What the scientists are saying…

Universal cancer screening A simple blood test that can detect ten types of cancer could herald a new era of “universal screening”, reports The Guardian. Known as a “liquid biopsy”, the test works by detecting tiny bits of DNA released by cancer cells into the blood. In a proof-of-concept trial involving more than 1,600 people, 878 of whom were newly diagnosed with cancer, it identified ovarian cancer with 90% accuracy, and cancers of the liver and pancreas with 80% accuracy. Presenting the findings at the conference of the American Society of Clinical Oncology in Chicago, Dr Eric Klein, from Cleveland Clinic’s Taussig Cancer Institute, predicted that the test would save many lives. “This is potentially the holy grail of cancer research, to find cancers that are currently hard to cure at an earlier stage when they are easier to cure.” However, it will take years of trials before the test is ready for general use. In any case, further refinement is needed, because the biopsy was less successful at identifying other cancers such as lymphoma, myeloma and bowel cancer.

Regenerating enamel Tooth enamel is a remarkable substance: the hardest material in the body, it is resistant to heat, cold and acid, and can last for years – but it has a flaw, says The Times: unlike other tissues, it can’t regenerate. When this protective coating is lost, as a result of decay or injury, the best dentists can do is apply a filling or extract the tooth. However, British scientists say they have developed a means of regrowing tooth enamel, or something very like it. Enamel forms early in our development, when a matrix made from proteins encourages minerals to cystallise. Based on this, the researchers developed a protein matrix that can pull minerals out of saliva to grow a crystallised material very like enamel. They now want to apply it to real teeth, to see if it will bond there – allowing cavities to be filled permanently. “We envisage a thin bandage, a few microns in thickness, that you can position on top of the tooth in areas that are problematic,” said Dr Alvaro Mata, of Queen Mary University of London. “Then it will use the saliva, and in time we will have this regeneration taking place.”

Marshmallow test revisited The famous “marshmallow test” – a supposed predictor of a child’s future successes – has been undermined by a new study. Devised in the 1960s by Stanford University psychologist Walter Mischel, the experiment involved giving 90 preschool children the option of eating one marshmallow there and then, or receiving two if they waited for 15 minutes. When Mischel followed the children up in their late teens, he discovered that those who’d waited were more likely to exhibit a range of desirable traits, including emotional robustness and high SAT scores. As a result, the idea took hold that the ability to defer gratification aged about four is a key indicator of future promise. But when a team of US researchers replicated the trial with more than 900 children, and included factors such as parental income when analysing the results, they found far less evidence to suggest that an early ability to delay gratification brings benefits in later life. Among the offspring of women with college degrees, for example, the children who were patient did no better in the long term than those who tucked into the first marshmallow. They argue that children’s capacity to hold out for bigger rewards is shaped by their socio-economic background, and it is that – and not being patient – that makes the difference to their future outcomes.

More children, more heart risk Bringing up a large family is more than just hard work: if you’re a woman, it could seriously affect your health. A University of Cambridge-led study, which looked at data on more than 8,000 American women, found that a woman’s risk of heart attack, stroke and heart failure all increase in line with how many children she has. Over a 30-year period, women with five or more children had a 40% greater risk of a serious heart attack than those with only one or two, a 30% increased risk of heart disease and a 25% increased risk of stroke. The study attributes this not only to pregnancies and childbirth putting a strain on the heart, but also to women with large families having fewer opportunities for self-care.