Researchers evaluated all studies done on red meat and six different disease outcomes and found almost no correlation. Are they right?
Amidst all the bad news we face almost daily were reports of a new study that gave men and women, at least the carnivore types, a reason to keep on living. The headlines were all variations of the following:
“New Study Finds Red Meat is Healthy, No Real Risks.”
Throughout the land, joyous meat-eating men and women put on their ketchup-concealing dark jeans and red gingham dresses and headed to the Outback Steakhouse, but was the impulse correct? Should they/we all be ordering the 20-ounce T-Bones or Teriyaki Filet Medallions, maybe starting with a Bloomin’ Onion, with dietary impunity?
Researchers at the University of Washington Institute for Health Metrics and Evaluation (IHME) have permanently arched eyebrows, like Trekkies doing some Spock cosplay at a Star Trek Convention. That’s because the IHME, like Spock, is inherently skeptical, in this case, skeptical of studies that try to find an observational link between some action – like eating pickled eggs or something – and cancer, some other disease, or plain old death.
In response to these sometimes-shoddy studies, the IHME uses a novel statistical method known as “burden of proof risk function” to quantitatively “evaluate and summarize evidence of risk across different risk-outcome pairs.” This allows them to scan all the data for a particular health risk and derive a number that translates to a 1-5 star rating system.
In this instance, they looked at all relevant studies pertaining to red meat and its association with six outcomes: breast cancer, colorectal cancer, type 2 diabetes, ischemic heart disease (coronary heart disease or hardening of the arteries), ischemic stroke (when a blood vessel to the brain gets blocked), and hemorrhagic stroke (a brain bleed).
Their analysis brought them to the conclusion that unprocessed red meat (cuts of beef, pork, veal, horse, and sheep, as opposed to the stuff you find on a pizza) was weakly associated with an increased risk of colorectal cancer, breast cancer, ischemic heart disease, and Type 2 diabetes by at least 6%, 3%, 1%, and 1%, respectively. Each of these pairs received two stars in their rating system.
As far as unprocessed red meat and ischemic or hemorrhagic stroke, they found no association, earning them each one star.
They concluded the following, all of which spits in the face of conventional health wisdom:
“The available evidence suggests that elevated unprocessed red meat has a weak association with the risk of colorectal cancer, breast cancer, ischemic heart disease, and type 2 diabetes. It may affect ischemic or hemorrhagic stroke, but there is currently insufficient evidence to draw this conclusion.”
As Spock would say, “Logical. Flawlessly logical.”
Maybe their findings and deductions were logical, and the consumption of red meat is fairly innocuous regarding human health. However, their study neglected to distinguish between the different types and subtypes of red meat.
To my mind, this study should have focused solely on steak (and hamburgers) and possibly pork since these variations are, for various reasons, a little different from other types of red meat. If they had, I think the associations between those types of red meat and the six outcomes that were the focal point of their statistical analysis would be stronger.
Consider steak. It has at least three variables that might have big-time implications on health. First, there’s portion size. As elegant as the IMHE’s number crunching was, it apparently didn’t consider the health implications of regularly eating 4-ounce portions as compared to 8, 12, or even the 16-ounce, toilet-seat cover slabs preferred by men who are part wolf or T-Rex.
Neither did they seem to include the type of cut in their calculations. A 4-ounce portion of sirloin tip has only about 6 grams of fat, while an 8-ounce ribeye contains about 49 grams.
The amount of fat is important for two reasons. First, unless the animal from which the cut was taken was grass-fed and grass-finished, the fatty acid ratio of the meat would be skewed and become a dietary handicap. (Grass-finished means they ate nothing but grass their entire lives, while grass-fed usually means they were started on grass but rudely switched to a grain diet a few weeks or months before slaughter.)
Grain-fed usually leads to an unhealthful ratio of omega-6 to omega-3 fatty acids. Once this ratio of fatty acids devolves to 18 or 20 to 1 from the desired 2 or 3 to 1, the meat becomes just another inflammatory component of our diet. Eaten often enough, in large enough quantities, and combined with all the other inflammatory aspects of modern life, it’s highly likely you’re more prone to one or more of the six health outcomes the IMHE tracked in their study.
Aside from fatty acid ratios, the sheer volume of fat consumed is also an issue. Some ground-breaking research by researcher Tyler Benson (that’s yet to be acknowledged by the bulk of cardiologists) found that a single, high-fat meal makes it hard for men’s blood vessels to dilate. Additionally, microscopic examination of their red blood cells showed that the high-fat meal had made their red blood cells “spiky” instead of smooth.
The “spiky” blood cells, instead of smoothly slipping past one another, have the potential to jam up like cars after a mass pile-up, and the inflexible blood vessels apparently can compound the problem by making narrower “highways” (i.e., turning a four-lane highway into a two-lane highway, complete with cattle guards). These jam-ups might easily cause stroke or a heart attack by destabilizing plaques.
While Benson’s study was small (10 men) and the changes noted in the red blood cells were temporary, the same researchers previously found that mice continuously exposed to high-fat meals experienced permanent changes to their red blood cells. It’s not a stretch to think the same thing might happen to humans.
Granted, Benson’s study had the men consuming 80 grams of fat through a milkshake comprised of ice cream, whole milk, and whipped cream, while the fattiest cut of steak I described above, the ribeye, has “only” about 49 grams of fat. However, it’s rare a steak isn’t eaten in conjunction with French fries, a baked potato with all the fixin’s, or some other high-fat accompaniment, none of which were likely considered in the IMHE’s calculations.
So, people eating grass-fed steaks could have skewed the IMHE’s statistics. So could people eating cuts of steak that weren’t as fatty as other cuts or steaks that were smaller sized.
Also, consider the question of what exactly is it that makes red meat different from, say, chicken or other “white” meats. Red meat is simply meat that’s red when it’s raw. This red color comes from an abundance of myoglobin, a protein found in striated muscles that’s responsible for supplying oxygen to the cells. The more myoglobin the meat contains, the redder it is.
(This myoglobin is often confused with actual blood, hence the term, a “bloody steak.” Steaks are not bloody. In truth, most of the blood was drained out at the slaughterhouse, and any residual red color your cooked steak has is merely myoglobin that wasn’t exposed to enough heat to denature it.)
My point is this: The classification “red meat” is almost meaningless and should not, in any way, by itself, convey any negative opinions about its healthiness. Its “redness” does not convey danger. After all, it’s not a red scorpion or a poison dart frog.
Again, the IMHE would have served us all better by just considering steak (and hamburger) and possibly pork in its calculations rather than lumping them in with lamb, horse, veal, or sheep, all of which are almost always served in their low fat, non-deleterious omega-6 to omega-3 ratio, non-spiky red-blood-cell forming variants.
And my suggestion to include pork in their calculations was based not on the typically low-fat pork chop (unless it’s got a ring of fat the size of an inner tube surrounding it), but its much more porcine cousins – pork belly and bacon (which is typically stripped from pork belly). The former is generally 50% fat, while a typical 8-gram strip of bacon has about 3.3 grams of fat (multiply that by how many strips the average bacon-crazed diner eats).
Eating meat, in general, can have lots of beneficial downstream health effects. The most immediate result from choosing a meat-based meal, red or otherwise, over a carb-based meal concerns insulin, or rather, lack of it. While the amino acids in meat do, in fact, elicit a rise in blood sugar and a corresponding rise in insulin, it’s marginal.
However, a lot of plant-based foods, particularly starchy, heavily processed plant-based foods, elicit high blood sugar levels and large insulin responses and having perpetually high blood sugar can, however, play a role in any of the big-six medical maladies included in the IMHE study, most prominently type 2 diabetes.
If, however, you build/re-build insulin sensitivity by substituting foods that don’t elevate blood sugar, like meat for carbohydrate, you not only generally lose body fat (which in itself has a bunch of downstream benefits), you suppress inflammatory proteins that play a role in cancer and heart disease.
As far as the specific red meats the IMHE included in their analysis, you can probably believe them when they say veal, horse, and sheep have a weak association with the risk of colorectal cancer, breast cancer, ischemic heart disease, type 2 diabetes and probably no effect on ischemic or hemorrhagic stroke, but you might arch an eyebrow when they try to say the same thing about steak, hamburger, or fatty cuts/varieties of pork.
The problem is, including all those other types of red meat in their study, and lumping all kinds of steaks and certain types of pork together might have thrown their conclusions out of whack, made it seem that steak, et al., were only minimally related to certain diseases (cancers, diabetes) and not significantly related to other diseases (stroke and heart attack) at all.
Regardless, you can make steak and hamburger as safe to eat as many of the things we consider to be healthy foods by doing a couple of things. For one, as suggested, always try to eat grass-finished steak and hamburger. That way, the fats you’re eating aren’t inflammatory.
If you don’t have access to grass-finished, just eat smaller portions (4 ounces) of lean(er) cuts like sirloin tip, top round steak, or even top sirloin. In the case of hamburger, buy 90% extra-lean ground beef.
Secondly, make sure you don’t turn yourself into an obligate carnivore. Eat other stuff, too, like lots of olive oil, lots of fruits and vegetables, and lots of fish (or take fish oil), but you already knew that.
Do both those things and maybe, just maybe, we might find that there’s indeed a legitimately weak correlation between steaks, burgers, some types of pork, and disease.
- Lescinsky H et al. Health effects associated with consumption of unprocessed red meat: a Burden of Proof Study. Nature Medicine. 2022 Oct;28:2075-2082.
- Benson TW et al. **A single high-fat meal provokes pathological erythrocyte remodeling and increases myeloperoxidase levels: implications for acute coronary syndrome.**Lab Invest. 2018 Oct;98(10):1300-1310. PubMed.