Metformin, used to treat Type 2 diabetes, decreased the rate of aging in male monkeys, as measured by physiological, imaging, and histological indicators.
Summary: https://medicalxpress.com/news/2024-09-metformin-aging-male-monkeys.html
Original paper (not open access): https://www.cell.com/cell/abstract/S0092-8674(24)00914-0?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867424009140%3Fshowall%3Dtrue
So eating a dozen doughnuts a day could ultimately make you younger?