Restriction on donating blood lifted

Dear Dr. Roach: I used to give blood regularly. While in the Air Force, I was stationed in England for four years in the early 1980s. Sometime in the 1990s, I was told that due to concern about mad cow disease, I would no longer be able to donate. Is that still true?

G.A.

Answer: The U.S. Food and Drug Administration recently lifted the previous restrictions on blood donation from service members and civilians who lived in the U.K. or in Europe. People suspected of having variant Creutzfeldt-Jakob disease (vCJD, so-called “mad cow” disease), those who have a family history of any similar disease, and a few other people at high risk are still prohibited from donating.

There have only ever been a handful of cases spread by blood transfusion. In the U.K. during the epidemic, there were measures put into place to reduce risk, and there were very few cases transmitted, despite most people being able to donate.

Blood banks always consider the real and perceived risks of the donated blood, as well as the danger that they might be turning away so many people that they can’t deliver all the blood they need. I’m glad they have made this change.

Dear Dr. Roach: Iam 72 years old. From 2018 to 2020, my DEXA scan showed minimal bone loss. This year, I lost a significant amount in my hips. I had greater loss in my left hip than my right. Why would there be such a difference in one hip?

L.D.

Answer: Bone loss is usually similar in both sides. I suspect that what has happened is a result of the error inherent within DEXA measurements. No matter how good the laboratory is, every measurement has the possibility of random error. With DEXA scans in particular, the amount of variability possible between one scan and another scan, just due to random factors, is large enough that it must be considered.

I suspect that future scans will show that the bone density in your hips are not significantly different from one another, but the bone density is likely to decrease, since all women in their 60s and 70s do lose bone density over time, unless they are taking active steps to prevent it.