Why can't i donate plasma at age 66 and over?

Safety: As we age, the reserves we have for stresses (such as plasma donation) decrease. The "maximum" age for plasma donation is not a set number, and varies from center to center; it usually is a safety mark so that they don't make an elderly, infirm person more so. There is literature that suggests blood from an elderly patient is just as good as any other, and some center have no maximum age.

Abnormalities: Age 65 is the cut off. This is due to the thought that there may be plasma abnormalties (more likely) that increase in frequency with age.