by Significant reductions in animal source foods, which are associated with many plant-based diets, will increase micronutrient and protein deficiencies that are already widespread, warns an article published this week in the scientific journal Frontiers in Nutrition.
The perspective article, written by Dr Alice Stanton from the Royal College of Surgeons in Ireland and the University of Medicine and Health Sciences, examines the reliability of claims that plant-based diets will provide, with greatly reduced intakes of foods from animal sources (ASFs). nutritional adequacy and protection against chronic disease incidence.
Protections provided by plant-based diets against non-communicable chronic diseases (NCDs) appear to be more strongly associated with reduced intakes of calories and salt, and with increased intakes of fruit, vegetables, nuts and whole grains, rather than with reduced intakes of ASFs. , Dr. Stanton’s analysis shows.
Her paper highlights many questions regarding the credibility of the science used to support the anti-meat recommendations of the EAT-Lancet planet health reference diet published in 2019.
The diet, which made headlines around the world, recommended that only 13 percent of calories in any diet should come from animal sources.
The EAT-Lancet Commission was confident that the diet, despite being so low in ASFs, would meet the nutritional needs of adults and children over two years of age.
“This confidence was surprising for a number of reasons”, Dr Stanton wrote, referring to published studies showing that as the percentage of energy from ASFs in national food supplies declines, the prevalence of insufficiency increases exponentially micronutrient.
She also referred to another recently published systematic literature review on the topic that found “clear evidence” that dietary changes resulting in lower intakes and status of a wide range of micronutrients were of public health concern. aim to reduce environmental impact.
And another paper was published that found that a reduction in animal source protein, even to the 50 percent level, led to significant reductions in vitamin B12 and iodine intake and status.
Further studies identified flaws in the assumptions and methods used, showing that no mortality-reducing effect of the EAT-Lancet diet “was greater than the effect of energy intake changes that would have prevented overweight” , only overweight and obese”.
Strict adherence to the EAT-Lancet reference diet has been reported to have “no additional protection against mortality” through further research including the Oxford component of the European Prospective Investigation into Cancer and Nutrition study, the prospective NutriNet-Santé Cohort study, and the Urban Prospective . Rural Epidemiology Study (PURE).
The dangers of ignoring good practice in nutritional epidemiology by using low or very low certainty evidence in the development of guidelines, or in the calculation of global health metrics, have been illustrated by the “very different” risk Global Burden Disease (GBD). estimates for unprocessed red meat, which are included in the GBD 2017, GBD 2019 and Burden of Proof (BoP) 2022 studies.
In the 2017 GBD estimates, based on associations with colorectal cancer and diabetes mellitus, the GBD Risk Factors Collaborative stated that diets high in unprocessed red meat were responsible for 25 thousand deaths and 1.3 million disability-adjusted life years (DALYs), worldwide .
However, in 2019, the GBD Collaborators reported that sufficient evidence was found supporting additional causal relationships of red meat intake with ischemic heart disease, breast cancer, hemorrhagic stroke, ischemic stroke and subarachnoid hemorrhage.
Therefore, they estimated that 896 thousand deaths and 23.9 million DALYs were attributable to the consumption of unprocessed red meat. This represented 36-fold and 18-fold increases over the 2017 GBD estimates for deaths and DALYs, respectively.
However, scrutiny by Dr. Stanton and others revealed that the evidence for the 2019 estimates came from in-house, newly directed, systematic reviews and meta-regressions that were not peer-reviewed or published, and that no certainty assessments were performed.
Many in the scientific community questioned the reliability of these widely varying estimates, and rightly called for publication of PRISMA (Selected Reporting Items for Systematic Reviews and Meta-Analyses) compliant reports on the reviews. recent systematics.
In response to the scrutiny applied to their report, the GBD collaborators publicly admitted that their 2019 risk estimates for unprocessed red meat for NCD events were erroneously inflated.
Dr Stanton noted that one of the EAT-Lancet Commissioners, Professor Jessica Fanzo, recently confirmed that their first version of the planetary health diet would result in significant deficiencies of essential micronutrients.
However, despite requests to the GBD authors, and to The Lancet editorial and ombudsman staff, no corrections have been applied to the published paper, and there is no change to the 2019 risk estimates on the GBD website.
Therefore, the accuracy of these 2019 GBD risk estimates remains in serious doubt.
Despite these important limitations, the 2019 GBD Risk Factor Study continues to be widely cited – more than 3650 times over the past four years.
Many people have used the 2019 GBD as the “lead evidence” of harmful outcomes from red or processed meat consumption.
“Worryingly, the monthly rate of these publications, using these erroneous estimates, is increasing,” Dr. Stanton wrote.
She said it is clear that any evidence that moderate consumption of ASFs is harmful to human health is “weak and inconclusive”.
It was also clear that the dramatic reductions in ASFs, advocated by many plant-based diets, will result in micronutrient and protein deficiencies that are already widespread around the world.
“Scientists, policy makers and all those involved in the food system should be wary of global health reports, guidelines or estimates that are not rigorously and transparently evidence-based.
“National and international guidelines for healthy diets should continue to include a wide range of sustainably produced, nutrient-rich foods from animal and plant sources, in appropriate evidence-based quantities.
“Further research, finance and effort should be focused on reliable objective measurements and improvements in the sustainability of all components of the food system; production; processing; distribution; retail ; consumption; and waste management.”
Earlier article: Authors admit errors in red meat reduction studies, but no corrections published yet
