Ageing is associated with a progressive decline in heart function. New research has now found that spermidine, a dietary polyamine, promotes long life and exerts a cardioprotective effect in mice. Feeding spermidine to old mice (≥23-month-old) delayed age-associated cardiac changes, such as diastolic dysfunction and cardiac hypertrophy, and increased autophagy and mitophagy in the heart, promoting cell repair. The cardioprotective effects of spermidine were abolished in mice lacking autophagy protein 5, supporting a crucial role for autophagy in the effects of spermidine. The team then conducted a food questionnaire in humans and found that dietary levels of spermidine were inversely associated with the risk of cardiovascular disease and high blood pressure, which indicates that spermidine supplementation could provide a new strategy for alleviating age-related cardiovascular disease.