Review of 350+ studies in Cell Press: less dietary protein may slow biological aging

A large review published in a Cell Press journal analyzed more than 350 scientific papers on dietary protein and aging, pravda.ru reports. The authors concluded that for many people excess protein may bring no benefit and may interfere with longevity pravda.rupravda.rupravda.ruOpen source ↗. The review appears as protein is added to coffee, water and breakfast cereals, and consumers are urged to eat more of it.

What the data show on protein restriction

According to the review, limiting dietary protein may slow biological aging, improve metabolism and help the body protect cells from damage. The authors note that this does not mean severe fasting: the composition of the diet proved important, not the total number of calories.

In animal experiments, lower protein intake extended lifespan even when calorie intake stayed the same. In studies with people, a lower share of protein helped participants reduce body fat and improve blood sugar measures.

A possible mechanism is the hormone FGF21, whose level rises when a person eats less protein. The hormone helps the body adapt to dietary changes, reduces inflammation and helps regulate blood sugar. In mice with raised FGF21, the researchers recorded a longer lifespan pravda.rupravda.rupravda.ruOpen source ↗.

Three amino acids were singled out: methionine, isoleucine and valine. Their excess may trigger growth processes that are useful at a young age but over the long term may contribute to age-related diseases such as diabetes or obesity.

Protein needs are individual

Lead author Dudley Lamming of the University of Wisconsin–Madison notes that protein is necessary for muscle growth and tissue repair. The problem, he says, is that most people today are sedentary, and for them excess protein may have negative metabolic effects.

The authors stress that the data do not call for giving up protein, and that the need for it is individual, so there is no single norm for everyone pravda.rupravda.rupravda.ruOpen source ↗. US dietary recommendations have recently shifted toward higher protein intake, while the researchers argue for a personalized approach based on actual physical activity and age.

The material names several groups. For athletes and active people, exercise makes the body use protein for muscle repair, which offsets potential harm. For older people, protein is critical for preserving muscle mass and preventing weakness and fall injuries. For pregnant women, additional protein is needed for fetal development.