Eating animal protein can protect against cancer: Know what a new landmark study has found

Animal vs. plant protein: What a major US study really found about longevity, heart disease, and cancer

Americans often wonder: Does eating more protein, whether from meat, dairy, or plants, raise your risk of dying early from heart disease, cancer, or other causes?

To find out, researchers dug into data from the NHANES III study (Third National Health and Nutrition Examination Survey), which tracked thousands of Americans from 1988–1994 and followed their health for nearly 20 years. The findings of the study have been published in Applied Physiology, Nutrition, and Metabolism journal.



Scientists analyzed nearly 16,000 US adults (ages 18+) who completed detailed diet surveys and provided biological samples.

They calculated each person’s usual protein intake, both animal protein (meat, dairy, eggs) and plant protein (beans, nuts, grains, veggies).

Using a reliable statistical method (Markov Chain Monte Carlo), they avoided the pitfalls of one-off food diaries.

They then linked these diet patterns with official mortality records (heart disease, cancer, and all-cause deaths).

Finally, they adjusted for lifestyle factors like age, sex, weight, smoking, and pre-existing health conditions.

What did the study find?

Eating animal protein has no increased risk of overall death or death from heart disease. Surprisingly, higher animal protein intake was slightly linked to lower cancer death risk (hazard ratio = 0.95 per extra gram, p = 0.04). In simple words: people who ate more animal protein had a modest reduction in cancer deaths.

Eating more plant protein was neutral, it neither raised nor lowered the risk of death from any major cause.

IGF-1, a hormone often linked to cancer risk, showed no relationship with mortality in this analysis.

"Our analysis revealed no significant adverse associations between dietary protein from either plant or animal origin and all-cause or CVD-related mortality. We also did not observe any association between total protein intake, systemic IGF-1 concentrations, and cancer-related mortality. We observed a small but significant protective effect of animal protein and cancer mortality. The current findings contradict some previously published findings that have linked animal protein intake to increased mortality risk," the researchers have said.

What does this mean for Americans?

Here’s the big takeaway:

• Eating animal protein (meat, dairy, eggs) in reasonable amounts does not increase your risk of dying from cancer, heart disease, or any cause.
• In fact, animal protein may have a slight protective effect against cancer deaths.
• Plant protein is still healthy for many reasons (fiber, vitamins, overall diet quality), but this study shows it doesn’t directly lower early death risk from heart or cancer.
• This study challenges the idea that “animal protein shortens your life” or that “only plant protein protects your heart.”

Good sources of animal protein

When most people think of animal protein, they picture a steak on the grill—and yeah, beef is definitely a solid source. But there are plenty of other high-protein foods from animals that fit different tastes and health goals.

Chicken and turkey are the go-to lean protein options. They pack a ton of protein without much fat, especially if you stick to skinless cuts. Fish and seafood are also awesome—think salmon, tuna, shrimp, and cod. Not only are they rich in protein, but fatty fish like salmon give you heart-healthy omega-3s too.

Eggs are one of the most versatile and affordable animal protein sources out there—boil them, scramble them, or toss them in a salad. If you’re more of a breakfast person, Greek yogurt, cottage cheese, and milk are great ways to sneak protein in early in the day.

And yes, lean cuts of beef and pork (like sirloin, tenderloin, or pork chops) can be part of a healthy diet, especially if you balance them with veggies and whole grains.

From poultry and seafood to eggs and dairy, you’ve got plenty of tasty ways to get high-quality animal protein without going overboard.

So how much should you eat?

"I recommend aiming for 4–6 ounces of high-quality animal protein per meal, about 1 gram per pound of your ideal body weight per day. Choose grass-fed, pasture-raised meats, organic poultry and eggs, and wild-caught fish. These are richer in omega-3s, B12, and zinc and lower in hormones, antibiotics, and inflammatory fats. Pair them with colorful plant foods for optimal health," says Mark Hyman, Founder Cleveland Clinic, Functional Medicine.

"Nutrition science evolves, and it’s essential to follow the data, not outdated dogma. Protein isn’t something to fear, it’s one of the most powerful tools we have to protect our health and longevity," he added in a long post on Instagram highlighting the findings of the study.



This large, long-term American nutrition study suggests that both animal and plant protein are neutral when it comes to overall mortality and heart health.

The smartest strategy? Balance and moderation—get your protein from a mix of sources.