High protein diet has similar cancer risks than smoking?!

I saw this in the daily mail this morning too. I am just so confused :-(

I saw this just after I'd been trying to talk a friend into eating more protein lol

Yeah I read this today too. Sounded a bit odd to me....But then the Guardian/Daily Mail both have a history of randomly naming stuff that gives you cancer, and then three weeks later saying it doesn't. It's all rubbish, I don't believe anything I read in either of those papers.

I saw this just after I'd been trying to talk a friend into eating more protein lol

The title is misleading. I think they are not saying that protein is bad, just that certain sources MAY be problematic. Your friend should still eat more protein!

The study is in no way conclusive, and the suggestion is only that high-protein in middle age *may* be problematic - the study even admits that low protein is likely to be a bad approach in later life. I wouldn't worry about it, on the strength of an observational, rather than experimental, study.

Found it!


http://download.cell.com/cell-metabolism/pdf/PIIS1550413114000655.pdf?intermediate=true

This is Christine Cronau's response
Sensational headlines! Meat and Cheese Linked to Earlier Death!

Or, are they? Every few years, there is a new study that claims that animal protein is bad for us, but every single one of those studies has been faulty. Two years ago it was claimed that eating more meat caused more death from heart disease and cancer. But, when the study was evaluated, it showed that those dying earlier:

—smoked more
—exercised less
—were more overweight
—were more diabetic
—were more hypertensive
—ate more in general
—ate less vegetables and fruit
—ate more red meat

Oh, there it is, thus, red meat causes cancer! Are they kidding?

What about this latest study?

Dr Longo said, "We provide convincing evidence that a high-protein diet, particularly if the proteins are derived from animals, is nearly as bad as smoking." Large claim.

The study stated that in humans, higher protein intake is 'associated' with higher rates of diabetes related deaths. Because we know excess carbohydrates causes diabetes (biochemistry), the fact that we don't know what was being eaten WITH the protein is a huge flaw in a study with this type of conclusion.

Also, were the diets of the participants carefully analysed over a long period of time to ascertain exactly what these people were eating? Ah, that would be a no. Nutrient intake was based on "food and beverage intake during a 24 hour period." What!?

They also studied mice and claimed that mice on a high-protein diet "ate less and were slimmer," but had a "reduced lifespan and poor heart and overall health."

Hmm. Mice are generally vegetarian. They have not evolved to eat large amounts of animal protein. Like comedian and health writer Tom Naughton says, "When investigators feed a diet to an animal that is completely unnatural for the animal, I don't care what the results are. I don't care if T. Colin Campbell can produce cancer in rats by feeding them an isolated dairy protein, because most rats don't milk cows. The ones who do don't have the technology to separate the proteins."

This shows we have so much to learn and unlearn. Remember each calorie has the same value, forget one may come with vitamins minerals and other beneficial things whereas others are completely of anything but the white stuff. READ, THINK, UNDERSTAND, CONSIDER, SIT ON A FENCE OR ACCEPT OR DISMISS.

False. And this is not a peer-reviewed study.

Er, yes it was actually, it was published in Cell Metabolism: http://www.cell.com/cell-metabolism/fulltext/S1550-4131(14)00062-X#Summary

Nevertheless, the way this has been interpreted in the press is very misleading and when you look into the actual data, the link is rather tenuous!!
1. The study only looked at people over the age of 50, who have a naturally higher risk of cancer anyway (everyone's risk of cancer increases as you get older simply because you have been around longer and exposed to carcinogens longer).
2. The point is not emphasised that the study found high protein intake seems to INCREASE life span over the age of 60.
3. Data about dietary intake was based on a survey - there is big scope for reporting errors here (e.g. people filling in a survey tend to withhold information if they think they're not giving the "right" answers - here on MFP we're generally pretty good about logging everything, but imagine if you were average Joe being asked to fill in a survey on your diet...you might be tempted to make yourself seem healthier than you really were!
4. Scientists know that people who have low levels of a molecule called IGF-1 have a reduced rate of cancer, and we know that restricting protein intake can reduce levels of IGF-1. This study used secondary data for which the actual IGF-1 levels were not available for more than half of the participants. Nevertheless, the researchers seem to have assumed that everyone who eats a low protein diet has low IGF-1. This is not necessarily very accurate.
5. I couldn't find anything in the original paper that suggested the researchers had adjusted their data to take into account things like smoking, alcohol intake or exercise (etc.). The attention-grabbing headline suggests that "high protein diets may be as bad as smoking", but we don't know whether the people in the study were in fact ALSO heavy smokers, or alcoholics, or motionless vegetables who took no exercise - maybe those confounding factors are why they were getting more cancers etc? Just because there is a statistically significant correlation between X and Y *doesn't* automatically mean that X *causes* Y.

There's plenty more, but that's enough reason for me to keep eating protein!!

High-carbohydrate diets are good for you. Just throwing it out there.