Sleep, dementia risk after 90, and the limits of dose

A sleep pattern may show up before Alzheimer's disease does

Researchers report that a feature of sleep may act as an early indicator of Alzheimer’s disease. That is the whole finding so far. The paper behind it has not been published, so nobody outside the team knows how many people were studied, how their sleep was measured, or how strong the link is.

Here is the background that makes it worth watching. Deep sleep is when the brain clears out waste most actively. Earlier studies have repeatedly found that people with broken or shallow sleep carry more of the two proteins linked to Alzheimer’s, amyloid and tau. The link runs both ways: poor sleep may add to the damage, and early damage may spoil sleep. So a sleep signal that appears before diagnosis may be an early sign of the disease rather than a cause of it. Nothing here changes how you should sleep or be assessed.

Source: ScienceDaily Press release

Reaching 90 without dementia does not mean the risk has passed

A new report says that people who reach 90 with their memory intact are still at risk of dementia in the years that follow. Only the summary is available. The number of people followed, for how long, and how much risk remains were not published.

The background supports the headline. Age is the strongest known predictor of dementia, and in the large studies that exist, new cases keep rising through the nineties rather than levelling off. The exact shape of that curve in the very old is debated, partly because fewer people remain to study and diagnosis gets harder.

The practical point is simple. Being sharp at 90 is good news, not a discharge. Regular memory checks, a review of sedating medicines, hearing and vision tests, and attention to blood pressure and blood sugar all still matter. This report does not tell us who is most at risk.

Source: ScienceDaily Press release