Is there a way to reduce the frequency of lipofuscin? Change of diet? Medication?

No. Lipofuscin is a wear-and-tear pigment that so far as we know does no harm. Despite "pop" claims in pathology books, even newborn babies' hearts are loaded with it. There are a few untreatable diseases in which it builds up (most famously, the cocker spaniel brain disease). Earwax pigment is lipofuscin. Specific concerns -- talk to a credible scientific physician.