Are herbal remedies medicines?

Depressing stuff - St John's wortIf herbal medicines are truly physiologically active, regardless of whether multiple ingredients are deemed necessary for efficacy, they should be assessed as medical products. The producers of such products should be able to offer evidence to prove this is the case and to offer safety advice regarding possible side-effects or contra-indications just as pharmaceutical manufacturers must do. The interactions and risks of countless unregulated supplements and herbal products are not known, there are usually no warnings for children, the elderly, pregnant women or those with chronic health problems turning to herbal remedies. Labelling, or rather the lack thereof, for herbal remedies is highlighted in my current editorial on Chemistry Views.

I asked industry expert Sheryl Torr-Brown for her opinion on the state of herbal medicine much of which is incorporated in the Chemistry Views article, but she had more to say than space would permit me to include, so here’s the spillover:

“Herbal medicine companies cannot have their cake and eat it,” Torr-Brown told me. “All chemicals, natural or otherwise are toxic. It is the method of limiting our exposure to such chemicals, whether it be hemlock pulled from the woods, or a paracetamol from the shelf, that determines whether they provide benefit or harm. Because of regulations and standards in the food and drug agencies around the world, we can be nourished and medicated with reasonable benefit and manageable risk. However, even in the best of circumstances, unexpected side effects can occur, sometimes serious enough to cause a drug or a food stuff to be withdrawn from public access.”

She adds that, “Herbal remedies often contain high concentrations of chemicals we usually see only in limited quantities in the foods we eat. The average consumer does not always appreciate it is possible to get too much of a good thing or that even small amounts of some chemicals can be dangerous to those taking certain medications. Even with limited quantities, the perfectly natural and unadulterated grapefruit juice can cause serious problems in patients taking certain blood pressure drugs.” The state of play regarding regulation of herbal medicine is, she adds, “A clear example of commercial interests outbalancing common sense and regard for consumer safety.”

Research Blogging IconRaynor, D., Dickinson, R., Knapp, P., Long, A., & Nicolson, D. (2011). Buyer beware? Does the information provided with herbal products available over the counter enable safe use? BMC Medicine, 9 (1) DOI: 10.1186/1741-7015-9-94

5 thoughts on “Are herbal remedies medicines?”

  1. The interaction between common aliments such as grapefruit and some medication: should we blame the grapefruit? Why not just say that, if a certain medical condition required (actually, recommends) you to take some medicine, it’s this conjuncture that should make you avoid eating citrus?

    Another common “antagonisms” says: don’t drink green or black tea when you’re taking iron pills. Why is that so?

    Well, actually it’s not all that straightforward. Tannins from tea can inhibit the absorption of iron, especially iron from plant sources (peas, beans, nuts, leafy green vegetables, enriched pastas and breads, fortified cereals) — the so-called called non-heme iron. However, the absorption of iron from animal sources, such as red and dark meat, is generally not affected by tannins.

    (Flavonoids in tea can bind nonheme iron, inhibiting its intestinal absorption. The consumption of one cup of tea with a meal has been found to decrease the absorption of non-heme iron in that meal by about 70%.
    Hurrell RF, Reddy M, Cook JD. Inhibition of non-haem iron absorption in man by polyphenolic-containing beverages. Br J Nutr. 1999;81(4):289-295.
    Zijp IM, Korver O, Tijburg LB. Effect of tea and other dietary factors on iron absorption. Crit Rev Food Sci Nutr. 2000;40(5):371-398.)

    Learning this, I could explain the anemia of a certain friend. She’s not only a big tea drinker, but also a vegetarian. Should she have been an omnivorous, she shouldn’t be in the need of taking iron pills… while suspiciously watching the teapot…

  2. Oh, I was forgetting Plantago major (Greater/Common Plantain). No, not that bloody P. psyllium. This one is used as tea or syrup instead or to supplement bronchiolitics/secretolytics/mucolytics such as bromhexine, ambroxol, acetylcysteine.

  3. You’re exaggerating, and this kind of articles are under-engineered.

    There are some herbs with known physiological effects, being these milder or not. E.g.:
    – Matricaria recutita (Matricaria chamomilla)
    – Tilia cordata (Lime/Linden)
    – Mentha piperita (peppermint), Mentha spicata/cordifolia (spearmint)
    – Salvia officinalis (common sage)
    – Achillea millefolium (common yarrow)
    – Crataegus monogyna (common hawthorn)
    – Valeriana officinalis
    – Leonurus cardiaca (motherwort )

    Then there are highly toxic/poisonous herbs, e.g.:
    – Digitalis purpurea (common foxglove)
    – Catharanthus roseus/Vinca rosea (Madagascar Periwinkle)
    – Aristolochia clematitis (European Birthwort)

    Then there are herbs with claimed properties that they don’t actually have, e.g.
    – Echinacea purpurea (purple coneflower)

    An after that come some herbs used as regular food, only that some magazines and websites praise their virtues. E.g.:
    – parsley
    – onion
    etc. etc. etc.

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