How menopause affects the brain | Lisa Mosconi

 

Information can make you sick

Trader turned neuroscientist John Coates in The FT on why economic crises are also medical ones.

As coronavirus infection rates peak in many countries, the markets rally. There is a nagging worry that a second wave of infections might occur once lockdowns are lifted or summer passes. But for anyone immersed in the financial markets there should be a further concern. Volatility created by the pandemic could itself cause a second wave of health problems. Volatility can make you sick, just as a virus can. 

To get an inkling of what this other second wave might look like, it helps to recall what happened after the credit crisis. That event was both a financial and medical disaster. Various epidemiological studies suggest it may be responsible for 260,000 cancer deaths in OECD countries; a 17.8 per cent increase in the Greek mortality rate between 2010-16; and a spike in cardiovascular disease in London for the years 2008-09, with an additional 2,000 deaths due to heart attacks. The current economic crisis may be far worse than 2008-09, so the medical fallout could be as well. 

Why do financial and medical crises go hand in hand? Many of the above studies focused on unemployment and reduced access to healthcare as causes of the adverse health outcomes. But research my colleagues and I have conducted on trading floors for the past 12 years suggest to me that uncertainty itself, regardless of outcome, can have independent and profound effects on physiology and health. 

Our studies were designed initially to test a hunch I had while running a trading desk for Deutsche Bank, that the rollercoaster of physical sensations a person experiences while immersed in the markets alters their risk-taking. After retraining in neuroscience and physiology at Cambridge University, I set up shop on various hedge fund and asset manager trading floors, along with colleagues, mostly medical researchers. Using wearable tech and sampling biochemistry, we tracked the traders’ cardiovascular, endocrine and immune systems.

My goal was to demonstrate how these physiological changes altered trader performance. Increasingly, though, I came to see that a trading floor provides an elegant model for studying occupational health. 

One remarkable thing we found was that traders’ bodies calibrated sensitively to market volatility. For humans, apparently, information is physical. You do not process information dispassionately, as a computer does; rather your brain quietly figures out what movement might ensue from the information, and prepares your body, altering heart rate, adrenaline levels, immune activation and so on. 

Your brain did not evolve to support Platonic thought; it evolved to process movement. Our larger brain controls a more sophisticated set of muscles, giving us an ability to learn new movements unmatched by any other animal — or robot — on the planet. If you want to understand yourself, fellow humans, even the markets, put movement at the very core of what we are. 

Essential to our exquisite motor control is an equally advanced system of fuel injection, one that has been misleadingly termed “the stress response”. Stress connotes something nasty but the stress response is nothing more sinister than a metabolic preparation for movement. Cortisol, the main stress molecule, inhibits bodily systems not needed during movement, such as digestion and reproduction, and marshals glucose and free fatty acids as fuel for our cells. 

The stress response evolved to be short lived, acutely activated for only a few hours or days. Yet during a crisis such as the current one, you can activate the stress response for weeks and months at a time. Then an acute stress response morphs into a chronic one. Your digestive system is inhibited so you become susceptible to gastrointestinal disorders; blood pressure increases so you are prone to hypertension; fatty acids and glucose circulate in your blood but are not used, because you are stuck at home, so your risks increase for cardiovascular disease. Finally, by inhibiting parts of the immune system, stress impairs your ability to recover from diseases such as cancer, and Covid-19. 

So why the connection with uncertainty? The stress response is largely predictive rather than reactive. Just as we try to predict the future location of a tennis ball, so too we predict our metabolic needs. When we encounter situations of novelty and uncertainty, we do not know what to expect, so we marshal a preparatory stress response. The stress response is comparable to revving your engine at a yellow light. Situations of novelty can be described, following Claude Shannon, inventor of information theory, as “information rich”. Conveniently, informational load in the financial markets can be measured by the level of volatility: the more Shannon information flowing into the markets, the higher the volatility. 

In two of our studies we found that traders’ cortisol levels did in fact track bond volatility almost tick for tick. It did not even matter if the traders were making or losing money; just put a human in the presence of information and their metabolism calibrates to it. Take a moment to contemplate that curious result — there are molecules in your blood that track the amount of information you process. 

Today, with historically elevated volatility, there is a good chance cortisol levels are trending higher. Immune systems could also be affected. When your body is attacked by a pathogen, your immune system coordinates a suite of changes known as “sickness behaviour”. You develop a fever, lose your appetite and withdraw socially. You also experience increased risk aversion. 

Central to the immune response is inflammation, the process of eliminating pathogens and initiating tissue repair. However, inflammation can also occur in stressful situations, because cytokines, the molecules triggering inflammation, assist in the recruitment of metabolic reserves. If inflammation becomes systemic and chronic, it contributes to a wide range of health problems. We found that interleukin-1-beta, the first responder of inflammation, tracked volatility as closely as cortisol. 

Recently we have focused on the cardiovascular system. Working with a large and sophisticated fund manager, we have used cutting-edge wearable tech that permits portfolio managers to track their cardiovascular data, physical activity and sleep. The cardiovascular system similarly tracks volatility and risk appetite.

In short, here we may have a mechanism connecting financial and health crises. On the one hand, fluctuating levels of stress and inflammation affect risk-taking. In a lab-based study, we found that chronically elevated cortisol caused a large decrease in risk appetite. Shifting risk presents tricky problems for risk management — and for central banks. Physiology-induced risk aversion can feed a bear market, morphing it into a crash so dangerous that the state has to step in with asset purchases. On the other hand, chronically elevated stress and inflammation are known to contribute to a wide range of health problems. 

We are not accustomed to combining financial and medical data in this way. But corporate and state health programs should start. 

The markets today are living through a period of volatility the likes of which I have never encountered. March was, to put it mildly, information rich. As a result, there is now the very real possibility of a second wave of disease. Viruses can make you sick, but so too can information.

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