QI: The Second Book of General Ignorance

by John Lloyd

  By the seventeenth century, European glass had become cheap enough for ordinary people to use it for windowpanes (as opposed to mere holes in the wall or the paper screens of the Orient). This protected them from the elements and flooded their houses with light, initiating a great leap forward in hygiene. Dirt and vermin became visible, and living spaces clean and disease free. As a result, plague was eliminated from most of Europe by the early eighteenth century.

  In the mid-nineteenth century, transparent, easily sterilised swan-necked glass flasks allowed the French chemist Louis Pasteur to disprove the theory that germs spontaneously generated from putrefying matter. This led to a revolution in the understanding of disease and to the development of modern medicine. Not long afterwards, glass light bulbs changed both work and leisure forever.

  Meanwhile, new trade links between East and West in the nineteeth century meant that a technologically backward China soon caught up. Today it is the world’s third-largest industrial power and its largest exporter, with total exports in 2009 of £749 billion.

  It is also the world’s largest producer of glass, controlling 34 per cent of the global market.

  What’s the name of the chemical that’s bad for you and is found in Chinese food?

  Despite its reputation in the press, monosodium glutamate is much less harmful than ordinary table salt.

  The list of charges against MSG is a long one. It has been accused of causing obesity, nerve damage, high blood pressure, migraine, asthma and altering hormone levels. But every concerned public body that ever investigated it has given it a clean bill of health.

  For centuries, it was agreed that there were only four basic tastes – sweet, sour, bitter and salty – until in 1908 Dr Kikunae Ikeda of Tokyo University discovered a fifth one: a ‘meaty’ taste that he named ‘umami’. This is the taste of MSG. Like soy sauce, it just makes your food a little more delicious.

  The MSG scare arose out of so-called ‘Chinese Restaurant Syndrome’. Dr Robert Ho Man Kwok coined the term in 1968, when a number of his patients complained of palpitations and numbness in their neck and arms after eating a large Chinese meal. Dr Kwok blamed monosodium glutamate, and though all subsequent research has proved that to generate such symptoms would require a concentration of MSG in food that would render it completely inedible, the stigma has somehow remained.

  We now know that glutamate is present in almost every natural food stuff (it is particularly high in parmesan and tomato juice) and that the protein is so vital to our functioning that our own bodies produce 40 grams of it a day. Human milk contains lots of glutamate, which it uses as an alternate enhancement to sugar – MSG and sugar are the two things that get babies drinking.

  A much more dangerous substance is recklessly sprinkled on food every time we eat. Excessive salt intake increases the risk of high blood pressure, strokes, coronary artery disease, heart and kidney failure, osteoporosis, stomach cancer and kidney stones. We’d be safer replacing it in our cruets with MSG.

  In the European Union, monosodium glutamate is classified as a food additive – E621.

  The dreaded ‘e-numbers’ listed on jars and tin cans are almost all completely benign; the ‘E’ stands for nothing more sinister than ‘European’. It is simply an international way of labelling the different substances (by no means all of them artificial) that are found in our foods. If you wanted to avoid E numbers altogether, you couldn’t: 78 per cent of the air we breathe is E941 (nitrogen) and even the purest water is made entirely from E949 (hydrogen) and E948 (oxygen).

  Salt, apparently, doesn’t have an e-number.

  JOHNNY VEGAS This is why I don’t wanna do shows like this!

  STEPHEN Why is that, Johnny?

  JOHNNY Well,’ cause now, I’m gonna lie awake at night, fearing that I’m lactating poison! I feel like I’ve already hurt people enough in my lifetime.

  STEPHEN It’s not poison; it’s good. We’re trying to suggest that MSG is not as bad as it’s been painted. You may not like the flavour, in which case, certainly, don’t have any.

  JOHNNY Yeah, but I don’t want meaty-tasting breasts!

  Does eating chocolate give you acne?

  No. Nothing we eat ‘causes’ acne (but go easy on the breakfast cereals).

  Acne affects over 96 per cent of teenagers at some time during their adolescence.

  Each human hair grows in an individual pouch in the skin called a follicle (from the Latin for ‘little bag’). Feeding into each follicle is a gland that secretes a waxy substance called sebum (Latin for ‘grease’ or ‘suet’). Next to each follicle is another gland, which carries sweat up to the surface of the skin through a tiny pore (from poros, Greek for ‘passage’).

  During puberty, testosterone levels increase in both boys and girls giving rise to an over-production of sebum. This spills out into the sweat pores, clogging them up with oily compost ripe for bacteria. The result is a pimple. A colony of these is called acne vulgaris (‘acne’ for short). Boys have higher levels of testosterone than girls, which is why they also tend to have worse acne.

  So it’s not chocolate, but testosterone, that ‘causes’ acne. But diet is a factor too, and some foods definitely make it worse.

  In 1981 Professor David Jenkins, a Toronto-based nutritionist, measured the effects of carbohydrates on blood-sugar levels. He found that starchy foods (like white bread, cereals and potatoes) raised blood-sugar levels dramatically; but sugary foods had much less effect. Starchy foods have a simpler chemical structure and are easier for the digestive system to convert into glucose, the most absorbable form of sugar. Protein, fats and more complex sugars (like chocolate) are harder to absorb. From this, Jenkins devised a scale called the GI, or Glycaemic Index (from Greek glykys, ‘sweet’, and haima, ‘blood’).

  Foods with a high GI score – the ones that raise blood-sugar levels most – create a surge in the production of insulin, the hormone that regulates the body’s intake of glucose. Insulin is itself controlled by testosterone, and dairy products are in turn thought to stimulate testosterone. So at breakfast, it’s the cereal and the milk (a double dose of hormonal stimulants) rather than the sugar that may aggravate the acne.

  The English word acne was first used in 1835, but it comes from a 1,500-year-old Assyrian spelling mistake. In the sixth century, Aëtius Amidenus, a physician from the city of Amida (now in modern Turkey), accidentally coined a new word – akne – to describe a pimple. He had meant to write akme (Greek for ‘point’).

  Munching your favourite chocolate bar produces endorphins, which help relieve pain, reduce stress and lower the risk of heart disease and cancer. But pure cacao doesn’t have the same effect. Mere chemicals are not enough to satisfy the craving: we also need taste, texture and memories to set our hearts (literally) racing. In 2007 a research company, The Mind Lab, showed that, for some people – especially women – eating a piece of dark chocolate made the heart beat faster, and for longer, than a passionate kiss.

  Who gets over-excited by sugary drinks?

  Parents.

  There isn’t a shred of scientific evidence that children become ‘hyperactive’ when given sugary drinks, sweets or snacks.

  In one test, a group of children were all given the same sugar-rich drink, but the parents of half the sample were told they’d been given a sugar-free drink. When questioned afterwards, the parents who thought their children hadn’t had any sugar (even though they had) reported far less hyperactive behaviour.

  In another study, some children were put on high-sugar diets and others sugar-free ones. No difference in behaviour was observed. Not even when (according to the British Medical Journal in 2008) the children had already been diagnosed with attention deficit hyperactivity disorder (ADHD). Because parents expect sugar to cause hyperactivity, that’s what they see.

  It all began in 1973, when a US allergy specialist called Benjamin Feingold (1899–1982) first showed that hyperactivity in children is linked to what they eat, and proposed a diet for p
reventing it. He recommended cutting out all artificial colourings and flavourings, including sweeteners such as aspartame. The Feingold Diet didn’t ban sugar but, as medical opinion gradually came to accept the connection between hyperactivity and diet, sugar somehow became confused in the public mind with ‘sweeteners’.

  No one has ever come up with a decent theory to explain exactly how sugar might have this effect on youngsters. If high blood-sugar levels were the cause, they’d be more likely to go ballistic after a bowl of rice or a baked potato.

  Throughout the centuries, food has been blamed for causing the behaviour that people were most worried about at the time. The sixteenth-century herbalist John Gerard warned against the herb chervil, which ‘has a certain windiness, by means whereof it provoketh lust’. Buddhist monks are forbidden to eat any member of the onion family, because they, too, are thought to cause lust when cooked – and anger when raw.

  In the nineteenth century, moralising Victorians attributed ‘degeneracy and idleness’ in the Irish to the supposed soporific effect of the potato. Englishwomen, by contrast, were warned off eating meat. Such ‘stimulating’ food was liable to bring on debilitating periods, nymphomania and insanity.

  ALAN Speaking as an uncle, I am often discouraged from giving them too much chocolate, because they go, in quotes, ‘mental’.

  How many glasses of water should you drink every day?

  Eight is too many.

  You lose water every second of the day through excreting, sweating or simply breathing, so you need to take in liquid to avoid becoming dehydrated. But the advice that you should drink eight glasses of water a day is just plain wrong.

  In 1945 a British Medical Journal report advised that adults should consume 2.5 litres of water daily but specified that ‘most of this quantity is contained in prepared foods’. In the sixty years since, this important final sentence seems to have fallen by the wayside. A normal diet contains enough embedded water for us, theoretically, not to need to drink anything at all.

  Drinking lots of glasses of water on top of your normal consumption of food and drink will only make you urinate more.

  It’s often said that drinking water is good for flushing out your system and keeping your skin blemish-free, but the evidence is patchy. Your kidneys may be helped to remove excess salt in the short term but unless you’ve been overdosing on crisps (or alcohol) there is no particular benefit. Chronic dehydration makes your skin drier and less elastic, but taking in extra water won’t remove your wrinkles and it’s unlikely to stop you from getting spots.

  Treating dehydration involves more than just water. You need to replace sugar and salts as well, so try eating watermelons. They’re rich in sugar, as well as calcium, magnesium, potassium and sodium. Papaya’s good, too, as are coconut, cucumber and celery.

  The salts and sugar are necessary because they help transport the water around the body. If you find watermelons spoil the line of your safari suit, you can buy sachets of rehydration powders from chemists and travel agents. These contain glucose and salts – but you’ll still need to source your own water to dissolve them in – which is where watermelons win: they’re 92 per cent water.

  Too much water, on the other hand, can be lethal. ‘Water intoxication’ or hyponatremia (from Greek hypo, ‘under’, Latin natrium, ‘sodium’ and Greek haima, ‘blood’) is caused by over-dilution of essential body salts. Excess water is expelled from the blood into other cells, which then expand and rupture – leading to nausea, headaches, disorientation and, eventually, death.

  What use is a sauna?

  Saunas do many things, but ‘sweating out the body’s toxins’ isn’t one of them.

  Sweat is 99 per cent water, with tiny amounts of salt and other minerals. Its function is to cool the body as the water evaporates from the skin, not to remove waste products. It’sthe liver and kidneys that deal with any toxins in the body, converting them into something useful, or arranging for them to be excreted.

  Nor does a sauna necessarily help you get rid of a hangover. Fifteen minutes in a sauna can lead to the loss of 1.5 litres (2½ pints) of sweat. Unless you drink lots of water to compensate, sweating heavily will only make you more dehydrated. Dehydration puts your kidneys under stress, which slows down the elimination of alcohol from your system.

  What a sauna can do well is clean your skin, by opening your pores as you sweat. A fifteen-minute session at a temperature of 70 °C and 40 per cent humidity raises the body’s surface temperature by 10 °C and its internal temperature by 3 °C. This increases blood flow to the skin and makes the lungs work harder, increasing the intake of oxygen by up to 20 per cent – which is why endurance athletes often use saunas as part of their training.

  A sauna followed by a cold shower generates feel-good endorphins in the brain, and can be used to treat mild depression. Research at the Thrombosis Institute in London has shown that the sauna–cold water combination also strengthens the immune system by increasing the number of white blood cells that fight disease. Saunas can also reduce the pain of arthritis and the Finns swear by them as a cure for the common cold.

  Though ‘sauna’ is a Finnish word, the idea of the sauna is an ancient one. Writing in the fifth century BC, the Greek historian Herodotus described how the Scythians, a nomadic tribe from Iran, used small tents for the purpose, in which they burned cannabis on the hot stones – so they got high as well as clean. ‘The Scythians’, he wrote, ‘enjoy it so much that they howl with pleasure.’ The Apaches of North America have always used ‘sweat lodges’ made from willow frames covered with skins, in which up to twelve people sit naked around heated rocks. These are periodically soused with water to make steam, cleansing both body and spirit.

  The sauna has a similar spiritual significance for the Finns. Traditionally it was a place for the family to gather, for women to give birth and for the dead to be washed before burial. An old Finnish saying is unassa ollaan kuin kirkossa – ‘behave in a sauna as in a church’.

  Finns who break this rule run the risk of being punished by the only permanent resident of the sauna, the saunatonttu, or ‘sauna elf’.

  The word ‘sauna’ is one of only two expressions in English borrowed from the Finnish language. The other is ‘Molotov cocktail’.

  What effect does drinking alcohol have on antibiotics?

  It doesn’t usually have any effect at all.

  The idea that alcohol ‘stops antibiotics working’ was first put about in the venereal disease clinics set up after the Second World War. Penicillin, identified by Alexander Fleming in 1928, had proved particularly effective at clearing up sexually transmitted infections. It was prescribed with the strict instruction not to drink while taking it. The reason for this was psychological rather than pharmaceutical. Drunken people are more likely to jump at the chance of casual sex. By scaring their patients into not drinking, doctors and nurses were giving the drug a chance to work before the infection could be passed on.

  This advice became standard medical practice, and it worked: most people still avoid alcohol when on a course of antibiotics. It’s true that it’s not a good idea to drink heavily on antibiotics, because the alcohol competes with the drug for ‘processing time’ in your liver. This means the drug may work a little more slowly. What it won’t do is stop it working altogether.

  Of over a hundred types of antibiotic available for prescription, only five are listed as having serious side effects if taken with alcohol.

  Of these, the only one commonly prescribed is Metronidazole, which is used to combat some dental and gynaecological infections and for treating Clostridium difficile, a bacterial infection picked up in hospitals. The drug prevents the body from breaking down alcohol properly, leading to a build up in the blood of the highly toxic chemical acetaldehyde – a close relative of formaldehyde, better known as embalming fluid. The effects are similar to an extremely bad hangover: vomiting, increased heart rate and severe headaches.

  In 1942 the American microbiologis
t Selman Waksman (1888–1973) – and his student Albert Schatz (1922–2005) – discovered streptomycin, the first drug to be effective against tuberculosis. Waksman described it as ‘antibiotic’ (from the Greek anti ‘against’ and bios ‘life’) because it killed living bacteria.

  Antibiotics are powerless against colds or flu, which are viral infections. It’s not clear what viruses are, or even if they can be said to be ‘alive’. They have genes (but no cells) and can only reproduce using a host organism. Scientists tend to refer to them as ‘biological entities’ or ‘organisms at the edge of life’.

  What does stop antibiotics working is not alcohol but overprescription. In farming 70 per cent of the antibiotics used are given to perfectly healthy animals. In medicine new strains of bacteria have become resistant to former ‘wonder drugs’ like streptomycin and the World Health Organisation estimates that a third of the world’s population now carries a drug-resistant strain of TB. There are fears that as many as 35 million people may die from it before 2020.

  Can you name a narcotic?

  LSD, cocaine, speed?

  None of the above. Medically speaking, a ‘narcotic’ is an opium derivative, such as morphine. A slightly looser definition might include any drug that causes unconsciousness – technically known as ‘narcosis’, from the Greek narke, meaning ‘numbness’ or ‘torpor’.

  Law enforcement agencies in the USA use the word ‘narcotic’ as a blanket term to mean any illegal drug – even though many of them are anything but narcotic in their effects, and many true narcotics, like codeine, are legal.