The Connection Between Dementia and Infections

Last Updated: August 27, 2018

A recent study from Harvard University suggests that the beta-amyloid protein may develop in the brain to fight off infections that have crossed the blood-brain barrier.The Connection Between Dementia and Infections

Learn more from this groundbreaking study about the connection between beta-amyloid, dementia and infections, and its implications on future studies.

How Silent Infections Can Lead to Dementia

A Harvard University study has found that silent, symptomless infections may lead to dementia. The study, published in the journal Science Translational Medicine, suggests that the production of beta-amyloid protein — a hallmark characteristic of the disease — is the brain’s immune response to fight infections.

When the infection enters the brain, passing through the blood-brain barrier, the brain will produce beta-amyloid to capture the infection, leaving behind only the amyloid.

Researchers have tested the connection between dementia and infections in lab settings using fruit flies, mice, petri dishes, roundworms and yeast. The study, led by Dr. Robert D. Moir and Dr. Rudolph E. Tanzi both of Harvard Medical School and Massachusetts General Hospital, began when the two researchers noticed the beta-amyloid protein strongly resembled proteins of the immune system.

In one study, researchers injected salmonella into the brains of mice with no beta-amyloid plaques in the brain. Dr. Tanzi said, “Overnight, the bacteria seeded plaques. The hippocampus was full of plaques, and each plaque had a single bacterium at its center.”

Researchers Change Their Approach to Beta-Amyloid, Dementia and Infections

In the past, researchers believed that beta-amyloid proteins were waste that had gathered in the brain but had little other research to confirm their findings, until now.

If infections in the brain are correlated to Alzheimer’s, then the herpes virus could be one of those infections wreaking havoc on brain health.

Drs. Moir and Tanzi acknowledge they have a strong hypotheses but are quick to say they have more work to do. Ultimately, researchers will look for microbes in the beta-amyloid plaques found in human brains. Dr. Tanzi says that:

“This is a big, big second step. First, we need to ask whether there are microbes that may sneak into the brain as we age and trigger amyloid deposition. Then, we can aim at stopping them.”

Did you know about the connection between dementia and infections? What are your thoughts on preventing the disease? Share your suggestions with us in the comments below.

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Please leave your thoughts and comments

  • Robyn Youlten

    Laboratory experiments on animals have NEVER proven ANYTHING conclusive in humans.WE have different metabolisms.

  • David burch

    My wife had a MRSA infection in her bloodstream. After heavy antibiotics she recovered but six months later she was diagnosed with AZ. I have always believed the MRSA triggered the AZ.

  • Marco Deon Collect
  • bv(FTD)

    I think dementia is an autoimmune disorder, whether caused by a viral, bacterial or fungal infection I can’t say, or perhaps it’s because we are unable to repel innocuous foreign agents.

    My fantastic and loving husband of 25 years ran away from me and the children the day after buying an expensive condo in secret then tore it up by going to bars every night and having one-night stands. He bought rentals, stores and yes, even a Ford Mustang convertible. He was diagnosed with frontotemporal dementia.

    He had terrible allergies and snored loudly all his life. He had a fungal infection in toe before he left and 10 months later at the doctor’s all of his toes were black.

    Alzheimer’s brains are said to have plaques and tangles. It makes sense to me, since dementia has infiltrated the brain years before symptoms are noticeable, that perhaps the plaque forms over some sort of infection in an attempt to protect the brain, and works for quite awhile until defenses are weakened and breached.

    Regardless, Pick’s, Alzheimer’s, ALS and so many other neurodegenerative disorders described well over a 100 years ago are still not well understood so cannot be cured because we are looking at them wrong.

  • Researcher did well to people with dementia to get more knowledge and get people more aware
    many peoples have allergies with different kind and we have to think about it.

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