We have heard it for decades. Red meat causes cancer, heart disease and an early death.
But does it? Does highest-quality evidence back those claims?
As we detailed in our recently updated and evidence-based guide to red meat, probably not.
It's true that many nutritional epidemiology studies show weak associations between eating red meat and poor health outcomes. Although these associations are statistically significant, they are not likely to give meaningful information about relationships between diet and disease, given healthy user bias, poor data collection, confounding variables and other study weaknesses. You can see more in our guide on observational versus experimental trials here.
Adding to the confusion, the majority of randomized controlled trials show no association between red meat and poor health outcomes. Even the epidemiology studies don't all agree.
Today we have even more evidence that the fear of red meat may be unfounded. A series of publications in the Annals of Internal Medicine further supports the assertion that red meat does NOT increase the risk of cancer, heart disease or death.
These papers are big news. Here's an example of just one of several articles in The New York Times:
The New York Times: Eat less red meat, scientists said. Now some believe that was bad advice.Here's our take.
The first paper examined all published randomized controlled trials, evaluating cardiometabolic and cancer outcomes in a higher- vs. lower- red meat diet. The authors found no significant associations with red meat intake and increased risk of heart events or cancer (incidence and mortality). However, they admit the quality of the data was low. Most of the included diets focused on reducing fat, which only lowered red meat intake indirectly.
Despite these limitations, evidence from randomized controlled trials is still stronger than that from uncontrolled observational trials, which make up three of the papers published in Annals. These all examined prospective cohort studies (which can only show associations, a weak type of evidence, as detailed in our policy for grading scientific evidence). Each of these papers concluded that there is insufficient evidence to recommend global lowering of meat consumption for health reasons.
The author's final conclusion, a dietary recommendation based on NutriRECS Consortium guidelines, is that adults should continue current red meat intake, as reducing consumption is unlikely to benefit our health.
Of note, unlike older studies involving meat, these meta-analyses were not funded by the meat industry, ruling out an obvious potential conflict of interest.
The reaction came fast and strong from advocates of almost-meatless diets. They called into question the quality of the evidence and are asking for an immediate retraction of the Annals papers.
What makes these studies noteworthy? As quoted in WebMD, the authors state they are taking an "individual approach rather than societal." This approach includes grading the certainty of the evidence. The authors note that prior evidence "often has no assessment of certainty of evidence, or if there is, it's often unreliable."
To sum it up, these researchers suggest we need to focus on the individual and create dietary recommendations based on higher-quality evidence.
Other researchers claim low-quality epidemiology studies are good enough, we don't need any other data, and it is most important to approach this from a population perspective.
Which perspective is most likely to help individuals make well-informed decisions about their own health?
You can probably guess where we stand. We have committed ourselves to grading the evidence we cite, believing we should rely on the highest-quality evidence whenever possible. When high-quality evidence isn't available, then we need to recognize the limitations of weak evidence.
Also, we are committed to making low-carb simple and helping individuals dramatically improve their lives. Therefore, the individualized perspective looks pretty good to us.
Studies aren't perfect. Science is not as perfect as we would like. But we applaud the authors for focusing on the quality of evidence and an individualized perspective.
Based on the available evidence, we agree. There is no compelling health reason to avoid red meat.
That said, we support those who avoid red meat but want to eat low carb, with resources like vegetarian and pescatarian meal plans and our vegetarian guide.
Both can be healthy. It's your choice.
Thanks for reading,
Bret Scher MD FACC