T Nation

Protein and Liver Cancer?


#1

I recently read a book the nutritional scientist T. Colin Campbell entitled "The China Study". In the book, one of the numerous studies he talks about deals with rats and mice, and how varying the amount of casein protein in their diet in effect controlled the promotion stage of cancerous liver tumor development. He found that rats and mice on lower casein diets, 5-6%, had dramatically fewer tumors and better survival rates than those fed with 20-22% casein diets.

He also fed another group gluten, plant protein, at the same levels, and noted that unlike the higher casein levels, equivalent gluten levels did not affect tumor development. This is scary, as I know we all use mass amounts of milk protein in our muscle-building efforts. Any of the nutrition gurus on the site have an explanation for this phenomenon? Do these results make biochemical sense??


#2

Forgot to mention, they were all dosed with aflatoxin, a highly carcinogenic compound.


#3

I read this book also. Quite interesting. The basic skinny of it is eat animal proteins and aflatoxins (ie. peanut butter) and you are at the highest risk for cancer. It is the most comprehensive study of its kind and makes you think for a second. Although no one on this site is honestly going to give a shit.


#4

yes but both the gluten group AND the casein group were dosesd with alflatoxin, which indicates that there may be some tumor promoting effects of casein... al though more studies need to be done


#5

"Too much protein can cause liver cancer..."

Meanwhile,there is still no cure for cancer(in drug from ).


#6

Point?


#7

Hmmm, since casein has a much higher BV than plant proteins, those studies were done on rats, I would assume it would affect tumor growth. Since cancerous cells are ravenous consumers of nutrients, more quality nutrients then faster growth.

I found this interesting;
"Cancer epidemiology closely mirrors risk factor spread in various countries. Hepatocellular carcinoma (liver cancer) is rare in the West but is the main cancer in China and neighboring countries, most likely due to the endemic presence of hepatitis B and aflatoxin in that population. Similarly, with tobacco smoking becoming more common in various Third World countries, lung cancer incidence has increased in a parallel fashion

The consensus on diet and cancer is that obesity increases the risk of developing cancer. Particular dietary practices often explain differences in cancer incidence in different countries (e.g. gastric cancer is more common in Japan, while colon cancer is more common in the United States). Studies have shown that immigrants develop the risk of their new country, suggesting a link between diet and cancer rather than a genetic basis.

Despite frequent reports of particular substances (including foods) having a beneficial or detrimental effect on cancer risk, few of these have an established link to cancer. These reports are often based on studies in cultured cell media or animals. Public health recommendations cannot be made on the basis of these studies until they have been validated in an observational (or occasionally a prospective interventional) trial in humans."


#8

I'm not a nutritionist but from a toxicological standpoint the argument is weak. It's making too many large leaps that would never pass a critical peer review and is the reason most of these arguments are in such books.

  1. First and most importantly, studying the effects after acute aflatoxin exposure and then concluding that the compound in question is a causal factor is incorrect. This is akin to someone stating that pouring saltwater on the skin "stings" only you forget to mention the fact that you first have to have a cut on the skin.

  2. Aflatoxin is not a known human carcinogen. Though, it is very, very hepatotoxic and in fairness, one can generally assume that it probably would cause hepatic cancer.

  3. The FDA has regulatory standards on aflatoxin in foods. So called third world or less developed countries would be where the greater concern is at.

  4. The data collected was in rodents.

  5. Going back to the first point, this is so important as you're talking about one compound which inherently causes one effect and then studying another compound's effect upon that, looking to see whether it exacerbates or inhibits that effect. Now, if we had a study where mice or rats were ONLY fed varying amounts of casein and established that the higher casein intake caused negative changes, that would be a different story.

The Conclusion: If you're a Ghanian rodent and suffer from acute aflatoxin exposure, you'll want to avoid a high casein diet.


#9

Checking if I give a shit...

Hold on...

No. Don't care.

Interesting thought, but I will continue as I have.


#10

So let's see... we give the mice cancer, then wonder as the cancer grows faster when being fed lots of good muscle-tissue-growing food. Boggling...


#11

I think the short answer is that tumors need protein to grow, too. Casein, being a better source of protein than gluten, helps the tumor grow faster (just like it helps muscle grow faster if you haven't got a tumor.)

This is why treating cancer is such a pain in the ass -- the tumor is pretty much you, only SLIGHTLY different. So what's good for you is good for the tumor, and vice-versa. Most of the common cancer treatments involve, effectively, exposing yourself to some toxic shit (ratiation, chemo) and then hoping the toxin kills the tumor before it kills you.


#12

The point is there are more important things out there like curing cancer than trying to prove that too much protein causes liver cancer.
Lets see.
How many people die from eating too much protein?
Now how many people die of cancer every year?


#13

Okay, but disregarding this particular faulty study, wouldn't you rather want to know what causes cancer so you can avoid getting it altogether rather than rely on pharmeceutical companies to solve our health problems?


#14

Living. Being alive causes cancer, but I'm going to risk it...


#15

I totally agree with you.
But we need to study this more.
However,I highly doubt protein it's self causes cancer of the liver.
This is nothing new.
The theory of too much protein causing cancer has been around for quite some time now.
There is a huge difference between too much,unwanted protein for someone who isn't really active and just enough protein for someone who is active.
You're right though.As long as you eat right,(and no,I don't mean a bunch of slim fast bars)exercise,and practice good hygene,then you'll not have to worry too much about geting cancer.


#16

I have to say, it didn't suprise me at all at the various ignorant responses I got to this post, but that was expected. There were a few insightful posts though, and to those posters I say thanks.

Cy, the study did vary the amounts of casein in the rat and mice diet, one group receiving about 5-6%, the other receiving about 20-22%. The issue tested was not whether aflatoxin initiates and promotes cancerous tumor growth, that is known (to be conservative, in mice and rats at least, whether in humans we don't know one could argue, but the argument is put forth that protein metabolism and requirements in rats is very similar to humans). The resulting incidence of liver tumor growth was much (significantly) higher in the higher casein group than the lower casein group. The equivalent high gluten group (20-22% gluten fed diet) was also low, roughly equivalent to the 5-6% casein.

To those that claim, yes, this is an obvious effect due to the higher BV of casein, fair enough. But think of the number of carcinogenic compounds your body is exposed to on a daily basis in our modern society (some may take issue with this as well, but I think you'd be proven grossly wrong by toxicological research). Campbell talks about how we all carry the "seeds" (initiation stage) of cancer in our bodies, yet whether they develop into cancer or not in large degree can be controlled by amount and type of protein intake. In other words, whether it goes into promotion is controlled largely by diet. It's an interesting postulate, advanced by a prominent nutritional researcher using sound methods.

It's funny also how some people think the pharmaceutical companies will save us all from cancer with amazing cures. Think again, they no doubt help in the effort, but as some of the writers on here have repeatedly stated, albeit in regards to muscle-building, "it's your diet stupid". Diet and exposure to environmental toxins, Campbell claims, to a lesser degree genetics, are the culprits. The genetics argument is interesting, as it allows for a kind of "Oh well!" fatalistic attitude towards ones current and future health, like it's out of their hands if they develop cancer or not. As we all know, diet is a hard, 24-hour/day ordeal, yet those who eat clean reap the benefits through lower disease rates and improved health and vigor.

Ok, well this grows long. I may have left out some points I wished to make. Spare me the ignorant posts (although I doubt that's likely). I look forward to the constructive posts.


#17

Sort of off topic, but I recall seeing a presentation from Dr. Judith Stern of UCSD (I think, I don't remember. It's one of the UC's) where she mentioned that a soy source protein diet decreases mortality due to kidney failure in lab rats used in her research. I think this was a point used against high protein rations for people, when I paraphrased Dr. Berardi by saying it only made sense, when overfeeding a given macronutrient, to overfeed protein.

My thoughts are:

  1. How much protein is a rat really made to eat? I would guess of the top of my head that they wouldn't handle a large protein intake as well as a people would.

  2. How old are the rats in the study. A year old rat is pretty damn old. It's bound to die of something.

That's about all I got, without consulting some literature.

I am curious about possible evidence of protein nephrotoxicity in lab rats.

Let the intellectual discourse continue.


#18

Great post BmacG.
I agree with what you're saying about cancer and the pharmaceutical companies.If I had a cure in my hands that cured any kind of disease or cancer that you could ever fathom and took it to the FDA,they'd probably take it and throw it away because they'd be out of business.
I believe most cancer/diseases are caused by:
Environmental toxins( like you said.Just look at the air)

Unhealthy diet(along with poor nutrition)

Unhealthy hygene

Not enough fruits and vegetables(like our mothers told us)

Toxins in our processed foods

And drugs themselves

I don't believe protein casues cancer.Although it may NOT help you if you have cancer,I don't belive protein causes it.The saying "you are what you eat" is true.
"Let your food be your medicine and your medicine be your food."
All physicians took the hippocratic oath; and yet they still go out and push deadly drugs.
You have geat insite on things BmacG.
It's great to talk to an intelligent human being.


#19

People aren't "ignorant" just because they have a different opinion than you about this subject.

Again, although said differently before, there are various foods and actions that people with cancer must be careful of, while those that don't, needn't worry about.

It is not necessarily useful to judge the effects of various foods on healthy people by looking at the effects of various foods on unhealthy people (especially when the studies in question were not performed on people).

That being said, if I had or previously had cancer, I would be more inclined to look deeper into the issue to see if there were food consumption choices that I could make.

Not having cancer, I focus on getting lots of various antioxidants through fruits, vegetables or supplementation, trusting the body to do its best to stay healthy if given the tools to do so.


#20

vroom, I was referencing the below-quoted post and trying to head off any possible future posts like it...