How odd hours are making you ill

PAY attention, shift workers and party animals — Adelaide scientists have discovered that late nights and midnight snacks cause more significant long-term health problems than previously thought.

IT’S a familiar scenario for millions of Australians employed as shift workers — the clock is ticking towards midnight and you’re stuck at work, so you snack on chips, chocolate or lollies to keep your brain alert.

But South Australian scientists are discovering that many of us are paying a high price for these late-night attacks of the munchies.

The University of Adelaide research is increasingly showing that shift work has a range of serious health implications that go far beyond the sociological pressure it imposes on family relationships and work-life balance.

About one in six working Australians are now employed in shift work, and their diet and sleep patterns are often drastically different to those employed in a traditional 9-5 job. This is contributing to our nation’s ballooning rates of obesity, heart disease and diabetes.

In some cases, it could even have serious lifelong health implications for their unborn children.

For most of us, an occasional late-night snack is nothing to worry about. But for those on night shift, that late night snack is actually a meal break — and our bodies simply aren’t designed to process food at 2am.

“Shift workers are being forced to work during the period when we’re normally asleep, when we’re normally not eating and not active,” says Professor David Kennaway, a senior research fellow at the University of Adelaide’s School of Paediatrics and Reproductive Health.

INTERFERING WITH OUR NATURAL RHYTHMS

Prolonged shift work can cause sleep disorders, impair alertness and impact on brain function.

Night workers are more prone to depression, heart attacks and strokes.

Now we have a growing body of research that indicates shift workers are also putting themselves at higher risk of developing metabolic syndrome, which contributes to obesity, cardiovascular disease and diabetes.

“Our body has this clock system set up with the expectation we’ll not be eating at night, we’ll eat during the day and so when you do eat at night — particularly if you are going for high-energy foods like glucose foods — your ability to handle that glucose is reduced,” says Professor Kennaway.

Glucose that sits in your system turns to fat. When this happens over a sustained period of time the body enters in to a pre-diabetic state, in which your blood glucose levels are significantly elevated and you are at risk of developing type 2 diabetes.

According to the World Health Organisation, obesity is a global epidemic and a major risk factor for a number of chronic diseases.

These include heart and lung disease but most commonly, type 2 diabetes.

It can shorten your life expectancy by eight years and rob you of almost two decades of a healthy life, as its impact on your body is non-reversible.

REDUCING THE RISKS WHEN WORKING AT NIGHT

But in a world where shift work is crucial to the efficiency of a range of industries, how do we manage this?

Professor Kennaway acknowledges that shift work is critical to Australia’s economic growth in fields as diverse as hospitality, aviation, medicine and emergency services. What he and his team are trying to do is develop a best practice model for industries to alleviate the long-term health consequences.

“The idea is to try and understand why it is that people are at higher risk or put themselves at higher risk of developing these chronic diseases and eventually come up with some strategies that might lower the risk,” he says.

One strategy is establishing different systems of rostering. But Professor Kennaway wants to take that further and look at break times and even foods to avoid late at night.

For those who have to eat at night, there are a few simple tips to minimise the impact on your waistline — and your long-term health.

ADAPT your mealtimes to be as close to a “normal” dinner time as your routine allows.

EAT small portions and don’t stuff yourself just before bed.

AVOID greasy, fatty foods like burgers or a yiros; sweet fizzy drinks and fruit juices; high-carb sugary foods like breakfast cereals; and dairy treats like ice cream or chocolate.

CHOOSE healthy options — carrot and celery sticks as a snack; vegetable-based meals with only small amounts of meat and carbohydrates.

DON’T be too sedentary when stuck at work — stimulate your metabolism through physical activity.

Professor Kennaway believes there are a certain number of people who are naturally at a higher risk of developing a chronic disease. This could be due to a poor diet, inactivity or genetics.

But when you put shift work and its risks on top of that, it just may be “the straw that breaks the camel’s back that sends them from pre-diabetic to diabetic”.

PASSING ON ILL-HEALTH TO THE NEXT GENERATION

Laboratory studies have shown shift work also impacts on the development of unborn babies during pregnancy. Through the continual changes of light and meal times, Professor Kennaway’s team believe shift work could cause pre-diabetes in infants.

So what are the two major types of diabetes — and how do they evolve?

Type 1 diabetes is a genetic auto-immune disease which prevents the pancreas from producing insulin and is often diagnosed in childhood. It is a lifelong chronic disease managed with regular injections of insulin.

Genetic factors can also contribute to type 2 diabetes, but the risk is greatly increased by high blood pressure, obesity, inactivity and poor diet. It is most common in older Australians but is increasingly being diagnosed in overweight children.

Professor Jenny Couper is head of paediatrics at the University of Adelaide and works in the Women’s and Children’s Hospital endocrine and diabetes centre.

Over the past 30 years she has seen children with a moderate risk of contracting type 1 diabetes shifting to a higher risk category.

“Fifty years ago the children getting (type 1) diabetes mainly had high-risk genes — nearly always,” she says.

“Now we have children with what we call more middle-risk genes, so less genetic risk. But clearly environment is a bigger factor in those children.”

It has been a long-held belief that the environmental factors impacting on these children began at birth. However, researchers are now realising they could actually evolve during pregnancy.

“I think we all know that the environment has changed dramatically over the last 30 years,” said Professor Couper.

“There are changes in nutrition, there are changes in people’s growth — patterns of very young children, changes in pregnancy management, and changes in antibiotic prescriptions. A lot of things that could affect the systems in the body.”

The first signs of type 1 diabetes in babies usually emerge after their first birthday but new research suggests it could be detectable as early as nine months.

OBESITY IN PREGNANCY PUTS BABIES AT RISK

While these lifestyle factors mean unborn babies who were at moderate risk of contracting type 1 diabetes are now considered to be at higher risk, it is important to differentiate between this and gestational diabetes, which is linked to obesity in pregnancy.

For both mother and baby, gestational diabetes increases the risk of developing type 2 diabetes later in life.

But obesity during pregnancy impacts on the development of the baby and the woman’s body in a myriad of other ways. Obese women are more likely to develop high blood pressure and the life-threatening condition pre-eclampsia.

It can also cause placental damage, which can result in a miscarriage, growth restriction of the unborn baby, a premature birth, an unexplained stillbirth and placental abruption.

Gus Dekker is professor of obstetrics and gynaecology at the University of Adelaide. He has been practising in South Australia for 17 years and witnessed a dramatic increase in obesity in pregnant women in his first 10 years here.

“We have now reached a point of plateau,” Professor Dekker says. “But it does not mean we cannot take measures to make sure we are at a healthy weight for a pregnancy.”

While women know they need to increase their use of folate in the months leading up to conception, to stop drinking and smoking, he says this is still not enough.

“If you are about to start getting pregnant, start to think about your weight,” he says.

HOW TO SUPERCHARGE YOUR SPERM

However, the impact of obesity on a pregnancy is not just a concern for women. There is a growing awareness that the sperm of obese men will also change what is happening to their unborn baby.

“Male obesity is also known to impact on the quality of the sperm,” says Dr Michelle Lane from the University of Adelaide’s School of Medicine. “Such as damaging the DNA of the sperm and therefore making it less likely that the sperm will be able to swim to an egg and also fertilise an egg if it does reach it.”

What has also emerged is how quickly the sperm can react to changes in lifestyle. For instance, smoking impacts on the quality of the sperm and may also affect its ability to attach to the egg. However, quitting smoking has an almost immediate effect on improving the quality of the sperm.

“Healthy weight and healthy diet is also important because we know those things are associated with better sperm outcomes,” says Dr Lane.

“We’ve seen that if you are overweight and obese and you undergo some diet and weight loss — that doesn’t need to be a huge amount of weight loss — it can really improve the outcomes of the quality of the sperm and the outcomes of the pregnancy.”

When Dr Lane began her research into male fertility in 2007 she was surprised that the male’s weight was not recorded when it came to looking at a couple’s fertility. In contrast, there was extremely detailed information on the women.

“The new information that we’ve become more aware of really in only the past two to three years is that keeping a healthy lifestyle and eating well and keeping a healthy weight is something that should be a consideration for the couple, not just the woman,” she said.

In the world rankings of obesity, Australia is 25th with our rate of type 2 diabetes doubling in just a decade. Obesity already costs the national economy tens of billions of dollars a year and this will only grow unless we take action now.

According to the Australian Institute of Health and Welfare, almost two-thirds of Australian adults are overweight or obese — and one-quarter of our children are following in their footsteps.

If we keep going the way we are it is estimated that in a decade, 83 per cent of men and 75 per cent of women aged over 20 will be overweight or obese. Food for thought next time you are reaching for those midnight snacks.