Higher education may be linked to a decreased risk of developing Alzheimer’s disease, according to a study in the BMJ.
Susanna C Larsson, PhD, of the Institute of Environmental Medicine at Karolinska Institutet in Stockholm, and colleagues conducted a Mendelian randomization study to assess 24 different alterable risk factors such as socioeconomics, lifestyle, diet, cardiometabolics, and inflammatory factors.
A total of 17,008 Alzheimer’s cases and 37,154 controls were grouped to genetically determine increases in any risks that might be associated with Alzheimer’s disease. These factors were assessed based on the category of each modifiable risk factor.
Genetic predictions resulted in decreased odds of Alzheimer’s disease in those with higher attained educations (OR, 0.89) per year of education completed and for completing college or university (OR, 0.74) per unit increase in log odds.
The researchers also found a link between a genetic predisposition to longer education and less daily cigarette smoking, lower chances of smoking, higher density lipoprotein cholesterol, lower triglycerides, lower fasting insulin, and lower BMI.
RS1051730, a genetic variant, suggested a correlation between genetically predicted increased smoking and decreased odds of Alzheimer’s disease (OR, 0.69); however, once this variant was omitted there was no correlation. Genetic predictions in consumption of alcohol, serum folate, serum vitamin B12, and commencing/ceasing cigarette smoking were not associated with Alzheimer’s disease.
The authors also observed a link between genetically predicted higher levels of 25-hydroxyvitamin D and reduced risk of Alzheimer’s disease (OR, 0.92) but found that increased coffee intake may increase Alzheimer’s risks (OR, 1.26).
The authors noted that “the associations with smoking and coffee were in opposite direction to those observed in conventional analyses.”
“Further research is necessary to understand the pathways underpinning these associations,” the researchers commented. “Furthermore, more work is needed to determine the possible role of smoking, coffee consumptions and vitamin D. “
- Larsson SC, Traylor M, Malik R, et al. Modifiable pathways in Alzheimer’s disease: Medelian randomization analysis. BMJ. 2017 Dec 7. doi: 10.1136/bmj.5375