Monday, 28 May 2012

The nuns' study

One of the most intriguing pieces of research into Alzheimer's is the ongoing nun study. In 1986 Dr David Snowdon, an epidemiologist and professor in Neurology, embarked on a revolutionary scientific study involving 678 spirited Catholic nuns; the School Sisters of Notre Dame. An ongoing project, the Nun Study has come to represent some of the world's most significant research on ageing and Alzheimer's disease. The participants, ranging in age from 75 to 106, have allowed Dr. Snowdon access to their medical and personal records; and these bright, articulate and altruistic women have each further agreed to donate their brains to the study upon their deaths. 

This link explains some of the findings: 

The most interesting finding, in my opinion, is that  'approximately one third of the sisters whose brains were found to be riddled with Alzheimer's plaques and tangles at autopsy had shown no symptoms and scored normal results in all mental and physical tests while alive! Though the opposite result was true in other cases; such contradictory results show that there is much more to Alzheimer's than neurological changes in the brain alone.'

In other words, there were nuns whose post mortems indicated that they had the classic plaques and tangles which are assumed to indicate Alzheimer's yet they had no symptoms. Likewise there were nuns who did have symptoms but in whom, post mortem, there was no sign of the plaques and tangles.

And yet, years later, you can still read over and over again, apparently authoritative descriptions of the disease which make no mention of these findings!

It's inexplicable.


  1. This is doubly interesting for me; my mum has vascular dementia and I got your link from the forum on the Alzeimer's website.
    Then there is the fact that I wanted to be a nun and spent a year in convent preparing to be one, till I left for elsewhere due to circumstances beyond my control. But anyway, the idea of my former colleagues?housemates? going forward for these tests tickles me, as I remember them as women who took everything in their stride and who all had an amazing sense of humour.

    I do wonder if studying nuns can give a totally acurate reading though, as I wonder how much such things as having a secure community around you helps with regard to symptoms and the ability to cope with them. If you live in one, secure place for the most of your life, among the same group of people, effectively your family, and don't have the 'normal' worries like mortgage, bills, retirement care, then you are not exposed to the same life problems as other people. Though I will be the first to insist that the life of a nun is not stress free and not easy, they do have worries, just different ones.... interesting....

    1. Thanks Helena. I agree that the nuns cannot be considered a refection of 'normal' society. But the most interesting bit about the symptoms and the pathology doesn't seem to me to be influenced by this. Some of them did succumb to this dreadful disease(regardless of whether they had the pathology) and some of them didn't(regardless of whether that had the pathology. I can't think of any reason why this should be different in a more represntative sample.

      Even in a secure and stable community, there will be different personality types and people will cope with any difficulties in different ways and with different degrees of success.

      I want to read more about it anyway. If there's anyone reading this who has already done so - contributions welcome!