What Those Controversial Meat Studies Really Found: Is Red and Processed Meat Healthy?
Nutrition Twitter is ablaze with the latest findings by the Annals of Internal Medicine – in FOUR studies – that eating meat doesn’t cause cancer or heart disease, and it doesn’t increase our risk of death.
So of course, the media is all over it: Cutting Back on Red and Processed Meat Won’t Improve Your Health! Meat is Okay! Study Greenlights Consumption of Red and Processed Meat!
So should we be eating more meat? The same amount? In the face of the latest push for more plant-based diets, these findings seem weird.
What did the meat studies really find?
Is Eating Red Meat Bad?
Red meat and its impact on our health has always been a contentious subject. On one side of the Twitter argument are the pro-meat, usually low-carb people, with some doctors too, saying that Ancel Keys was a hoax (Ancel Keys was the guy who first proclaimed saturated fat as harmful, leading to North America to adopt a more carb-heavy diet..which, we all know how that turned out)
On the other side are people – many of them plant-based eaters, some doctors, some scientists, saying that the saturated fat and other compounds in meat are harmful to our health.
It’s like a merry-go-round between these two groups that won’t stop. So much so, that I’ve stopped chiming in and started to scroll right by.
My overall feeling about meat has always been congruent with most of how I feel about every other food: too much is probably not great for us, but some is likely harmless. It’s like any other food: too much of anything isn’t healthy. Seriously.
Sure, studies have linked saturated fat with heart disease and inflammation, but these studies are far from conclusive. And there’s a reason for that, which I’ll get to.
Which brings me to the point of my post: what were these studies all about?
The first study:
Red and Processed Meat Consumption and Risk for All-Cause Mortality and Cardiometabolic Outcomes: A Systematic Review and Meta-Analysis of Cohort Studies.
Method: A panel did a systematic review of observational evidence for links between processed and unprocessed meat consumption in varying amounts and cardiometabolic disease and the risk of dying overall.
Results: The evidence that links both processed and unprocessed meat to disease is weak and low-certainty.
The second study:
Patterns of Red and Processed Meat Consumption and Risk for Cardiometabolic and Cancer Outcomes: A Systematic Review and Meta-Analysis of Cohort Studies.
Method: Reviewers assessed certainty of evidence from observational studies with 1000 or more participants.
Results: Low or very-low certainty evidence that red and processed meat consumption is linked to cardiometabolic and cancer outcomes.
The third study:
Effect of Lower Versus Higher Red Meat Intake on Cardiometabolic and Cancer Outcomes: A Systematic Review of Randomized Trials.
Method: Reviewers assessed the risk of bias and certainty of evidence in 12 trials.
Results: “Low- to very-low-certainty evidence suggests that diets restricted in red meat may have little or no effect on major cardiometabolic outcomes and cancer mortality and incidence.”
The fourth study:
Reduction of Red and Processed Meat Intake and Cancer Mortality and Incidence: A Systematic Review and Meta-Analysis of Cohort Studies.
Method: Reviewers assessed the link in 73 observational studies between red meat consumption and cancer incidence.
Results: “The possible absolute effects of red and processed meat consumption on cancer mortality and incidence are very small, and the certainty of evidence is low to very low.”
The overall recommendations that resulted from these studies?
Continue to do what you’re doing. Eat meat, it’s okay.
Oh, and vegetarian diets might not even be healthier than diets with meat.
My take, and I know it might be controversial, is:
These meat studies don’t really tell us anything.
Most nutrition studies don’t tell us anything.
They’re more like an educated guess, because observational studies suck. (Remember that egg study?)
Here are the problems with them:
Everyone is genetically different, and therefore we each process nutrients differently. Saturated fat might raise my cholesterol, but not my husband’s. Gut bacteria might have something to do with how we process food differently, as well – and everyone’s microbiome is different. Observational studies can’t account for these and all of the other confounding variables that can skew results.
Researchers try to control for smoking, sedentary lifestyle, and disease, but they just can’t control for every single thing. That means, and particularly for these studies, that the results may be affected by other factors.
In these studies, red and processed meat were lumped together. Such a fail.
Nutrition studies can’t really pinpoint the source of study outcomes, because they’re all observations. In other words, nobody will agree to live in a lab for years and years, being fed a supervised and carefully prepared diet, to see what really happens to our bodies when we consume saturates. So instead, we ask people what their regular diet consists of, and then we track them for years to see what happens to them. Do they die? Do they get sick? Are they healthy?
Usually, study subjects fill out a food frequency questionnaire (how often do you eat vegetables?) one time at the beginning of the study, and that’s it.
Food frequency questionnaires are notoriously boring, long, and hard to fill out. People forget what they’ve eaten. They lie. They get annoyed with the long form and just start skipping and filling out shit carelessly. Also: if someone happens to change their diet within the course of the study, that won’t reflected in the results. And considering that some studies are over 10 years long, this is an important thing to consider.
In other words? We should probably stop it with the observational studies, but there’s really no other alternative for studying how what we eat may affect us.
So what do we eat?
If we can’t rely on observational nutrition data, which is pretty much every nutrition study that comes out, what are we supposed to do?
Here are my recommendations:
Eat a variety of foods. That means: vegetables, meat, fish, eggs, cheese, butter, beans, cake, yogurt, fruits, Oreo cookies, and whatever else.
Try to eat as many whole, minimally processed foods as you can.
Don’t be afraid of food. Find joy and peace with eating. Eat in a way that helps you maintain a comfortable weight for you. That makes you feel good.
And stop believing media headlines about nutrition studies.