Protein intake and cardiovascular diseases: an umbrella review of systematic reviews for the evidence-based guideline on protein intake of the German Nutrition Society

Abstract Purpose This umbrella review aimed to investigate the evidence for an association of dietary intake of total protein as well as animal and plant protein with the incidence of coronary heart disease (CHD), stroke and total cardiovascular diseases (CVD). Methods PubMed, Embase and Cochrane Database were systematically searched for systematic reviews (SRs) of prospective studies with or without meta-analysis (MA) published between January 2012 and April 2024. Methodological quality, outcome-specific certainty of evidence, and overall certainty of evidence were assessed using established tools and predefined criteria. Results Ten SRs were considered eligible for the umbrella review; all were based on prospective cohort studies, and six conducted a MA. Dietary intakes of total, animal and plant protein were not associated with the risk of CHD or stroke. For CHD, the overall certainty of evidence for the absence of an association was “probable” for total, animal and plant protein. For stroke and total CVD, the overall certainty of evidence was rated as “possible” for the absence of an association with the intake of total protein and plant protein and insufficient for animal protein intake. Conclusion Given that most SRs on dietary protein intake did not indicate an association, it seems that protein intake plays no major role in the development of CVD. This investigation was registered at PROSPERO as CRD42018082395.