Clocked: Social jet lag, where we are out of sync with our environment and suffering sleep disruption, is linked with a greater risk of obesity, depression and anxiety. It exacerbates Type 2 diabetes and is also linked with post-traumatic stress disorder.In ancient times, people woke at sunrise, slept after sunset and the rhythms of our lives matched those of nature.
Scientists have known since at least the 1960s, and the seminal experiments of German physiologist Jochen Nash, that people had an internal body clock. His subjects were medical students who were asked to live inside converted second World War bunkers, where they were exposed only to artificial light. “When you put people in this sort of environment, their 24-hour readings kept going,” Coogan adds.
Social jet lag, where we are out of sync with our environment and suffering sleep disruption is a serious consequence of modern life, linked with a greater risk of obesity, depression and anxiety. It exacerbates Type 2 diabetes and is also linked to post-traumatic stress disorder . When we binge watch Netflix, or constantly scroll through our phones late at night, it delays sleep onset, and contributes to social jet lag, he points out.
An area of the brain called the suprachiasmatic nucleus, or SCN, is thought to be the “master clock” regulating how our body responds to the 24-hour cycle. “It is the bridge in the brain that gets signals coming into the visual system,” Cryan adds. “We humans have evolved to have this master clock.” When the biological clock is disrupted, such as occurs with jet lag, Curtis says macrophages – the white blood cells that are one of the immune system’s “first responders” to foreign substances – begin to lose function and start to resemble older cells. “There is an age-related effect and there is more of the production of pro-inflammatory cytokines as well,” she says.