Artemisia in the Gerson Therapy: Tarragon, Wormwood and Cancer-Causing Parasites

Table of Contents

1. At a Glance
2. The Artemisia Family: Tarragon, Wormwood and Sweet Wormwood
3. Where Artemisia Appears in the Gerson Therapy
4. How the Gerson Books Treat Parasites
5. Which Parasites Cause Cancer
6. Artemisinin Drugs Against Cancer-Causing Parasites
7. Wormwood Itself Against Parasites
8. Tarragon's Own Research
9. Artemisinin and Cancer Itself
10. What the Evidence Shows Overall
11. Key Research Papers
12. Connections
13. Featured Videos

At a Glance

• The only Artemisia in the Gerson Therapy is tarragon (Artemisia dracunculus), listed among the mild herbs allowed in small quantities for flavoring. Wormwood (Artemisia absinthium) and sweet wormwood (Artemisia annua) do not appear on the Gerson food lists or the Gerson Institute's shopping list.
• The Gerson books do not use any Artemisia to kill parasites. They list parasites among the infections they say contribute to illness, and intestinal parasites among the illnesses they say the diet treats, but the approach described is the whole program — diet, juices and enemas — not an antiparasitic herb.
• Three parasites are classified as definite causes of cancer by the World Health Organization's International Agency for Research on Cancer (IARC): two liver flukes linked to bile-duct cancer and one blood fluke linked to bladder cancer.
• Artemisinin drugs from sweet wormwood have real human evidence against one of them: given repeatedly, they cut the rate of schistosome (blood-fluke) infection compared with placebo, and added to the standard drug praziquantel they raised cure rates. On their own they cured fewer people than praziquantel, and in a trial against the cancer-causing liver fluke, artesunate cured 1 of 24 children.
• Tarragon's antiparasitic research is limited to two laboratory-dish studies against Leishmania, a parasite not linked to cancer. There are no human studies of tarragon against any parasite or cancer.

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The Artemisia Family: Tarragon, Wormwood and Sweet Wormwood

The three plants share a genus name but are used very differently:

• Tarragon (Artemisia dracunculus) is a culinary herb. A 2011 critical review (Obolskiy and colleagues, Journal of Agricultural and Food Chemistry) describes Russian and French types with different chemistry; its essential oil can contain up to 82% estragole and up to 39% methyleugenol.
• Wormwood (Artemisia absinthium) is one of the bitterest herbs, used in traditional medicine for digestion and appetite, and in absinthe. It is covered on the wormwood pages.
• Sweet wormwood (Artemisia annua) is the source of artemisinin, whose drug forms, such as artesunate and artemether, have been widely used to treat malaria (Lam and colleagues, 2018). It is covered on the Artemisia annua pages.

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Where Artemisia Appears in the Gerson Therapy

In the Gerson book. The Gerson Therapy by Gerson and Walker, following Dr. Gerson's 1958 instructions, says that the aromatics in herbs and spices interfere with the healing response, so herbs are limited to small quantities of relatively mild ones. Tarragon is on that list, together with allspice, anise, bay leaf, coriander, dill, fennel, mace, marjoram, rosemary, sage, saffron, thyme, sorrel and summer savory; basil and oregano are avoided for their high aromatic-acid content. The full lists are on the Foods Allowed and Forbidden page.

In the Gerson Institute's cookbook. The shopping list in the appendix of the Gerson Therapy Cookbook, posted by the Gerson Institute, includes tarragon among its herbs and spices, and its herb and spice pairing chart suggests tarragon with asparagus (with dill), beets (with horseradish, allspice, coriander and fennel) and kale (with dill, marjoram, thyme, allspice and coriander).

What is not there. Neither wormwood nor sweet wormwood appears in these lists. In the Gerson Therapy, Artemisia is present only as tarragon, in small amounts, as a flavoring.

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How the Gerson Books Treat Parasites

Parasites do appear in the Gerson literature, but not as a target for herbs:

• As a cause of illness: in its list of forty-nine everyday factors said to undermine health, the book includes "infections — parasites, viruses, bacterial infections, fungal infections" (see How Nutrition Heals).
• As an illness treated: the same book lists intestinal parasites among fifty-two illnesses against which the authors report the therapy has been effective.
• In a patient story: a patient described in the book reported seeing large numbers of parasites in his stools while taking frequent coffee enemas (see Therapy for Weakened Patients).

In each case the approach described is the Gerson program as a whole. No Artemisia preparation, and no other antiparasitic herb, is part of the protocol described in these books.

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Which Parasites Cause Cancer

The link between some parasites and cancer is firmly established. The World Health Organization's International Agency for Research on Cancer reviewed biological agents in 2009 (summarised by Bouvard and colleagues in The Lancet Oncology), and three parasitic worms are classified in its Group 1 — "carcinogenic to humans" (as summarised by Feng and Cheng, 2017):

• Opisthorchis viverrini and Clonorchis sinensis — liver flukes, linked to cancer of the bile ducts (cholangiocarcinoma). See Liver Flukes and Bile-Duct Cancer.
• Schistosoma haematobium — a blood fluke, linked to bladder cancer. See Schistosoma and Bladder Cancer.

The full list and the evidence behind it are on Parasites Classified as Carcinogens, and other proposed links are on Other Suspected Parasite–Cancer Links.

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Artemisinin Drugs Against Cancer-Causing Parasites

The Artemisia compounds with human evidence against these parasites are the artemisinin drugs made from sweet wormwood — prescription medicines, not the herb as a food or tea.

Schistosomes (blood flukes)

• Prevention: a 2012 meta-analysis (Pérez del Villar and colleagues, PLoS One) found that repeated doses of artesunate (relative risk 0.11) or artemether (relative risk 0.25) sharply reduced infection compared with placebo, mainly with Schistosoma japonicum. A 2011 meta-analysis (Liu and colleagues, Parasites & Vectors) reported protection rates of 65% to 97% with multiple doses at 1- or 2-week intervals.
• Treatment: the same 2012 meta-analysis found that artesunate alone cured significantly fewer people than praziquantel (odds ratio 0.27), while an artemisinin drug combined with praziquantel cured more people than praziquantel alone (odds ratio 2.07).

Liver flukes

• In a 2011 randomized trial in 125 schoolchildren in Laos infected with Opisthorchis viverrini (Soukhathammavong and colleagues, The Lancet Infectious Diseases), praziquantel cured 14 of 25 children and reduced egg counts by 98.4%. Artesunate cured 1 of 24 and reduced egg counts by 31.5%. The authors concluded that artesunate "did not show an effect".
• A 2018 review (Lam and colleagues, Pharmacological Research) summarises studies of artemisinin drugs against many other worms, including liver flukes, mostly in animals, and describes them as potentially useful drugs that still need study.

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Wormwood Itself Against Parasites

• Dwarf tapeworm in mice: a 2018 study (Beshay, Journal of Helminthology) found that a water extract of wormwood paralysed and killed Hymenolepis nana tapeworms in the laboratory and lowered egg counts and worm burden in infected mice, although the best results were obtained with praziquantel.
• Trypanosomes in the laboratory: a 2018 review (Naß and Efferth, Phytomedicine) lists wormwood among the Artemisia species whose extracts inhibited trypanosome parasites in laboratory tests, and calls the field "still in its infancy".
• No human trials of wormwood against parasites linked to cancer were found. The full picture is on Wormwood for Parasites: Evidence and Limits.

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Tarragon's Own Research

• Against parasites: two Iranian laboratory studies tested tarragon extracts on Leishmania major, the parasite of cutaneous leishmaniasis. In one (Rezaei and colleagues, 2017), an ethanol extract reduced the number of parasites by more than half after 72 hours at 10 to 25 micrograms per millilitre; in the other (Mirzaei and colleagues, 2016), the concentration needed to inhibit half the parasites after 72 hours was about 586 micrograms per millilitre. Both were done in laboratory dishes, and Leishmania is not one of the parasites linked to cancer.
• In people: no human study of tarragon against any parasite or cancer was found. The one randomized human trial found tested tarragon extract on blood sugar in people with impaired glucose tolerance (Méndez-Del Villar and colleagues, 2016), described on the wormwood and glucagon-like peptide-1 page.
• Safety at kitchen amounts: the 2011 critical review notes concerns about estragole and methyleugenol, two of tarragon's main constituents, but reports that no acute toxicity or mutagenic activity has been found at doses relevant to human consumption, and that water extracts contain very little of either compound.

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Artemisinin and Cancer Itself

Separately from parasites, artemisinin drugs have been studied as possible cancer treatments. The most-cited human study is a 2015 randomized, double-blind, placebo-controlled pilot trial in the United Kingdom (Krishna and colleagues, EBioMedicine): 23 people awaiting bowel-cancer surgery received 14 daily doses of oral artesunate (200 mg) or placebo, and 20 completed the trial. Signs of tumour-cell death above the trial's threshold were seen in 67% on artesunate and 55% on placebo; over a median of 42 months, the cancer returned in 1 patient on artesunate and 6 on placebo. It was a small pilot, and a larger trial has not reported results. The details are on Artemisinin and Artesunate in Cancer Research.

These are studies of a purified drug at medicinal doses. They say nothing about tarragon as a seasoning.

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What the Evidence Shows Overall

Taken together: the Gerson Therapy contains tarragon only as a mild seasoning, and no study shows that tarragon in food kills parasites or prevents cancer. The Artemisia compound with real human evidence against a cancer-causing parasite is artemisinin, a prescription drug made from a different plant, used against schistosomes — and it is not part of the Gerson protocol.

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Key Research Papers

1. Bouvard V, Baan R, Straif K, et al. (2009). A review of human carcinogens--Part B: biological agents. The Lancet. Oncology — PubMed PMID: 19350698
2. Feng M, Cheng X (2017). Parasite-Associated Cancers (Blood Flukes/Liver Flukes). Advances in Experimental Medicine and Biology — PubMed PMID: 29052139
3. Pérez del Villar L, Burguillo FJ, López-Abán J, et al. (2012). Systematic review and meta-analysis of artemisinin based therapies for the treatment and prevention of schistosomiasis. PloS One — PubMed PMID: 23029285
4. Liu R, Dong HF, Guo Y, et al. (2011). Efficacy of praziquantel and artemisinin derivatives for the treatment and prevention of human schistosomiasis: a systematic review and meta-analysis. Parasites & Vectors — PubMed PMID: 22004571
5. Soukhathammavong P, Odermatt P, Sayasone S, et al. (2011). Efficacy and safety of mefloquine, artesunate, mefloquine-artesunate, tribendimidine, and praziquantel in patients with Opisthorchis viverrini: a randomised, exploratory, open-label, phase 2 trial. The Lancet. Infectious Diseases — PubMed PMID: 21111681
6. Lam NS, Long X, Su XZ, et al. (2018). Artemisinin and its derivatives in treating helminthic infections beyond schistosomiasis. Pharmacological Research — PubMed PMID: 29727708
7. Beshay EVN (2018). Therapeutic efficacy of Artemisia absinthium against Hymenolepis nana: in vitro and in vivo studies in comparison with the anthelmintic praziquantel. Journal of Helminthology — PubMed PMID: 28606189
8. Naß J, Efferth T (2018). The activity of Artemisia spp. and their constituents against Trypanosomiasis. Phytomedicine — PubMed PMID: 30166103
9. Obolskiy D, Pischel I, Feistel B, et al. (2011). Artemisia dracunculus L. (tarragon): a critical review of its traditional use, chemical composition, pharmacology, and safety. Journal of Agricultural and Food Chemistry — PubMed PMID: 21942448
10. Rezaei R, Hazrati Tappeh K, Seyyedi S, et al. (2017). The Anti-leishmanial Efficacy of Artemisia dracunculus Ethanolic Extract in Vitro and Its Effects on IFN-γ and IL-4 Response. Iranian Journal of Parasitology — PubMed PMID: 28979350
11. Mirzaei F, Bafghi AF, Mohaghegh MA, et al. (2016). In vitro anti-leishmanial activity of Satureja hortensis and Artemisia dracunculus extracts on Leishmania major promastigotes. Journal of Parasitic Diseases — PubMed PMID: 27876985
12. Méndez-Del Villar M, Puebla-Pérez AM, Sánchez-Peña MJ, et al. (2016). Effect of Artemisia dracunculus Administration on Glycemic Control, Insulin Sensitivity, and Insulin Secretion in Patients with Impaired Glucose Tolerance. Journal of Medicinal Food — PubMed PMID: 27097076
13. Krishna S, Ganapathi S, Ster IC, et al. (2015). A Randomised, Double Blind, Placebo-Controlled Pilot Study of Oral Artesunate Therapy for Colorectal Cancer. EBioMedicine — PubMed PMID: 26137537

Books and Gerson Institute Documents

• Gerson C, Walker M. The Gerson Therapy. Chapter Eight, “Foods on the Gerson Diet Plan” — the herb and spice list (summarised on the Foods Allowed and Forbidden page).
• Gerson M (1958). A Cancer Therapy: Results of Fifty Cases. — the original dietary instructions.
• The Gerson Institute. Gerson Therapy Cookbook, appendix: shopping list, sample menu and herb and spice pairings, pp. 208–211 — Gerson Institute PDF

PubMed Topic Searches

• PubMed: artemisinin drugs and schistosomiasis
• PubMed: artesunate and the liver fluke Opisthorchis viverrini
• PubMed: tarragon (Artemisia dracunculus)

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Connections

• Gerson Therapy
• Foods Allowed and Forbidden
• Gerson Recipes
• How Nutrition Heals
• Gerson Cancer Treatment
• Cancer and Parasites
• Parasites Classified as Carcinogens
• Liver Flukes and Bile-Duct Cancer
• Schistosoma and Bladder Cancer
• Artemisinin and Artesunate in Cancer Research
• Artemisia annua (Sweet Wormwood)
• Wormwood
• Wormwood for Parasites

Educational information only, not medical advice. The Gerson Therapy is described here as its books and the Gerson Institute describe it. Artemisinin drugs are prescription medicines; parasitic infections and cancer are diagnosed and treated by clinicians.

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