This week I was fortunate to be able to listen to a virtual talk by Professor Stafford Lightman FRS, one of the steering group members for the EPSRC Centre for Predictive Modelling in Healthcare, Exeter. His talk (hosted by the Centre for Systems Modelling and Quantitative Biomedicine, Birmingham) was entitled ‘The Body Needs Rhythm’ and was an overview of some of his and other experts’ work in the field of circadian rhythms and ultradian cycles.
Now, in a time where I’m sure many people’s normal daily and weekly schedules are completely off-track, I wanted to see how this research relates to our moods and stress levels.
Prof. Lightman talked about circadian rhythms (our body’s daily rhythms) and ultradian cycles (phases that happen more than once daily). As well as these processes, both humans and animals can have monthly and even yearly rhythms too, which are governed by internal factors (e.g. menstruation) and external factors (e.g. seasons).
Our brains are where it all starts – the suprachiasmatic nucleus (SCN) is a part of the brain that acts as our body clock. This is kept accurate by the amount of light that we see – it regulates our sleep/wake cycle. The SCN links with other areas of the brain to release hormones including cortisol (this release is known as glucocortisoid), which pulses continually creating oscillating patterns with peaks at certain times of the day.
Stress results in an increased amplitude of glucocortisoid oscillations, which can affect a variety of things in our bodies including:
- body clock genes
- activity cycles
- brain connectivity
- working memory
- emotional response
- sleep
Prof. Lightman’s research has included a study of over 8M posts on Twitter (tweets) from the UK across a 4 year period. Using a mathematical tool to look at tweets in a meaningful way, he used psycholinguistics to measure the mood of the population. Certain words peaked and troughed at particular times of the day e.g. ‘bus’ was most used during morning rush hour and then across a slightly wider time period in the evenings which tied in with people’s pre-COVID work/school schedules.
In the research, words denoting positivity were found to peak during early morning and early evening, with negative words appearing most frequently late at night. The positive and negative had different circadian rhythms, and were not a mirror image. Over a year, negativity was at its highest during the winter months of February/March and September/October, with positivity peaking in the summer months.
This research shows that it is natural to feel highs and lows at certain times of day/week/month/year. As well as individual rhythms, mood cycles of the wider population also factor into our stress levels. Establishing routine and exposure to natural light can help reduce stress, alongside regular exercise, a balanced nutrition intake, and making time to rest and give yourself a break. For those of us struggling to accomplish necessary tasks during the current social restrictions, UKRI innovation fellow Yolanda Hill suggests the following tips:
- Get dressed!
- Make the most of being flexible – in terms of work, consider when you are least focussed, and use that time to do something else such as exercising or cleaning
- Try to stick to a schedule and block out work time (slotting in bits and bobs around it)
- Get fresh air
- Talk to people
So, in the words of Gloria Estefan, ‘The Rhythm is Gonna Get You’… but that’s not a bad thing, especially in these changing times.
