Is red meat responsible for one in ten early deaths?

Question

The red meat and cancer link has already been addressed here: Does eating meat increase your risk for cancer? But recent reports suggest a broader more worrying relationship to variety of other causes of death.

The Guardian reports the study thus:

Regularly eating red meat increases significantly risk of death from heart disease and cancer, according to a study of more than 120,000 people carried out over 28 years.

The findings show that each extra daily serving of processed red meat – equivalent to one hot dog or two rashers of bacon – raised mortality rate by a fifth...

...The study found that cutting red meat out of the diet entirely led to significant benefits. Halving red meat consumption could have prevented 9.3% of deaths of men and 7.6% of women taking part in the study.

Not everyone agreed:

The findings were challenged by Dr Carrie Ruxton, of the Meat Advisory Panel, an expert body funded by the meat industry.

She said: "This US study looked at associations between high intakes of red meat and risk of mortality, finding a positive association between the two. However, the study was observational, not controlled, and so cannot be used to determine cause and effect."

So given the nature of the study, are the headline results credible?

Answer 1

Denise Minger posted a rebuttal at Will Red Meat Kill You? Although she is not a scientist, her article breaks down the arguments against red meat in a very straightforward manner, such that a non-scientist can judge their validity without needing a Ph.D. The points made are:

• The quoted study is purely observational, and based on people filling out a survey of food types they have eaten in the past (one survey every four years). DM makes the point that the researchers overstated the case:

The lead researcher Frank Hu claimed the study “provides clear evidence that regular consumption of red meat, especially processed meat, contributes substantially to premature death,” despite the fact that the study is innately incapable of providing such evidence. (my emphasis)

I will note that the OP provided an example of that incorrect conclusion: The study found that cutting red meat out of the diet entirely led to significant benefits. Except, that's not what the study did - that statement implies that someone actually cut red meat out of their diet, and saw health improvements (which didn't happen). Now, if they had done a controlled study, and actually changed people's diet (removing one factor at a time), the quoted statement, might be a legitimate result.

• The study's conclusion does not take into account other factors, such as total calories consumed, exercise levels, alcohol consumption, and smoking.

The folks eating the most red meat were also the least physically active, the most likely to smoke, and the least likely to take a multivitamin (among many other things you can spot directly in the table, including higher BMIs, higher alcohol intake, and a trend towards less healthy non-red-meat food choices).

• Study result that the Media failed to report:

Here we see the folks eating the least red meat have the highest rates of elevated cholesterol, while the red-meat-indulgers have the lowest rates. Given the media’s eagerness to assign cause and effect to this study, it’s mighty strange none of the headlines proclaimed “Red meat reduces cholesterol!”

• Then there's the bad statistics:

Those numbers thrown around in the fear-mongering news clips—20% increased risk of death from all causes for processed meat and 13% increased risk of death from all causes for unprocessed meat—are classic examples of how even the most ho-hum findings can sound dramatic if you spin them the right way (and remember to attribute them to Hahhh-vard). If your risk of dying from a particular disease is 5% to start with, a “20% increased risk” only bumps you up to 6% in the grand scheme of things. That’s a lot less scary.

The original study is at: Red Meat Consumption and Mortality