Higher protein diets and risk of chronic disease
Despite numerous studies demonstrating metabolic advantages
of higher protein diets, there remains concern that long-term
consumption of higher protein diets contributes to the development
and progression of chronic disease. Recent cross-sectional
and laboratory animal studies have linked diminished longevity,
increased all-cause mortality, cancer development, and fracture
risk with diets that are both high in protein (Levine and others
2014; Solon-Biet and others 2014) and dairy (Michaelsson and
others 2014). These results should be interpreted cautiously given
the nature of their study designs (Couzin-Frankel 2014; Schooling
2014). Renal dysfunction is, perhaps, the most commonly cited
potential risk of consuming a higher protein diet. This is certainly
important for individuals with compromised renal function, who
benefit from consuming a protein-restricted diet (Fouque and
Laville 2009). There is no evidence, however, that renal function
in healthy individuals is diminished by consuming higher protein
diets (Martin and others 2005). Glomerular filtration rate generally
increases when consuming higher protein diets (Schwingshackl
and Hoffmann 2014), but renal function is not compromised,
particularly in healthy, physically active individuals consuming
2 to 3 times the RDA for protein (Poortmans and Dellalieux
2000; Manninen 2004). The IOM (National Academy of Sciences
2005), WHO (World Health Organization 2011), and the
Australian and New Zealand (2014) reports on dietary protein requirements
are in agreement and state that there is no link betwee