Dr Keith Siew, Scientific Editor, Physiology News

Julia Turan, Managing Editor, Physiology News

https://doi.org/10.36866/pn.122.5

Welcome to another issue of Physiology News. Hopefully as this arrives in your pigeonhole (or inbox for those of you reading this online), you will be enjoying the first days of summer. For many of us, last summer was our first bit of respite from the socially distanced “new normal”. What came with it was a strange new quietness to suburban life, a sky devoid of the roar of jet planes overhead or constant hum of traffic, the air itself smelled sweeter.

And it may seem like an eon ago, but as the world approached 2020, global warming was set to be top of the world’s agenda. Be it in the wake of the UN Climate Action Summit, when our children took to the streets in the first global climate strike, or after the young Greta Thunberg made an indelible mark on us all with her powerful COP25 speech. Eventually it became all but impossible to ignore with the images of hellish infernos emblazoned across our screens, the Southern hemisphere itself from the Amazon to the Australian Bush seemingly ablaze. That was until the world stopped.

The temporary lull in activity due to the pandemic led to one of the most significant drops in air pollution in modern history. And while this brought glimmers of hope to those in the fight against climate change, the health implications for many were more profound. In the short term it was estimated that around 24,200 premature deaths had been avoided between February and March in China alone, and in the long term, a potential 300,000 additional deaths may be averted across China and Europe combined1. And as life slowly returns to normal, flights resume and with more cars on the road, Abigail Whitehouse’s expert discussion of the types of air pollution we encounter in urban life and the pathophysiology that underlies the deterioration in health many face couldn’t be more timely (p. 30).

Come summer 2021, with the continued vaccines rollouts across the world, the relief we all feel will hopefully be more enduring this time round. Many large events with little to no social distancing are set to return, and perhaps none more anticipated than the postponed Summer Olympic Games set to go ahead (at the time of writing) in Tokyo, Japan. If you’re one of those rare few athletes, or those of us lucky enough to travel for holidays in the coming months, it will no doubt be a jarring experience to once again traverse time zones. And in this issue of PN, our Editorial Board’s own Dr Philip Lewis along with Professor Thomas Erren have composed a guide to tackling jet lag for your convenience (see p. 22).

In addition to keeping your chronobiology in sync, those undertaking endurance exercise and working up a sweat may want to keep their acid–base balance in check2. For the reader in search of a new perspective on an old dilemma, we invite you to read the essay by Dr Jon-Emile Kenny on the virtues of the Stewart Model of acid–base balance (see p. 26), which is garnering support among those who deal with physiology more acutely in the clinical realm.

Alternatively, you may also want to look at some dietary hacks to improve your performance, and the team of authors at Anglia Ruskin University have you covered, with an article on the surprising properties of various juices and concentrates from your five-a-day (see p. 18). For the more controversial, we also have a piece on hacking your physiology with Eftestøl and Bruusgaard discussing the long-lasting cellular memory and epigenetic effects of exogenous hormones like testosterone and erythropoietin (see p. 34).

Lastly, this issue would not be complete without acknowledging the centenary of the discovery of insulin. One of the biggest breakthroughs in medical history that revolutionised the treatment of diabetes and brought about a revolution in hormone replacement therapies in the decades that followed. Although, like most discoveries, things were not so straightforward or without strife, and the new chair of The Physiological Society’s History and Archives, Professor Angus Brown, delves into the drama surrounding the perfect storm of insulin’s discovery and how it could have so easily gone wrong (see p. 14).

We hope you enjoy this issue and have a wonderful summer.

References

1. Giani P et al. (2020). Short-term and long-term health impacts of air pollution reductions from COVID-19 lockdowns in China and Europe: a modelling study. The Lancet: Planetary Health 4, E474-82. http://doi. org/10.1016/S2542-5196(20)30224-2
2. Sumi D et al. (2018). The effects of endurance exercise in hypoxia on acid-base balance and potassium kinetics: a randomized crossover design in male endurance athletes. Sports Medicine – Open 4, 45. http://doi. org/10.1186/s40798-018-0160-1