When I was originally diagnosed in 1994 I was told I could no longer give blood. The they changed it so that I could. I can't now because of other meds I take. I didn't even realize they had put a ban on pp who used beef or pork. I guess that's relatively new.
I guess something new was found or discovered that makes it a bad idea. I wouldn't worry about it. You wanting to donate to do a good deed. If our blood doesn't help there are certainly things that you could do that would be helpful.
I went on the Red Cross website and they suggest:
Eligibility criteria, such as certain medical conditions, may prevent you from being able to donate blood in general.
Spread the word that the need for blood is constant.
In the meantime, you can still support the blood donation cause:
Send an eCard inviting friends and family to donate
Join us on Facebook, inviting friends to donate or support the cause.
Help host a blood drive.
Volunteer your time at a blood drive.
Make a financial donation to support the mission of the American Red Cross.