According to researchers at the Columbia University Medical Center in New York, high levels of education may help ward off Alzheimer’s disease, but they also speed up its progression once the disease has developed.
The findings are based on 312 New Yorkers aged 65 and older, who were diagnosed with Alzheimer’s disease and monitored for a period of over 5 years.
Alzheimer's disease, is one of the main causes of dementia in the elderly, and although it manifests itself later in people who are well educated, once it does appear it's progression is speedier.
Lead researcher Dr Nikolaos Scarmeas, monitored the progression of the illness in 312 people with a wide ability range from illiterates to highly educated patients.
All the patients underwent around four neurological assessments, each of which comprised a dozen separate tests of brain function and were then followed for a period of five years.
Overall mental agility declined every year among all the patients, but each additional year of education equated to an additional 0.3 per cent deterioration.
The level of this drop off was particularly evident in the speed of thought processes and memory.
The researchers also examined other factors, independent of age and mental ability at diagnosis, such as high blood pressure, depression, vascular disease and age, that could affect brain function and have an impact on the disease.
Scarmeas says one of the possible explanations for the finding is the theory of ‘cognitive reserve'.
This theory suggests that the brain’s ability to cope with Alzheimer’s disease varies from person to person, but the amount of nerve connections (neurons) and information hubs (synapses) are likely to be more numerous in people who are highly educated.
Alternatively, even if the quantity of neurons and synapses is no different, the synapses are likely to be more efficient and/or the alternative circuitry is likely to be operating in those who are highly educated.