A Sydney television news program recently reported that Asian ginseng might cause breast cancer, and during the program an endocrinologist said women should not take this herb. In traditional Chinese medicine, Asian ginseng (Panax) has been used for around 4000 years. It is prescribed according to a specific diagnosis, commonly for men and often as part of a formula. As there are more than 3000 published scientific papers on this herb, plus a wealth of practical information contributed by herbal practitioners throughout the world over many centuries, my assessment is there is enough evidence to prescribe it within a Western framework.
American ginseng (Panax quinquefolius) is not as well researched but is becoming increasingly popular. These two species of ginseng contain some of the same categories of therapeutic constituents, such as ginsenosides. Other types of ginseng, such as Siberian ginseng, are quite different. There is no evidence that medicinal doses of this plant trigger or cause cancer in humans.
Perhaps some medical researchers report ginseng is harmful and/or ineffective for preventing or treating anything whatsoever because they have not had time to read all the evidence, much of which is published in Korean, Japanese, Chinese and Russian scientific journals and not commonly read in Western countries.
Ginseng and breast cancer
It\’s true that a study published in the journal Menopause (2000, 9: 145-50) concluded that American ginseng “significantly induced the growth of a human breast cancer cell line (MCF-7)”. This study was done on isolated cells, in a laboratory. The same researchers also tested ginseng in rats and found no oestrogenic activity. The rats were given the ginseng for four days. When I prescribe ginseng for menopausal women it is for stress rather than oestrogenicity and the minimum duration is one month.
You may be aware that laboratory studies are academically interesting but do not relate to how substances work within the body. For example, any number of naturally occurring substances in fruits and vegetables can be shown, experimentally, to cause cancer, but scientists don\’t send out press releases warning people not to eat fruits and vegetables. Experimentally, even presumed healthy plant components such as chlorophyll and vitamin C can be shown to be mutagenic (disrupt cells). If these studies were pertinent, no plant food would be safe to eat.
Now, let\’s look at a few examples of the published scientific evidence indicating that ginseng or its constituents may actually prevent breast cancer:
- In a series of experiments, American ginseng was shown to be oestrogenic in breast tissue but, paradoxically, it did not increase cell growth. When ginseng was added to breast cancer medical chemotherapy, this resulted in further decreases of cell growth, suggesting ginseng does not interfere with these cancer drugs but may make them more effective. (Journal of Surgical Oncology, 1999; 72: 230-9). This study also used MCF-7 cells!
- Laboratory study indicating that ginsenoside has “anti-cancer proliferation, differentiation and chemopreventive effects in certain breast cancer cell lines”. (International Journal of Oncology, 14; 869-75: 1999).
- Bioginseng, panaxel and panexel-5 inhibited the development of mammary tumours in mice. (Journal of Korean Medical Science, 16; S42-53: 2001).
- Panaxytriol in Asian ginseng inhibits tumour cell growth in cells and in mice. (Cancer Chemotherapy and Pharmacology, 35; 291-6: 1995).
- Bioginseng decreased the incidence and multiplicity of mammary gland tumours in rats. (Biull Eksp Biol Med; 115; 59-61: 1993).
- Researchers concluded that Asian ginseng has breast cancer antitumour activity in experimental cell studies and in animals. (Adverse Drug React Toxicol Rev, 19; 223-40: 2000).
- In Korea, where medical studies have been conducted on humans, Asian ginseng users generally had a 50 per cent lower risk of cancer compared to non-users. In respect of breast cancer, there was no association (positive or negative) with ginseng intake.
Animal and human evidence is more relevant than a study on cells in a laboratory and, considering all the evidence, I prescribe Asian ginseng for women because:
- There is no evidence that medicinal doses cause or trigger breast or other cancers in humans or animals. Studies using oestrogen binding tests are contradictory or inconclusive. However, a few isolated case reports indicate that ginseng may have some type of oestrogenic effect, so to be on the safe side I do not prescribe it to women with breast problems.
- Ginseng is an effective antistress herb; I have observed over 20 years that menstrual and menopausal symptoms are frequently linked to stress.
- Ginseng is an effective tonic and fatigue is a common affliction. Tonics such as ginseng are not taken for more than two or three months.
- I have prescribed Asian and Siberian ginseng in my clinic for over 20 years and can\’t recall any male or female patient reporting adverse effects. I have only recently started using American ginseng, especially for glucose metabolism and concentration problems, and to date the results have been pleasing with no reported adverse reactions.
Other cancers
A search of one database (Medline) reveals that 126 scientific and medical papers have been published on the relationship between ginseng and cancer, the majority of studies being on Asian ginseng. My assessment from reading the abstracts is that approximately two per cent of these indicate that ginseng may cause or trigger cancer while 98 per cent indicate that ginseng is likely to be preventive or even helpful as a treatment.
There is insufficient evidence to recommend ginseng as a treatment for cancer and this is likely to be the case indefinitely because there are no funds or incentives for large-scale human trials on herbs. However, there is also insufficient evidence to say this herb is linked to breast or other cancers and the overwhelming evidence is that medicinal doses appear to be cancer-preventive. If you wish to take ginseng, be aware that there are different qualities of products available and I recommend you follow the label or practitioner dosage and take it as a periodic tonic for no more than two to three months without a break. Always take ginseng in the mornings, otherwise it may cause insomnia.
