Shift Work Dangerous to Your Health

A growing body of evidence suggests the modern world's move away from 9-to-5 jobs is taking a toll on workers' health -- and society's pocketbook.

Shift work appears to throw off the body's natural rhythm enough to lead to chronic sleep disturbances, gastrointestinal problems and even heart disease. With increasing economic and social demands, we are rapidly evolving into a 24-hour society.

Working on non-traditional schedules, which may include staying up all night, throws off the body's circadian rhythms. These rhythms are governed by the body's internal "clock" and help control the sleep/wake cycle as well as a host of biological processes such as hormone production and blood pressure. And the human clock has evolved to match the light/dark cycle.

Attempts to sleep at inappropriate phases of the circadian cycle will usually result in shorter sleep episodes and more awakenings. Such attempts are frequent in workers on night shifts. The investigators compare the short-term effects of shift work to symptoms of jet lag, such as daytime sleepiness, disturbed sleep, gastrointestinal problems and blunted alertness. The difference, the authors note, is that travelers will eventually adapt to their environment, while shift workers live out of synch with their daily surroundings. And over time this may take a toll.

A number of studies indicate shift workers face a higher risk of heart disease -- possibly due to the metabolic effects of working and sleeping unusual hours. There is also a price for society. For one, sleep loss may make shift workers less productive. And accidents that stem from sleepiness, such as car accidents, exact a high cost. According to the researchers, "sleepiness-related accidents" cost the US about $16 billion a year.

Employers and individuals need to be aware of the major performance and alertness decrements associated with night activity and how to best manage and counteract them. Some tactics that may help circadian rhythms adapt to unusual hours include getting an adequate amount of sleep -- whatever time of day that is -- controlling caffeine and alcohol intake, and sleeping in a dark, quiet environment.

Biological time is not only scientifically important, but it also greatly affects the productivity and health of a nation. The cost to the nation's health of working out of phase with our biological clocks is probably incalculable at present. This is such an important topic that I felt a condensed version of the article would be helpful: The 24-hour society is an environmental challenge that outstrips our biological adaptation to the natural 24-hour cycle of light and darkness. In the course of evolution, the behavior and physiology of most organisms, including human beings, have developed internal temporal characteristics. It is thought that by timing behaviors such as sleep so that they complement the organism's spatial ecological niche, internal stability is maintained and the chances of an organism's survival are increased.

In addition to health problems there is a substantial cost to the economy in terms of decreased efficiency and productivity. The cost of sleepiness-related accidents can vary substantially, but in general, the estimated total cost of such accidents per year is US$16 billion in the USA, and US$80 billion worldwide. Circadian (about 24 h) rhythms, are controlled by a master biological clock. In mammals, the master biological clock is located in the suprachiasmatic nuclei of the hypothalamus.

At the subcellular level of organization, circadian rhythms are generated by transcriptional and translational feedback loops involving multiple clock genes.13 The precise periodicity (or cycle length) of the biological clock is known to be genetically determined,14 and variation in clock genes is thought to be related to individual differences in natural wake and sleep times.

The biological clock generates and maintains circadian rhythms in most physiological, biochemical, and behavioral variables, for example: core body temperature triacylglycerol blood pressure sleep-wakefulness alertness mental performance It is also responsible for the synthesis and secretion of many hormones including growth hormone, cortiso,l prolactin, and melatonin.

Source: The Lancet Return to Top

Decreased Sleep = Increased Risk for Diabetes

Chronic lack of sleep may cause far more serious problems than a tendency to nod off the next day. People who do not get enough sleep on a regular basis may become less sensitive to insulin which, over time, can raise the risk of obesity, high blood pressure, and diabetes In fact, Dr. Eve Van Cauter at the University of Chicago found that chronic sleep deprivation -- 6.5 hours or less of sleep a night -- had the same effect on insulin resistance as aging.

Just like a poor diet, sedentary lifestyle, chronic stress and aging, sleep loss is a risk factor (for type 2 diabetes). Type 2 diabetes occurs when the body loses its ability to respond to insulin, the body's key blood sugar-regulating hormone. This insulin resistance causes blood sugar levels to rise, which in turn can increase the risk for a number of serious medical complications including kidney damage, heart disease, blindness and lower limb amputations.

According to the study healthy adults who averaged 316 minutes of sleep a night -- about 5.2 hours -- over 8 consecutive nights secreted 50% more insulin than their more rested counterparts who averaged 477 minutes of sleep a night, or about 8 hours. As a result, "short sleepers'' were 40% less sensitive to insulin.

The researchers suggest that sleep deprivation, which is becoming commonplace in industrialized countries, may play a role in the current epidemic of type 2 diabetes.

A poll by the National Sleep Foundation found a steady decline in the number of hours Americans sleep each night. In 1975, the average American slept 7.5 hours, down from 9 hours in 1910. Today, adults sleep about 7 hours a night.

Source: American Diabetes Association Return to Top

If you are carrying a few extra pounds - whether in the form of belly fat, love handles, a beer gut or potbelly - you're not alone.

In recent years, the number of people who are overweight has increased dramatically worldwide. Two-thirds of American men are overweight or obese. But this is one case where following the crowd is not the best idea, because extra weight - especially belly fat - can be downright risky. And while women often put on extra pounds in the hips, thighs and legs, men are much more likely to gain belly fat.

Michael Jensen, M.D., an endocrinology specialist at Mayo Clinic, Rochester, Minn., answers common questions regarding belly fat and what you can do about it.

Why is losing belly fat important? Although the link between belly fat and health is not entirely clear, experts do know that people with a lot of belly fat are at higher risk of health problems than are people who accumulate fat in other areas - and men are more likely than women to put on weight around the waist.

Our bodies are designed to store fat for release during times when there is not enough food. But when we put on weight and never have these lean times, fat cells begin to release fat molecules into the blood at a higher rate. This affects normal metabolism and the way the body uses insulin. These metabolic changes can worsen or increase your risk of health problems, including: Diabetes, Some types of cancers, High blood pressure, Sleep apnea, Abnormal lipids - high triglycerides and low HDL ("good" cholesterol), Insulin resistance, and Metabolic syndrome.

When you lose fat through exercise and improved eating habits, you improve your metabolism. This reduces your risk of health problems - and may improve existing health problems.

How can you tell if you have too much belly fat? Not surprisingly, how big around you are at the waist is a good indicator of whether you have too much belly fat. Although measurements that compare your hip and waist circumference (waist-to-hip ratio) or compare your height and weight (body mass index) are more precise and can be useful for research, your waist size alone can give you a pretty good idea of how much belly fat you have.

For most men, the risk factors for heart disease and other diseases increase with a waist size over 40 inches (102 centimeters).

To accurately measure your waist: Place a tape measure around your bare abdomen just above your hipbone. The tape measure should be snug - but not so tight it pushes into your skin. Check to make sure the tape measure is level all the way around. Relax, and measure your waist after you breathe out - no sucking in your belly!

What role does exercise play in losing belly fat? To lose weight - and keep it off - you have to get regular exercise. This means doing something active most days of the week. Most people need at least 30 minutes a day of moderate exercise to stay healthy. But to shed the pounds in the first place, you may need longer periods of activity. Aerobic exercise such as bicycling, swimming or strenuous yardwork - the kind of exercise that gets you breathing hard and gets your heart rate up - is the best kind of exercise to burn fat.

One great way to get regular aerobic exercise is to walk. Using a pedometer, a simple device that measures how many steps you take, can help you make sure you're getting enough activity. For many men, walking 10,000 steps a day - plus eating right - is enough to stay at a healthy weight. Men with more weight to lose may need to walk farther. You may need to slowly build up the amount of exercise you get.

Once you get the weight off, you may not need to do as much exercise to keep it off. But the more weight you lose, the more activity you'll need to keep the pounds from coming back.

Can you reduce belly fat with sit-ups? Sit-ups will make your abdominal muscles stronger, sure. And, you may look thinner by building your abdominal muscles because you can hold in your belly fat better. But strengthening your stomach muscles alone will not specifically reduce belly fat. There are no particular "spot" exercises that are best at reducing belly fat. But most people do lose belly fat before losing fat in other parts of their body when they get more exercise of any kind.

Does age play a role in gaining belly fat? Men tend to put on more belly fat as they get older. While some men struggle with their weight their whole life, a lot of men start to notice their increasing waistline in their 30s - and gradually put on pounds as the years go by. For many men, the eating and exercise habits that kept them thin in their youth are just not enough to keep the weight off as they get older. The solution? As you get older, you have to change the way you eat and how active you are to stay slim or lose weight.

Is belly fat inherited? While some men are more likely to put on extra pounds because of their genes, for the vast majority of men, the problem has a lot more to do with lifestyle than inherited traits. Simply put, when you take in more calories than you burn - the excess calories are stored as fat. We've had a huge change in our environment. Men - and women - used to have much more active lifestyles. But our lifestyles today allow us to live and work with virtually no opportunity for physical activity. About 60 percent of American adults get no vigorous exercise in their leisure time at all. We are also eating larger amounts of high-calorie foods than we used to, such as "fast food" that is high in fat and carbohydrates. People are responding to this change in the way you'd expect - by gaining weight. Men need to be more active - to get out and keep moving.

What role does diet play in losing belly fat? Diet plays an important part in losing weight. Getting more exercise is important, but it is really tough to get enough physical activity to lose belly fat without changing your eating habits. To lose weight, you have to burn more calories than you consume. This means you need to avoid eating too much food high in fat and carbohydrates, and eat smaller quantities.

Can you really get a beer belly from drinking? We do know that there is a link between drinking excess alcohol and gaining belly fat - the "beer belly." However, it isn't just beer that can increase belly fat. Drinking too much of any kind of alcohol can have that effect.

What's the secret to losing belly fat? There's no secret, no one best approach for losing belly fat. More activity and eating less are key. The good news is that while there's no easy trick or shortcut, with more exercise and fewer calories, belly fat is the first kind of fat to go. The only tried-and-true method to lose fat of any kind is: Reduce the amount of calories you take in. You can do this by eating smaller amounts of food, or stick to foods that have fewer calories. Burn fat by making physical activity part of your daily routine.

An important part of staying healthy is not only losing weight, but also keeping it off - this means after you lose weight, you still need to watch what - and how much - you eat and get regular exercise. However, it takes more effort to lose weight in the first place than it does to keep it off.

Don't despair, you can lose the spare tire - it just takes patience and effort. And once you shed even a few extra pounds, you'll feel better and lower your risk of health problems. Source: http://www.mayoclinic.com Return to Top