Sleeping before midnight is more important than at other times, a lie-in can make up for a sleepless night, a small glass of alcohol can help you fall asleep quicker… But is all this really true?Faced with the many preconceived ideas circulating on the subject, several scientists from the School of Medicine at New York University (United States) conducted a study that has just been published in the Sleep Health journal. Rebecca Robbins, researcher and lead author of the work, consulted with her colleagues on more than 8,000 websites to compile the knowledge we thought we had on sleep and then presented it to a committee of experts on the subject. This allowed them to identify what was false and what could even be dangerous for the health. Here are the details.1- 5 hours of sleep per night is enough for adultsFALSE: ‘5 hours or even less’ is the surprising answer given by internet users to answer the following question: ‘If you want to be able to function at your best throughout the day, without being sick and being strong mentally and leading the life you want, how many hours of sleep do you need?’For Professor Jean-Louis Girardin, who was part of the study, this is ‘the most problematic assumption’ he found. Indeed, an adult must sleep between 7 and 10 hours a night, depending on their age. Last March the NHS warned that most adults now sleep less than 7 hours a night. This is not without health consequences. ‘Sleep plays a crucial role in metabolic and thermodynamic balance, tissue restoration, wound repair, growth, memory, sorting ideas and regulating emotions,’ the report concluded.2- Snoring is annoying (especially for your companion) but it is harmless FALSE. Obviously, we are talking here about recurrent snoring and not the kind that punctually accompanies our nights when we have a cold. This manifestation of sleep apnea is not to be taken lightly. According to the National Institute of Heart, Lung and Blood (USA), this sleep disorder increases the risk of heart attacks, atrial fibrillation, asthma, high blood pressure, glaucoma, cancer, diabetes, kidney problems, cognitive dysfunction and behaviour disorders. This is why it is essential to consult someone if you are a snorer, for your health and... your partner’s sleep!3- It doesn’t matter when you sleep, as long as you sleepFALSE: Working nights, alternating or staggered hours... This all has an impact on health, and all this comes from our biological clock that acts like the conductor of our body. That is why it must be respected. The synchronisation of this internal clock is mainly done by the natural light\/dark cycle.When this no longer agrees with the outside world, you feel ‘out of control,’ disoriented, you go through the day in a fog and fatigue is felt when you should be functional. The same sensations as when you experience jet lag after a trip.People then suffer from a lack of sleep, are overweight or even obese, and suffer from mood and attention disorders. Studies have shown that in the long term, this can increase the risk of cardiovascular disease, ulcers, depression and some cancers.