From make-up to medicine, scientists warn that people are wrong to think natural must be best
Robin McKie, science editor
The Observer
Far from being the best forms of nutrition, medicine or cosmetics on the market, natural products can pose serious health risks, Britain's leading chemists will warn this week.
By contrast, synthetic chemicals, tightly regulated and generally safe, are being unfairly blamed for causing cancers and other illnesses, the researchers state. The warning comes in 'Making Sense of Chemical Stories', to be published on Wednesday, in which chemists and toxicologists highlight growing fears about people's misconceptions about chemicals in everyday life.
'Synthetic chemicals are often much safer for human health than so-called "natural" ones and unfounded anxiety about chemicals is encouraging people into ideas and remedies that make no scientific or medical sense,' they say. Among examples are expensive detoxification cures - including tablets, diets and body wraps - that are less effective than a glass of water; henna tattoos that can cause severe allergic reactions; and hair dyes and eyeliners, such as kohl and surma, that contain toxic lead compounds.
'Kohl is put in the inside of eyelids,' said Professor John Henry of Imperial College London. 'The lead dissolves in teardrops and is absorbed by the body. The result is lead poisoning. By contrast, standard eyeliners made with synthetic chemicals contain no lead chemicals and are safe.' Another example is the dangers from henna tattoos. Black henna contains the dye paraphenylenediamine, which can cause an allergic reaction and lead to permanent scarring.
Henry also warned about the use of traditional medicines such as St John's wort: 'There is no doubt that it can be effective for treating depression, but it is difficult to administer. We do not know what its active ingredient is and that means you cannot assess its dosage.'
By contrast, the active ingredients of standard medicines and cosmetics are known, can be manufactured synthetically and accurately administered. Yet it is the synthetic chemical that attracts hysterical media coverage, the report adds. Campaigns by environmental groups have highlighted the presence of dangerous chemicals in pregnant women and their unborn babies. However, it is never mentioned that the toxins are present in fewer than one part per billion. Some also alleged that tiny traces of different man-made chemicals can combine to produce a single, highly toxic effect, but there is no evidence to support the idea.
In short, says the report, published by the charity Sense About Science, there is a wide mismatch between the public's attitudes to man-made and natural substances. People think the former lead to cancer and are responsible for many of society's woes. As a result, they try to lead a chemical-free lifestyle. The idea is nonsense, says the report. 'Claims that products are "chemical free" are untrue.'
Research chemist Derek Lohmann points out: 'If someone offered you a cocktail of butanol, isoamyl alcohol, caffeine, geraniol, 3-galloyl epicatechin, and inorganic salts, it sounds pretty ghastly. Yet it is just a cup of tea.'
By contrast, there has been a steady increase in uncritical acceptance of natural products. 'This has happened partly as a result of intensive merchandising of "alternative" products, lifestyle ideas and campaigns that play on misconceptions about chemicals and about how the body works,' states the report. 'Something needs to be done.
Robin McKie, science editor
The Observer
Far from being the best forms of nutrition, medicine or cosmetics on the market, natural products can pose serious health risks, Britain's leading chemists will warn this week.
By contrast, synthetic chemicals, tightly regulated and generally safe, are being unfairly blamed for causing cancers and other illnesses, the researchers state. The warning comes in 'Making Sense of Chemical Stories', to be published on Wednesday, in which chemists and toxicologists highlight growing fears about people's misconceptions about chemicals in everyday life.
'Synthetic chemicals are often much safer for human health than so-called "natural" ones and unfounded anxiety about chemicals is encouraging people into ideas and remedies that make no scientific or medical sense,' they say. Among examples are expensive detoxification cures - including tablets, diets and body wraps - that are less effective than a glass of water; henna tattoos that can cause severe allergic reactions; and hair dyes and eyeliners, such as kohl and surma, that contain toxic lead compounds.
'Kohl is put in the inside of eyelids,' said Professor John Henry of Imperial College London. 'The lead dissolves in teardrops and is absorbed by the body. The result is lead poisoning. By contrast, standard eyeliners made with synthetic chemicals contain no lead chemicals and are safe.' Another example is the dangers from henna tattoos. Black henna contains the dye paraphenylenediamine, which can cause an allergic reaction and lead to permanent scarring.
Henry also warned about the use of traditional medicines such as St John's wort: 'There is no doubt that it can be effective for treating depression, but it is difficult to administer. We do not know what its active ingredient is and that means you cannot assess its dosage.'
By contrast, the active ingredients of standard medicines and cosmetics are known, can be manufactured synthetically and accurately administered. Yet it is the synthetic chemical that attracts hysterical media coverage, the report adds. Campaigns by environmental groups have highlighted the presence of dangerous chemicals in pregnant women and their unborn babies. However, it is never mentioned that the toxins are present in fewer than one part per billion. Some also alleged that tiny traces of different man-made chemicals can combine to produce a single, highly toxic effect, but there is no evidence to support the idea.
In short, says the report, published by the charity Sense About Science, there is a wide mismatch between the public's attitudes to man-made and natural substances. People think the former lead to cancer and are responsible for many of society's woes. As a result, they try to lead a chemical-free lifestyle. The idea is nonsense, says the report. 'Claims that products are "chemical free" are untrue.'
Research chemist Derek Lohmann points out: 'If someone offered you a cocktail of butanol, isoamyl alcohol, caffeine, geraniol, 3-galloyl epicatechin, and inorganic salts, it sounds pretty ghastly. Yet it is just a cup of tea.'
By contrast, there has been a steady increase in uncritical acceptance of natural products. 'This has happened partly as a result of intensive merchandising of "alternative" products, lifestyle ideas and campaigns that play on misconceptions about chemicals and about how the body works,' states the report. 'Something needs to be done.
Ce qui est dangereux c'est la tendance à confondre "naturel" avec "sain et sans danger". Après tout, l'arsenic est un produit naturel. Rappelons-nous également que la plupart des médicaments ont pour base une molécule trouvée dans la nature, le plus souvent dans des plantes. Ils ne sont pas pour autant considérés comme "naturels". Comme quoi, cette appellation est attribuée de façon très arbitraire par les partisans du retour à la Nature (ne pas confondre avec les écologistes).
Aucun commentaire:
Enregistrer un commentaire