Lower levels of "bad" LDL cholesterol could mean a lower risk of dementia and Alzheimer's disease, a new study says.

The findings suggest that the shingles virus might play a role in causing at least a subset of dementia cases, Geldsetzer says, and the vaccine may protect against that. Alternatively, it could be that certain vaccines, such as the one for shingles, lead to a broader immune system activation that lowers the risk of dementia developing.

The research is part of a growing understanding about how many factors influence brain health as we age – and what we can do about it.

Scientists have developed a blood test for Alzheimer’s disease that can help diagnose the neurodegenerative disease while also indicating how far it has progressed. The results could help doctors decide which medications to prescribe depending on how long they’ve had the condition.

A new blood test test could determine how far Alzheimer's has progressed and could also help confirm whether another condition is causing a person’s cognitive symptoms.

The new test could help identify which patients are most likely to benefit from new Alzheimer’s drugs. A newly developed blood test for Alzheimer’s disease not only helps confirm the presence of the condition but also provides information about how far the disease has progressed,