Is red meat good or bad for your health? Numerous studies have suggested that consuming processed or unprocessed red meat is associated with an increased risk of cancer, cardiovascular problems, and premature death, among other negative results. And based on this and similar evidence, it was recommended to reduce the consumption of red meat as much as possible.
However, in recent days, a controversial new study suggests that red meat may not have as detrimental impact on health as previously thought.
The new guidelines, available in their entirety through the Annals of Internal Medicine , have sparked a huge reaction from researchers and clinicians around the world, who have expressed concern.
But where do these new guidelines come from and what do they really say?
The panel of authors that issued the new set of recommendations includes 19 dietitians and nutritionists, who are part of an independent research group called the Nutritional Recommendations Consortium (NutriRECS). In their article, the experts explain that they had seen the need to reevaluate the existing evidence on the relationship between red meat consumption and negative health outcomes for several reasons.
First, existing recommendations are “primarily based on observational studies” that often cannot establish cause and effect relationships and do not “report the absolute magnitude of possible effects,” the authors state.
They also allege that “the organizations that produce guidelines did not conduct or have access to rigorous systematic reviews of the evidence, limited themselves to addressing conflicts of interest, and did not explicitly address the values and preferences of the population.”
For these reasons, the NutriRECS researchers decided to re-evaluate the existing evidence, conducting five systematic reviews. The reviews analyzed dozens of randomized trials and observational studies, including thousands of participants among them. To do this, they developed their own evaluation method based on the grading of recommendations, evaluation, development and evaluations (GRADE) method.
The GRADE method or system classifies evidence according to certainty rates: very low certainty, low certainty, moderate certainty and high certainty.
What did you find?
In 4 of the 5 reviews, the researchers looked at whether a realistic reduction in red meat intake had any effect on the risk of certain negative health outcomes, including all-cause mortality, cardiovascular mortality, stroke, heart attack , diabetes, cancer incidence, and cancer-related mortality.
They defined a “realistic” reduction in red meat consumption as a reduction of 3 servings per week, for example, going from 7 to 4 servings of red meat per week.
This definition, the authors explain in their article, is based on the fact that “the average consumption of red meat is 2 to 4 servings per week in North America and Western Europe.”
Not so bad
After evaluating the evidence presented by relevant studies, the researchers concluded that while there may be an association between the consumption of red meat and the risk of health problems, it is not clear that eating this type of meat actually has a significant negative effect. in health.
The evidence that reducing your intake of processed and unprocessed red meat would reduce the risk of cancer, cardiovascular disease and premature death was, in most cases, with “low to very low certainty ,” say the researchers.
What does this mean?
Based on their evaluations, the researchers recommend that adults over 18 who eat red meat continue to do so.
“For most people, the desirable effects (a reduced potential risk for cancer and cardiometabolic outcomes) associated with reduced meat consumption are unlikely to outweigh the unwanted effects (impact on quality of life, burden of modification culture and personal preparation of meals and eating habits “, comment the experts.
However, the team recognizes that people should consider it as a suggestion and that each should think about whether they find this information valuable or useful.
“This is not just another study on red and processed meat , but a series of high-quality systematic reviews that result in recommendations that we believe are far more transparent, robust and reliable,” says Bradley Johnston of Dalhousie University in Nova Scotia. (Canada) and leader of the work.
Study limitations
Johnston also reiterates a caveat the research group mentioned in their article: The reviews only took into account evidence related to human health. It was not intended to address issues related to animal welfare or sustainability.
“We focus exclusively on health outcomes and do not consider animal welfare or environmental concerns when making our recommendations,” adds Johnston.
What scientists say
Giota Mitrou, Director of Research at the World Cancer Research Fund, who was not involved in the study, told the Science Media Center :
“The International NutriRECS Consortium’s recommendation for the public to continue with their current level of red meat consumption is no different than our own recommendation on red meat: that eating three or fewer servings of red meat a week is best for the population. Cancer prevention. The public could be at risk if they interpret this new recommendation to mean that we can continue to eat as much red and processed meat as they want without increasing their risk of cancer. This is not the case. The message people need to hear is that we should eat no more than three servings of red meat a week and eat little, if any, processed meat. We support our rigorous research over the past 30 years and urge the public to follow current recommendations on red and processed meat. “
“It is important to remember that consuming red and processed meat is a component of our overall diet and exercise pattern and it is unlikely that specific foods are unique factors important in causing or protecting against cancer. Instead, different dietary patterns and physical activity throughout life combine to make you more or less susceptible to cancer, “concludes Mitrou.
David Spiegelhalter, president of the Winton Center for Risk and Evidence Communication at the University of Cambridge, who was not involved in the study, told the Science Media Center :
“This rigorous, even ruthless review finds no clear evidence of significant health benefits from reducing meat consumption. In fact, you don’t find any good evidence at all – all studies are rated as ‘low’ or ‘very low’ certainty . We could expect even more controversy when this group turns their attention to other “risky” things we consume. In contrast to their health findings, I think we can be confident that reducing meat consumption would benefit the planet. “
Review
The dissemination of these studies has generated a great stir in society but, as The Conversation publishes in its article on the matter, “the studies provided in the aforementioned guide are not disposable. It is added information regarding the consumption of meat and health. They do not contain evidence to change current recommendations, but they do contain evidence for further investigation . ” Thus, we must continue to preserve and promote the Mediterranean Diet as a healthier dietary option.
Referencia: Unprocessed Red Meat and Processed Meat Consumption: Dietary Guideline Recommendations From the Nutritional Recommendations (NutriRECS) Consortium Free. Bradley C. Johnston, PhD; Dena Zeraatkar, MSc; Mi Ah Han, PhD; Robin W.M. Vernooij, PhD; Claudia Valli, MSc; Regina El Dib, PhD; Catherine Marshall; Patrick J. Stover, PhD; Susan Fairweather-Taitt, PhD; Grzegorz Wójcik, PhD; Faiz Bhatia, PEng; Russell de Souza, ScD; Carlos Brotons, MD, PhD; Joerg J. Meerpohl, MD; Chirag J. Patel, PhD; Benjamin Djulbegovic, MD, PhD; Pablo Alonso-Coello, MD, PhD; Malgorzata M. Bala, MD, PhD; Gordon H. Guyatt, MD Annals of Internal Medicine 2019 DOI: 10.7326/M19-1621
