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Will L-lysine for Cold Sores Protect the Brain from Alzheimer’s?

Harvard researchers have come up with a novel hypothesis about the cause of Alzheimer's disease. A reader wonders if L-Lysine for cold sores could help?

A connection between cold sores (caused by herpes simplex virus type 1 or HSV-1) and Alzheimer’s disease has been tossed around for decades. How good is the evidence? This reader would like to know if L-lysine for cold sores might be worthwhile.

Q. I have a family history of Alzheimer’s and have been doing a lot of research on how to try to prevent it. I just read that cold sores and other infections may contribute.

This is quite upsetting to me as I get cold sores frequently. I have started using L-lysine tablets to reduce outbreaks. Is there any evidence that it will protect my brain?

A. A recent study from Harvard offers a novel theory on Alzheimer’s disease (Science Translational Medicine, May 25, 2016).  The conventional view holds that plaque made of harmful beta-amyloid protein destroys neurons.

The new hypothesis suggests that beta-amyloid protein is part of the body’s immune response to pathogens as varied as those that cause cold sores, Lyme disease or HIV. It appears to act as a natural antibiotic, but it can cause damage when the immune response goes haywire.

Gina Kolata of the New York Times (May 25, 2016) explains it this way:

“Could it be that Alzheimer’s disease stems from the toxic remnants of the brain’s attempt to fight off infection?

Provocative new research by a team of investigators at Harvard lead to this startling hypothesis, which could explain the origins of plaque, the mysterious hard little balls that pockmark the brains of people with Alzheimer’s.”

Cold Sores (HSV-1) and Alzheimer’s Disease:

For more than 40 years scientists have been reporting an association between herpes virus infection (HSV type 1) and dementia (Alzheimer’s & Dementia, June, 2015).  In the 1980s a pathologist by the name of Melvyn J. Ball, MD, suggested that the virus that causes cold sores invades tissue within the central nervous system called the trigeminal ganglia. He hypothesized that the virus moves in two directions when it is activated. It migrates down nerves to the lips or face to trigger a classic cold sore and may also travel up into the brain to cause damage there in the form of neurofibrillary tangles. You can read much more about Dr. Ball’s research on herpes and Alzheimer’s disease at this link.

Another possibility is that the immune system reacts to the presence of the herpes virus by creating plaques and tables. This is the hypothesis put forth by the Harvard researchers in Science Translational Medicine.

L-Lysine for Cold Sores?

We don’t know whether treating cold sores with L-lysine or antiviral drugs (acyclovir, famciclovir, valacyclovir) would help reduce the risk.

There has been very little research on the effectiveness of L-lysine for cold sores. We did find this study about L-lysine for HSV-1 infections (Dermatologica, vol. 175, no. 4, 1987).  There is clearly no consensus from the medical community about this amino acid. It is essential for human health and is a building block for protein formation, but the question of whether it will help control herpes outbreaks remains surprisingly unanswered.

One theory of the antiviral mechanism behind L-lysine for cold sores has to do with its ability to inhibit the action of arginine, another amino acid. Arginine is important in the replication of the herpes virus. Supposedly, L-lysine suppresses HSV-type outbreaks by keeping the virus from multiplying.

Without big, well-controlled clinical trials we are unlikely to get an answer to the controversy of L-lysine for cold sores. After all, no drug company would spend millions on a study for which no profit could be made. In the meantime, all we have are anecdotes. Many visitors to our website do report that L-lysine can help prevent cold sore outbreaks. Here are just a few of the stories we have received over the years:

Janet, Palm Beach County, FL, writes:

I have suffered with cold sores since I was a child. As an adult, I worked in several hospitals, and the chief pharmacist in one suggested all the possibilities he had heard of that could help.

“It wasn’t until several years later that I heard about L-lysine. I bought it and tried it. What a blessing!

“At the first tingle, I take 1000 mg in the morning and another dose before bed. The blisters never even form! I’ve been caught by surprise when traveling, and by the time I could get to a drugstore the blisters had all formed. By starting out doubling the dose the first day and then dropping back to the 1000 mg level after that, the blisters actually go back down — no sores or scabs.

“Now I’ve found the 500 mg capsules are easier to swallow, and still work as well. Thank heavens for L-lysine for cold sores. I have also heard of several physicians who knew about L-lysine and are recommending it to patients with shingles to help reduce the pain and length of the outbreak.”

Ruth offers this long-term experience with L-lysine for cold sores:

“I had cold sores all the time but then I added 500mg L-lysine to the vitamin that I take. I am 70 years old and have not had a cold sore in 30 years. If I do feel a warm spot on my lip I take an extra 500mg L-lysine and the warm spot disappears.”

Art offers an interesting perspective:

“Q. What’s the difference between love and herpes?

“A. Herpes lasts forever!

“The Herpes Simplex Virus (which was once known as,”The Kissing Disease,” which is why the Roman Empire of old prohibited kissing among their legions) and which some 80% of Americans carry, is what causes cold sores on the mouth.

“Once the virus is initially contracted from an infected person or infected object, the virus travels to, and permanently resides in the trigeminal nerve and reoccurs periodically, usually triggered by stress, certain types of spicy foods, sunlight, etc. in episodic outbreaks.

“The initial outbreak can be quite painful, unsightly, and lasts for 7-10 days.

“Subsequent outbreaks, while still painful, will generally become less severe over the course of time.

“Home remedies help alleviate the pain and discomfort and help to shorten the duration of an outbreak.

“L-lysine, an over the counter supplement, works well in the long run by bolstering your immune system. L-lysine is quite affordable and free of any side effects that I know of.

“The home remedies mentioned on the People’s Pharmacy website by contributors to the site, are good for treating the symptoms of herpes labialis, another name for cold sores.

“Whatever works for you I say!”

Other remedies for cold sores:

We have collected lots more home remedies for cold sores on our website. They include kiwi fruit, buttermilk and ice to name just a few. Here is a link. And if you like the idea of home remedies for a variety of common ailments, we encourage you to check out our book, The People’s Pharmacy Quick & Handy Home Remedies. There is a reason why readers have given this our highest rating, 4.9 stars out of a possible 5 stars.

Bettie in Wilkesboro, NC sums it up nicely:

“I love the book. I use the mustard for leg cramps often and it always works; also the cough (Vicks on the feet) which also works). I also tried the raisins before bedtime and only had to get up once [to pee]. Thank you so much.” 

Read other comments at this link.

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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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