What the scientists are saying…
Radical treatment for depression Ketamine could be used to alleviate the symptoms of depression in patients for whom “nothing has helped”, reports The Independent. For the past six years, an Oxford University team has been using ketamine – a licensed anaesthetic that is also used as a recreational drug – to treat 101 patients whose severe depression has proved resistant to drugs and therapies. They found that when the ketamine was given in small doses intravenously, followed by oral top-ups, 42 of the patients experienced a sustained improvement. One patient explained that the drug had slowed down the “constant, overwhelming bombardment of negative intrusive thoughts” and given her a chance to “fight back”. According to Dr Rupert Mcshane, who runs the programme, only electroconvulsive therapy (ECT) has better results – but many patients are unwilling to undergo ECT because of its associations with brutal treatments in the past. Depression, he explained, is “a disorder of overactivity. In people who are depressed, there is an excessive connectedness between the emotional regulation area and other areas of the brain.” Both ECT and ketamine appear to reduce this.
“Clean eaters” risk osteoporosis Young people shunning dairy as part of a so-called “clean-eating” diet could be risking osteoporosis in later life, a charity has warned. The National Osteoporosis Society (NOS) commissioned a survey of 18- to 24-year-olds, and found that four in ten people in that age group had tried such a diet, while one in five had significantly cut their intake of milk or cheese. The NOS says this may leave them calcium deficient, at a time when they need to be building bone strength – and leave them with permanently weakened bones. The Food Standards Agency recently found that 46% of young adults believe they are either allergic or intolerant to cow’s milk. However, research suggests only around 5% of the population are lactose intolerant.
Brain forms double memories When we experience an event, it seems our brains create two copies of the memory: one is formed in the hippocampus – where short-term memories are accessed – while the other is formed in the prefrontal cortex, for long-term storage. The finding surprised even the researchers who made it: previously, the assumption was that memories were formed in the hippocampus and then slowly transferred to the “memory bank” in the cortex. In the USJapanese study, lab mice were given mild electric shocks when they went into particular chambers, and were then monitored to see how well they remembered them. Meanwhile, light beams were used to switch memories in the two different parts of their brain on or off. The results suggest that episodic memories, of specific events, are formed in both places simultaneously, but that the memories in the cortex remain “silent” – inaccessible – until they reach maturity, after about two weeks. The memories in the hippocampus then slowly fall silent, but they do not disappear (the researchers could activate them artificially). “[The memories] are formed in parallel but then they go different ways from there. The prefrontal cortex becomes stronger and the hippocampus becomes weaker,” said Mark Morrissey, one of the authors of the study, published in the journal Science.
Obesity is a killer after all A new study has further undercut the “obesity paradox” – the notion, suggested by earlier research, that people who are overweight are actually less likely to die early than those of a “healthy” weight. The Harvard team gathered data on more than 225,000 people from three studies, and looked at the fluctuations in their body mass index over a 16-year period. They then looked at their death rates over the next 12 or so years, and found that the participants who had been overweight or obese at their peak BMI had an elevated risk of dying from any cause – as well as from specific causes such as heart disease. The highest risk of death was among participants who experienced significant drops in weight: however, the authors said this was probably because they had lost weight as a result of illness. They suggest that their study is more accurate than the ones that support the “obesity paradox”, because it looked at people’s weight over time, rather than relying on measurements taken at a single point in time.