A study by the Leibniz Institute on Aging – Fritz Lipmann Institute (FLI) in Jena shows that the chemical composition of proteins in the brain undergoes fundamental changes with aging. In particular, ubiquitylation—a process that marks proteins and thus controls their activity and degradation—undergoes drastic changes in the aging brain. Interestingly, a change in nutrition, such as short-term dietary restriction, can partially revert some of these molecular patterns. These findings open up new opportunities to better understand the aging process of the brain and related diseases.