A link has been discovered between educational attainment and the formation of Alzheimer's disease precursory symptoms.
Researchers at McGill University in Montreal, Canada used brain imaging on two groups of asymptomatic patients who either carried a familial Alzheimer's disease gene or had parental history of the sporadic form of the disease. In both groups, over a third carried the gene variant APOE-ε4, which is known to be associated with increased development of amyloid plaques. The researchers found that staying in education longer was associated with reduced formation of amyloid plaques in both groups.
'Because we've assumed that the effects of these genes can't be changed, very little research has been done on whether we can modify the trajectory of the disease,' said Dr Sylvia Villeneuve, assistant professor in psychiatry and study senior author. 'It's exciting to see that education may play a role in delaying the start of this devastating disease, which affects people during the prime of life.'
Amyloid plaques are accumulations of misfolded proteins between nerve cells. They are considered to be one of the main causes of Alzheimer's disease. In this study, it was observed that those with less than ten years of education had about twice the amount of amyloid plaques compared with people with more than 16 years of education.
'While it has been believed that people with familial Alzheimer's disease, with its strong genetic causes, may have few ways to slow development of the disease, our study shows that education may be somewhat protective, perhaps promoting brain resistance against these plaques, just as it has been shown to be in people with unknown causes of the disease,' said Dr Villeneuve.
Alzheimer's disease affects more than 520,000 people in the UK and usually develops in people over 65. Though the disease is usually sporadic, familial Alzheimer's disease affects one-six percent of the population. Familial Alzheimer's disease is associated with rare genes that cause an early onset of the disease, with symptoms appearing in people during their thirties to fifties. Sporadic Alzheimer's disease can also be caused by rare genes, including the APOE-ε4 gene variant.
Dr Sara Imarisio from Alzheimer's Research UK, who was not involved in the study, told The Times: 'These findings provide more evidence that education could delay the development of the disease, allowing the brain to resist against disease for longer. While we can't change the genes we inherit, this research shows that our lifestyle can still help to stack the odds in our favour.'
The authors highlighted that further work is needed, specifically to expand the study to look at the effect in non-white participants and to consider socioeconomic factors on educational quality.
This research was published in the American Academy of Neurology.