The Nun Study

By Jane Verity ©

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. In this editorial, we share a few of the most exciting findings gained through the study bringing promising news that will empower and enrich the lives of our senior citizens, people with Alzheimer’s, their families and carers. The study’s findings are bound to influence the way we think about Alzheimer’s; its causes; and what can be done.

Remarkable Findings

One of the primary questions the Nun Study attempts to answer is how pathology in the human brain relates to the expression of Alzheimer’s symptoms. Today, it is known that plaques and tangles are the two most important pathological features of Alzheimer’s disease. However, some stunning results from the Nun Study show that Alzheimer’s is not a yes/no disease. Rather, it is a process… one that evolves over decades and through interacting with many other factors.

The study shows quite dramatically how pathology alone can often mislead. For example, approximately one third of the sisters whose brains were found to be riddled with Alzheimer’s plagues 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.

Diagnosing Alzheimer’s

It is increasingly clear from this study that many different factors influence our amazing brain and to thoroughly diagnose Alzheimer’s is an incredibly complex undertaking; one that requires a combination of neurological tests, blood tests, brain scans and a comprehensive battery of psychological tests.

Diagnoses made without sufficient evidence can often lead to misdiagnoses and unnecessary suffering. Therefore, if there is any doubt, it is imperative that a reliable second opinion be obtained.

Interestingly, the Nun Study further reveals that more disabled sisters are particularly sensitive to the emotional tone of voice of the person carrying out the testing. This influence on results makes it crucial that anyone conducting Alzheimer’s and dementia testing needs to emphasise the positive, and compliment the participant for his or her achievements.

If we think of the current push toward seeking a computer test to tell us if we are at risk of developing Alzheimer’s, it is important to thoroughly consider the above findings and also one of Dr. Snowdon’s lessons:

‘When people learn that they have a higher risk of a disease, it sometimes leads them to conclude that the illness has either struck already or will soon. To live in fear of a disease that you do not have – and may never develop – exacts a high price.’

It is also be worth thinking about the financial consequences for someone being “picked” as being at risk of developing Alzheimer’s. How might this influence their life insurance application or premium; assuming of course that they are able to get insurance! This concern was brought home to Dr. Snowdon after the publication of one of his papers citing a possible link between the better educated nuns testing more resistant to the symptoms of Alzheimer’s, despite showing the neurological changes associated with the disease.

‘Within a few days we were inundated by calls from insurance companies that wanted us to develop a standardised pen-and-paper test for susceptibility to Alzheimer’s. We firmly declined… but the point had been made.’

The Healthy ‘Non-Alzheimers’ Brain

The Nun Study has taught Dr Snowdon and his team the amazing lesson that Alzheimer’s disease is not an inevitable consequence of ageing. Their research has already revealed that nearly 40 percent of the people in the study who died between ninety-six and one hundred showed a strong resistance to the development of Alzheimer’s.

The Nun Study is also endeavouring to discover what preserves a healthy brain. It explores whether this might be something in a person’s diet, genes, or immune system, their education or something else in their life history or environment that is yet to be realised.

Below are some interesting findings in regard to diet that you may wish to act on for yourself and/or for those in your care who have dementia.

How Nutrition can Help us Live Longer, Healthier Lives Without Alzheimer’s.

Dr Snowdon’s dream is to be able to demonstrate that certain foods or supplements protect the body, and especially the brain, from the effects of aging and Alzheimer’s disease. His study has contributed to some of the major nutrition findings – and controversies – of our time.

Findings from the Nun Study strongly suggest that a “‘stroke-free brain’ can compensate for Alzheimer’s lesions to some extent and mute the symptoms of the disease.”

This link between Alzheimer’s disease and strokes has led Dr. Snowdon to become a great missionary for stroke prevention. He is constantly exploring how the diets currently recommended as beneficial in preventing strokes and heart disease may also help prevent Alzheimer’s.

Incidentally, this is exactly the same premise Australian holistic physician, Dr. Ruth Cilento, describes in detail in her two books Age without Alzheimer’s.

Food for Thought

High levels of homocysteine is now considered one of the primary risk factors for heart disease and stroke. To break down homocysteine into a useful form, we need folic acid to join with vitamin B12. Folic acid, or folate, is a B group vitamin found in abundance in dark leafy vegetables, such as spinach and silver beet; and also in beans, nuts, citrus fruits and liver. We all need to eat some of these folate sources every day.

Another interesting finding, which provides much food for thought, is that the nuns who lived longer and continued to function at a higher level regarding their self-care had high blood levels of lycopene. Lycopene is a red pigment found in a small number of plants, including tomatoes, guavas, watermelon, and pink grapefruit. There is no known equivalent substance produced in the human body, so we do need to obtain lycopene through eating these few foods.

In addition, there is proof that lycopene is best absorbed when consumed with some fat. In other words, a lycopene pill might not have the same effect as ingesting lycopene in a tomato-based spaghetti sauce. And, unlike some vitamins that are damaged through cooking, lycopene is actually more obtainable from cooked tomatoes than from fresh ones.


Vitamins C and E and beta-carotene have one thing in common – together with many other substances – they are all antioxidants. They protect the body from oxidative stress; the wear and tear we incur simply by being alive. This process can be likened to the same one that causes iron to rust.

Oxidation is one of the central unifying theories of aging and disease and neuropathologist Dr. William Markesbury and other scientists have proposed that oxidation plays a major role in Alzheimer’s disease.

Brain tissue from people with Alzheimer’s shows higher levels of oxidation, compared to healthy controls. Amyloid, the ingredient of the plaques, also appears to generate free radicals that add to the damage done to neurons. Tissue damage in turn creates more free radicals, setting off a destructive cascade of events that can lead to the atrophy and death of brain tissue.

The body limits the damage by producing its own substances to absorb free radicals but we can assist this mopping up process by increasing our consumption of antioxidant foods and vitamins.

Dr. Markesbury recommends that people in the early stages of Alzheimer’s take considerably higher doses of vitamin E, vitamin C and folic acid.

The Power of Emotional Support

The Nun Study has also shown that weight loss in the elderly is associated with a high risk of losing both mental function and physical abilities. Depression, isolation and lack of interest are often the critical factors. One of the participants, Mother Georgia, says:

‘Healthy nutrition requires warm conversation as well as hot meals.’

A Final Point

From the sisters, we learn the importance of living in communities with people we love and who love us; and, despite our age, to keep looking towards a future filled with hope.

Does a positive outlook early in life contribute to longevity? The data suggests the answer is yes.

The fascinating results revealed through the study to date are documented in David Snowdon’s book Aging with Grace, where you will find one of the most precise, yet very simple and descriptive, definitions of plaques and tangles we have come across.

You can also find out exactly what an MRI scan is in down-to-earth terms. And, if you would like to know how Alzheimer’s came to be discovered and where it got its name from, the details are also in the book.

For more information on the role diet, genes, immune system, education and other factors play in Alzheimer’s disease and in maintaining a healthy “Alzheimer’s free” brain, we strongly recommend that you read Aging with Grace by Dr. David Snowdon.

Further Reading

  • The Nun Study  – Jane Verity (Learn further details of Dr. David Snowdon’s amazing findings including an important link between Alzheimer’s disease, stroke & diet; learn how nutrition can help us live longer lives without Alzheimer’s; plus discover critical factors & interesting influences associated with Alzheimer’s.)
  • How to Help People with Dementia Improve  – Jane Verity (Learn the first step to assisting a person with dementia to improve; how our focus determines the experience; discover how beliefs are maintained; learn how our brain operates a clever filtering system plus more on NLP.)
  • Symptoms & Stages of Dementia – (The 4 stages of dementia & why they should only serve as guides; read examples of how people with dementia compensate for missing memories, their wonderful language & the meanings behind gestures & body language.)
  • 3 Powerful Myths about Dementia – (We dispel 3 powerful and harmful myths about dementia. Discover the one thing people with dementia & children do have in common; Helpful tips to find out what they like/need and want; plus learn the 5 points critical to storing long term memories.)
  • How can Aromatherapy Help People with Dementia? – E. Joy Bowles BSc. How the sense of smell is non-verbal & can get through to emotions when words fail; the use of smells can help orient people with dementia to time & space; tips for choosing & using the right oils to lessen anxiety, agitation & depression.)
  • Brahmi – The Traditional Ayurvedic Brain Tonic  – Dr Ruth Cilento – How Brahmi improves learning processes & memory; how it works; who can benefit; why brahmi is particularly therapeutic for the elderly, plus more on its health benefits.)
  • Gingko Biloba – Dr Ruth Cilento – (The many healing properties of Gingko Biloba; its positive effects on memory &learning abilities and for arresting symptoms of dementia.)
  • The Garbage Run Miracle – Colin’s amazing real-life story of improvement.
  • The Garbage Run Miracle Continued – Colin’s incredible improvement continues.