A study which linked red meat consumption with an increased risk of certain diseases needs to make public the evidence it used to reach its conclusions, a group of experts has insisted.

The international group, which includes Prof Alice Stanton of RCSI University of Medicine and Health Sciences and Prof Patrick Wall of UCD, is referring to the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) 2019.

The academics have raised concerns about the substantial differences in estimates of disease burdens attributed to dietary risk factors between GBD 2019 and GBD 2017.

In a letter published in The Lancet journal,  the experts pointed out that the 2019 estimates of deaths attributable to unprocessed red meat intake increased 36-fold, and estimates of DALYs (disability-adjusted life years) attributable to unprocessed red meat intake increased 18-fold.

DALYs are an internationally recognised measure of the impact of diseases on populations.

Based on these findings, GBD 2019 reported that red meat intake contributes to the causation of a range of diseases, including heart disease, breast cancer, stroke, diabetes and colon cancer.

The experts said that it appears that the dramatic increase in the 2019 estimates is dependent on two assumptions - that the optimal intake of red meat is zero and that risk rises sharply even with moderate red meat consumption.

However, Prof Stanton described it as concerning that GBD 2019 provided “little or no evidence regarding the scientific basis for the assumption that moderate consumption of red meat results in sharp increases in risk of cancers, heart attacks and strokes”.

“If the current public health message advising moderate consumption of red meat as part of a healthy balanced diet is replaced by the message that any intake of red meat is harmful, childhood malnutrition, iron deficiency anaemia in women of child-bearing age and elderly fragility will greatly increase,” she warned.

The experts said that they wrote the letter in order to emphasise the importance of making research data publically available so that guidelines and policies can be developed based on a full understanding of the evidence.

The letter recommends that the GBD 2019 dietary risk estimates are not used in any national or international policy documents until comprehensive independent peer reviews have been conducted of the evidence underpinning the revised estimates.

The letter published in The Lancet can be viewed here.