Night Shift Work, Blood Sugar, and Cavities: A Hidden Connection
If you work night shifts, you may already know how hard it can be on your sleep. But did you know it might also increase your risk of diabetes and dental problems?
A 2019 study from Indonesia reveals that night shift workers experience changes in blood sugar, saliva flow, and oral health that may raise their risk for type 2 diabetes and dental caries (cavities).
What Did the Study Look At?
Researchers compared 27 male night shift workers to 27 daytime workers, analyzing:
Fasting blood glucose (FBG)
2-hour post-meal glucose (2-PP BG)
Saliva flow rate
Saliva pH
DMF-T Index (decayed, missing, filled teeth – a common measure of cavity risk)
What They Found
| Measurement | Night Shift Workers | Day Workers | Significance |
|---|---|---|---|
| Fasting Blood Glucose (FBG) | 121.6 mg/dL | 91.2 mg/dL | Higher risk |
| Post-meal Glucose (2-PP BG) | 163.1 mg/dL | 98.7 mg/dL | Higher risk |
| Saliva Flow Rate | 0.24 mL/min | 0.57 mL/min | Lower |
| Saliva pH | ~5.9 | ~5.7 | No difference |
| DMF-T Index (Cavity Risk) | 9.7 (very high) | 3.5 (moderate) | Higher |
(Source: Roestamadji et al., 2019)
Why This Happens
Night shift workers experience circadian rhythm disruption — their body clocks get out of sync with natural light/dark cycles.
This disruption leads to:
Insulin resistance, making it harder for the body to manage glucose
Higher blood sugar levels, increasing diabetes risk
Lower saliva production, which weakens natural defenses against tooth decay
Dry mouth, which reduces the mouth’s ability to wash away food and bacteria
Plus, night shift workers are more likely to snack late and neglect oral hygiene due to fatigue — a perfect storm for dental problems.
The Cycle: Blood Sugar & Cavities
High blood sugar causes dry mouth and acidic saliva
Acidic saliva promotes growth of bacteria like Streptococcus mutans
These bacteria form plaque and produce more acid
The acid erodes enamel, leading to cavities
Fewer protective minerals (like calcium) in diabetic saliva worsen the damage
What You Can Do
If you’re a night shift worker, consider these steps to protect your health and teeth:
Get screened for blood sugar changes and cavities
Brush and floss diligently, even during overnight shifts
Stay hydrated to support saliva flow
Avoid sugary snacks during shifts
Use xylitol gum or fluoride rinse to boost saliva and protect enamel
Talk to your doctor about melatonin — it may help restore healthy sleep patterns
Why It Matters
Night shift work isn’t going away — but with better awareness, you can stay ahead of the health risks. This study highlights that oral health and metabolic health are deeply connected, especially when your body clock is off balance.
If you're struggling with fatigue, cavities, or high blood sugar, it may be time to consider how your schedule is affecting your whole-body health.
TL;DR
Night shift workers have higher blood sugar and more cavities
Poor saliva flow and disrupted sleep rhythms may be to blame
Better oral hygiene, hydration, and blood sugar control can help
Sleep and metabolic health are linked — even in your mouth
Source:
Roestamadji RI, Nastiti NI, Surboyo MDC, Irmawati A. The Risk of Night Shift Workers to the Glucose Blood Levels, Saliva, and Dental Caries. European Journal of Dentistry. 2019;13(3):323–329.
DOI: 10.1055/s-0039-1697211