Red meat consumption. Is it really as harmful as we have been told in the past or can we eat it safely?
Red meat has been demonized for decades after the groundbreaking research of Ansel Keyes, whose research "Seven Countries Study" showed that dietary fat intake affects cholesterol.
But is it time to update our knowledge and accept that eating red meat is not the end of the world, at least in terms of health?
Six new meta-analyses suggest that it should.
Let's start with why these analyses found these results so that we can conclude whether this way of thinking is correct.
RED MEAT IS NOT AS BAD AS THE STATISTICS MAKE IT SEEM.
And this is true even for the six meta-analyses. You see, most epidemiological studies, when they do a study on meat, look at red meat along with processed meat (e.g. salami, sausages, corned beef, etc.).
Red meat is one thing and processed meat is another. Red meat can be lean, processed meat usually has too much fat. Red meat can be minimally salted, processed meat will always have too much salt.
In short, if we removed processed meats from the surveys, the results would probably be more favourable.
BAD STUDIES WILL PRODUCE UNRELIABLE RESULTS
Red meat is now what eggs were in the 1980s. Although recent studies have shown that eating eggs is not harmful to health, a series of studies in the 1980s showed the opposite. Why?
In the 1980s, due to the fact that dietary fat intake affects cholesterol, the advice from doctors and nutritionists was to avoid them.
In short, the part of the population with the highest egg consumption was the one that ignored the advice of experts, which means that they were not particularly interested in their health. And this was something that greatly influenced the results of epidemiological studies.
So when you assume in a study that eating a burger and the stew you cook at home are the same thing, and that the mortality chances of someone who spends most of their day on the couch are similar to someone with ideal cardiovascular health, there's a problem.
TMAO AND ATHEROSCLEROSIS
TMAO, or N-oxide of trimethylamine, is a metabolite of choline. Choline is an otherwise incredibly beneficial nutrient found primarily in animal foods.
Theoretically, TMAO can lead to the development of atherosclerosis, but the truth is that there are many pieces missing from this particular puzzle.
For example, the number of studies that have shown that TMAO causes atherosclerosis is the same as those that show the opposite.
Choline is also found in fish and a number of non-animal products such as beans. There research has failed to show any correlation.
I personally think that at this time it is best to keep the TMAO studies in mind, but nothing more until we understand exactly if and whether there is a real correlation.
And this obviously raises the following question: But if there is no correlation between TMAO in fish and non-animal products and atherosclerosis, while the other results lead to uncertainty, does this not mean that there is at least some statistical correlation, however small, between red meat and atherosclerosis, even if it is independent of TMAO?
Apo(B) and red meat
So far we have told the good news: That so far research has done red meat an injustice. Time to look at the data to the contrary.
Apo(B) is the apolipoprotein that makes LDL-c or "bad cholesterol" dangerous as it has atherosclerotic properties.
So since we know that saturated fat intake raises LDL-c levels, it makes sense to avoid excesses not only in fatty meats, but in fatty animal foods in general.
This obviously doesn't mean that we should avoid red meat altogether, but prefer lean meat.
Going out with your friends and ordering a steak once a month is not going to give you a heart attack. It goes without saying that blood tests should be done frequently and if your Apo(B) is at favorable levels, then you may be able to consume more freely.
IRON AND NON-COMMUNICABLE DISEASES
High levels of ferritin, the body's main iron storage protein, are associated with all non-communicable diseases.
Cancer, metabolic syndrome (hypertension, high blood sugar levels, obesity, high LDL-c, low HDL-c or triglyceride levels), diabetes, cardiovascular diseases are some of them.
And we don't stop here. Women are usually iron deficient which means that almost all research looking at the relationship between red meat consumption and mortality is unreliable as there should be a separation of sex and its effects separately.
Even worse, caffeine affects iron metabolism. In short, coffee lovers have lower ferritin levels. Research that does not take this simple fact into account is invalid.
In short, here we see the opposite of the first two sections of the article. Statistics have favored the role of meat in a number of longevity indicators.
So as not to repeat ourselves: You understand that eating fatty, salt-laden meat is bad for your health.
Avoid processed meat.
Glucotoxins, or advanced glycosylation end products or AGEs, are also associated with many non-communicable diseases.
Meats, high-sugar and/or high-fat foods and highly processed foods are likely to develop high levels of glucotoxins.
Conditions associated with baking, freshening, roasting and frying methods such as high temperatures, low humidity and alkaline pH contribute to the formation of new AGEs.
WHAT IT ALL MEANS
Let's recap very quickly and briefly.
The demonisation of meat consumption in the past was unfair. However, there is still plenty of evidence that excessive consumption of meat can lead to adverse health effects.
As we have said in "Ketogenic Diet: Some Useful Tips", try to avoid fatty meats, prefer lean meats and avoid processed meats altogether.
-Suprastratum: The authority on health, fitness and nutrition
The six meta-analyses:
- Zeraatkar D, Johnston BC, Bartoszko J, et al. Effect of Lower Versus Higher Red Meat Intake on Cardiometabolic and Cancer Outcomes: a Systematic Review of Randomized Trials. ann Intern Med. doi: 10.7326/M19-0622
- Valli C, Rabassa M, Johnston BC, et al, for the NutriRECS Working Group. Health-Related Values and Preferences Regarding Meat Consumption: A Mixed-Methods Systematic Review. ann Intern Med. doi: 10.7326/M19-1326
- Vernooij RW, Zeraatkar D, Han MA, et al. Patterns of Red and Processed Meat Consumption and Risk for Cardiometabolic and Cancer Outcomes: a Systematic Review and Meta-analysis of Cohort Studies. ann Intern Med. doi: 10.7326/M19-1583
- Zeraatkar D, Han MA, Guyatt GH, et al. Red and Processed Meat Consumption and Risk for All-Cause Mortality and Cardiometabolic Outcomes: a Systematic Review and Meta-analysis of Cohort Studies. ann Intern Med. doi: 10.7326/M19-0655
- Han MA, Zeraatkar D, Guyatt GH, et al. Reduction of Red and Processed Meat Intake and Cancer Mortality and Incidence: A Systematic Review and Meta-analysis of Cohort Studies. ann Intern Med. doi: 10.7326/M19-0699
- Johnston BC, Zeraatkar D, Han MA, et al. Unprocessed Red Meat and Processed Meat Consumption: Dietary Guideline Recommendations From the Nutritional Recommendations (NutriRECS) Consortium. ann Intern Med. doi: 10.7326/M19-1621