More education linked to delayed age of onset for genetic Alzheimer’s
Protective effects of education most pronounced for those with highest risk
Among people with a genetic form of Alzheimer’s disease, those with more formal education tend to be older at disease onset, a new study suggests.
Data indicate that the protective effects of education are particularly pronounced among patients with the highest genetic risk of Alzheimer’s, which suggests that “programs to increase early years of education may be particularly important as preventative measures” to help guard against Alzheimer’s, researchers wrote.
“Higher educational attainment may have a protective effect against cognitive impairment, even in the presence of strong genetic risk factors,” Yakeel Quiroz, PhD, study co-author at Massachusetts General Hospital, said in a press release.
The study, “Effect of apolipoprotein genotype and educational attainment on cognitive function in autosomal dominant Alzheimer’s disease,” was published in Nature Communications.
Some people with APOE gene variant at higher Alzheimer’s risk
Among people with Alzheimer’s disease, there’s a lot of variability from person to person in the timing of when cognitive problems first appear. The reasons for this remain poorly understood, but several factors have been found to play a role.
One of the strongest known factors affecting age of onset in Alzheimer’s is genetics, particularly variants in a gene called APOE. People with a variant in this gene called e4 are at higher risk of Alzheimer’s and also tend to develop symptoms earlier, whereas people with another variant called e2 tend to develop symptoms later.
Some studies have also suggested that patients with higher educational attainment (that is, more years of formal education) tend to be older at Alzheimer’s onset and experience slower cognitive decline, compared with patients with less formal education. These associations have mostly been studied in people with the more common types of Alzheimer’s: sporadic or idiopathic disease, meaning the underlying cause is not known.
People can develop Alzheimer’s if they have mutations that are known to cause the disease. One Alzheimer’s-linked mutation is PSEN1 E280A. People with this mutation tend to develop early-onset Alzheimer’s, with cognitive issues usually appearing in their late 40s.
In this study, scientists in the U.S. and Colombia wanted to see whether factors that affect age at onset in sporadic Parkinson’s, namely APOEÂ variants and educational attainment, also influence the age at onset in people carrying the PSEN1 E280A mutation. To find out, the team analyzed clinical data on 675 Alzheimer’s patients carrying this mutation.
Higher educational attainment may have a protective effect against cognitive impairment, even in the presence of strong genetic risk factors.
PSEN1 E280A mutation, APOE e4 variant linked to earlier cognitive decline
Results showed that patients with the PSEN1 E280A mutation who also carried the APOE e4 variant tended to experience cognitive decline at an earlier age. Conversely, the age at onset tended to be later among patients with the APOE e2 variant.
Patients with more formal education were found more likely to be older at disease onset. The effect of education was most pronounced among patients who carried the APOE e4 variant or did not have the APOE e2 variant — in other words, among patients with the highest genetic risk of disease.
“Despite the additional risk conferred by APOE e4, the strongest genetic risk factor for sporadic Alzheimer’s disease, our results suggest that educational attainment may be a critical mechanism of cognitive reserve in familial Alzheimer’s disease,” Quiroz said.
The researchers noted that this study is limited by its use of data collected at only one point in time, highlighting a need for additional research to evaluate how these factors affect patients over time. They also emphasized a need for more studies to understand the biological underpinnings of these associations.
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