Last month, this column touched upon just a few of the health risks associated with rotating night shift work: cancer, dementia, diabetes, non-alcoholic fatty liver, and cardiovascular disease. The longer a person does night shift work, the greater their risk of developing these conditions.
However, our society needs night shift workers in order to function. Without people working the night shift, the power grid would fail, hospitals would only provide services during business hours, there would be no law enforcement at night, and we'd have serious supply chain issues, among other things.
Because of this, it's critically important for shift workers to know what they can do to stay healthy while working the night shift. Unfortunately, most of the medical research on night shift work and health is focused on the many health risks and the possible pathomechanisms involved, rather than prevention or treatment strategies.
The good news is that new research on circadian biology and metabolic health do provide us with some plausible strategies that may help to minimize the health risks associated with night shift. These strategies may also be effective in minimizing jetlag in travelers who cross multiple time zones.
So without further ado, here's what every shift worker needs to know if they're interested in maintaining good health throughout their career.
Keep your body clocks aligned
Every cell in our bodies has its own "clock" that keeps the time and is programmed to tell the cell to do specific things at certain times during a 24-hour cycle. There is one main clock called the "central clock" that is located in the suprachiasmatic nucleus (CSN) of the hypothalamus of the brain, and other "peripheral clocks" that are located everywhere else.
If you want to stay healthy and avoid chronic disease, it's critically important to make sure that your central clock and your peripheral clocks are aligned (AKA they have the same "time" displayed on their user interface).
Knowing how to keep these clocks in alignment involves understanding how they know what time it is in the first place. The central clock stays in rhythm based on light and dark cues from your environment, and the peripheral clocks tell time based on food cues.
Light
Outside on a sunny day, you're exposed to over 100,000 lux (a measurement of illuminance or brightness), which sends a very strong signal to the SCN that it's time to be awake and alert. In the shade, you're still exposed to around 20,000 lux, and on an overcast day you get about 2,000 lux. In contrast, a typical office space, grocery store, laboratory, or hospital will expose you to around 500 lux. Outside at night during a full moon, you're only receiving 0.108 lux. This tells the SCN that it's time for sleep and cellular repair and cleanup.
Note that a lux of 500 is less than what you'd get on an overcast day, but more than you'd get from a full moon-lit night. This is why you may not feel as alert or you may even feel a little depressed during a night shift rotation. Transcranial bright light treatment via the ear canals for 12 minutes upon waking will expose the SCN to enough lux to simulate 12 minutes of sunlight, signaling to your central clock that it's morning.
A meta-analysis published in June 2021 looked at varying methods of light therapy for shift workers and made the conclusion that moderate intensity, short duration light therapy is an effective way to improve alertness during night shaft work as well as promote better sleep during off hours.
Dark
Wearing blue light blocking glasses towards the end of a night shift (especially after sunrise) and sleeping in a dark, cool, and quiet room is also crucially important for promoting restorative sleep at the end of the workday.
Melatonin microdosing with 0.3 mg of melatonin before bedtime may also be useful since shift workers have been found to have lower levels of melatonin than people who keep standard hours.
Making these small adjustments is not difficult. It just takes some planning. The more challenging part of the equation is aligning the peripheral clocks with the central clock.
Meal timing
Since the peripheral clocks are highly influenced by food intake, a shift worker's meal schedule can mean the difference between maintaining good metabolic health over the course of a career or developing metabolic syndrome (abdominal obesity, high blood pressure, high blood glucose, low HDL cholesterol, and high LDL cholesterol).
Eating breakfast upon waking will tell the peripheral clocks that it's morning and time to be alert. Not eating towards the latter half of the work shift will also signal to the peripheral clocks that it's time to get prepared for sleep. Finally, finishing all meals by 8 or 9 p.m. (if possible) will prevent high blood glucose levels and weight gain that can occur on rotating night shifts.
If the night shift begins at 7 p.m. and ends at 7 a.m., for instance, "breakfast" could be eaten around 4:30-5 p.m. Then a large "dinner" could be eaten at the beginning of the shift. The shift worker could then fast for around 20 hours, relying on muscle glycogen and fat stores to finish out the shift.
Intermittent fasting
The ability to easily shift between using carbohydrate and fat for energy is strongly linked with markers of good metabolic health, such as normal cholesterol and blood glucose levels, normal blood pressure, healthy liver function, and smaller waist size.
Fasting for 16-20 hours could be difficult for a shift worker with low metabolic flexibility - the ability to easily shift between carbohydrate and fat for energy. If fasting for 16-20 hours causes unpleasant symptoms such as headache, fatigue, or excessive hunger, this is a sign of low metabolic flexibility.
To increase metabolic flexibility, one simply needs to practice intermittent fasting and increase one's level of physical exercise. If either of these are too unpleasant in the beginning, supplementation with exogenous ketones can make the process easier.
In people with high metabolic flexibility, intermittent fasting does not cause unpleasant symptoms because the body readily produces a low level of endogenous ketones that serve as an alternate fuel source for the brain when muscle and liver glycogen stores have been depleted.
But in people who rarely ever deplete their glycogen stores because they never go longer than eight hours or so without food, the body may have "forgotten" how to produce its own ketones. Exogenous ketone supplementation mimics the body's natural production of ketones during fasting and can be detected in the bloodstream within minutes of supplementation.
Some of the benefits of exogenous ketone supplementation include enhanced mental focus, decreased physical fatigue, and less hunger during fasting.
Tracking
What health biomarkers should night shift workers track to keep tabs on their health status? Stay tuned for next month's issue to learn about some important health biomarkers that may be disrupted by shift work, and what precautions to take if they are.
Questions or comments? Email [email protected]. Looking for exogenous ketones that fit your budget? Go to DrJamieKoonce.com.
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Dr. Jamie Koonce, DACM, L.Ac., Dipl.OM offers a health optimization program that is tailored to your specific health needs and goals. This may include a combination of laboratory testing, nutrition and lifestyle recommendations, herbal medicinals, nootropics, and acupuncture. Jamie is also the founder and CEO of Good Glucose, Inc., a tech startup that is combining AI and gamification with continuous glucose monitoring in order to help individuals avoid the top 10 causes of morbidity and mortality in the United States. Learn more at GetGoodGlucose.com.