Before we dive into the findings, let’s first understand how the study was conducted. Using the Swedish Total Population Register (TPR), researchers from University College London in the United Kingdom and the Karolinska Institutet in Sweden gathered information on over 4.3 million Swedes born between 1911 and 1961. The participants also had to be residents of Sweden in 1991 to provide the research team with census data on their socioeconomic standing.
The participants were then monitored between 1993 and 2010 for diagnoses of brain tumors. In particular, the team was interested in three tumor types: gliomas, meningiomas, and acoustic neuromas.
The team found that of the 3.1 million Swedes who fit the criteria for assessment, 5,635 men and 7,101 women developed a brain tumor. In teasing out this data, they report that people with higher education (as defined by having 3 or more years of university training) had increased risk of brain cancer. Men with university degrees were 19 percent more likely to develop gliomas. The odds were even worse for women, as higher education put them at 23 percent increased risk for gliomas.
And it’s not just a higher degree. The team also reported that male high income earners had an increased risk for glioma. As a corollary finding, people who work in intermediate and higher non-manual jobs were at higher risk than people with low manual jobs.
But, is this really the case? Does having a higher education somehow cause your brain to grow tumors? In a word: no.
First and foremost, the study is an observational study, meaning that the research team observed the participants for development of an outcome – in this case, it was brain tumors. As such, the findings are merely observations, and do not demonstrate cause and effect.
Additionally, there are limitations to the study, which the authors fully disclosed. This included lack of information on the participants’ lifestyle factors, which could conceivably alter their risks for brain cancer. Error in reporting or in documenting changes in jobs and statuses also contribute to an incomplete picture of the purported association.
Still, given the sheer size of the study, the results are nothing to scoff at. Furthermore, this association is consistent with previous findings, proving that it’s not a one-off chance finding. But then, why did the team find such a striking association? In other words, what gives?
As for this question, the researchers did not hazard too many guesses. They do mention jobs that exposure people to carcinogens could increase the risks of brain cancer, but this point has already been well established, and does not really why the association exists. Thus, the answer to the second question is an unsatisfying one: We don’t know (yet).
So, should you abandon your degree in fear of brain cancer? No, it would be a fallacy to conclude from this study that higher education or socioeconomic status causes brain cancer. A far more interesting endeavor would be to pursue higher education to answer why such association exists in the first place.
Additional source: MNT