Some science journalists have been complaining about the new food pyramid. When asked for evidence for their support for low red meat consumption they cited an old JAMA Int Med analysis. I am certainly not MAHA but I think these sort of guidelines, in either direction, are foolish and a diversion from far more important issues. Here’s what I wrote:
I’m a retired medical journalist but here are a few questions I’d want to ask about this study in JAMA Internal Medicine. I have no dog in this fight but I am a long term skeptic of “expert” advice and guidelines in the nutrition and lifestyle sphere, unless the data is really really really good. (It almost never is! Smoking is the biggest exception.) I also believe we would be much better off if the experts and scientists stopped telling us what to do about every minute detail about our lives in the absence of utterly persuasive evidence. Many years ago I wrote that guidelines, like war, should be waged rarely and only with utter caution. World War II and childhood vaccinations are good examples of appropriate usage, Vietnam and routine aspirin are good examples of inappropriate usage.
One other very important point: I would hate to be taken to be a MAHA supporter! Just the opposite. Instead I strongly believe the “experts” should focus first on readily agreed principles: cut excess sugar and highly processed foods! This would actually be broadly popular (like banning cell phones in schools) and might potentially have an enormous impact on public health, much greater than the impact of even any potential benefit from cutting red meat. And if we are going to oppose MAHA, as we should, our focus should be the defense of vaccines and the integrity and preservation of the FDA, CDC, and NIH. (Which is not to say that these institutions would not benefit from careful, thoughtful reform!) The red meat debate is like an argument over the selection of music by the orchestra on the Titanic. Let’s focus on what’s important.
Question: Correlation does not equal causation. The authors of the study attempted to adjust for a large number of potentially relevant factors but it is simply impossible to do this persuasively in the absence of a massive difference in outcome (as seen with smoking). I would imagine, for instance, that people who limit their red meat consumption are much more likely to follow other “expert” medical advice than people who don’t limit red meat, and some (one hopes, much) of that advice might actually be beneficial. I absolutely love the science of statistics, but multivariate analyses should never be taken for settled science. How many times do we need to get burned by this?
Question: Why is the proportion of people with high cholesterol actually lower in red meat eaters? (7.9% in the highest quintile of red meat consumption versus 14.8% in the lowest quintile.) Doesn’t this contradict the entire hypothesis of the anti-red meat forces? If reducing red meat doesn’t lower cholesterol what is the purported mechanism of benefit? Does it suggest the possibility that, say, there’s no benefit in avoiding bacon at breakfast if you’re going to eat Sugar Pops instead?
This brings up another big problem with these sort of guidelines. The small print of these guidelines may contain all sorts of qualifications about the overall quality of the totality of the diet but the headlines, and the message received by the vast majority of people, will be that red meat is bad for you. This is another reason I think it is preferable to support fewer and simpler scientific recommendations about diet, such as reducing the consumption of added sugars and highly processed foods.
All federal guidelines are political – especially the most recent ones. All nuance has been lost by this administration, but clearly anything that puts red meat and cheese at the top of the food pyramid is problematic. The false precision and health hierarchy imposed by food pyramids break down quickly, because there are potential roles for almost all foods in a healthy diet, based on an individual person’s goals, health status, and preferences. Guidelines don’t address that, not only because science has been politicized, but because of another core problem: nutritional epidemiology often provides very low-quality evidence. Because people feel very strongly about food, and because it attracts so much attention, the buzz and the guidance tend to outstrip the science and become confusing. There are some clinical trials and natural experiments of diet and nutrition that genuinely are helpful, but this upside-down pyramid doesn’t reflect them. It doesn’t capture the data. It captures vibes (and bad ones at that). Regarding saturated fat, there’s a lot of space between eating a controlled portion of red meat and eating junk food. I reject this false dichotomy strawman argument that advocates of eating saturated fat lean on heavily. The bottom line is at over a dozen randomized clinical trials going back to the 1960s consistently show reductions and CVD events. The contrarians will carp that those trials were imperfect (as are all trials) but they are consistent with each other, were conducted in different populations with different designs, and fit established lipoprotein biology. Indeed, the reduction in LDL cholesterol observed with falls on the same line that fall for reducing events. It’s very consistent biology and compelling. A lot more compelling than cherry-picking data from observations, animal studies, and anecdotes.
Larry, you make a very good point here. But please don’t limit your scope of meaningful, fewer and simpler scientific recommendations for health improvement to diet. Please look at dentistry. It is time to get off the monumental edifice of skewed dental scientific research, publications, professional education, lobbying, and public relations created and funded by the ADA. Its affiliates held patents on dental amalgam and unlike the AMA, it puts a seal of approval on specific products. Mercury in dental fillings has never been great for anyone. Now that there are safer alternatives that work in all clinical applications, we should follow other nations and relegate dental amalgam to the dustbin of history. It is especially damaging to children and adults with certain gene types who don’t methylate well. In addition, you might delve into why its removal should only be done by a dentist who follows the SMART protocol created by IAOMT to minimize mercury vapor exposure to the patient, dentist, and staff. Biological dentists can be found through the IAOMT and IABDM websites. I am posting a reference website below. Thanks.