Ginseng for cancer fatigue? The jury’s still out

Ginseng has been tested to see if it can help reduce cancer-related fatigue

As well as some of the exciting developments from this years’ ASCO cancer conference, we also spotted trial results, presented at the conference, which suggested that the herbal supplement ginseng could reduce cancer-related fatigue. This got a fair amount of media coverage.

As the researchers state in their abstract, the study enrolled around 360 cancer patients who were either having or had recently finished curative cancer treatment.  For 8 weeks, half of them took 2000mg of American ginseng (Panax quinquefolius) per day, and the other half took a placebo.

At the end of the study, those taking the ginseng had significantly lower fatigue scores for both ‘general’ and ‘physical’ fatigue. But there was no difference in ‘mental or emotional’ fatigue, and those taking ginseng didn’t rate themselves as having more energy (‘vigor’).

Overall, this is an encouraging and interesting study – anything that can help with the devastating fatigue some people feel after a course of cancer treatment is very welcome.  But, as is so often the case, there are caveats.

Firstly, people with other cancer symptoms, such as pain, were excluded; and those taking part presumably didn’t have advanced cancers as they were having curative treatment. So unfortunately these findings can’t be generalised to everyone with cancer fatigue.

Also, we don’t know what it is in the ginseng that might have helped to lower people’s fatigue scores.  The constituent chemicals of plants vary with type as well as growing conditions, and there are several different types of ginseng.  Types on sale in the UK mostly seem to be Asian or Korean ginseng (and in fact, American ginseng – as used in this study – is now an endangered species and exports are banned).

But most importantly for those taking other medicines, there’s evidence that ginseng is one of the plants that can affect the metabolism of other drugs, by affecting enzymes involved in drug absorption (particularly an enzyme called CYP3A4).

This means that taking ginseng could cause higher or lower levels than intended of other drugs that your doctor has prescribed for you. There is information about why you should tell your doctor about herbal remedies you are taking on our patient information website.

Furthermore, the Medicines and Health Regulatory Authority (MHRA) advise against taking ginseng if you are on warfarin, as there is some preliminary research evidence that it could affect blood clotting.

Liz

Liz Woolf manages Cancer Research UK’s patient information website, CancerHelp UK