Women's Brains Age Faster?
Dear friends of women in science,
Sonia Pressman Fuentes sent me a link to an article about women's brains in aging and it was not good news. In an article July 30 in the Washington Post, illustrated with an off-putting drawing of a brain in a frying pan, Michael Slezak discussed a newly released study on brains in aging people. Mehmet Somel and collaborators at UC Berkeley looked at the transcriptome, the collection of RNAs, in the brains from 55 people. They looked at 13000 RNAs in four different brain sections. This collection is not comprehensive, either in terms of the messenger RNAs examined or in terms of brain regions that might be important in aging. There is a pattern of how this transcriptome changes with age, some messenger RNAs increasing and others decreasing. What they predicted was that, since women live longer, their patterns would change to the "old" messenger RNA levels slower than men's. But their results showed just the opposite. Of 667 RNAs that changed differently in men and women, 98% of the differences showed the women had expression patterns more typical of old age. Some of these changes in gene expression have previously been linked to cognitive decline and to diseases that cause degeneration in the brain.
The authors don't want to be too quick to conclude anything overarching from their results. They noted that about half the female samples had what appeared to be accelerated aging while the other half did not, a pattern that could mean environmental causes such as stress rather than pure aging drove the results. That idea fits the group's previous data on monkeys subjected to stress, where faster brain aging was detected in the transcriptome responses. In any case, the results must be repeated and tested with variations to rule out any other causes, such as inflammation, infection, or hormonal imabalance, as well as to test the role of stress more directly.
Somel, the prinicipal investigator, is interested in applying such methods to people in different cultures where women's roles vary greatly, to see if they occur in association with particular environmental variables. He will also examine aging rodents. In any case, these results and the way some in the press interpreted them give us food for thought. Doubtless women would prefer to age to older ages than men with their neuronal transcription intact, if possible.
Meanwhile, I'd just say I haven't seen any great declines in brilliance in my older female friends, so the possible bottom line that aging of the brain happens faster in women doesn't pass the approximation test for me.
cheers,
Laura
Hi Laura,
I don't know, at first I was sorry you'd covered this and invited discussion if it was such a small study without all the proper controls with such big claims in the news. But then, one of my students saw it online and I was kind of glad you'd brought it to my attention so I could respond appropriately to the student.
Mixed feelings! If scientists would only ballyhoo their stuff to the press when it was really well established, I would like it better, But I doubt that's feasible.
SSW
Hi Sara,
Yes, I know what you mean. But with the headlines screaming women lose brain power in aging, I do think it needs a little expose of how limited the study actually was.
best,
Laura
Hi Laura,
This is just too preliminary to even comment on. I guess when the news media make a big deal about it, you feel you have to respond, but it's so preliminary! We should all just say, fine but we really need data before we say anything about this interesting idea. It's certainly not established that women's transcriptomes are programmed to go down in aging. Geez!
Sara C.
