Is animal or plant protein better for healthy ageing?
This question cannot be answered based on the available sources. For a well-supported answer, consult studies that directly compare animal and plant protein in ageing populations.
The provided research sources contain no direct comparison between animal and plant protein in relation to healthy ageing. The available abstract concerns the global burden of cardiovascular disease, but contains no data on protein sources or dietary patterns.
Based on what has been supplied here, the question simply cannot be answered. Studies that compare both protein sources on outcomes such as lifespan, muscle retention, cardiovascular health or other measures of healthy ageing are absent.
If you want an answer to this question, you need other sources, for example studies that have specifically tracked dietary patterns or protein intake in older people. That information is not present in the supplied claims.
The only supplied source (PMID 38199801) concerns the global burden of cardiovascular disease and contains no comparative data on animal versus plant protein. The question cannot be answered on the basis of this source.