Meat & heart disease

Introduction

On July 20th, 2021, yet another meat paper was published (Papier et al) (Ref 1). This one was a systematic review and meta-analysis, which is considered one of the best pieces of evidence. However, it pooled together many epidemiological studies, which is weak generally as evidence and suffers from limitations.

I did wonder when I saw the paper – what can possibly be new? As we've had so many papers attacking meat for so long. This one opened by saying that "There is uncertainty regarding the association between unprocessed red and processed meat consumption and the risk of ischemic heart disease (IHD), and little is known regarding the association with poultry intake."

The authors reported that results from previous meta-analyses on unprocessed red meat and IHD were based on few studies. Two early meta-analyses – one from 2010 and one from 2014 – found no association with meat intake and fatal or non-fatal IHD. Two more recent meta-analyses (both 2019) found a positive association with meat intake and fatal and non-fatal IHD. The evidence for processed red meat has been similarly mixed. The context of this paper, therefore, was that the topic was in need of review.

Ischemic heart disease (IHD) is used interchangeably with coronary heart disease (CHD) and sometimes also with coronary artery disease (CAD). It's the term given to heart problems caused by narrowed heart (coronary) arteries that supply blood to the heart muscle.