What the scientists are saying…

Daily aspirin is not for everyone Millions of people take a daily dose of aspirin, but unless they have heart problems, they probably shouldn’t. Several studies have shown that for patients with heart disease, taking regular low doses of the blood-thinning painkiller can help prevent heart attacks and some forms of stroke – a benefit that is thought to outweigh the elevated risk of gastrointestinal bleeding. To see if this remained the case in other patients, researchers from the US and Australia recruited 19,000 healthy people, mostly over the age of 70; half were given a low-dose aspirin to take daily, the rest a placebo. Five years later, they found that the aspirin had made no apparent difference to the risk of heart attack or stroke; nor had it prolonged the number of years people lived disability-free. However, the aspirin-takers had suffered higher rates of internal bleeding. John Mcneil, who led the study at Monash University in Melbourne, said that “millions of healthy older people” are exposing themselves to unnecessary risks by taking a daily aspirin.

The undervalued wasp Wasps “have nothing divine about them as the bees have”. So wrote Aristotle, and more than two millennia later it seems this negative attitude persists: an online poll created by researchers from University College London has found that whereas people associate bees with words such as “honey,” “flowers” and “buzz”, the top three words that wasps call to mind are “sting”, “annoying” and “pain”. In a paper published in the journal Ecological Entomology, scientists warn that we demonise wasps at our peril: they pollinate flowers and crops just as bees do, while, as predators, they help control crop pests and disease-carrying insects. “We need to actively overhaul the negative image of wasps,” said Seirian Sumner, the chief researcher. “They are facing a similar decline to bees, and that is something the world can’t afford.”

Air pollution found in placentas Air pollution particles have been found in human placentas for the first time, raising fears that they could be entering the bloodstreams of unborn babies and affecting their development, reports The Daily Telegraph. Researchers gathered placental tissue from five non-smoking women from London who had given birth to healthy babies, and – using an optical microscope – examined particular cells called macrophages. Found all over the body, these form part of the immune system, and work by engulfing harmful particles such as bacteria and pollutants. Among 3,500 macrophages identified by the researchers, 60 contained small black areas that they believe were carbon particles. “Our results provide the first evidence that inhaled pollution particles can move from the lungs into the circulation and then to the placenta,” said Norrice Liu of Queen Mary University, London. The team believe the finding could help explain previous research showing that women living in polluted areas are more likely to have premature births and low birthweight babies. Separately, research looking at the impact of airborne pollution on dementia rates found that people living in the parts of London with the highest levels of nitrogen dioxide were 40% more likely to develop dementia over a seven-year period than those in the least polluted areas.

Killing zombies to stop dementia Scientists have found evidence that by clearing “zombie” cells from the brains of mice, they can slow the progress of dementia, says The Guardian. Zombie cells, or senescent cells, are cells that no longer divide but won’t die. Initially, they were thought to be harmless, but more recently their presence has been associated with a range of age-related conditions, including arthritis and Parkinson’s. Previous research has suggested killing off the zombies can increase the lifespan of elderly mice. Now, a team at the Mayo Clinic in the US has found that mice engineered to produce tangles of tau proteins in their brains (as found in Alzheimer’s patients) have unusually high numbers of senescent cells; and that when the cells are removed, the neuron damage and memory loss associated with this damage slows. Experts described the finding as “promising”, but cautioned that any treatments based on it remained many years away.