Today, St. Johns wort is one of the most popular feel-good herbal supplements. Millions take it as a natural way to fight depression, chase the blues, or lift themselves out of the dumps.
Food manufacturers, who know a good thing when they see it, have started adding small amounts to breakfast cereals, fruit drinks, canned soups, snack chips, and even chocolate bars.
Despite five years of scrutiny, however, the questions about St. Johns wort far outweigh the answers. Most of the news since our last look (Herbs for Nerves, October 1998) hasnt been encouraging.
Depression is a serious condition that should be treated by a qualified health professional.
In European studies, St Johns wort seemed to help about half the people with mild to moderate depression who took it for at least three to four weeks, but the first large-scale U.S. study showed no benefits.
St. Johns wort can make many prescription medications less effective, so make sure your physician and pharmacist know if youre taking the herb.
You dont have to know anything about how the body breaks down chemicals to understand that if youre taking a prescription drug, you don't want an herbal supplement to remove the drug from your blood before it's had it's chance to do its job.
But that's just what St. Johns wort appears to do with some of medicine's most powerful tools.
Let your physician know if you're using St. Johns wort and taking prescription drugs. Researchers have reported that the herb lowered blood levels of most of the drugs listed below. Other medications made the list because they're metabolized and removed from the body in the same way as drugs that are affected by St. Johns wort.
Types of Drugs
Antidepressant selective serotonin reuptake inhibitors like Paxil, Prozac and Zoloft.
Anti-epilepsy drugs like phenytoin (Dilantin), carbamazepine (Epitol, Tegretol), and phenobarbital.
HIV non-nucleoside reverse transcriptase inhibitors like delaviridine (Rescriptor) and nevirapine (Viramune).
HIV-I protease inhibitors like indinavir (Crixivan), ritonavir, (Norvir), and saquinavir (Invirase).
Cyclosporineused to keep the body from rejecting transplanted organs.
Digoxin (Lanoxin)used to treat heart disease.
Theophyllineused to treat asthma.
Warfarin (Coumadin)an anti-clotting drug used to prevent strokes and heart attacks.
Sources: Food and Drug Administration
St. Johns wort Links
| ||More than a dozen studies, all conducted in Europe, have found that St. Johns wort relieves some of the symptoms of mild to moderate depression in about half the people who take it for at least three or four weeks.1 Thats the same success rate as prescription anti-depressants like Prozac, Zoloft, Elavil, and Tofranil. Placebos, on the other hand, appear to help about a quarter of those with depression.|
What really sets St. Johns wort apart is that the side effects commonly experienced with prescription antidepressants, such as a dry mouth or diminished sex drive, are milder and less frequent with the herb.
After reviewing all the evidence, the American College of Physicians-American Society of Internal Medicine told its 115,000 members last May that St. Johns wort may be effective in treating mild depression in the short term. But that conclusion was reached before the first large U.S. study found that people taking St. Johns wort fared no better than those taking a placebo.
| || Top|
| || |
| ||The studies of St. Johns wort done in Europe, while impressive, left many questions unanswered, says Jacques Bradwejn, Chief of Psychiatry at the Royal Ottawa Hospital in Canada. Among them:|
Who benefits? St. Johns wort has been studied almost entirely in people with mild to moderate depression. Thats a persistent state of sadness, decreased energy, irritability, or other symptoms that interfere with work, sleep, eating, and activities that were once considered pleasurable. (Since depression can lead to suicide, it should be treated by a qualified health professional and not left to self-medication.)
Still unsettled is St. Johns worts effect on moderate to severe depression or on anxiety symptoms. Whats more, there is no evidence that it can elevate mood in people who are not depressed, says psychiatrist Richard Shelton of Vanderbilt University, who conducted the latest U.S. study.
For how long does it work? The European studies lasted an average of only about 5 ½ weeks. Just one exceeded two months. No one knows how long the benefits of St. Johns wort last.
How much of which extracts work? The European studies used 300 to 1,800 mg a day of any of 11 different formulations prepared from the St. Johns wort flower, so theres no way to tell which brands work consistently in which amounts.
How does it compare with prescription antidepressants? St. Johns wort has only been tested against low doses of the older tricyclic antidepressants like Elavil and Tofranil. Researchers dont know how well St. Johns wort would do in a head-to-head competition with higher doses or with the newer generation of antidepressants like Prozac or Zoloft.
Given the promising results from the European research, the National Institutes of Health (NIH) has made St. Johns wort the subject of the first federally funded, large-scale trial of an herbal supplement in the U.S.
At 12 medical centers across the country, researchers are giving 336 patients with at least moderate depression one of three identical-looking preparations: 900 mg a day of the LI-160 extract of St. Johns wort (available as the Kira brand), the prescription antidepressant Zoloft, or a placebo (sugar pill). Those who respond to St. Johns wort during the two-month trial will take it for four more months. Results are not expected until next year.
Meanwhile, the first large-scale study of St. Johns wort in the U.S. has turned up disappointing results. At Vanderbilt University and ten other medical centers, Richard Shelton and his colleagues gave 200 patients with moderate depression either 900 mg of the LI-160 extract of St. Johns wort or a placebo every day for eight weeks. Those who didnt respond to the herb after four weeks were given up to 1,200 mg a day.
After eight weeks, St. Johns wort was no better than a sugar pill. Our data suggest that St. Johns wort is no more effective than a placebo in patients with at least moderate depression, says Shelton. The study, funded by Pfizer (which makes Zoloft), has not been published yet.
Why might the U.S. trial have contradicted the European research?
Some of the earlier studies in Europe were conducted in primary-care practice settings with physicians who may not have had any experience with research in depression, says Shelton. We selected highly respected researchers here in the U.S. who were more experienced with doing a study on depression.
| || Top|
| || |
| ||Part of St. Johns worts appeal is that it causes milder and less frequent side effects than prescription antidepressants. But that doesnt mean its harmless. Alarming new reports suggest that the herb can interfere with prescription drugs.|
St. Johns wort seems to stimulate enzymes in the liver that inactivate and help remove drugs from the body. In other words, St.-Johns-wort-users eliminate some drugs from their systems faster than they otherwise would. That can decrease drug levels in the blood to the point where they are too low to fight disease.
In one report earlier this year, eight healthy men and women who were taking a protease inhibitor called indinavir (Crixivan), which combats the HIV virus, began taking St. Johns wort. The results were dramatic, says NIHs Stephen Piscitelli.
They all showed a marked drop in blood levels of indinavir ranging from 49 to 99 percent. That would render the drug virtually useless.2
In another report, when two men whose heart transplants had worked smoothly for a year began taking St. Johns wort, their bodies quickly started rejecting their new hearts.3 Apparently, the herb speeded up their bodies normal removal of cyclosporine, the immunosuppressant drug they were taking to prevent rejection.
Other prescription drugs that may be weakened by St. Johns wort include oral contraceptives and medications used to treat heart disease, depression, seizures, and certain cancers (see Worts the Matter?).
Interactions between St. Johns wort and these drugs can be dangerous, warns Piscitelli, so its important for patients to keep their physicians and pharmacists informed about the use of any herbal products.
| || Top|
| || |
Supplement manufacturers continue to have problems producing high quality St. Johns wort products. At least four organizations two newspapers, a magazine, and a Web site have analyzed dozens of brands of St. Johns wort during the past two years. All four found serious deficiencies in many of the products.
In January of 2000, for example, the Boston Globe sent seven brands of St. Johns wort to two labs for two different kinds of tests. Only one brand, Natures Resource, was at least 0.3 percent hypericin, the standard amount of what may be one of the active ingredients in St. Johns wort. The brands that had less: CVS, Herbalife, Natrol, NatureMade, Quanterra, and YourLife.
And only two of the brands Quanterra and NatureMade passed a test of the supplements capacity to block the uptake of the chemical serotonin by animal brain cells in test tubes. (St. Johns wort may work by interfering with serotonin uptake, which leaves more relaxation-inducing serotonin in the brain.)
Earlier this year, www.vitacost.com, a Web site that analyzes and sells supplements, sent eight brands of St. Johns wort to an independent lab for testing. Only two, Natures Way Standardized Extract and Natrol Mood Support, were at least 0.3 percent hypericin and 3.0 percent hyperforin (another compound that may be an active ingredient in St. Johns wort). Lower levels may be ineffective. Brands that contained less hypericin or hyperforin: Natures Answer, Natures Herbs, Natures Way Mood Aid with St. Johns Wort, Natures Way St. Johns Wort Herbal Single, Thompson, and Twinlab Maxilife St. Johns Wort and Kava.
| || Top|
| || |
| ||The Food and Drug Administration (FDA) has never approved St. Johns wort as a food additive. Nor has the FDA or any manufacturer declared it to be Generally Recognized As Safe (GRAS). But that hasnt stopped companies like Fresh Samantha from putting St. Johns wort into its Oh, Happy Day fruit beverage, or South Beach Beverage from lacing its SoBe Wisdom drink with the herb.
Earlier this year, the FDA finally started notifying manufacturers that without approval as a food additive or GRAS affirmation, St. Johns wort cannot legally be added to food. So far, the companies havent responded.
If you see a food or drink whose label or ad suggests that it can elevate your mood with St. Johns wort, save your money. Most companies dont divulge how much of the herb they put in their products. Chances are, what they add is just an excuse to jack up their prices too little to do you any good (or harm).
For more information and links to the studies mentioned in this article, click here.
| || Top|
1: Ann. Intern. Med. 132: 743, 2000.
2: Lancet 355: 547, 2000.
3: Lancet 355: 548, 2000.