good friend the cod pod God, Mr. Evo

Terra. And remember, while I am a board certified

physician, I am not your physician. Please talk

with your board certified doctor, not a

chiropractor, certainly not a functional medicine

doctor and a registered dietitian before making

any big changes to your diet. Yes, I still eat red

meat. I sometimes have tofu. I probably should

have it more often. And you should too. Oh, and

here's a culinary tip. When you like your steak,

marinate it in some rosemary that actually cuts

down on some of the heterocyclic amines and

produces less carcinogenic compounds when it's

grilled. Culinary tip for the day from the doctor.

Alright everybody, have a good week.

All right? Ivo, after all this protein talk, fish

tacos or bacon cheeseburger? Which one's going on

your plate? Me. I kind of like the fish tacos

around here. They're freaking delicious.

>> Speaker B: Oh yeah, fish tacos have been my go to for quite a

while now. They're amazing. Speaking of which, I

didn't edit out when you mistakenly called me the

cod podfather.

>> Dr. Terry Simpson: You know, because I like Code M.