Mind games may improve our performance at work”, reads the headline in The Times today. The newspaper reports that a new study has shown that volunteers who took part in “rigorous exercises designed to tax their mental agility… stimulated problem-solving abilities in the brain that can be applied to a variety of circumstances.” It says that other forms of mental exercise such as Sudoku or crosswords “have limited value because they help mental improvement only at similar tasks”.
This story is based on a non-randomised controlled experiment using student volunteers to look at the benefits of a particular form of working memory training on “fluid intelligence” – the ability to solve new problems. Because the groups in this study were not randomised, it is not clear whether all of the benefit seen was due to the training received. More importantly, the study did not assess whether the training had any effect on their jobs or studies.
Although this study by itself does not prove that brain training improves intelligence, other studies have suggested that keeping the mind active may have various benefits, including a reduced risk of dementia. In general, it would seem sensible to keep the mind as well as the body active. There are many ways to do this, and it certainly has not been proven that the only way to do this is by using a computerised training program.
Being overweight may not be as unhealthy as it was 40 years ago," BBC News reports. New research has found a body mass index (BMI) of 27 is linked to the lowest rate of death – but someone with a BMI of 27 is currently classed as being overweight. BMI is a score calculated by dividing your weight (usually in kilograms) by the square of your height (usually in metres and centimetres). Currently, a BMI of 25 to 29.9 is classified as being overweight. Researchers looked at 120,528 people from Copenhagen, recruited from 1976 to 2013, and separately compared those recruited during the 1970s, 1990s and 2000s. They were followed up until they died, emigrated, or the study finished. The BMI linked to the lowest risk of having died from any cause was 23.7 in the 1970s group, 24.6 in the 1990s group, and had further risen to 27 in the 2003-13 group. It may be the case that the suggested upward shift in optimal BMI is the result of improvements in preventative treatments for weight-rela...