READING PASSAGE 1
Questions 1-13
Healthy Food?
A The shelves of every supermarket are packed with probiotic yogurts that can supposedly ease constipation and fend off infections, butter substitutes that claim to reduce cholesterol, tomato extracts said to keep skin looking young while warding off cancer, infant cereals enhanced with micronutrients essential for development, and so on. Have food companies taken on a higher level of morality or are there other motives for this concern over the health value of their produce?
B Food companies have taken to trumpeting the supposed health and nutritional benefits of their products for several reasons. Such products may appeal both to health-conscious buyers and to people who know they eat unhealthily, but hope that some vitamins here and some probiotics there might compensate for the junk. Best of all, from the food companies’ point of view, these “functional foods”, which blur the line between foods and drugs, hold out the promise of higher margins and faster growth. In western Europe sales of functional foods grew by 10.2% a year between 2006 and 2009, for example, whereas sales of packaged food grew by 6.3%. That is why Nestlé, the world’s biggest food company, is making a big bet on functional foods as a source of future growth.
C All this has attracted the attention of regulators on both sides of the Atlantic. They are concerned that some of these health claims may be misleading or unsupported by evidence, and are tightening the rules. On October 20th America’s Food and Drug Administration (FDA) said it would overhaul the rules for nutritional claims on food labels and issue new standards early next year. It has already rebuked General Mills, the maker of Cheerios, a popular breakfast cereal, for claiming that it is “clinically proven to lower cholesterol”. The European Food Safety Authority is also cracking down, requiring companies to back up health and nutrition claims with scientific studies. Hundreds of applications submitted to its scientific panel have just been turned down. The panel has decided that there is not enough evidence to claim that, for instance, heather helps you sleep, dried cocoa extract helps you lose weight, quinoa makes your hair grow and Jerusalem artichokes make your gut healthy.
D Many in the industry are howling that these rules are heavy-handed, given that most of their products are perfectly safe and that some health claims go back decades or more. Demanding expensive studies to justify such claims will stifle innovation, they argue, and tilt the playing field against smaller firms, which will be unable to afford them. Surely, they say, firms that find profit in adding iron, iodine, zinc and vitamins to their products, or cutting levels of high-fructose corn syrup or saturated fat, ought to be applauded, not denounced. Many food brands started off as a means of reassuring customers that products were trustworthy. The desire to defend their brands gives food firms a strong incentive to ensure that their products are safe.
E The situation now however is that food companies are claiming their products provide specific benefits—not merely that they are safe to eat. Ordinary folk cannot tell whether health claims made by food marketers are scientifically valid, so there is a case for regulatory scrutiny of such claims. What’s more, even though it is difficult to imagine someone being harmed by eating too much breakfast cereal or yogurt, say, there is a risk of harm if health claims made about functional foods encourage people to see them as substitutes for drugs or lifestyle changes, they may need. A few helpings of vegetables will do better than any probiotic yogurt.
F A lesson from the drugs industry is that industry-funded studies have a clear tendency to produce results that please their sponsors. So, food companies should have to register all studies and publish even those with unfavorable results. Clear guidelines on labelling are also important. To its credit, the FDA recently proposed rules that would force food companies to publish all the important components of their products on the front of their packages, rather than picking out the healthy ones and keeping quiet about the fat, salt and sugar.
G The industry’s claim that greater scrutiny will kill innovation is off the mark. Those firms making misleading claims will suffer; those prepared to invest in proper scientific studies to back up their supposed breakthroughs will benefit. And in pharmaceuticals, smaller firms seem to be more innovative than bigger ones. If food companies wish to make the sorts of claims about their products that pharmaceutical companies do, they must be prepared to submit to similar scrutiny. Extraordinary claims, after all, require extraordinary evidence.
READING PASSAGE 2
Questions 14-27
Fitter with friends
THE enduring image of Sylvester Stallone's legendary pugilist Rocky Balboa is that of a solitary athlete, braving the elements, and his own demons, to prepare for a big fight. Yet according to a new study he might have done better by having a bit of company on his long workouts.
Research by Emma Cohen, an anthropologist at Oxford University, suggests that a better model is provided by Hicham El Guerrouj, a Moroccan middle-distance runner who is the current holder of the world 1,500-metres and one-mile records. Before retiring in 2006 Mr El Guerrouj was known for the throngs of training partners that followed him everywhere in Morocco. This was a good strategy because, as Dr Cohen reports in a forthcoming issue of Biology Letters, training in a synchronised group may heighten tolerance for pain. That, in turn, could allow athletes like Mr El Guerrouj to reach even higher levels of fitness by being able to train longer and harder.
The reason is almost certainly the effects of endogenous opioids, better known as endorphins. When these are released in the brain they make a person feel good. What causes their release is, however, more complex. Biologists think it is part of an evolved mechanism which rewards behaviour that may not be immediately pleasant but is ultimately useful to the species.
Endorphins show up nearly everywhere. Hunting an animal may be tiresome but necessary, so endorphins are secreted during exertion to numb the discomfort induced by lactic acid production in the muscles. Collaboration makes it easier to kill animals while others set traps.
Dr Cohen wanted to see if combining exercise and collaboration would heighten the effect. One of the study's co-authors, Robin Ejsmond-Frey, vowed for Oxford and thought it would be a good activity to study. For one thing, it is easy to spot a crew that is not well synchronised. Secondly, ergometers, machines on which rowers train, provide data on the power exerted on each stroke. In addition, it can be rather painful so the endorphins should be out in droves.
The researchers got 12 members of Oxford's heavyweight squad to row on machines in four 45-minute sessions over two weeks. In two sessions they rowed in complete isolation and in the others in groups of six, perfectly synchronised. Immediately following each session their endorphin levels were tested. Because endorphin levels can only be measured directly through an invasive lumbar puncture-unfeasible, even for notoriously pain-hungry oarsmen-the researchers used a readily accepted proxy: they deduced pain tolerance, and hence endorphin levels, by gradually tightening a cuff around each rower's arm. When he said "now" they stopped squeezing and noted the pressure.
As expected, the rowers' pain thresholds were significantly higher following the group sessions. This was despite nearly identical power outputs in all four tests and efforts to control for possible confounding variables, such as the time of day.
The athletes may be rewarding themselves for their collaboration. Whether heightened tolerance is due specifically to rowing synchronously remains unclear. Data from other studies suggest that co-ordinated physical exercise can heighten social bonds, as in military training. The reverse may also be true. As the rowers had been teammates for nearly a year it is possible that the mere presence of friends explains the observed effect. The researchers are keen to replicate the study to test for such things. Meanwhile, solitary joggers might want to take along a friend or two.
READING PASSAGE 3
Questions 28-40
Glue bones
A Torn flesh is usually easy to put back together with stitches, but when bone breaks, repairs are nowhere near as simple. Fractures that run in a straight line can often be placed back in their proper alignment and set in a cast for a period of time that allows the break to heal. Complex fractures, though, those that involve bones shattered into fragments, are more challenging. Large fragments can, with the aid of metal screws and pins, be reattached and set in place for healing. Small fragments cannot be treated in the same way, as they are often too tiny to be connected with metal hardware. Medics have long sought a glue to do this work, and now Russell Stewart of the University of Utah may have found one in the secretions of a marine worm.
B The sandcastle worm, as the beast is known, lives in a mineral shell. It does not, however, secrete this shell directly in the way that, for example, a mollusc would. Instead, it secretes a glue and uses this to stick bits of sand together to form its casing, in the way that a freshwater caddis fly larva does. The glue does not dissolve in water. Indeed, it is able to displace water and thus adhere to surfaces in aqueous solutions. It also solidifies soon after being secreted. It, or something like it, therefore sounds ideal for repairing bones.
C Dr Stewart and his team began by analysing sandcastle-worm glue to see how it works. What they found was a mixture of proteins, some positively charged and some negatively charged, and also a lot of calcium and magnesium ions. The combination produces a material that can, when circumstances are right, bind the protein molecules so tightly together that any water molecules between them are expelled.
D The trigger for this to happen is a change in acidity. The gland in which the glue is generated is mildly acidic. In these circumstances the glue remains liquid. Seawater, however, is alkaline. This alkalinity causes the glue to set. It solidifies into a foam within 30 seconds and becomes a flexible, leathery substance over the course of several hours.
E Having understood how the sandcastle worm performs its trick, Dr Stewart was in a position to replicate it. Instead of proteins, he and his team used two synthetic polymers. These, however, had the same crucial chemical groups as their natural counterparts, and also similar electric charges.
F The result, as the team reported to a recent meeting of the American Chemical Society, was a substance even better, from a medical point of view, than the natural glue. Not only did it solidify in response to changes in acidity, it also did so in response to changes in temperature, being liquid at room temperature and solid at body temperature.
G The resulting glue not only sticks bits of bone together in watery environments, but also does so with twice the strength of the glue used by the worm. In addition, although it is still early days, preliminary tests suggest it is both non-toxic and biodegradable. If further testing confirms this, it means that, as the broken bone heals, the glue will disappear naturally. Complex fractures will thus heal more easily.
