Herbal medicine and its dangers

I recently heard a talk by Thomas Efferth of the Institute for Pharmacology of the University of Mainz on herbal medicine. There is a common point of view that substances derived from plants are harmless and good while the chemical drugs of standard medicine are evil. The speaker emphasized that plants have good reasons for not being good to those who eat them. They do not have immune systems of the type we do and they cannot run away and so it is natural that they use poisons to defend themselves. Herbal medicines are effective in some cases but they need to be subject to controls as much as do substances obtained by artificial chemical means. In the talk a number of examples of the dangers of ‘natural’ medicines were presented and I will write about some of them here.

The first example is that of Aristolochia. This a large genus of plants, some of which are poisonous. One of these, Aristolochia clematitis, has been extensively used in herbal medicine. It was used extensively in the west in ancient times and is used in traditional Chinese medicine until today. In the talk the story was told of an incident which happened in Belgium. There was a product sold as a means of losing weight which contained a Chinese plant. It sold so well that the manufacturer’s supplies of the plant were running out. When more was ordered a fateful mistake took place. There are two plants which have the same name in China. The one is that which was originally contained in the weight-loss product. The other is the poisonous Aristolochia fangchi and it was the one which was delivered. This led to more than 100 cases of kidney failure in the people using the product. Another way in which plants can be dangerous is as weeds in crop fields. In the Balkans contamination of grain with Aristolochia clematitis led to a kidney disease called Balkan nephropathy, with 35000 recorded cases. The substance, aristolochic acid, which is responsible for the kidney toxicity is also known to be a strong carcinogen. Interestingly, this substance is not poisonous for everyone and its bad effects depend a lot on the variability in liver enzymes among individuals.

A class of substances used by many plants to protect themselves against insects are the pyrrolizidine alkaloids. These substances are hepatotoxic and carcinogenic. They may move through the food chain being found, for instance, in honey. It has been noted that there may be risks associated to the amount of these substances contained in medicinal herbs used both in the West and in China. It was mentioned in the talk that drinking too much of certain types of herbal tea may be damaging to health. The problem is usually not the plants that are the main components of the teas but other plants which may be harvested with them in small quantities. There is at least one exception to this, namely coltsfoot (Tussilago farfara). In one case the death of an infant due to liver disease is believed to be due to the mother drinking this type of tea during pregnancy. After that the sale of coltsfoot was banned in Germany.

There were some remarks in the talk on heavy metals which I found quite suprising. One concerned ayurvedic medicine which has an aura of being gentle and harmless. In fact in many of these substances certain heavy metals are added delibrately (lead, mercury and arsenic). According to Wikipedia more than 80 cases of lead poisoning due to ayurvedic ‘medicines’ have been recorded. Another remark was that there can be significant concentrations of heavy metals in tobacco smoke. The negative health effects of smoking are sufficiently well known but this aspect was new to me.

Another theme in the talk was interactions between herbal medicines and normal drugs. Apparently it is often the case that patients who use herbal remedies are afraid to mention this to their doctors since they think this may spoil the relationship to their practitioner. Then it can happen that a doctor is suprised by the fact that a drug he prescribes is not working as expected. Little does he know that the patient is secretly taking a ‘natural’ drug in parallel. An example is St. John’s wort which is sometimes taken as a remedy for depression. It may work and it has no direct negative effects but it can be problematic because it reduces the effects of other drugs taken at the same time, e.g. the contraceptive pill. It changes the activity of liver enzymes and causes them to eliminate other drugs from the body faster than would normally happen, thus causing an effective reduction of the dose.

We are surrounded by poisonous plants. I was always sceptical of the positive effects of ‘natural’, plant-derived medicines. Now I have realised how seriously the dangers of these substances should be taken.

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Honesty is the best policy

Yesterday I did the following thought experiment. I imagined a situation where someone asked me two questions, saying that I should answer spontaneously without thinking too long. The first question was ‘Are you happy with your life?’ and the second ‘Are you happy with the society around you?’ My answer to the first question was ‘yes’ and to the second ‘no’. I then started thinking about the cause of the discrepancy between these two answers. I came to the conclusion that it has a lot to do with the concept of ‘honesty’. I believe in and live according to the phrase in the title of this post, ‘honesty is the best policy’ while I feel that in the society around me lies have a huge influence. It is also worth remarking that lies are not the only kind of dishonesty.

If I am honest what is the reason? One important influence is my upbringing. I grew up in a family which was very attached to telling the truth. Here the influence of my mother was particularly strong. What influenced me was not so much what she said on the subject as the example of how she behaved. My mother’s attachment to honesty had a lot to do with her attachment to religion. I did not inherit her religion, becoming an atheist in my teens. I also did not inherit her moral convictions but I did inherit certain patterns of moral behaviour. One thing that stops me telling lies is simply that I find it very unpleasant due to childhood conditioning. Since truth plays a central role in mathematics it is perhaps natural that mathematicians should tend to be truthful, also in everyday life. It might also conversely be the case that among people who go into academia those with a specially strong attachment to truth might tend to go in the direction of mathematics.

Probably the main motivation for lying is the hope to gain some advantage by doing so. This may be short-sighted if despite a short-term profit the net long-term payment is negative. The idea that this is often the case is one motivation for me not to lie. Another is the fact that lies require management in order to profit from them. It is necessary to remember the lies you told so as not to betray yourself and it is also necessary to remember the corresponding true version. A lot of profitable lies require a lot of management and this is stress which I like to avoid. More thoughts in similar directions can be found on this web page
http://www.becomingminimalist.com/why-honesty-is-the-best-policy-for-simplicity/

What types of dishonesty in society bother me? One is political correctness. It means sanctions againt telling the truth, or just speaking plainly rather than in euphemisms, in many situations. There are some cases where there may be good reasons for measures like this but I think that in the majority of cases there are no good reasons. They are based on arbitrary conventions or at best on misguided ideas of well-meaning people. I prefer to speak openly but I often avoid doing so and simply keep quiet in order to avoid problems. I would prefer if this was not so often necessary. A related topic is that of reference letters. When I write references for people applying for academic jobs I generally feel free to tell the truth. For jobs outside academia things are very different. There telling the truth might easily lead to disaster since open criticism is often effectively forbidden. Instead it is necessary to write in code and even then the information which might be helpful for the employer, or for the applicant, might not get through. In other situations it is necessary to be careful when criticising people but it is wrong not to criticise. Constructive criticism can be good. I am happy when I receive constructive criticism although it may be unpleasant at the moment it arrives. I believe that it is also important to make statements in certain situations like ‘in my opinion person X is better than person Y at doing task Z’. This is not a comparison of the value of the two people in general but just in the context of a particular ability.

One other theme I want to mention is marriage, because my marriage is one of the things in my life which contributes most to my happiness. When I use the word ‘marriage’ here I mean it to denote a long-term romantic relationship, not only one which is recognised legally by a piece of paper. I have been married in the latter sense for eight years but the underlying relationship goes back sixteen years. I would not dare to write here about individual marriages (apart from my own) but I will say something about averages. It seems that with time marriages in our society become less and less stable and last for shorter times. I believe in marriage in the old-fashioned sense of ’till death do us part’ and I think it is very unfortunate for many people that they have replaced this by a sequence of shorter-term relationships accompanied by difficult separations. The relation of this topic to that of honesty is as follows. I think that separations often result from the fact that the people involved are pursuing short term gains at the expense of the partner. Then the short-term gains turn into long-term losses. In a talk I heard recently the speaker voiced the opinion that the kind of degradation of marriage (or of love) I have been talking about is due to the fact that many people going into relationships have not had the experience of good marriages in their childhood. I had the advantage of growing up in surroundings where this type of relationship was widespread and I had very direct experience of how it was in the case of my own parents.