A recent Mendelian randomisation study found that genetically higher education level was associated with lower risk of major mental disorders and most somatic diseases, independent of intelligence.
Education is an important health social determinant. It has been proposed as a modifiable risk factor for a number of disorders and diseases, including depression, cardiovascular disease and cancer. However, it is often unclear whether these associations are causal and/or independent of intelligence.
Mendelian randomisation can be used to measure the causal association between an exposure and an outcome. In other words, by comparing the risk of a disease across individuals who have been classified by their genotype, we can estimate the causal effect with substantially less bias than other analyses.
Education is an upstream health determinant that influences social and community networks, and individual lifestyle choices. Therefore, it impacts the risk of various health outcomes. For example, higher educational attainment has been linked to income, alcohol consumption and physical activity. It also has inverse associations with smoking, BMI and sedentary behaviour. However, whether this is due specifically to intelligence or education level is still unclear. This study aimed to disentangle the causal role in neurological disorders and somatic diseases.
The Role of Education
They found that genetically predicted education level was causally associated with a lower risk of most diseases. This included 8 of the 11 mental and neurological disorders, all 9 cardiovascular disorders and all 3 of the cancers studied.
On the other hand, genetically predicted intelligence was linked to many diseases and disorders, including OCD, anorexia, schizophrenia, and some cancers. However, after adjusting for genetically predicted education level, only the association with schizophrenia persisted. Their results are broadly in line with previous studies.
Potential Mechanisms
The researchers hypothesised 3 possible pathways linking education to health outcomes. The first was that education impacts many of the modifiable risk factors which underlie disease, thus producing a positive effect. The second was that there may be direct effects on education-related brain structures. For example, gene methylation or silencing in specific brain regions could impact the development of mental and neurological disorders.
The final hypothesis was that subjective wellbeing and meaning of life can be influenced by education level. An individual’s mindset may have profound effects on mental and somatic diseases, both directly and indirectly.
The results of the study suggest that more than knowledge itself is affecting how people live their lives. Therefore, it is important to consider further explanations, such as the relationship between high education and the standard of life that follows it, which could have a positive health effect on the individual.
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