I think it depends on the individual, but for example my grandfather lived completely healthy life till his 89 and was donating his O- blood frequently his entire life. And by frequently I mean at least 6x a year.
> It is healthy to donate once or twice each week, if there is a 48-hour period between each donation. Plasma is 90% water and frequent donation will not harm you. It can lead to side effects such as dizziness and fatigue, but staying hydrated can help avoid these.
HAVE YOU lately experienced a craving for chocolate milk? If you’re lucky, it’s just a symptom of lactose intolerance. If you’re less fortunate, there’s a serious glitch in the space-time continuum.