We Looked Into The Protein Debate. We Wish We Hadn’t.

steak debate

The world of nutritional science seems rife with contradictions and turnarounds: top minds in the field  disagree about nutritional guidelines and basic facts, like whether milk is healthful or harmful. So we shouldn’t be surprised to see a debate raging around the value of protein from meat.

The loudest voices in the protein argument belong to Loren Cordain, PhD, and T. Colin Campbell, PhD.  Cordain wrote The Paleo Diet, which claims that the anthropological record documents our ancestors eating copious amounts of meat. He’s convinced protein can prevent and reverse disease. Meanwhile, Colin Campbell’s book The China Study offers similarly compelling evidence that animal protein causes diseases like cancer and heart disease. He is now a vegan and advocates a plant-based diet for all.

In Favor of Animal Protein

 

Author of the Paleo Diet, this expert on exercise research advocates eating more protein from animal meat.

Author of the Paleo Diet, Dr. Loren Corain advocates eating more protein from animal meat.

In favor of more protein, Cordain says our bodies can absorb lots of protein. The current “very high protein” diet for the average male is 125 – 186 grams per day, and 89 – 133 for females, but the body’s physiological limit for protein (after which point it becomes toxic) is much higher, up to 187 – 270 g/day for males, 134 – 246 for females, or almost half one’s calories.

There’s evolutionary evidence that our ancestors ate lots of animal meat. Ancient stones and animal bones indicate that humans have hunted and eaten meat since the very origin of the genus Homo. Historically studied hunter-gathers got most of their energy from meat. The Ethnographic Atlas showed that most (73%) of the world’s hunters-gathers obtained >50% of their energy from hunted fish and animal foods.

Against Animal Protein

Dr. Colin Campbell is the author of the China Study and sees a strong link between animal protein and cancer, as well as other diseases.

Dr. Colin Campbell is the author of the China Study and sees a strong link between animal protein and cancer, as well as other diseases.

Arguing against excess protein, Colin Campbell says most people need less than 9% of their total calories to come from proteins. That’s 48g for a 132 lb woman and 56 g for at 154 lb man. People eating this little protein can do very well in terms of physical health and athletic ability.

Animal protein is linked to cancer.

There is a 80-90% correlation between animal protein intake and breast, prostate, colon, ovarian and kidney cancer. The countries that eat more animal protein have higher incidences of these cancers. When animal protein intake increases beyond 10%, say from 10% to 20% of calories consumed in a day, heart disease, diabetes, hypertension, osteoporosis, multiple sclerosis and kidney stones become far more common.

The China Study finds a strong correlation between meat consumption and certain cancers.

The China Study finds a strong correlation between meat consumption and certain cancers.

Meanwhile, some diseases are cured by reducing or removing animal proteins from the diet. Switching away from animal-protein-based food to whole-plant-protein based food has been shown repeatedly to control conditions like multiple sclerosis and heart disease. In some cases, cutting out protein shrinks cancer tumors.

At Power 20, we believe Dr. Campbell is right. Here’s why.

We’re better off when we lower our animal-protein consumption. It’s our (non-medical) view that both may be right, but Dr. Campbell’s low-protein approach is far better for modern society. Here’s why we side with low-protein, no animal-fats:

  • Today’s meat is mostly terrible. The meat is cooked at super high heats, the animals are themselves often unhealthy, much of the meat we eat is processed, and much of the meat people eat has lots of fat in it.
  • Today’s meat is environmentally unsustainable. We spend more energy feeding cows and pigs than we get from eating them. They take a tremendous amount of water and fuel to raise and distribute.
  • Today’s meat is raised in unethical environments. Most meat comes from Concentrated Animal Feeding Operations, or CAFOs. Their lives are painful and miserable.
  • The evidence linking animal proteins to disease is too strong. The strong evidence of the many diseases brought on by a slight increase in animal proteins should be enough to compel anyone to at lease consider cutting out all processed meat. And when you do eat meat, go for high-quality, organic, lean cuts.
  • Cordain falls into a common science trap. He follows a long line of nutrition experts who think eating a vitamin C supplement is the same as eating an orange. It’s reductionist thinking – the kind that leads him to first calculate the absolute maximum amount of protein one can eat before it turns toxic, and then prescribe that limit to people. This approach seems, to us, unreasonable.

Power 20 recommends a bit of both.

Cordain is right on one point: we should avoid sugary foods and drinks, including pasta and potato chips, since these simple carbohydrates lead to insulin resistance, which in turn leads to diabetes and obesity. And Campbell is right to recommend a plant-based diet. If we must eat meat,  we should have lean cuts from organic sources. But the planet, the animals, our wallets, our water systems, and our personal health will all improve if everyone adopts a plant-based diet and stops trying to bulk up on protein from animal meat.

Get these books to learn more about the debate.

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  • Power 20

    We’ve updated the chart to be less confusing. It was originally posted as a correlation between fat (as a proxy for meat consumption) and cancer, but that was confusing to readers, so we’ve found the China Study’s chart on colon cancer and meat intake.

  • J Lee

    Doesn’t it seem obvious that to adhere to the “Paleo Diet” would be perfectly healthy if you physically chased down your ‘meat’ source miles from ‘home’ and were successful at this task every few days if you’re good at it and lucky. Driving to the supermarket and buying yourself a big steak for dinner everyday might just be another thing health wise. Quantity matters.

  • friend

    Protein here i come. seems the reasons for non protein diets are all for society gains not physical to the person doing the eating….

  • http://arshadchowdhury.com/ Arshad Chowdhury

    You missed an important point: “Switching away from animal-protein-based food to whole-plant-protein based food has been shown repeatedly to control conditions like multiple sclerosis and heart disease. In some cases, cutting out protein shrinks cancer tumors.”

    So you can reduce and avoid some chronic illnesses by avoiding protein. That’s a powerful benefit to you.

  • susan

    I didn’t have to read the article to know where it would head. Just look at the biased photos that they used for the authors: Campbell looks all professional and is smiling while the awful picture of Cordain is from a screen-grab that just about every single solitary angry vegan uses to demonstrate their animosity toward paleo (and to demonstrate that he’s not a pale, pasty vegan, but an obese meat-eating animal killer).

    I’m not defending paleo at all, at least not as written by Cordain, but I know that I feel better with a small amount of lean meat once per day with veggies and some starches (the ones that I can tolerate) rounding out the rest. It took me a damn long time to find my right formula, and I had to go through a lot of pain of being told I was “just doing it wrong” by know-it-all vegans who yelled at me for not eating more bananas. Thank you, but after four years of being vegan I ended up with two issues: intolerance for soy and insulin resistance (aka pre-diabetes). I wasn’t a junk food vegan, either. We’re simply all different when it comes to diet, so one-size-fits-all is really dangerous.

    Besides, for as many doctors advocating a vegan or vegetarian diet as the holy grail of health, complete with tons of anecdotes to prove their message and claims of curing all things that ail you, there are other doctors who have the same number of “improved my health” testimonials while allowing for some animal products. Basically they all agree that fruits and veggies are important and dairy is pretty bad; where they differ is grains, oil, and animal products. Let’s focus only on that.

  • Power 20

    Hi Susan,

    Your criticism of Dr. Cordain’s picture was noted and updated. Thanks for that.

    Our goal with this post was to look at the core arguments made by these two influential figures and give our opinion on which of the two is more persuasive (in our company’s opinion). We can’t really comment on your personal experience experimenting with food, but it is too bad that a culture of anger, defensiveness, and guilt surrounds any conversation about diet, no matter what opinion people may hold.

  • RedFishBlueFish

    Another “scientific” stance chosen based on political views. This article chooses a scientific position because of probability and anecdotes. It’s the same type of folks saying global warming is a myth because it’s snowing outside.

  • gershon

    Nice article. The China Study was probably the last opportunity to find clusters of people with homogeneous diets.The research was solid and well-documented.

  • Stan Harris

    A quick note here and I’m not coming down on either side. I’m still looking at the evidence and the analyses.

    It does seems Cordain and his paleo diet miss the important point that simply because the paleo diet (as we understand it) provided survival advantage in the paleolithic time period does not necessarily mean that it was or is optimal for human health.

    It seems to me that perhaps there’s another point being missed here (if I missed that point, so be it), and that is there is likely no diet that is optimal for everyone.

    If the people at Power20 are right that still leaves me with a bit of a conundrum. Do I eat for the good of the planet or for the good of my health?

  • Mr. Adams

    The studies that look at meat consumption don’t seem to look at is, what else are they eating. How is the meat being cooked? Usually with higher meat consumption signals industrial country. Which means that the 80% of foods have sugar and other cancer causing substances. Study people that eat paleo and their health markers are 100% better than most of the population.

    To tell me eating more greens, veggies, and lean meats and get rid of sugar and other inflammation causing substances is going to be unhealthy, I just can’t understand that. If you look at the big picture, they are cherry picking studies.

  • Mr. Adams

    The studies that look at meat consumption don’t seem to look at is, what else are they eating. How is the meat being cooked? Usually with higher meat consumption signals industrial country. Which means that the 80% of foods have sugar and other cancer causing substances. Study people that eat paleo and their health markers are 100% better than most of the population.

    To tell me eating more greens, veggies, and lean meats and get rid of sugar and other inflammation causing substances is going to be unhealthy, I just can’t understand that. If you look at the big picture, they are cherry picking studies.