A few weeks ago, I almost killed my wife with herbal tea. Well, she thinks I did and many others believe that what I gave her to drink may have damaged her liver. I've suffered headaches, not because of the tea but just defending myself and wrestling with a series of surprisingly complicated questions.
Should the sale of herbal teas be regulated? Banned altogether like those head shops we've been reading about? Would that drive them underground? And what's the difference between a herbal tea and a herbal remedy?
I bought the comfrey tea in a huge box at my local health-food shop. It would make a change, I thought idly, from the endless cups of peppermint and camomile we drink at night, when coffee isn't always a good idea. I laid hands on the box with excitement because, as a keen amateur food-grower, I know that comfrey is a wonder plant. Its deep roots accumulate minerals from the subsoil that can be harvested in the leaves and used to enrich your compost heap. I dimly remembered reading that it has curative properties for human beings, too.
Not that I actually bothered to look up any of that, mind you, when I got home. I just made pots of tea every so often and served them up. If I gave the matter any thought, it was only to grumble that this new comfrey tea, being loose-leaf, would need a strainer and I couldn't always remember where to find one.
Over the weeks that followed, Harriet often complained that she was feeling queasy. Then one evening when the teapot arrived she eyeballed it sternly, opened a laptop and started to look up comfrey online.
She quickly discovered that the Food and Drug Administration (FDA) in the US considers the use of comfrey in dietary supplements with "serious concern" because it contains pyrrolizidine alkaloids that are "firmly established to be hepatotoxins in animals". That is, they have been shown to poison animals' livers. Additionally, the FDA contends that pyrrolizidine alkaloids are carcinogenic.
My wife was furious. An outsider peering through our windows that evening would have seen her a) studiously not talking to me at all before b) giving me yet another wigging as she waved her teacup and shouted "poison".
Obviously, I felt awful -- guilty, that is, though not queasy, despite having drunk just as much tea as Harriet. But I had not set out to kill her.
Now I went online. I was dismayed to find the single word "poisonous" beside comfrey on the Royal Horticultural Society website. Other sites said much the same, or worse. "If you have comfrey in your house," one self-appointed health blogger wrote, "dispose of it immediately. Take it to your pharmacy for proper and safe disposal".
I'm no herbalist, but as a gardener I knew enough to laugh at such hysterics. Comfrey is not radioactive and it's not a wild animal, liable to bite you. It has been used medicinally for centuries, to remedy indigestion, stomach and bowel problems, menstrual flow, hoarseness, periodontal diseases, bleeding gums, thyroid disorders, diarrhoea, gastrointestinal ulcers, hernia, glandular fever, coughs, haemorrhaging, cancer, catarrh, anaemia, sinusitis, lupus, high blood pressure, hiatus hernia, as a blood purifier, and to ease inflammation of the joints and mucus membranes.
I have no idea how successful those remedies were, but did they poison anybody? The FDA's concern appears to arise from studies in Japan and Australia, which found that forcing baby rats to ingest huge quantities of ground comfrey leaves and roots did them no good at all. Some developed tumours. But the average adult human would need to ingest 20,000 comfrey leaves to produce a comparative dose, and trials on long-term comfrey users have apparently found no harmful effects.
Toxicity in comfrey varies greatly, according to a US study. Roots contain higher levels of alkoloids than leaves, and some leaves contain virtually none. Additionally, it appears that the toxicity is reduced when leaves are dried. Phew!
The managing director of the company that distributes the tea I bought said that there can be high levels of toxicity in the root, but that Harriet would need to drink gallons of leaf tea every day for a long time before problems arose.
Harriet was unimpressed. "How do they know I won't drink gallons of comfrey tea every day? There's no warning on the box."
She had a point. But there are no warnings on regular tea either and she doesn't drink that by the gallon. "That's different," she says. "And anyway, this should not have been sold as a tea, with pretty flowers on the box. It should have been packaged as a medicine."
I wasn't sure. But as the suspected poisoner in my marriage, I felt unable to push the point.
Should comfrey tea be banned? I don't think so. Banning something only drives it undergound, which makes it harder to regulate. Most herbalists, represented by organisations such as the European Herbal and Traditional Medicine Practitioners' Association, want to be regulated, in accordance with a tough EU directive that comes into force next year; then, they say, we can buy teas with confidence.
But the pharmaceutical lobby has delayed regulation of herbalists for a decade, arguing that this would confer unmerited respectability. What those lobbyists don't shout so loudly is that, without regulation, Big Pharma will from next year enjoy sole control of remedies that historically have been freely available.
Of course, they remain freely available if you grow your own. I want to believe in comfrey's merits, as listed by ancient herbalists, and I'm tempted to wander into my garden and munch leaves from my own comfrey plants just to say boo to the bloggers who write such extravagant nonsense about it.
But I can't deny that I've been rattled, and won't be serving comfrey to anybody else. It is possible that Harriet reacted badly to the tea. We'll never know. But she looks a lot happier now that I've disposed of the remaining contents of that packet in a place where they will certainly produce great benefits -- on my compost heap.