Alzheimer’s disease remains a complex illness without a cure, but researchers might have made a step forward in understanding how certain risk factors play a role in the development of the disease.

In a new study published in the British Medical Journal, an international team of researchers looked at 24 risk factors and how they correlate with the disease. The results show that spending more time in higher education is associated with a reduced risk of developing Alzheimer’s. In fact, each year spent in education reduces Alzheimer's risk by around 11 percent. 

The study was part of the International Genomics of Alzheimer’s Project and used data from 17,008 Alzheimer’s patients, with a control sample of 37,154 people. The team used a process called Mendelian randomization to link the risk factors with a higher (or lower) chance of developing the disease.

However, the approach didn't provide a conclusive explanation for why completing a university degree could protect people against the disease. Nevertheless, the team suggests that people with degrees might have an increased "cognitive reserve", a way for the brain to use alternative paths to access information. This could help to fight off the physical effect that Alzheimer’s has on the brain.

The researchers also point out that educational achievements are usually associated with a higher socio-economic status and jobs that might involve less exposure to occupational hazards. Medication use, depression, and chronic stress could also play a part.  

The data showed that there were suggestive associations with Vitamin D deficiency, alcohol consumption, coffee consumption, and the number of cigarettes smoked in a day. But none of these factors were strongly linked to Alzheimer's and all were found to have less influence on the development of the disease than education.

Genetic information related to body mass index, cholesterol, blood pressure, and other cardiometabolic factors don’t seem to play a role in the development of the condition. At least, not according to this analysis.

The study is compelling in its findings and it's somewhat comforting to know that the longer you study, the better chance you have of staving off dementia. Still, this doesn’t mean that an academic career makes your brain Alzheimer’s-proof. And the researchers themselves admit that the results might have limitations due to our current understanding of genetics.

Alzheimer’s disease is the most common form of dementia and it affects over 50 million people worldwide.