What the scientists are saying…
Smokers’ lungs can heal
Lungs have an almost “magical” ability to heal the damage caused by smoking – but only if you stop, a study suggests. The findings, published in Nature, add to the evidence that it is never too late to give up smoking: it appears that as well as preventing further damage from occurring, quitting allows the lungs to “regenerate”, significantly reducing the risk of cancer. For the study, researchers from the UK and Japan analysed lung biopsies on 16 people, including smokers, former smokers and adults who’d never smoked. As expected, the lung cells of current smokers showed far more mutations (including potentially cancer-causing ones) than those of nonsmokers. While the lung cells of former smokers also exhibited more mutations than normal, up to 40% of their cells had no signs of damage at all – four times the rate in current smokers. The scientists suspect that these healthy cells are descended from stem cells that are dormant while the person still smokes, enabling them to evade damage. “Once the person quits smoking, the cells gradually proliferate from this safe harbour to replace the damaged cells,” said Dr Peter Campbell of the Wellcome Sanger Institute.
Penguins keep it brief
The honking breeding calls of “jackass” penguins share some basic traits of human speech, scientists have discovered. In all human languages, the more often a word is used, the shorter it tends to be. (In English, “the” and “to” are examples.) A separate “law” states that cumbersome words like “onomatopoeia” tend to be made up of short syllables. While these principles are known to apply to the “speech” of primates, they have never previously been observed in birds. But when researchers analysed the calls of three colonies of African penguins in Italian zoos – known as jackass penguins on account of their braying – they found that their most common sounds were also the shortest, and that the longer their calls lasted, the more short sounds they contained. “This is the first compelling evidence for conformity to linguistic laws in vocal sequences of a non-primate species,” the scientists wrote in Biology Letters.
How to prevent miscarriages
The hormone progesterone should be given to any pregnant woman who has suffered more than one unexplained miscarriage, scientists have claimed. The hormone, secreted by the ovaries just after ovulation, helps maintain the lining of the uterus and protects the placenta during pregnancy. While it has often been suggested that women who suffer recurrent miscarriages would benefit from boosting their progesterone levels, evidence for the practice has been deemed inconclusive. Now a University of Birmingham study claims to show for the first time that it really can reduce the risk of miscarriage. The researchers analysed two recent UK clinical trials, one looking at women with a history of unexplained recurrent miscarriages, and the other at those who’d experienced early pregnancy bleeding. In the first trial, women given progesterone had a 3% higher live birth rate than those who were given a placebo; in the second, the figure was 5%. The report, in the American Journal of Obstetrics and Gynecology, estimates that if every highrisk woman in the UK was given two daily doses of progesterone, it would lead to “an additional 8,450 live births per year”.
Can tea help stop Alzheimer’s?
Drinking at least one and a half cups of tea a day could reduce your risk of developing Alzheimer’s. Flavonols are a group of compounds found in plant-based foods including tea, red wine and cocoa, and it has long been thought that they promote cardiovascular health. Now a study suggests that they also help “stave off” dementia. Researchers at Rush University in Chicago tracked 921 people with an average age of 81, dividing them into five groups, or “quintiles”, based on their consumption of flavonols. Those in the highest quintile, who consumed more than 15.3mg a day (equivalent to one and a half cups of tea), had a 48% lower rate of Alzheimer’s disease compared with the lowest, who consumed under 5.3mg. Of four types of flavonol considered by the researchers, one called kaempferol appeared to be most beneficial: it is found in tea, kale, beans, spinach and broccoli.