Scientists have been searching for ways to unveil many of the mysteries surrounding Alzheimer's disease for decades. A group of researchers from the University of Chicago who chose to look at a group of almost 1,000 nuns, priests, and monks found that those who were the most conscientious had the lowest chance of developing the disease.
Interestingly, the scientists found that being conscientious might make people better able to cope with plaques that build up in the brain and are believed to lead to the disease.
In the study, “conscientiousness” refers to a person's tendency to control impulses and be goal-directed, and is also known as will, work and dependability, according to background information in the article.
The latest study followed a group of nuns, monks and priests from across the United States over a period of 12 years. They were chosen as a group because they were deemed more likely to be willing to take part in a study that might help others in the future, but not themselves.
As well as assessing their medical well-being, the researchers also asked the group to rate themselves on areas such as self- discipline, reliability and being hard- working.
The average score among the group was 34 out of 48 - perhaps surprisingly, similar to scores among the general population.
Dr. Robert Wilson, the lead researcher from Rush University in Chicago, said that during the study, 176 people developed Alzheimer's. But those with the highest scores for conscientiousness appeared to have a lower risk than lazier counterparts.
Nuns, priests and monks with scores in the top 10 per cent had an 89 per cent lower risk of developing Alzheimer's than those with scores in the lowest 10 per cent.
The researchers, writing in the journal Archives of General Psychiatry, also found that conscientiousness was associated with a slower rate of mental decline.
But an examination of 324 brains of those who died during the study did not find any link between conscientiousness and signs of the disease. The brains of the conscientious had similar levels of plaques and tangles which build up and cause Alzheimer's as those of the less conscientious.
Dr Wilson said this was not unexpected. He said the trait of being conscientious may just help the brain cope better with the physical causes of Alzheimer's.
One reason for the link between being conscientious and a lower risk of Alzheimer's is that people who are hard-working also experience educational and career success, which has been linked to a lower risk of the disease.
The researchers said that being conscientious has also been linked to resilience and to coping with difficulties. Dr Wilson said that, by working hard and being conscientious, people might reduce their risk of Alzheimer's.
However, Professor Clive Ballard, director of research at the Alzheimer's Society, urged caution, saying: "It is important to remember that this study only looked at one group of people and may not translate to the whole population."