The HN submission Could leak in blood-brain barrier cause poor memory? (2021) may provide a clue: https://news.ycombinator.com/item?id=26520453 https://news.yco

The HN submission Could leak in blood-brain barrier cause poor memory? (2021) may provide a clue: https://news.ycombinator.com/item?id=26520453 https://news.ycombinator.com/item?id=26520453 >People with ApoE4 have a hard time getting rid of amyloid beta peptide in their brains, which causes an accumulation of plaque. With healthy aging, the pumps in the blood-brain barrier work less efficiently in getting rid of the amyloid beta peptide. The pumps work even less well in people with Alzheimer’s disease. >Recent work suggests that the leak in the blood-brain barrier that occurs with Alzheimer’s may be due to an age-related loss of pericytes. Astrocytes, by contrast, seem to be overactive. Recent work suggests that preserving pericyte function by giving the factors that they secrete or even transplanting them could lead to a healthier blood-brain barrier. >Other findings raise the question of whether the brain’s source of nutrition and its grip on control of the immune and endocrine systems could deteriorate with aging. Another finding raises the possibility that the rate at which many drugs are taken up by the brain may explain why older folks sometimes have different sensitivities to drugs than their children or grandchildren. Pair that with this part of OP: >This regulation is important in preventing proteins from going rogue and clumping together, which is what happens to the amyloid and tau proteins in the brains of people with Alzheimer’s disease, the most common cause of dementia. I'm just a layman, but it sounds like BBB health is a major factor for regulating this in the brain. In some individuals, including those with identified genetic biomarkers for increased Alzheimer's risk, the BBB ages faster, leading to decreased regulation of protein/peptides. So learning more about how to improve BBB health could eventually help people maintain a healthy brain longer. Avoiding excessive alcohol seems to be an important factor for BBB health, according to this 2021 study performed on mice: https://pubmed.ncbi.nlm.nih.gov/33516661/ https://pubmed.ncbi.nlm.nih.gov/33516661/ ; also this research published in 2022: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9204474/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9204474/ OP refers to "amyloid and tau proteins" while the 2021 article I referenced refers to "amyloid beta peptide" - at this point, I'm really not sure how precisely these terms are being used. Are they interchangeable in this context, or is there an important nuance that I'm missing?