Age, medical history, lifestyle and genetics appear to pose the most substantial impact on one’s risk for developing degenerative brain conditions, though this list is growing exponentially. The latest study posits that men who are taller in young adulthood, as an indicator of early-life circumstances, evidence a lower risk of dementia in old age.
“Our results point to an association between taller body height in young men and a lower risk of dementia diagnosis later in life, which persists even when adjusted for educational level and intelligence test scores,” explained senior author Merete Osler, Professor at the Center for Clinical Research and Prevention, Bispebjerg and Frederiksberg Hospital, and at the University of Copenhagen. “Our analysis of the data concerning brothers confirms these findings, and suggests the association may have common roots in early-life environmental exposures that are not related to family factors shared by brothers.”
It’s extremely difficult to asses the severity of confounding factors because there are so many associated with the development of dementia.
The new report, published in the journal eLife, isn’t the first to forward height as a correlate for dementia. However, it is the first to survey its potential as a risk factor all on its own and in relation to environmental and neuropathological contributors.
Early-life factors and our cognitive reserve
The researchers drafted their thesis around the 666,333 men born between 1939 and 1959 logged in the Danish National registry.
Of the 666,333 participants, 608 were brothers and 7,388 were twins. A collective 10,599 involved in the initial analysis developed dementia at some point later in life.
Further inspection revealed a 10% reduction in the risk of developing dementia for every six centimeters that an individual was above the average height for a man (5’6′ ). Intellect and education had a marginal effect on this outcome. These two elements in particular were linked to our cognitive reserve.
The cognitive reserve refers to an individual’s histological and behavioral ability to resist damage done to the brain. It used to be suspected that these measures dramatically governed one’s susceptibility for adverse age-related brain changes. While epidemiological data suggests that education, engaging in leisure activities and occupational attainment improves our cognitive reserve, there seems to be stronger indicators that act alongside each other.
The height factor was so profound in the new report it was even discernible among participants who shared similar genetic material. In other words, brothers and twins of varying heights successfully demonstrated the authors’ postulation. Further research needs to be conducted in order to determine whether or not the outcomes indexed are generalizable to women.
“A key strength of our study is that it adjusted for the potential role of education and intelligence in young men’s dementia risk, both of which may build up cognitive reserve and make this group less vulnerable to developing dementia,” wrote Osler in reference to the new paper.
The study, titled Body height in young adult men and risk of dementia later in adult life, was co-authored by Terese Sara Høj Jørgensen, Gunhild Tidemann Okholm, Kaare Christensen, Thorkild IA Sørensen, and Merere Osle. It can be read in full in the latest issue of ELife.