Patrick Holford recently posted a blog post talking about the link between high protein diets and cancer. Here’s a snippet from the article:

High protein cancer link

 “A study from the University of Southern California has found that a high protein diet, as advocated by Atkins and others, is associated with a 75% increase in overall mortality and a four-fold increase in cancer death risk in people aged 50 to 65.”

However, I wanted to know if anyone else had any opinions on the matter. It’s not good to get all your information from just one source, right? One thing that jumps out at me is that 50 to 65 is a somewhat narrow age range. What about people aged 0 to 49? What about those aged 66 or older?

WebProNews had this extra bit of information about older people:

High-Protein Diet May Raise Cancer Risk

Participants aged 65 or older actually need more protein than those in the low protein group, due to the fact that those over 65 suffer from protein malnourishment as their body weight starts to drop.”

However, the paragraph above it did distinguish between animal and plant protein sources:

“When researchers analyzed the animal-plant protein variable, they found that when they removed animal protein from the statistical sample, the link between high protein consumption and mortality disappeared. Researchers suggest that consuming a high level of animal proteins can lead to death by all health-related causes, including cancer.”

This suggests that the issue is not the protein, but the animal protein. So, even if older people do need more protein, if they get it from vegetable sources they should avoid the risks of excess animal protein.

Scientific American explained this a bit further:

Diet High in Meat Proteins Raises Cancer Risk for Middle-Aged People

“The link between high-protein intake and risk of cancer almost vanished when the researchers considered participants whose protein mainly came from plants, such as beans. This may be because proteins in plants have a different composition, and don’t stimulate growth hormones as efficiently as meat proteins… The study suggests that the Mediterranean diet, which is low in animal protein and high in carbohydrates, may be best for extending life span…”

However, took things a stage further, and challenged the view that protein may be as dangerous as smoking, by stating that not all animal protein sources are of equal quality:

High-Protein Diets Linked to Cancer: Should You Be Concerned?

“Yes, dietary protein was implicated in mortality. No, it isn’t as harmful as smoking… Poor diet is a ubiquitous problem. Processed meats are a staple of poor diets. Processed meats also tend to have protein. The study made no differentiation between different animal sources… Chicken breast is not comparable to processed bologna meat…”

So, the question that still remains for me is:

Is vegetable protein healthier for you than animal protein?

While the title of Holford’s article is a little misleading in that it suggests that all protein is bad in large amounts, if you read the article it does go on to say that protein from fish and vegetable sources is better than protein from meats. WebProNews and Scientific American also highlight that the study showed that vegetable protein did not raise cancer risk like animal protein did.

But it seems that the issue that Spencer Nadolsky at has is that maybe good meat is just as good as vegetable protein, and that it is bad processed meat which is the problem. Nadolsky’s issue is that the study didn’t say what animals the protein came from, or whether it was processed or unprocessed.


Out of the 4 articles I read and quoted here, 3 of them state that high animal protein can increase cancer risk, but 1 of them wasn’t convinced due to a lack of clarity on the type of animal protein. I think the important thing to keep in mind is that you should make whole foods and fresh vegetables the majority of your diet. If you like a bit of meat, that’s okay as long as it’s good quality, unprocessed and not the main focus of your meal. Eat it as a small part of a meal mostly consisting of good quality vegetable foods.

Oh, and white meat is better than red meat. Just when you thought I’d finished quoting other websites, here’s a little snippet from the American Heart Association:

Eat More Chicken, Fish and Beans than Red Meat

“In general, red meats (beef, pork and lamb) have more cholesterol and saturated (bad) fat than chicken, fish and vegetable proteins such as beans. Cholesterol and saturated fat can raise your blood cholesterol and make heart disease worse. Chicken and fish have less saturated fat than most red meat.  The unsaturated fats in fish, such as salmon, actually have health benefits. Omega-3 fatty acids, found in fish and some plant sources, may reduce the risk of cardiovascular disease.”

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