José M. Ordovás
Senior scientist and scientific advisor at the Jean Mayer USDA Human Nutrition Research Center on Aging and professor at the Gerald J and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts University.
It is a comprehensive, interesting and timely review, but it is not a new clinical trial, nor does it prove that reducing protein intake prolongs human life. The most compelling evidence on longevity still comes from animal models, whilst studies in humans are few and, generally speaking, of short duration.
The study serves as a counterbalance to the increasingly widespread notion that more protein is always better. However, it does not justify recommending less protein for everyone: requirements vary according to age, physical activity, nutritional status and clinical condition.
We should not replace the slogan ‘more protein is better’ with another equally simplistic one: ‘less protein prolongs life’. The sensible message is to consume an adequate amount – not necessarily the maximum – paying attention to the quality and source of food and tailoring intake to each individual.