Archives for November, 2008

Olive Leaf

Olive Leaf

So many products on how to control shingles with natural treatments flood the market that it sometimes seems impossible to sort out which ones are good and which ones are not. What I do is visit product sites, take a look at their claims, then go to PubMed and my various herbal medicine manuals and see what I can find about the activity of the ingredients. One such “miracle” product that I evaluated recently is olive leaf extract.

Folk Medicine

Olive leaf is listed among folk medicines for use as an antihypertensive (i.e., for lowering blood pressure) and diuretic. Very little good research is available regarding these claims. Nevertheless, modern supplement manufacturers have made quite a big deal of this application. The only study that I could find in support of it (Life Sciences 55: 1965-1971, 1994) showed that the active ingredient, oleuropein, decreased blood pressure and dilated arteries surrounding the heart. It was an animal study whereby the treatment was administered by injection.

The most significant reference in my library that evaluates olive leaf is the German Commission E Monographs on herbal medicines. This commission concludes that the effectiveness of olive leaf for the above claimed uses is not sufficient to support the claims.

Antiviral Studies

Oleuropein was also the subject of an antiviral survey of several plant ingredients (Chem. Pharm. Bull. 49: 1471-1473, 2001). The results of this study showed that none of the active ingredients from several plant species, including oleuropein, had any significant activity against HSV-1 (herpes simplex type 1) or Flu-A (influenza type A). Oleuropein, however, showed significant antiviral activities against RSV (respiratory syncytial virus), and Para 3 (parainfluenza type 3), both of which cause infections of the lower respiratory tract.

Recommendation

The good news is that olive leaf and its main active ingredient do, indeed, have an antiviral activity that will benefit you during the flu season. The bad news is that it has no activity against the only herpes virus that has been examined so far. Since all members of the herpes family are so similar in their responses to antivirals, this does not bode well for the use of olive leaf against shingles.

Dr. D

Mainstream medicine generally offers vaccines to boost immunity to specific microbes, but only when such vaccines are available and approved for clinical use. In regard to viral vaccines, annual flu vaccination seems to be very popular, according to the flu season scares that appear in the media every year. Vaccines against polio and other viral diseases have also become important tools in the battle against certain diseases

At the moment, however, there are two vaccines that have been approved in the U.S. against Herpes zoster, the chickenpox and shingles virus. One is Varivax, a vaccine for chickenpox, and the other ix Zostavax, a vaccine for shingles. Zostavax was officially recommended in the U.S. for healthy adults aged 60 and over. This recommendation is based in part on a 2005 study of 38,000 adults over 60 years old, where the vaccine prevented half of the cases of shingles.

Who Can Benefit from Zostavax, the New Shingles Vaccine?

At this time, the vaccine is approved for use in people 60 and older who have had chickenpox. The Advisory Committee on Immunization Practices for the Centers for Disease Control and Prevention recommended that it be given to people who have had shingles. The manufacturer’s price for the vaccine is about $150. The patients’ cost in the United States is often $300.

The approval of Zostavax in the U.S. is limited to an older age group because experiments did not include younger people. Nobody knows how effective it might be for younger adults or what the long-term effects or side-effects might be in any age group. Indeed, because of so many unknowns, population-wide use of Zostavax is not practiced in the UK or other parts of Europe, even though it is licensed for use in the UK.

What About Long-Term Expectations

Dozens of research articles are published each year on the scientific search for additional vaccines against herpes viruses. At any one time several trials may be underway using cell cultures or laboratory animals, but very few ever reach the stage of clinical experimentation on humans. At the moment, the predictions for more herpes vaccines are optimistic, which is the nature of such predictions. (Does anyone remember the widely publicized prediction in 1985 by top government officials that we would have an AIDS vaccine in a few short years?) But very little is available right now, even on Zostavax, and predictions are hard to evaluate until we see more research progress.

In current practice, because people in their 50s account for one in every seven cases of shingles, some physicians administer the vaccine “off label” to those younger than 60, even though its safety and effectiveness in younger people are not known. Also unknown is whether the vaccine is safe to administer to people whose immune systems are already weakened.

More Unknowns of Zostavax

Follow-up studies are under way to determine how long the vaccine remains effective. If immunity wanes, a booster shot may be necessary. Until the unknowns are resolved, the vaccine is not recommended for those with immune systems weakened by disease or drug treatment, women who are pregnant or might be pregnant and people with active untreated tuberculosis. Nor should the vaccine be given to anyone who has had a life-threatening allergic reaction to gelatin or the antibiotic neomycin.

Dr. D