The Dark Side of Transportation: Health Risks Faced by Night-Shift Truck Drivers

One of the most challenging aspects of the trucking industry is the extended work schedules many truck drivers maintain. From working more than 12 hours a day to driving exclusively at night, truck drivers put their mental and physical health at risk to fulfill their job responsibilities. A 2022 study by the National Toxicology Program (NTP) examined how regularly working night shifts is associated with health risks that may lead to cancer.

According to the Centers for Disease Control and Prevention (CDC), the NTP study concluded that there is a “high level of confidence” that regularly working night shifts disrupts the circadian rhythm and may cause cancer in humans. These conclusions are based on evidence from human studies involving breast and prostate cancer, laboratory animal studies, and research into the mechanisms behind cancer development.

Many truck drivers may wonder how working night shifts is connected to the development of these diseases and what steps they can take to protect their health. First, it is important to clarify that working at night does not mean a person will necessarily develop cancer. However, according to the CDC, several factors associated with staying awake at night may increase the risk of developing certain diseases.

Night Work: Circadian Rhythm Disruption and Cancer Risk

The CDC explains that, according to findings from the NTP study, many biological systems—including sleep and wake cycles, appetite and digestive patterns, body temperature, and even mood—follow daily patterns known as “circadian rhythms.” These cycles are regulated by circadian clock genes found in nearly every cell in the body. When sleep patterns or light and darkness signals are severely disrupted, a condition known as “circadian rhythm disruption” occurs.

Circadian rhythm disruption means that our internal rhythms are no longer working in sync. This can make us feel sick, increase our risk of poor health, and make us more likely to make mistakes that put our own safety and the safety of others at risk.

In this way, circadian rhythm disruption can damage biological systems that help protect against cancer. For example, in addition to promoting sleep, melatonin may also slow tumor growth and help protect against the spread of cancer cells. In most of the studies conducted by the NTP, an increased risk of breast cancer was found primarily among women who had worked night shifts for many years, worked them frequently, or accumulated a substantial number of night shifts throughout their lives.

The CDC explains that although specific cancer risks potentially associated with night-shift work are not yet fully understood, NTP reports indicate that people who regularly work night shifts appear to face the greatest risk. This is particularly true for individuals who:

• Work at least three hours at night between midnight and 5:00 a.m.
• Work night shifts three or more times per week.
• Work night shifts over an extended period (10 years or more).
• Begin working night shifts during their early adult years (before age 30).

Additionally, other factors commonly found among night-shift workers may contribute to cancer risk. These include workplace or social stress; lifestyle behaviors such as smoking, consuming more alcohol than recommended, having a poor diet, not getting enough physical activity, and being overweight or obese; and lower vitamin D levels.

How Can These Risks Be Prevented?

To help prevent health risks associated with night work, the CDC recommends taking the following steps:

• Schedule regular medical checkups.
• Tell your doctor if you experience any of the following potential symptoms associated with night-shift work: extreme fatigue or sleepiness when you need to be awake, difficulty sleeping, stomach or intestinal problems, irritability or mood changes, poor performance, or unexplained weight gain or loss.
• Get enough sleep.
• Eat a nutritious diet.
• Exercise regularly.
• Avoid tobacco use and limit alcohol consumption.

Health risks can often be prevented or reduced when addressed promptly and appropriately. For more information, visit the Centers for Disease Control and Prevention (CDC) website.

Your health comes first.