Reducing protein intake in the name of longevity is counterproductive, as it accelerates muscle loss (sarcopenia), which is a major factor in the decline of functional independence.

noli's read

Dr. Gabrielle Lyon emphasizes here the crucial role of muscle tissue as a metabolic organ and a survival factor. Scientifically, it is established that age-related loss of muscle mass is associated with increased mortality, a finding supported by numerous observational studies (e.g., review in The Journals of Gerontology). Regarding the mTOR mechanism and IGF-1, research indeed shows that while the activation of these pathways is regulated for longevity, it remains essential for muscle protein synthesis, especially in seniors (RCT studies on increased protein requirements with age). The argument that insulin, rather than protein, is the primary driver of problematic IGF-1 elevation is an interesting, albeit complex, mechanistic perspective, as insulin does indeed influence IGF-1 bioavailability. It is important to note, however, that the link between 'molecular longevity' and 'muscle mass' is still the subject of intense academic debate, with no definitive consensus on the optimal balance. This advice is therefore based on sound physiological principles, although it simplifies highly nuanced biology.

the sources

1. 1Wu Y, Wang W, Liu T, Zhang D 2017
2. 2Li R, Xia J, Zhang X, et al. 2018
3. 3Morton RW, Murphy KT, McKellar SR, et al. 2018
4. 4Leidy HJ, Clifton PM, Astrup A, et al. 2015