In 2020, it was published in the Global Burden of Disease Study (GBD) 2019 the lancet. According to their findings, a “substantial” increase in diet-related burden was observed, which the authors associated with red meat intake.
In the 2017 GBD analysis, 25,000 deaths and 1.3 million disability-adjusted life years (DALYs) were attributed to diets high in red meat. Red meat consumption was among the least important of the 15 dietary risk factors.
However, for GBD 2019, estimates of deaths attributable to unprocessed red meat intake had increased by 36-fold, and estimates of DALYs attributable to unprocessed red meat intake had increased by 18-fold.
Two years after the publication of GBD 2019, a team of international researchers is challenging these findings, citing “serious concerns” about the most recent systematic analysis of GBD risk factors.
A 36-fold increase in estimated deaths
A 36-fold increase in estimated deaths and an 18-fold increase in estimated DALYs attributable to unprocessed red meat intake is “significant,” the researchers noted in an article published by the lancet in February of this year. In fact, the authors of GBD 2019 admitted it at the time.
Three main sources were judged to be responsible for the substantial increase: changes in crossovers between alternative and reference methods for estimating dietary intake, new systematic reviews and meta-regressions, and more empirical standardized methods for selecting the theoretical minimum risk exposure level (TMREL). ) for protective factors.
For red meat, all three sources influence the estimates. However, the researchers suggest that new systematic reviews and meta-regressions and setting the TMREL for red meat at 0 g per day appear to be two sources of ‘particular’ importance.
Whereas all previous GBD risk factor analyzes used data from published peer-reviewed systematic reviews and meta-analyses (as well as the World Cancer Research Fund criteria for convincing or probable evidence of risk-outcome pairs) to “construct the relative risk curves” and to determine the TMREL for each risk factor, the GBD approached it slightly differently.
The GBD 2019 risk factor contributors conducted or updated their own systematic reviews for each dietary risk and its related outcomes. As explained in the February 2022 article, based on these reviews, the GBD 2019 Risk Factors Collaborators reported “sufficient evidence to support a causal relationship of red meat intake to ischemic heart disease, breast cancer, stroke hemorrhagic stroke and ischemic stroke.
These results were then added to previously identified associations with diabetes and colon cancer.
“These findings of additional causal relationships for red meat are not in agreement with other recently conducted systematic reviews and meta-analyses.” noted the authors of the article.
Is red meat inherently harmful?
According to these researchers, this implies that the 2019 GBD analysis does not adhere to agreed best practices, which they consider “deeply concerning”.
Of particular concern are the possible consequences of the results of the GBD 2019 study. Since its publication, GBD 2019 has been cited by 635 documents, including 351 scientific articles and nine policy documents.
The researchers question whether the ‘full’ nutritional effects of red meat were considered in the study’s meta-regressions. “If the TMREL is assumed to be zero, red meat would de facto present itself as an inherently harmful food.” they wrote “This assumption would ignore the well-documented nutritional benefits regarding the supply of essential nutrients and bioactive components.”
If public health messages are based on the GBD 2019 study to inform policy, this could also be problematic. If governments warn that eating red meat is harmful, for example, researchers worry that some children may suffer from iron deficiency anemia or sarcopenia. These conditions, they stressed, are already responsible for a “considerably” higher global burden of disease than a diet high in red meat, particularly in low- and middle-income countries.
The 2019 GBD risk factor data was cited “widely” in the UK National Food Strategy evidence document, which the researchers noted is of “great concern”.
clarifications required
The researchers are calling for action. “Given the substantial influence of GBD reporting on nutrition policy decision-making around the world, it is of considerable importance that GBD estimates are subject to critical scrutiny and continue to be evidence-based in a rigorous and transparent manner. ”.
Specifically, the paper’s authors want the GBD 2019 risk factor contributors to clarify the details of their study, including a rationale for updating red meat’s relative risk dose-response curves for a range of risks for Health. They have also called for “empirical evidence” to change the TMREL for red meat from 22.5 g per day to 0 g per day.
“Finally, the GBD 2019 risk factor contributors need to clarify whether the additional deaths and DALYs from iron deficiency anemia, sarcopenia, and childhood and maternal undernutrition that would result from the imposition of a zero red meat TMREL have been included in the estimates. of GBD 2019. .
The World Cancer Research Fund (WCRF) International supports the researchers’ call for further clarification and justification for the TMREL of zero.
“Not only does the increase in estimated load seem implausible, but the lack of transparency in the assumptions underlying the calculations undermines the authority of the GBD estimates.”
WCRF continued: “When the assumptions used within a study are not clearly stated and explained, the results become questionable and replication is difficult.
“Estimates of avoidability depend exquisitely on their underlying assumptions, as described in discussions around population-attributable fraction methodologies.”
Does the WCRF link red meat consumption to cancer?
WCRF International claims to be at the forefront of exploring the relationships between diet, nutrition, physical activity and cancer for more than two decades.
So, according to the nonprofit organization, does eating red meat cause cancer? Based on its review of the evidence related to raw red meat, WCRF concludes that red and processed meat are causal contributors to the development of colorectal cancer.
“However, neither WCRF nor other international organizations recommend completely avoiding meat. In many diets around the world, red meat is an important source of several nutrients.” noted in an article published in the lancet last month
“Eliminating meat from such diets is neither practical nor realistic and carries a risk of nutritional deficiency that is thought to outweigh future cancer risk.
“The absence of an explicit rationale for the assumptions underlying GBD estimates is problematic, unsupported by evidence, and unrealistic.”
Font:
the lancet
‘Global burden of 87 risk factors in 204 countries and territories, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019’
Posted on October 17, 2020
DOI: https://doi.org/10.1016/S0140-6736(20)30752-2
Authors: Christopher JL Murray, Aleksandr Y Aravkin, Peng Zheng et al.
the lancet
’36 times higher estimate of deaths attributable to red meat intake in GBD 2019: is this reliable?
Published 25 February 2022
DOI: https://doi.org/10.1016/S0140-6736(22)00311-87
Authors: Alice V Stanton, Frédéric Leroy, Christopher Elliot, Neil Mann, Patrick Wall, Stefaan De Smet
the lancet
‘Worrying assumptions behind GBD 2019 on the health risks of red meat’
Posted on August 6, 2022
DOI: http://doi.org/10.1016/S0140-6736(22)01283-1
Authors: Vanessa LZ Gordon-Dseagu, Martin J Wiseman, Kate Allen, Judy Buttriss, Christine Williams
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