Genetic evidence that education reduces Alzheimer’s risk

Thursday December 7th, 2017

A genetics study out today has added further weight to the theory that education helps to protect against Alzheimer’s disease.

Enrolling 17,000 patients with Alzheimer’s disease, researchers from the University of Cambridge, England, studied genetic variants that increase the risk of a variety of different environmental risk factors to see if these were more common in those with the disease.

The study, undertaken as part of the CoSTREAM project, found the strongest association with genetic variants that predict higher educational attainment.

Professor Hugh Markus from the university's Department of Clinical Neurosciences said: “Many studies have shown that certain risk factors are more common in people with Alzheimer’s disease, but determining whether these factors actually cause Alzheimer’s is more difficult.”

He used Mendelian randomisation to look at DNA and compared genes associated with environmental risk factors to see which of were also associated with Alzheimer’s disease. If a gene is associated with both, then it provided strong evidence that this risk factor does cause the disease.

Writing in the latest edition of The BMJ, first author Dr Susanna Larsson, now at the Karolinska Institute, Sweden, said the study provides further strong evidence that education is associated with a reduced risk of Alzheimer’s disease.

“It suggests that improving education could have a significant effect on reducing the number of people who suffer from this devastating disease,” she added.

Previous studies have shown that the same amount of damage in the brain is associated with less severe and less frequent Alzheimer’s in people who were more educated.

It is believed that ‘cognitive reserve’ – the ability to recruit alternative brain networks or to use brain structures or networks not normally used to compensate for brain ageing – could partly explain it.

The researchers also looked at other environmental risk factors, such as smoking, vitamin D, and alcohol and coffee consumption, but the results were inconclusive.

Larsson, SC et al. Modifiable pathways in Alzheimer’s disease: Mendelian randomisation analysis. BMJ 7 Dec 2017; doi: 10.1136/bmj.j5375

Tags: Brain & Neurology | Genetics | UK News

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