Lockdown, daylight saving time, and the impact on health

As some Australian states and territories change over to daylight saving time in October, experts warn of the health and socioeconomic consequences of disrupting our body clocks (circadian rhythm).

In the face of the current COVID-19 pandemic, one or more of these disruptors can be present. As some Australians remain in lockdown due to the COVID-19 pandemic, there is a greater risk of having disrupted circadian rhythms, which is linked to poor mood, sleep and general health.

The changeover to daylight saving time will add to this disruption.The health and societal effects of disruption of our circadian rhythms can cause a huge socio-economic cost to Australia. According to the 2019 report “Bedtime Reading: Inquiry into Sleep Health Awareness", 40 per cent of Australians get insufficient sleep. The report estimated the direct financial cost of inadequate sleep by Australians to be $26.2 billion annually.

In March, two Monash experts put a proposal to Federal Minister for Health, The Hon Greg Hunt, seeking to address the health and socioeconomic consequences of ‘body clock’ disruption to Australia’s public health.

Professor Paul Zimmet AO, Professor of Diabetes at Monash University put to Minister Hunt that shortly after the daylight saving changeover, there is evidence of more heart attacks, more traffic accidents and sleep disruption. The long-term effects of living slightly out of sync with the world is seen in populations living on the western part of time zones. Due to the mismatch of body time and clock time, there are greater metabolic issues, more heart attacks, poorer sleep. There are also economic differences, with lower productivity.

Professor Zimmet warns

“There is a strong case for attention to this detail with some immediacy given the circadian disruption already underlying the impact of the pandemic."

“As we approach the changeover to daylight saving time, the practice remains controversial to the extent that the European Union Parliament has recently voted to cease recommending the practice. It has left individual nations to decide for themselves.”

The disruption of the body clock is a part of nearly all chronic illness. Multiplicity of adverse health outcomes such as poor mental health, obesity, type 2 diabetes and gastrointestinal disorders.

Associate Professor Sean Cain, from Monash University’s Turner Institute for Brain and Mental Health, explains thatthe key disruptor for the body clock is poor light exposure, which is amplified by both the lockdown and the changeover to daylight saving time. The adverse effects on performance and mental wellbeing such as depression, increase in vehicular accidents, injuries, work absenteeism and child and adolescent education and behavioural difficulties.

In June 2019, the International Society for Research on Biological Rhythms published a position statement against daylight saving time. The scientific evidence favours permanent standard time over the yearly change to daylight saving.

Associate Professor Cain supports this position. “The human body is composed of clocks that determine health and sickness and a disruption to this leads to poor health.

“Daylight saving time is not just an issue the week of the changeover, but results in us all living a little out of time with the natural light/dark cycle, something that negatively impacts long-term health.”