Your body is a wonderful machine, full of sci-fi things. One of the more complicated ones is the adrenal system. It has the effect of a turbocharger, with none of the problems of having to spend several minutes warming up or getting falsetto-voiced Formula One commentators going on about its reliability.
You can be drifting off to asleep and if your wife nudges you and hisses “There’s a burglar in the kitchen” or murmurs “Hey lover, do you remember that picnic we had in the forest when we were on honeymoon?” Within a second you’re in a heightened state of awareness, ready to defend your turf and relive fond memories.
So how does your body register stress?
So how does it work, exactly? The pituitary gland at the base of your skull signals the adrenal glands just above your kidneys to release adrenaline, which is like nitrous oxide to a high-performance engine. It’s powerful, but intended only to be used for short, sharp bursts, enough for fight or flight.
It was ideal for man the hunter-gatherer and could get him out of trouble when he encountered large, aggressive animals while foraging for food. Nowadays we live in a state of heightened tension for what may feel like years at a time. It’s not because you’re worried that a woolly mammoth will pounce from behind the photocopier or because you might fall into a tar pit while walking to the water cooler.
Constant stress of urban life a killer
In his book The Food Doctor in the City, Ian Marber notes that the problem is that the human body is only meant to be subjected to stress for short periods. In modern, urban life we’re constantly being stressed by something: traffic, caffeine (which deprives the body of magnesium, a mineral the adrenal glands need to function optimally), exposure to pollutants, job security and simply lack of time alone.
Free radicals are another problem: like adrenaline, they play a role in the short term, but become problematic when they’re around for too long.
So let’s look at the short- and long-term effects of stress:
- When stressed, your body produces cortisol. This is a hormone that helps prevent infection and inflammation from the scratches sustained while scrambling though brambles to escape the mammoth. In the longer term the presence of cortisol suppresses the some functions of your immune response, heightening the risk of infection. It also raises the levels of blood glucose, which leads to the release of insulin, a hormone that controls blood-sugar levels. Prolonged stress can damage the cells that produce insulin.
- Your bloodstream retains some sodium, which has a vital role in causing blood vessels to constrict temporarily. This enables oxygenated blood and nutrients in the blood to be delivered to the body’s cells and to remove carbon dioxide and waste products. It gives the muscles a temporary surge of power needed to say, leap a deep gulley to evade a mammoth, or to perform some intricate bedroom manoeuvre you read about in a book.
- But when sodium levels are raised for too long, they can disrupt the natural passage for nutrients to the body’s cells. Also, when the blood pressure is raised for too long it can damage the heart muscle. Too much sodium can also interfere with your heartbeat.
- When it’s fight-or-flight time, glucose that’s been stored in the body as glycogen is broken down at lightning speed and squirted into the bloodstream, giving you a short, sharp spike in energy levels. Too much stress and your body’s natural blood sugar or blood glucose level is knocked out of kilter. This not only makes you feel drained of energy but can place strain on the pancreas and the adrenal glands.
- In times of extreme stress, amino acids in your bones and muscles are released into the bloodstream to increase your energy levels. Stay stressed for too long and your bones and muscles are not rebuilt properly.
- In the same way, adrenaline causes fats stored in your body’s cells to be released and converted into energy. This can be so effective that it leads to raised levels of cholesterol and blood lipids (Fat in the blood, basically) during times of stress. But sustained levels of blood lipids can cause your blood to have too many triglycerides, which can increase your risk of heart disease.
The bottom line? Find time out from stress. Give your body a break from caffeine. It needs at least five hours to process it, so a Red Bull at 1a.m. and a double espresso to get going at 4 a.m. is like poison. Find places where you’re serene, whether it’s cycling alone on the road and alone with your thoughts, or leaping around in a sweat-drenched aerobics class. And take the leave your job allocates you each year. Nobody will thank you for having a heart attack at your desk, least of all your widow. (William Smook)