Blood tests to detect Alzheimer’s and exercise to prevent it

A study involving more than 1,700 people from five hospitals has validated a scalable blood test system that detects the risk of Alzheimer’s disease early with more than 90% accuracy, using the biomarker phospho-tau217 (p-tau217). This automated and easy-to-apply test could in many cases replace more complex and sometimes invasive methods such as lumbar puncture or PET imaging, making diagnosis more accessible, faster and cheaper.

The test, led by the Barcelonaβeta Brain Research Center, a centre of the Pasqual Maragall Foundation, and the Hospital del Mar Research Insitute, together with the universities of Gothenburg, Lund and Brescia, establishes two cut-off points. These are levels above which it is certain that the person will develop the disease or below which it can be said that they are free of risk. These help guide clinical diagnosis and reduce unnecessary testing, although their use should always be interpreted by specialised professionals. The results promise to improve equitable access to early diagnosis and significantly reduce healthcare costs.

This research follows a study published by the same team a few months ago in which they compared several biomarkers in blood to detect Alzheimer’s disease. The researchers identified the biomarker p-tau217 as the most accurate of all those tested. Levels of this phosphorylated protein in plasma correlate closely with those in the cerebrospinal fluid. According to the authors, these two investigations, ‘carried out thanks to the collaboration of our patients’, reinforce the potential of blood tests as accessible and reliable diagnostic tools for early detection of Alzheimer’s disease in clinical practice.

More physical activity, less chance of Alzheimer’s

A third study led by the Barcelona Institute for Global Health (ISGlobal), also in collaboration with the Barcelonaβeta Brain Research Center, concludes that increasing physical activity between the ages of 45 and 65 reduces the accumulation of beta-amyloid protein – one of the causes of the development of Alzheimer’s disease – and increases cortical thickness, which is related to memory. For four years, the researchers worked with a cohort of middle-aged people with a family history of Alzheimer’s disease. They found that those who increased their physical activity to meet WHO recommendations had significant benefits in brain health. Also, in those volunteers who were not sedentary, but who did not reach the proposed goals, improvements were seen in some brain markers.

Although the results were shown to be dose-dependent (the greater the increase in activity, the greater the reduction in amyloid load), ‘any increase in exercise, however small, can contribute to the prevention of Alzheimer’s disease’, stresses Eider Arenaza-Urquijo, ISGlobal researcher and leader of the study. These findings reinforce the importance of promoting movement in midlife as a public health strategy.