Recent studies have identified risk factors for cognitive decline: some linked Alzheimer’s disease to herpes viruses (notably the one causing cold sores); others linked vaccines, antibiotics and over-the- counter anti-inflammatories (such as ibuprofen and aspirin) to lower dementia risk.
US scientists at the University of Pittsburgh, whose study was published in Cell Reports, identified a link between infections with the herpes simplex virus-1 (HSV-1) which causes cold sores and development of Alzheimer’s. Senior study author Professor Or Shemesh told medicalnewstoday.com: ‘We detected HSV-1-related proteins in postmortem human brain samples.’
Researchers at the University of Illinois, whose study was published in mBio, used mouse models to identify the potential route (via nose exposure) through which HSV-1 can penetrate the brain and lead to cognitive impairment; once in the brain, the herpes virus caused persistent cognitive problems and anxiety in the mice.
Senior author Professor Depak Shukla explained how this might work in humans: ‘If an infected individual is shedding virus via tears, it could reach the nasal cavity, where it could go more directly to the brain. This infection is under- diagnosed and under-studied, but the neurological consequences are much more severe than you would normally see with fever blisters or ocular infection.’
Conversely, if viruses such as HSV-1 and potentially other pathogens ‘could increase a person’s risk of cognitive decline’, it is ‘not surprising’ recent evidence suggests ‘vaccines, antiviral drugs and antibiotics could play a protective role in brain health’, commented medicalnewstoday.com.
That conclusion was drawn by a UK review of existing evidence published in Alzeheimer’s and Dementia: Translational Research & Clinical Interventions which analysed data from 14 studies including over 130 million people and found anti-microbial medication, vaccines and NSAIDs were linked to reduced dementia risk.
Review co-author Professor Ben Underwood at the University of Cambridge said: ‘We urgently need new treatments to slow the progress of dementia, if not to prevent it. If we can find drugs already licensed for other conditions, then we can get them into trials and, crucially, may be able to make them available to patients much, much faster than we could do for an entirely new drug.’
Additionally a new Dutch study at Erasmus University Rotterdam, published in the Journal of the American Geriatrics Society, analysed data collected from 11,745 participants and found long-term use of NSAIDs such as ibuprofen and aspirin for a period over 2 years was associated with reduced dementia risk – except for people with a genetic predisposition for dementia.
