An estimated 22 million American workers earn an income during the nighttime hours or with a constantly changing schedule. Known to many as the graveyard shift or shift work, those with disrupted or reversed sleep/wake schedules appear to have a greater need for maintaining their heart’s health. Research into the effects of working a graveyard shift indicates that living harmoniously with your circadian rhythm favors several metabolic factors. As one of its primary components, the cardiovascular system usually suffers when metabolic health is strained.
The National Sleep Foundation reports that shift workers are more likely to experience stomach problems, colds, flu, weight gain, heart problems and higher blood pressure caused by the stresses that shift work can put on a person’s mind and body. This stress originates from interrupting the body’s innate 24-hour sleep/wake clock, commonly known as the circadian rhythm.
Correlating with the earth’s natural light and dark cycles, your circadian rhythm is like a natural alarm clock that helps regulate your hormones, body temperature, heart rate and other functions to the time of the day. Those working through the night and sleeping during the day, or having a constantly changing schedule that significantly varies bedtime, must operate in opposition to their natural circadian rhythm. While there are some ways graveyard or shift workers can help their circadian rhythm readjust, these individuals remain in a higher risk category for a variety of metabolic disorders.
Likely the result of poorly adapting to sleeping and eating at abnormal circadian times, many healthcare workers recognize that shift work is associated with an increased risk for obesity, diabetes and cardiovascular disease. Two studies examining different components of proper heart function have contributed to this understanding.
- According to a study published in the March 2009 issue of the Proceedings of the National Academy of Sciences, working the night shift appears to lead to hormonal and metabolic changes that raise the risk for heart disease. By continuously changing participant’s sleeping and eating schedules, researchers were able to affect their circadian rhythms as if they were shift workers. They found that this circadian misalignment provoked a drop in levels of the weight-regulating hormone, leptin. By prompting increases in appetite and decreases in physical activity, plummeting leptin levels hastens the onset of obesity and heart disease.
- A 2000 Italian study also found that shift work puts people at a higher risk of heart disease. As printed in the journal Circulation, a publication of the American Heart Association, a team at the University of Milan found that the nerve activity that accelerates the heart is lower in people working an overnight shift as compared to morning or afternoon shifts. These researchers found that levels of cortisol, a hormone that stimulates the heart rate, digestive system, breathing and other functions during the day, did not adjust to help night shift workers stay alert. The investigators concluded that a heart is unprepared for the stress it will inevitably encounter during a work shift, putting those cardiovascular systems in a greater category of risk.
Tips for Abnormal Circadian Times
With the wide range of occupations requiring people to work through the night, being employed from 9am to 5pm may not be an option. To minimize the metabolic health risks of sleeping during the day or at different times each day, the following tips can help those working the graveyard shift protect their heart:
- Make sure you have sufficient time to relax and sleep
- Avoid caffeine within five hours of bedtime
- Eliminate light from your environment with light-blocking blinds or eye shades
- Block ambient noise with a fan or wear ear plugs
- Consider supplements that support cardiovascular health
- Take a warm bath or listen to soothing music before bed
- Make sure to include daily aerobic exercise into your routine
- Avoid the convenient foods more easily available at night like vending machine sweets and fatty, greasy fare
- Choose nutritious, low-fat, high-fiber foods to fuel your body
Because working in opposition to your circadian rhythm can put additional strains on your heart, those who work through the night must be extra vigilant about their metabolic and cardiovascular health. By having a good routine for sleeping, eating, supplementing and exercising, you can protect your heart from the metabolic perils of working the graveyard shift.