An Herbal Cure for Peanut Allergy?

Peanut allergy is uncommon but devastating. Even a tiny trace of peanut can cause an anaphylactic reaction and death. That’s why labels specify “produced on shared equipment with nuts or peanuts” or “produced in a facility that also processes nuts.” There is no effective treatment: patients have to rely on avoiding peanuts and carrying emergency epinephrine injectors. Parents of peanut-allergic children live in fear that their child will be inadvertently exposed at school or at a friend’s house. Wouldn’t it be great if we could fix it so they could eat peanuts with impunity?

There is a ray of hope. Studies are underway on a Chinese herbal medicine (FAHF-2) that shows promise. I generally shy away from Chinese herbal remedies, because they are marketed without adequate testing and the products are not quality controlled. The typical course of events is (1) a preliminary study or a history of use in China, (2) marketing in the U.S. with overblown claims.

This is different.

FAHF-2 has been tested in a mouse model in well-designed studies at reputable U.S. institutions (Mount Sinai and Johns Hopkins). Research was funded by private foundations and government grants (not by manufacturers or business interests) and published in a reputable peer-reviewed journal, The Journal of Allergy and Clinical Immunology. As far as I can find, it’s not being marketed in the U.S. No claims are being made for it. It hasn’t been tested in humans. The NCCAM has funded the first clinical trial with an estimated completion date of December 2009.

The researchers had been studying a mouse model of allergic asthma and had had some success with another herbal formula. This prompted them to look into peanut allergy. Food allergy is not described in the traditional Chinese medicine (TCM) literature, but there was an herbal formula called Food Allergy Herbal Formula -1 (FAHF-1) that had been used in Asia for prevention of allergies and asthma. It contained ling zhi, an herb that had anti-inflammatory and anti-allergy properties, and wu mei wan, which had been used to treat gastrointestinal symptoms. It also contained 9 other herbs.

They tested FAHF-1 on a mouse model of peanut allergy. They found that it completely blocked the anaphylactic reaction when the allergic mice were challenged with peanuts. It not only blocked clinical symptoms, but it reduced mast cell degranulation, histamine release, peanut-specific serum IgE levels, and Th2 cytokine secretion. They checked the mice for possible toxic effects on liver and kidney and for possible immune suppression, and found no abnormalities.

Two of the ingredients were worrisome. Xi xin is wild ginger, which can contain aristolochic acid. Fu zi contains aconite. Both are toxic to humans. Aristolochic acid was implicated in an epidemic of kidney damage in Belgium from a contaminated herbal weight loss product. They simplified the mixture by removing these two ingredients, and called the new formula FAHF-2. They tested this new formula and found it worked just as well. The effects persisted for several weeks after treatment was discontinued.

They wondered if using just wu mei or ling zhi alone would work. In preliminary studies it appeared that neither was as effective as the whole formula. They postulated that some kind of synergism was at work. I wondered why they didn’t try eliminating herbs one by one, starting with the ones they thought were least likely to contribute. I find it difficult to imagine that all 9 herbs are necessary for the synergism, especially since they already removed 2 herbs without making any difference. It’s always possible that one herb might be acting antagonistically and that removing it might improve the effect.

Lo and behold, in 2008 they did almost what I thought they should. They tested individual components and found only partial activity in them. They concluded that the whole shebang was the best thing to use in continued testing.

The formula they are now working with contains:

• ling zhi (ganoderma lucidum), 28.17%
• wu mei (fructus pruni mume), 28.17%
• huang lian (rhizoma coptidis), 8.46%
• ren shen (radix ginseng), 8.45%
• huang bai (cortex phellodendri), 5.63%
• gan jiang (rhizoma zingiberis officinalis), 8.45%
• dang gui (radix angelicae sinensis), 8.45%
• gui zhi (ramulus cinnamomi cassiae), 2.81%
• chuan jiao (pericarpium zanthoxyli bungeanum), 1.41%

They have experimented with different extraction methods and have tried to minimize the bitter taste.

A clinical trial was approved by the NCCAM and is in progress. It is only a small preliminary study with 18 subjects. If this trial is successful, they will go on to larger trials.

Most drugs that enter initial clinical testing never make it to market. I don’t have high hopes for this one. It may not have the same effect in humans. It may turn out to have harmful side effects. The mouse model may be flawed. One or more ingredients may be superfluous.

There doesn’t seem to be any rhyme or reason to the particular combination of nine ingredients. That doesn’t mean it can’t work, but it makes me wonder. How many evidence-based remedies can you think of that contain multiple herbal ingredients? I can’t think of any offhand. They thought for a while that PC-SPES was one. It was a mixture of 8 herbs that appeared to slow the progression of prostate cancer, but it turned out to be a real fiasco. Double-blind testing showed it was significantly better than placebo – but only because the manufacturer had been spiking the mixture with 3 pharmaceutical drugs! Independent lab analysis of early batches showed significant amounts of diethylstilbestrol (DES), which is a synthetic estrogen, and indomethacin, a potent anti-inflammatory drug. Later batches showed that warfarin, a powerful anticoagulant (blood thinner), had been added to counteract the tendency of DES to cause blood clots. The researchers were sincere, but their suppliers were engaged in deliberate and dangerous hanky-panky.

Whether FAHF-2 pans out or not, I have to applaud the researchers. They didn’t patent it as a diet supplement and try to sell it to the public. They are doing good science. This is the way all herbal medicine claims should be handled, with stepwise investigation including attempts to isolate effective components.

If it does turn out to work, they’ll have to come up with a snappier name.

Posted in: Herbs & Supplements

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