What Is Ginseng - Panax? Benefits, Harms and Use in Cancer

What Is Ginseng?

Named after the Greek expression healing everything represented by Panacea, ginseng (Panax) has occupied an important place in Chinese Medicine for many years. As its name suggests, it is believed to be a miraculous plant effective against many health problems. It is claimed to have numerous properties, including calming, aphrodisiac, antidepressant, diuretic and immune system stimulating effects; it is claimed to be effective in treating health problems such as diabetes, Alzheimer's disease, erectile dysfunction (erection problems) and infections. In recent years, its purported effects in preventing and treating cancer and reducing cancer-related complaints have also been emphasized. However, studies do not confirm these effects. Although some studies of its effects on colds, diabetes, Alzheimer's disease and erectile dysfunction have produced positive results, it is too early to say anything definitive. In cancer patients, it has only been shown to be effective in reducing fatigue associated with cancer and cancer treatment. Although ginseng is considered a relatively safe product, it can cause significant drug interactions. At present, it therefore seems reasonable to use ginseng in cancer patients only for cancer-related fatigue. However, this must always be done with oncologists' knowledge and supervision.

What Are Its Characteristics?

The botanical name, Panax, comes from Panacea, meaning “healing everything” in Greek. The plant's English name, ginseng, originates from the Chinese word renshen. Because its forked roots resemble human legs, the Chinese words “ren,” meaning human, and “shen,” meaning plant root, were used. Although seven ginseng species are distributed across Asia and North America, there are primarily two main types with medicinal properties that have been studied: the Latin name panax ginseng refers to Asian (Chinese or Korean) ginseng and Panax quinquefolius, American ginseng. Asian is also called red ginseng. Both contain ginsenosides, but differing contents lead traditional Chinese medicine to call Asian ginseng warming (yang) and American cooling (yin).

American and Asian ginseng, claimed to be effective for many health problems, have become particularly popular in recent years. Ginseng products, whose consumption is increasingly widespread, are manufactured and marketed in many forms. Products are available as powders, capsules, tablets, soft gels, liquid extracts, tea and coffee. Some energy drinks even include ginseng.

For many years, American and Asian ginseng have been tested in numerous studies for many health problems. The literature contains many studies of effects such as calming, aphrodisiac, nervous-system stimulating, antidepressant and diuretic activity. Effects on physical performance, psychomotor performance and HSV-2 infection have also been investigated. Ultimately, however, its effectiveness in any of these conditions has not progressed beyond reasonable doubt. A few studies also report effectiveness in treating erectile dysfunction, but they are insufficient to draw conclusions. Evidence relating to the immune system, cognitive performance and blood sugar control is relatively stronger but remains unconfirmed. A small study involving 19 people suggested that American ginseng might help prevent low blood sugar after meals. A study assessing long-term safety as an adjunct to standard treatment in diabetic patients found no significant difference in side effects. A study of American ginseng's immune-supporting properties involving 279 people found fewer colds among those taking it for 4 months at 2 capsules a day compared with those not taking it. A preliminary study involving few patients also found that American ginseng improved memory performance. Another study observed improved cognitive performance in Alzheimer's patients with Asian ginseng.

Cancer claims have attracted attention, but strong evidence for prevention or treatment is absent. Benefits have been demonstrated for fatigue from cancer and treatment.

Does It Prevent or Treat Cancer?

Claims about ginseng's effects in cancer prevention and treatment are based primarily on laboratory studies. The few clinical studies performed have not produced strong evidence for these effects. The American health institute also states that there is insufficient evidence that ginseng is effective in preventing and treating cancer.

In a laboratory study, American ginseng extract inhibited cell growth in colorectal cancer cell lines; this effect was greater when combined with the chemotherapy drug 5-fluorouracil (5-FU). It was therefore suggested that American ginseng might reduce the required 5-FU dose in the future. Another laboratory study found that American ginseng extract inhibited cell proliferation in breast cancer cell lines. In another study of breast cancer cell cultures, American ginseng inhibited cell growth alongside the chemotherapy drugs methotrexate, cyclophosphamide, doxorubicin and 5-fluorouracil. Yet another study found that American ginseng extract triggered cell death in colorectal cancer cell lines. A study of Asian ginseng in mice observed that it prevented tumor spread to the lungs and the formation of new blood vessels (angiogenesis).

A 2006 observational study found better quality of life and somewhat longer survival in breast cancer patients using ginseng, but ignored type and dose. A clinical study of 40 healthy participants suggested protection of lymph cells against radiation.

Does It Help Cancer-Related Fatigue?

Fatigue is among the most common, most distressing and most physically limiting complaints in cancer patients. Statistics show fatigue in %59 to %96 of patients receiving chemotherapy and %65 to %100 of those receiving radiotherapy, with complaints continuing for an average of 5-10 years after diagnosis. Certain inflammatory processes and inadequate control of blood cortisol are held responsible for fatigue in cancer patients. Laboratory studies have shown anti-inflammatory and cortisol-regulating effects of ginseng, suggesting it could help cancer-related fatigue. A comprehensive study conducted by Mayo Clinic Cancer Center, a leading oncology organization, presented at the 2012 ASCO (American Society of Clinical Oncology) meeting, showed that high-dose (2000 mg/gün) American ginseng benefited cancer-related fatigue. From 40 separate institutions, 364 cancer patients participated in the study testing capsules obtained from pure American ginseng roots. After 8 weeks, cancer-related fatigue improved on the standard fatigue scale of 100 points by 20 points. Those actively receiving cancer treatment benefited more than those who had completed treatment. No significant difference in side effects was observed. The study specifically used pure ginseng; it noted that commercially sold products acquire estrogen-like properties during processing with alcohol and may harm breast cancer patients. Given the limited effective treatments available for cancer-related fatigue, the study concluded that American ginseng could be tried. In a study testing Asian ginseng for cancer-related fatigue, 30 patients received high-dose Asian ginseng for 29 days (800 mg/gün), resulting in a marked reduction in fatigue without a difference in side effects. Given Asian ginseng's similarity to American ginseng, it is likely to be effective in this regard. However, this was a preliminary report and needs support from further studies.

What Are the Possible Side Effects and Risks?

American ginseng is in category 1 of the American Herbal Products Association's safety rating, meaning it is generally considered safe when used appropriately. A study assessing dose-related side effects divided 290 people into groups taking daily doses of 750 mg, 1000 mg, 2000 mg or no ginseng. No significant difference in side effects between groups was observed during follow-up. Nevertheless, many adverse effects, particularly drug interactions, have been reported in the literature. Reported effects include nausea, diarrhea, headache, nosebleeds, high blood pressure, low blood pressure and breast pain.

Studies have established that ginseng products processed with alcohol can have estrogen-like effects. It has therefore been emphasized that people who need to avoid estrogen should not use ginseng (36, 37, 38). A laboratory study also found that ginseng stimulated cell growth in breast cancer cell lines.

Drug interactions are the most important concern about ginseng use. Ginsenosides, ginseng's active components, are held responsible. Studies have shown that ginsenosides interact with the drug group called monoamine oxidase inhibitors. There is also a study of interaction with nifedipine. It can interact with warfarin (Coumadin), causing bleeding disorders; with imatinib, causing liver damage; and with antidepressants, causing the onset of mania. A clinical study in 20 healthy people also showed that American ginseng reduced warfarin's anticoagulant effect, emphasizing that physicians should ask patients about ginseng use when prescribing warfarin.

What Should Be Done?

In conclusion, ginseng is an herbal product claimed to be effective in preventing and treating many health problems. However, studies have not demonstrated many of these effects. Research on colds, diabetes, Alzheimer's disease and erectile dysfunction is promising but remains insufficient for clinical application. Studies of cancer prevention and treatment are primarily laboratory experiments and are extremely limited. More research is needed to clarify ginseng's role in cancer, appropriate dose, side effects and drug interactions. The only clear benefit demonstrated in cancer patients to date is reduced cancer-related fatigue. Given the limited treatment options, considering ginseng for this purpose may be reasonable. However, great caution is needed regarding drug interactions. Certain commercial forms have been reported to cause harm in breast cancer patients through estrogen-like effects. It is therefore extremely important that physicians understand these interactions and monitor patients closely, and that patients consume no health-related products without their physicians' knowledge and supervision.

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