Are you a night owl or a morning person? A new study suggests that it could make a big difference to your health and it’s not good news for late risers. According to the paper authored by Dr Kristen Knutson and Professor Malcolm von Schantz, of Northwestern University (Chicago) and the University of Surrey (UK) respectively, night owls have an increased risk of early death, psychological disorders and respiratory illness than people who are, so to speak, up with the lark. The paper backs up previous research that suggests people who regularly go to bed late are more likely to suffer ill health. Over a six-year period, night owls were found to have a 10% greater risk of death than larks, according to the paper. This finding held true even after adjusting for expected health problems in people who go to bed late, such as metabolic dysfunction and heart disease. Using data extracted from the UK Biobank, a data store containing medical and genetic information relating to some 500,000 people aged 40 to 69 from across the UK, the researchers were able to determine the effect a lack of sleep has on individuals. While night owls often make up for their lack of sleep during the week by staying in bed longer at weekends – referred to as “social jet lag” - it is seemingly not enough to combat the potential health problems they face. Commenting on the findings of the research, Dr Knutson said that “night owls trying to live in a morning lark world may have health consequences for their bodies. They shouldn’t be forced to get up for an 8am shift. Make work shifts match people’s chronotypes. Some people may be better suited to night shifts.” Being a night owl was also associated with psychological stress, lack of sleep, lack of exercise, eating at the wrong time, and drug or alcohol use. So, if you're someone who regularly goes to bed late and doesn't get enough sleep during the week, maybe it's time to change your habits.
The benefits of a full night’s sleep are well known. Insomniacs across the world will tell you what sleep deprivation can do to your mind and body. But now it seems that just a few nights of bad sleep could impact your mental health too. A team of scientists from the University of Oxford in the UK ran a small experiment using four volunteers who normally sleep just fine. The volunteers were fitted with monitors to track their sleep. For the first three nights of the study, they were allowed to sleep normally. For the next three nights, their sleep was restricted to just four hours per night. Each day of the study, the volunteers filled out questionnaires about how they were feeling and kept video diaries. Three out of the four volunteers said the experience was unpleasant, while one said he was largely unaffected. However, tests showed that his mood was significantly impacted, with positive emotions falling and negative emotions rising. Doctoral student Sarah Reeve, one of the scientists who ran the experiment, was surprised by how quickly the volunteers’ moods changed. "There were increases in anxiety, depression and stress, also increases in paranoia and feelings of mistrust about other people", she said. "Given that this happened after only three nights of sleep deprivation, that is pretty impressive."
Long naps of more than an hour during the day could be a warning sign for type-2 diabetes, according to a new study by Japanese researchers. The link was discovered by the researchers at the University of Tokyo while analysing observational studies involving more than 300,000 people. Their findings will be presented at a meeting of the European Association for the Study of Diabetes in Munich. Specifically, their research found that people who napped for more than an hour during the day had a 45% greater risk of type-2 diabetes than those who didn't take daytime naps. Interestingly, no link was found with naps of less than 40 minutes. UK experts have said that individuals with undiagnosed diabetes and other long-term illnesses often feel tired during the day. However, they also said there is no evidence at present to suggest that napping during the day increases a person's risk of developing diabetes. One possible explanation is that sleep deprivation, caused by busy work schedules and/or social commitments, potentially leads to increased appetite, which in turn could increase the risk of type-2 diabetes. Commenting on the researchers' findings, Naveed Sattar, a professor of metabolic medicine at the University of Glasgow, said: "It's likely that risk factors which lead to diabetes also cause napping. This could include slightly high sugar levels, meaning napping may be an early warning sign of diabetes."