One in ten people over 70 suffers from dementia due to Alzheimer's disease, but there is also 10% of the population over seventy who suffer from the disease, although they have not yet experienced any symptoms. This is the conclusion of a pioneering study conducted with more than 11,000 blood samples from Norwegian citizens and published this Wednesday in the journal NatureTo assess the prevalence of Alzheimer's disease, an international team of researchers used a database and biological samples from 250,000 Norwegians at the University of Trøndelag (HUNT). From these, they used blood samples from 11,486 people aged 58 and older and analyzed the levels of Tau, the protein responsible for the internal structure of neurons and the proper transmission of molecules. This marker serves as an indicator of amyloid plaques in the brain, a substance that accumulates in large quantities and is considered an unequivocal sign of Alzheimer's. In addition to these analyses, the researchers administered cognitive tests to participants over 70 years of age to compare Tau levels with the presence of dementia. The results of this research showed that approximately 10% of the participants over 70 years of age had Alzheimer's disease and exhibited both symptoms of cognitive decline and elevated Tau levels. Another 10% had elevated Tau levels and showed mild cognitive impairment. Finally, one in ten participants over 70 years of age had high Tau levels but, instead, did not experience symptoms of cognitive decline, a condition known as preclinical Alzheimer's.

The stress caused by traumatic events, such as the loss of a partner or financial problems, triggers changes in the brain that are linked to Alzheimer's, according to a study by the Barcelona Institute for Global Health (ISGlobal), a center supported by the La Caixa Foundation, and the Barcelona Beta Brain Research Center (BBRC), affiliated with the Pasqua Foundation. The results, published in the journal Neurology, suggest that grieving for the loss of a partner, having a low educational level, and being unemployed are factors that increase the risk of suffering from alterations associated with this disease. However, the researchers emphasize that there are differences in the brain's response to stressful life events depending on whether the affected person is male or female.

The first generation of people who have interacted with digital technology for much of their lives has reached an age where they are at risk for dementia. And the question quickly arises: has technological exposure helped or harmed their cognitive abilities? The digital dementia hypothesis predicts that a lifetime of exposure to technological devices worsens these abilities. But a study published in Nature Human Behavior points in another direction: it suggests that the use of computers, mobile phones, or the internet in people over 50 can combat cognitive decline.