The People's Perspective on Medicine

Can Antiviral Herpes Drugs Reduce the Risk of Alzheimer Disease?

Decades-old research suggests that herpes virus infections might contribute to Alzheimer's disease. Could antiviral herpes drugs help prevent dementia?

There are few more devastating diagnoses than dementia. Alzheimer disease robs people of their memories, their personalities and their ability to care for themselves. It is often a tortuous decline that impacts friends and families in life-shattering ways. Despite billions of dollars spent on research and drug development, there has been little progress made against Alzheimer’s. But a review in Frontiers in Aging Neuroscience (Oct. 19, 2018) offers a glimmer of hope that antiviral herpes drugs might help attenuate the decline into dementia.

Antiviral herpes drugs like acyclovir (Zovirax), famciclovir (Famvir) or valacyclovir (Valtrex) have been available for many years. (Zovirax was first marketed by Burroughs Wellcome as an ointment in 1982 and in capsule form in 1985.) These antiviral medications are prescribed to treat herpes infections such as shingles (herpes zoster), chickenpox (varicella), genital herpes (HSV-2) and herpes labialis (cold sores caused by HSV-1).

Herpes Simplex Virus 1 and Alzheimer’s Disease:

Over 40 years ago Swedish researchers reported a connection between herpes virus infections and dementia. They noted that people with severe depression or “atherosclerotic dementia had a significantly higher incidence of herpes simplex virus” than was found in healthy controls (British Journal of Psychiatry, March, 1974).

Dr. Ball’s Radical Theory: Herpes and Dementia

Melvyn J. Ball, MD, was a pathologist at the Oregon Health and Science University. He is now retired. In 1982 he suggested that HSV1 (the herpes simplex virus that causes cold sores) might be contributing to the brain pathology of Alzheimer’s disease.

Dr. Ball knew that the herpes virus hibernates in the trigeminal ganglia in the brain. In its dormant state it doesn’t do much damage. Every once in awhile it travels down a nerve pathway to the lips or face and causes a cold sore outbreak. This can happen after exposure to bright sun at the beach or on the ski slopes. People under stress may also have an attack.

Most neuroscientists assumed that the virus only traveled downward. Dr. Ball proposed the virus could travel up and into brain tissue Canadian Journal of Neurological Sciences, Aug. 1982). A few other scientists began pursuing this radical concept.

Dr. Ruth Itzhaki Continues the Research:

Ruth Itzhaki, PhD, is a British neuroscientist. She is Professor Emeritus of Molecular Neurobiology at the University of Manchester. In 1991, her team reported that the cold sore virus (HSV-1) was prevalent in the brains of senior citizens (Journal of Medical Virology, Apr. 1991).

By 1997, Dr. Itzhaki and her colleagues had reported that the combination of HSV-1 plus the gene APOE-e4, was a strong risk factor for Alzheimer’s disease (Lancet, Jan. 25, 1997). Writing about her research in The Conversation (Oct. 19, 2018) Dr. Itzhaki states () :

“The virus can become active in the brain, perhaps repeatedly, and this probably causes cumulative damage. The likelihood of developing Alzheimer’s disease is 12 times greater for APOE4 carriers who have HSV1 in the brain than for those with neither factor.”

“We believe that HSV1 is a major contributory factor for Alzheimer’s disease and that it enters the brains of elderly people as their immune system declines with age. It then establishes a latent (dormant) infection, from which it is reactivated by events such as stress, a reduced immune system and brain inflammation induced by infection by other microbes.”

Antiviral Herpes Drugs to the Rescue?

In her recent article Dr. Itzhaki makes a crucial point:

“It’s important to note that all studies, including our own, only show an association between the herpes virus and Alzheimer’s – they don’t prove that the virus is an actual cause. Probably the only way to prove that a microbe is a cause of a disease is to show that an occurrence of the disease is greatly reduced either by targeting the microbe with a specific anti-microbial agent or by specific vaccination against the microbe.

Antiviral Herpes Drugs:

Dr. Itzhaki goes on to note:

“Excitingly, successful prevention of Alzheimer’s disease by use of specific anti-herpes agents has now been demonstrated in a large-scale population study in Taiwan. Hopefully, information in other countries, if available, will yield similar results.”

Actual Research on Antiviral Herpes Drugs Against Alzheimer’s:

In one study antiviral treatment of herpes virus infections with drugs like acyclovir, famciclovir or valacyclovir dramatically reduced the likelihood of developing dementia (Neurotherapeutics, Apr. 2018).  In that epidemiological study, roughly 28 percent of HSV patients developed dementia during the 10-year follow-up. Among similar patients treated with antiviral drugs, fewer than 6 percent progressed to dementia.

Dr. Itzhaki describes the research this way:

“Even more strikingly, a group of HSV-infected patients (N= 7, 215) who had been treated with one of various anti-herpes agents (acyclovir, famciclovir, ganciclovir, idoxuridine, penciclovir, tromantadine, valaciclovir (VCV—the biodrug of ACV, which is better absorbed) and valganciclovir), showed a dramatic reduction of almost 10 fold in the later incidence of SD [senile dementia] compared with those who received no treatment.”

From the Researchers Themselves:

The Taiwanese investigators recruited 33,448 people:

“8,362 with newly diagnosed HSV [herpes simplex virus] infections and 25,086 randomly selected sex- and age-matched controls without HSV infections…”

The study was described this way:

“This retrospective cohort study is to investigate the association between herpes simplex virus (HSV) infections and dementia, and the effects of anti-herpetic medications on the risk involved, using Taiwan’s National Health Insurance Research Database (NHIRD).

“The usage of anti-herpetic medications in the treatment of HSV infections was associated with a decreased risk of dementia. These findings could be a signal to clinicians caring for patients with HSV infections.”

Final Thoughts About Antiviral Herpes Drugs and Alzheimer Disease:

Dr. Itzhaki and her colleagues bemoan the fact that scientists have been overlooking research data linking infections and Alzheimer’s disease for three decades.

She concludes:

“Surely, now is the time to rectify the situation by determining and then using the best means of treatment at hand.”

Frontiers in Aging Neuroscience, Oct. 19, 2018

We suspect that most health professionals have never heard of the herpes virus theory of Alzheimer disease. Fewer still have read about the study from Taiwan demonstrating benefit from antiviral herpes drugs.

Not surprisingly, readers would like to know if antiviral herpes drugs might be helpful. Here is an article we wrote on this topic based on just such a question.

Other Anti-Alzheimer Disease Resources:

We have interviewed two neuroscientists who are at the cutting edge of Alzheimer disease research. You may find our one-hour interview of great interest.  These scientists discuss the role of infection in dementia and talk about the anti-viral activity of amyloid beta. Here is a link to that show.

You can listen to the streaming audio, an mp3 file, the podcast, or request a CD that you can share.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.” .
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I normally develop five or so cold sores a year. Last November I started using selenium after listening to Dr. Gerhard Schrauzer talk about viruses on I haven’t had one since, so it’s been about one year.
My father had frequent cold sores and he died at 84 with Alzheimers. I think the cause of his death was due to psych meds which were used on patients in the care facility. Off label use to keep them sedated.

Here in the UK a vaccine against shingles is available on the NHS to people aged 70-80. I am 85, have had shingles once (after my spleen was removed because of a surgical mistake) and get cold sores from time to time. Have any studies been done on the effect of this vaccine on the incidence of dementia – or is it too recent? I don’t know how to get the vaccine privately, and the NHS claims that it is less effective after 80 (which could be just cost-cutting).

Whenever I feel a cold sore coming on (the telltale “tingly feeling”) I take L Lysine tablets. 1000 mg a day, and often the cold sore will never develop. If it got a head start, it is gone several days sooner. Is there anything in Lysine that could be helpful in preventing dementia? I’m going to start taking it every day, maybe 500 mg a day. Can’t hurt, might help.

There are quite a few different types of dementia, all with different causes and disease progression. I’ve heard Alzheimer’s being used interchangeably with dementia by both professionals and lay people. This causes confusion. Alzheimer’s is linked to the APOE4 gene. The other forms of dementia can have causes such as atherosclerotic changes in the brain, advanced alcoholism with hepatic encephalopathy as well as medication interactions and other toxicities. I see the words Alzheimer’s and dementia being used interchangeably even in this article. It makes a difference because there would be very different reasons why, how or if antiviral drugs would work. For example, would it have to do with the gene or the actual viral process being interfered with by using Valcyclovir – the preferred form? What are the possibilities that would work in the absence of the heroes virus? It’s very compelling and I would love to continue to see research updates on this subject.

People with Alzheimer’s may or may not have the APOEe4 gene which, based on current research, is a risk factor only.

I frequently get cold sores on my mouth and recently have been experiencing short term memory loss. Could this be the precursor to dementia? My mother had dementia.

Had herpes all my life had two shingles vaccinations no further problems would that also be helpful. How would I take the antiviral medication every day? I am in my seventeen’s and fear alzheimer’s all the time. Just wonder if the rebounder helps I think all the shaking helps the brain

I would like to know if there is an association between genital herpes and Alzheimer’s. I have had genital herpes since 1974–44 years–and I haven’t noticed any cognitive decline at all. In fact, I think I have become smarter as I’ve aged.

Long ago a dentist spotted a cold sore on my lip and recommended the amino acid L-Lysine, as he was also susceptible to cold sores. I take about 500mg a week & haven’t seen a cold sore in years. My mother had the beginnings of an outbreak of shingles (also a herpes virus) and took the L-Lysine for several days. It completely vanished, never to return. Perhaps this could be of some benefit in researching dementia, etc.??

Thank you. This is very encouraging for those of us who have suffered from herpes.

Are they suggesting that everyone take an antiviral such as Valtrex, to prevent Alzheimers?

I am a board-certified Integrative Medicine physician. As detailed in neurologist Dale Bredesen’s excellent book, The End of Alzheimer’s, we have known for several years that various infections contribute to dementia, including herpes viral infections, the borrelia bacteria which causes Lyme disease and other pathogens. In addition, hormonal, toxin and metabolic issues contribute to the disease, whether or not the person has a genetic susceptibility. To learn more about how to apply the exciting new research which Dr. Bredesen published showing prevention and reversal of symptoms, watch the videos available on our website at

I take 3 daily Lysine tablets to prevent cold sores with this in mind. It really does keep down the recurrence of sores. I have a prescription for Zovirax which I almost never use because of the cost. Can you tell me if Lysine is a preventative too?

Should we sufferers take this medicine only when we feel an outbreak or should it be taken all the time?

Interesting info. My mother developed Alzheimer’s disease in her late 70’s while she was still very active both physically and mentally as a business owner for 35 yrs. She had the occasional fever blister but was in otherwise very good health. No daily prescription meds. This could be an explanation as to what happened to her as we have struggled to understand this illness. Thanks.

My husband began taking L-Lysine 500 mg daily for 30+ years for cold sores and only rarely has had a break-out. He’s 81 and no Alzheimer’s at this point.

Is it possible to reverse dementia or Alzheimer’s with this therapy?

I started to have rosacea on my skin (like my dad), and at That time, one of the side effects was cold sores. After taking the MetroGel, I had Horrible long-lasting cold sores. They seemed to never stop. My dr. said an old time remedy to try was L-Lysine and they are gone as long as I take that every day. When I couldn’t get it for a while, horrible cold sores popped out immediately. However, the side effect is no longer listed on that generic. I have found Aveeno works great for the Rosacea but must still take the L-Lysine every day. My mom died of dementia at 73 and I’m 82- and scared.

This is the one that scares me, but… My mom had cold sores and ended up with Alzheimer’s. I honestly think she got infected by my dad. He often had cold sores, and I remember that even as a child. However, he had no dementia when he died at 88. I never had them until I was infected by a boyfriend!

I do keep a Valtrex handy. The first time I got a cold sore, it was huge. Gradually it got to be way less, and often just inside my nose. Then, a couple of years ago I had the worst outbreak ever. I didn’t have Valtrex on hand, so waited a couple of days. It was awful, and all around my mouth, on my chin, my nose, and probably other areas. Really scary, uncomfortable and awful looking. I think I had to do 2-3 rounds of Valtrex before it finally started to slow down.

I try to take L-lysine now, but don’t always because I forget to take it without food. At the first inkling, I take Valtrex, and that seems to do the trick.

I wonder if known anti viral herbs would work the same way.

Drug companies have no interest in drugs that they can’t make money on.

Not sure what you mean, given the drugs are already available…

Both parents had dementia…mom would have an occasional cold sore, Dad never had one to my knowledge..Dads dementia started in his 70’s, Mom started in her mid 80,s

You can have the cold sore virus but never have cold sores. I have never had one, but I tested positive for HSV1 when I was pregnant.

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