Red meat does not increase health risks, new research finds

health scientists from Washington University carried out a survey in which they evaluated several studies on the relationship between red meat consumption and various diseases. Recently updated, work Health effects associated with consumption of unprocessed red meat: a Burden of Proof study (Health Effects Associated with Consumption of Unprocessed Red Meat: A Burden of Proof Study), published in the journal Nature, showed that diseases such as type 2 diabetes, colorectal cancer and cardiovascular disease — especially the cerebral vascular accident (CVA) — do not have strong enough evidence to be linked to unprocessed meat intake.

No showmetech, you can check out details of this study in the United States and find out how other health researchers evaluate this relationship.

What did Washington (USA) scientists discover about red meat?

Researchers from Institute for Health Metrics and Evaluation (IHME; Institute of Metrics and Health Assessment, in free translation), which belongs to the university, raised several scientific works that dedicated attention to red meat and how it was linked to diseases. Decades of research were looked at and the authors understood that there were some flaws.

Among them, there were inappropriate methods to point out the relationship with food and disease, in addition to the little variety of target populations of the studies; non-consistent statistical measures; and, above all, lack of interest in investigating more varied diets. That is, the study authors found that the research they investigated did not have the ideal scientific rigor to assess the link to dietary health conditions. Therefore, the search name contains the expression burden of proof: is an essential element to say that a situation leads to an outcome, provided that it is possible to prove that this happens.

“We saw weak evidence regarding the association between consumption of unprocessed red meat and colorectal cancer, breast cancer, type 2 diabetes or heart disease. Furthermore, we found no evidence of an association between unprocessed red meat and ischemic or hemorrhagic stroke.”

Authors of the IHME study, linked to the University of Washington

Burden of proof risk function: fundamental method for the study

The work published in Nature in October 2022, updated in April of this year, made use of an important method, called burden of proof risk function. In addition to assessing how well the analyzed research actually proved the link between red meat and disease, the Washington researchers applied a function that “assesses and summarizes evidence of problems across different risk outcome pairs".

In other words, the authors applied a method that gives the possibility to see data from several studies, pointing to some disease. With the support of this tool, you arrive at a number that can be used in a five-star rating system, more or less how it works in running apps. Thus, researchers are able to see these relationships more quickly.

The application of the function uses stars as follows: if the cause related to the disease does not exist, it receives only one star; two stars for the probability of 0% to 15% of the eating habit causing some health problem; three for odds of 15% to 50%; four for 50 to 85%; and five for a value greater than 85%. It turns out that the authors of the study IHME, when using the formula, did not find any research, with data on eating habits, that scored more than two stars.

As for the data found by the institute, the neurologist at Yale University, Steven Novella, indicates that the study in question confirms a common diagnosis: eating habits without diversity lead to bad diets. So, the occurrence of problems such as cancer and CVA become frequent, due to the already known eating problem.

“There is more evidence for health risks from low vegetable consumption. This really is a defect of diets that prioritize meat consumption — the calories from this food are replacing the energy values ​​of vegetables.”

Steven Novella

What other risk factors may be associated with heart disease?

The US researchers took into account that several behaviors can contribute to increasing the chances of developing cancer and cardiovascular disease. Taking too little exercise or eating too few vegetables, giving priority to other foods, can lead to health problems, including the conditions that were the focus of the Washington research.

In relation to the heart, health risks involving blockage of the blood passage still lead lists of diseases that kill the most in the world. Data from World Health Organization (OMS), for example, show that of the 17 million deaths caused by silent diseases (that is, those that do not have very obvious symptoms) in 2019, almost 40% were caused by cardiovascular diseases.

Another recent study even showed that pregnancy complications can also lead to heart disease. According to the authors of the research, published in British Medicine Journal (BMJ), it is possible that diabetes during pregnancy and pre-eclampsia may increase the risk of cardiac complications by 54% and 30%, respectively.

What do Brazilian researchers say about the consumption of processed meats?

Different from the red meat researched by IHME, ultra-processed foods, made with processed meat and other products (even ox blood), are negatively viewed by other researchers. Mortadella and sausages are manufactured, for example, with less valued cuts or even carcasses.

Dirce Marchioni, teacher at School of Public Health da University of São Paulo (FSP/USP), states that there are processes that can lead to the creation of hazardous substances. They are formed, according to the researcher, when they react to substances formed during smoking or color fixation. Fábio Campos, also from FSP and member of Brazilian Society of Proctology (SBP), agrees with the teacher.

"If you eat too much fat and too little fiber, there won't be enough fatty acids to protect your gut, which can create an imbalance in long-term health."

Fabio Campos

Do you consume meat often? Has anyone you know ever had health problems because of their diet? Tell us in the comments section of showmetech!

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Source: Big Think | Nature | WHO (in English) | CNN | UOL (Live Well)

reviewed by Glaucon Vital in 18 / 5 / 23.