Lipoprotein(a) [Lp(a)] is a low-density lipoprotein (LDL) associated with increased cardiovascular disease (CVD) risk. High Lp(a) levels are genetically determined and lack effective pharmacotherapy. This case report describes a 67-year-old, vegan male with elevated blood pressure (BP), total cholesterol (TC), LDL, and Lp(a) who underwent a 10-day, medically supervised water-only fast followed by a 6-week SOS-free diet (free of added salt, oil, and sugar). At the 6-week-follow-up visit, he experienced significant reductions in several CVD risk markers, including blood pressure, total cholesterol, LDL, and high-sensitivity C-reactive protein. He also experienced an unexpected decrease in Lp(a), from 236.3 nmol/L to 143.4 nmol/L (39%). This decrease is comparable to reductions achieved with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. These findings suggest that prolonged water-only fasting and/or an SOS-free diet may be an effective alternative approach for managing high Lp(a) levels and reducing CVD risk in a vegan population, warranting further research.