What the scientists are saying…

Diet drinks linked to diabetes Drinking two glasses of fizzy drink a day doubles a person’s risk of developing type 2 diabetes – even if those drinks are the diet variety, according to a Swedish study. Researchers at the Karolinska Institutet interviewed more than 1,000 people with diabetes about their diets in the previous year, and compared them with a diabetesfree control group. They found that consuming more than two 200ml servings of soft drinks a day was associated with a 2.4-times increased risk of type 2 diabetes, while drinking a litre a day was associated with a tenfold increased risk. There was also a strong link between soft drinks and the rarer latent autoimmune diabetes. The researchers speculate that diet drinks leave people hungrier, and craving sweet foods. It may also be that they cause chemical reactions in the gut that lead to glucose intolerance, which is often a precursor of diabetes. However, the study does not prove a causative link: excessive thirst is a symptom of diabetes, so it may be that in some cases, the patients had consumed more soft drinks because they already had undiagnosed diabetes. Also, high consumption of fizzy drinks tends to be part of a broader pattern of poor lifestyle habits, which are hard to fully account for in such studies.

The alcohol gender gap Having historically been the more abstemious gender, women are now just as likely to drink alcohol as men – and to overdo it, research suggests. A team at the University of New South Wales, Australia, analysed data from 68 international studies to explore how the “gender gap” in drinking habits has changed over the past 100 years or so. They found that men born in the first few decades of the 20th century were – and continued to be – about twice as likely to drink alcohol as women of their age; but that the gap started to close in the 1980s, among those born after 1966, and since then, near parity has been achieved: men born since 1991 are only 1.1 times more likely to drink than their female peers; and their risk of drinking at levels likely to cause harm is also more or less the same. Experts said the findings were worrying, as women have a lower tolerance to alcohol than men, partly on account of having smaller livers. NHS figures suggest that women aged 15 to 19 are 30% more likely to be admitted to hospital with alcohol poisoning than men of the same age group.

Monkeys make tools, by mistake At the start of the Stone Age, around three million years ago, our ancestors began hammering rocks together to make “tool- like flakes” – slithers of rock, that could be used to fashion arrow heads, or spear tips. This was believed to be a habit unique to early humans, and was regarded as a landmark in our evolution, because it required such dexterity and foresight. But now bearded capuchin monkeys in northeast Brazil have been observed making flakes of their own, not by design, but while banging rocks together in order – it is presumed – to extract the nutrient silicon, or remove lichen. The study, published in Nature, raises the possibility that some previously discovered flakes attributed to hominins might have been made unintentionally. “The fact that monkeys can produce the same result does throw a bit of a spanner in the works in our thinking on evolutionary behaviour and how we attribute such artefacts,” said Dr Michael Haslam of Oxford University, one of the co-authors. However, the team stressed that whereas the monkeys didn’t use the flakes, archaeological evidence suggests humans did.

Hip ops don’t improve mobility Hip replacements do not make people more active, according to a University of East Anglia study. Researchers looked at before-and-after data for 1,030 men and women who had the operations, and found they made no discernible difference to mobility. Hip replacements are mainly carried out to reduce pain – including that associated with movement. So the team was surprised to discover that, following the procedures, patients were no likelier to go for walks, climb the stairs, or take up cycling or other forms of exercise. Tom Withers, of UEA’S School of Health Sciences, said the results were worrying, and that hip-replacement patients needed to be “encouraged to be more active”.